Dear editor,Telomeres are the physical ends of eukaryotic chromosomes, and their structures are essential to maintain genome stability and limit cell proliferation . NormallCancer cells must avoid the regulatory role of the telomere-p53 axis to ensure replicative immortality. To achieve this, they need to activate a telomere-maintenance mechanism (TMM), in which 90% of the cells reactivate telomerase, and 10% activate alternative lengthening of telomeres (ALT) ,5. AnothC16ORF72, which they renamed Telomere Attrition and p53 Response 1 (TAPR1) , as well as p53-induced senescence/apoptosis. This placed this newly identified protein in a key position at the nexus of telomere integrity and p53 regulation.Both of these phenomena highlight the central role of the telomere-p53 axis in the process of carcinogenesis. Recently, Benslimane et al. uncovered the function of a previously unannotated gene, TAPR1, the authors suggest that this molecule may have a role in cancer biology by suppressing p53 activity. Therefore, we tried to gather evidence for this by performing an analysis of this gene in the 33 tumors of The Cancer Genome Atlas (TCGA) using cBioPortal, GEPIA, and UALCAN  and are absent in 10 out of 33 types of cancer. Additionally, alterations in TAPR1 do not change the overall and disease-free survival of patients (data not shown).First, we show the somatic alteration landscape of  cancers . ProportTAPR1 and TERT (telomerase protein subunit), ACD , and TP53. Interestingly, we noticed a trend of co-occurrence between mutations in TAPR1 with TERT , ACD , and TP53  in TCGA cancers. Next, we analyzed the TAPR1 gene expression and found that all tumors express this gene (data not shown).The authors who identified this gene also reported a genetic interaction between TAPR1 modulates p53, we compared the mRNA levels of this gene in relation of TP53 mutation status (when available) (p<0.05), we found that TAPR1 is more expressed in tumors  with p53 mutations. This reinforces the oncogenic role of TAPR1 when there are deficiencies in p53. The only exception to this phenomenon is in BRCA, in which TAPR1 is upregulated in cancers without mutations in p53.Considering that ailable) . Taking TAPR1 has differential expression in cancer in relation to normal tissue (only in tumors where control is available) . On the other hand, TAPR1 may have a protective role in cancer progression since its downregulation increases the risk of disease relapse (p<0.0001). In the original study, the authors suggest that TAPR1 may have a double behavior in cancer: it can suppress both apoptosis/senescence (oncogenic role) and the tumorigenesis process itself (tumor suppressive role).Next, we analyzed whether ailable) . The UALTAPR1 in cancer, so we verified its association with each cancer individually using a hazard ratio heat map. The upregulation of TAPR1 was significantly associated (p<0.05) with poor overall survival in LGG and THCA (TAPR1 in these cancers. On the other hand, in KIRC, the upregulation of TAPR1 had a protective role in terms of both overall (The previous analysis did not elucidate the general role of and THCA  and withand THCA . These f overall  and dise overall , suggestP53 is probably the most important tumor suppressor in the human genome. Among its various functions, it keeps telomere length in check, thus limiting cell proliferation . For thiTAPR1 in cancer. Our analyses reinforce the hypothesis that this newly identified gene may have an important role in oncology. Using TCGA datasets, we showed an association between TAPR1 expression and p53 mutation status in several cancers and that this gene is differentially expressed in CHOL and HNSC.When Benslimane et al.  discoverTAPR1 expression and cancer survival in some tumors. However, this association can be both positive and negative. This suggests that the role of this molecule is context-dependent and needs to be studied further. Evidently, more robust studies are needed to understand the exact role of TAPR1 in disease progression, but this gene may become an important target in oncology or a new player in cancer biology.In addition, our analysis indicates an association between


Dictyostelium and mammals. These have processing pathways similar to p67, and are thought to have phospholipase B-like (PLBL) activity. The mouse PLBD2 crystal structure revealed that the PLBLs represent a subgroup of the larger N-terminal nucleophile (NTN) superfamily, all of which are hydrolases. NTNs activate by internal autocleavage mediated by a nucleophilic residue, i.e. Cys, Ser or Thr, on the upstream peptide bond to form N-terminal α (gp32) and C-terminal β (gp42) subunits that remain non-covalently associated. The N-terminal residue of the β subunit is then catalytic in subsequent hydrolysis reactions. All PLBLs have a conserved Cys/Ser dipeptide at the α/β junction (Cys241/Ser242 in p67), mutation of which renders p67 non-functional in RNAi rescue assays. p67 orthologues are found in many clades of parasitic protozoa, thus p67 is the founding member of a group of hydrolases that likely play a role broadly in the pathogenesis of parasitic infections.p67 is a type I transmembrane glycoprotein of the terminal lysosome of African trypanosomes. Its biosynthesis involves transport of an initial gp100 ER precursor to the lysosome, followed by cleavage to N-terminal (gp32) and C-terminal (gp42) subunits that remain non-covalently associated. p67 knockdown is lethal, but the only overt phenotype is an enlarged lysosome (~250 to >1000 nm). Orthologues have been characterized in  Trypanosoma brucei ssp.) are parasitic protozoa that cause human African trypanosomiasis , as well as nagana in livestock. These diseases have devastating impact throughout sub-Saharan Africa, wherever the tsetse fly vector is found. A total of >65 million people in 36 countries are at risk of transmission, and although reported human cases have fallen steeply in recent years, it remains a serious veterinary problem. Only a handful of drugs are in use for treating HAT, all of which are either toxic, expensive and/or require a difficult regimen. As vaccination is not possible, and infection is inevitably fatal, there is a critical need for new drug development. Thus, a better understanding of the basic biology of the parasite is essential, particularly of targets amenable to therapeutics. The lysosome is such a target as it impacts the host–pathogen balance in multiple ways. Expression of lysosomal activities is differentially regulated through the life cycle  intermediate glycoform  trypanosome ricin-binding proteins , and containing much internal membranous material as seen by transmission electron microscopy  makes a nucleophilic attack on the upstream carbonyl group leading to peptide bond hydrolysis creating N-terminal α and C-terminal β subunits. The subunits remain non-covalently associated, and the upstream linker region is typically trimmed, by a second round of autocatalysis or by another protease as proposed for cephalosporin acylase  activities, but phospholipase B (acylase) activity has been claimed (see below).The NTN superfamily of hydrolases was first proposed based on the common et al., et al., Dictyostelium, mice and humans   was identified by proteomics of mannose-6-phosphate selected lysosomal proteins, and lysosomal localization was confirmed by immunofluorescence  and C-terminal (β) subunits, analogous to gp32 and gp42 of p67, respectively. The N-terminus of the 40 kDa β subunit is C249, which is equivalent to C241 of p67  and T. brucei . Most orthologues are soluble proteins; all have conserved Cys/Ser dipeptides at the α/β junction mapped for p67 and PLBD2  in mice, humans and other mammals, and many more orthologues throughout the Eukaryota, often with multiple paralogues in a given species, e.g. eight in ntamoeba . Intereset al., Dictyostelium and human orthologues these proteins have been annotated as PLBs. However, this designation has been challenged by the fact that most NTN enzymes are amidases, not esterases, and because the PLBD2 active site may be too small to accommodate typical phospholipids  wild type and double mutant p67 genes, each with a C-terminal HA-tag for discrimination from the native protein. The mutations are Cys241Ala/Ser242Ala spanning the known N-terminus of gp42. The wild type and mutant RNAiR genes are designated p67CS and p67AA, respectively. These have been constitutively expressed in an inducible p67 RNAi cell line targeting the endogenous gene product. Upon induction of RNAi the parental cell line ceases growth over a 24 h period . These results establish that one or both of the residues at the gp32/gp42 junction is essential for p67 function. Collectively, these data provide compelling supportive evidence that p67 is an NTN of the PLBL subgroup: (i) lysosomal localization; (ii) conserved autocatalytic residues; (iii) similar biosynthetic processing to α (gp32) and β (gp42) subunits; (iv) good structural modelling and (v) essentiality of C241/S242 at the gp32/gp42 junction.Is there more evidence that p67 is an NTN of the PLBL subgroup? First, the p67 sequence, despite only 28% identity, models tightly onto the PLBD2 crystal structure . Importah period , top. Gret al., et al., et al., p67 is an essential lysosomal membrane protein in African trypanosomes. For many years, it was assumed to play an ill-defined role in maintenance of lysosomal physiology – until recently when homology to the PLBL class of lysosomal hydrolases has been recognized. These enzymes are part of the NTN superfamily, but are poorly studied in any system. There is evidence that they do in fact have PLB activity , and hence are likely to have the same activity. On the contrary, the two mammalian orthologues are only 32% identical and are likely to have different substrate specificities. That said, there may be considerable redundancy. PLBD1−/− and PLBD2−/− knockout mice are viable, and at least in the PLBD1 knockout there are no overt phenotypes . This could explain why no lysosomal storage diseases have ever been associated with mutations in these genes. The situation in other parasitic protozoa is likely to be even more complex given the greater number of paralogous genes in the individual species. The T. brucei p67 RNAi cell line may provide a novel approach to defining these specificities. Xeno-complementation (rescue) of the RNAi phenotype by orthologous genes from other parasitic protozoa would indicate overlapping enzymatic activity with p67. Failure to complement would suggest a different activity/substrate specificity, and in this case constitutive expression in trypanosomes, in conjunction with ‘Omics’, could provide insights into enzymatic activity. Most interesting would be xeno-complementation with the human PLBD genes, which might provide insights into the possibility of specific therapeutic targeting of p67 in trypanosomes. Finally, all of these efforts would be augmented by structural studies that push beyond modelling on the known PLBD2 structure, and these efforts are also underway.The reassignment of p67 as a lysosomal hydrolase raises many questions – foremost being what is its enzymatic activity? The answer to this question will come from lipidomic and metabolomic analyses of RNAi silenced cells, and these studies are currently underway. Elevated levels of any specific metabolite or lipid will point to the likely substrate(s), and this in turn will provide opportunities for enzyme assay development, and perhaps even small molecule inhibitor screens. A broader question is what are the enzymatic activities of orthologues from other parasitic protozoa, and from mammals? The two Whatever comes of these future experiments the outlook for research on this understudied group of enzymes is bright. For too long p67 has remained a protein without a function, but it is likely soon to take its rightful place as the founding member of a novel class of important lysosomal hydrolases.


Selenium is an essential trace element required for human health, and selenium deficiency has been associated with many diseases. The daily recommended intake of selenium is 60 µg/day for adults, which increases to 65 µg/day for women when pregnant. Selenium is incorporated into the 21st amino acid, selenocysteine (sec), a critical component of selenoproteins that plays an important role in a variety of biological responses such as antioxidant defence, reactive oxygen species (ROS) signalling, formation of thyroid hormones, DNA synthesis and the unfolded protein response in the endoplasmic reticulum (ER). Although 25 selenoproteins have been identified, the role of many of these is yet to be fully characterised. This review summarises the current evidence demonstrating that selenium is essential for a healthy pregnancy and that poor selenium status leads to gestational disorders. In particular, we focus on the importance of the placental selenoproteome, and the role these proteins may play in a healthy start to life. Pregnancy is a condition of enhanced demand for nutrients and heightened oxidative stress. Deficiencies in micronutrients such as selenium hinder antioxidant responses and can expose the placenta to an accumulation of free radicals and oxidative insult. This can cause placental insufficiency and dysfunction, leading to complications in pregnancy such as pre-eclampsia, preterm birth, gestational diabetes (GDM), inter-uterine growth restriction (IUGR) and small for gestational age (SGA) babies ,2,3. An According to the Australian Government (NHMRC), the RDI of selenium is 60 µg/day in women, which increases to 65 µg/day in pregnant women and 75 µg/day during breastfeeding. Similarly, in the US, the recommended daily allowance according to the NIH is 55 µg/day in women, and this increases to 60 µg/day in pregnancy and 70 µg/day during lactation. When considering the daily intake of selenium, this recommended dosage increases to 95 µg/day to maximally express selenoproteins such as plasma glutathione peroxidase ,5. HowevPre-eclampsia (PE) is a hypertensive disorder of pregnancy, which is the leading cause of maternal mortality and morbidity , occurrip < 0.0001). Serum/plasma selenium levels of >95 µg/L were considered selenium sufficient, and significantly reduced pre-eclampsia incidence was reported for countries above this value (p = 0.0007) [Many studies have demonstrated that selenium concentrations in women with pre-eclampsia are significantly lower than those women experiencing a normal pregnancy, suggesting that selenium status is associated with the incidence of pre-eclampsia ,10,11,12 0.0007) . This st 0.0007)  have demMore recently a double-blind placebo-controlled pilot trial randomised 230 primiparous UK pregnant women to either 60 µg/day of selenium or placebo from 12–14 weeks of gestation until delivery . The priHigh levels of oxidative stress and endoplasmic reticulum stress because of reduced antioxidant capacity in the placenta are characteristic of pre-eclampsia. Selenoprotein activities in pregnancy have been investigated in numerous studies, where the activity of enzymes such as glutathione peroxidases (GPx), thioredoxin reductases (TrxR) and selenoproteins S, or selenoprotein P  has demoIUGR is defined as a foetus that has failed to reach its growth potential. It affects 10–15% of pregnancies and is the second most frequent cause of perinatal morbidity after pre-maturity . IUGR isp = 0.013) [1 quartile (≤56.60 µg/L) had approximately three times higher risk of SGA  compared to women in the higher quartiles [The relationship between selenium in the aetiology of IUGR/SGA infants has been analysed due to the importance of antioxidant selenoproteins in the development of gestational disorders . Less ex= 0.013) . The sam= 0.013) . In anotuartiles . OverallPreterm birth complications are a major cause of foetal death worldwide occurring in 5–18% of pregnancies across 184 countries with more than 60% of these preterm births occurring in Africa and South Asia . An infat = 2.9, p = 0.001) [As detailed above, selenium has been implicated in pregnancy complications associated with poor placental function such as pre-eclampsia and IUGR, which are also a common cause of preterm birth. There are a variety of studies that measure the levels of selenium in preterm birth which have presented conflicting evidence. Studies measuring the relationships between first trimester levels of selenium in a cohort of Polish women found significantly lower levels of selenium in pregnancy-induced hypertension in women who delivered in <34 weeks compared to >34 weeks . A simil= 0.001) . Further= 0.001) . Africa GDM is one of the most common diseases that develops in pregnancy, affecting up to 14% of pregnant women . GDM devp  =  0.005) [Supplementary antioxidants such as selenium have been widely studied as a therapy to reverse the oxidative status in pregnancies complicated by GDM. There have been multiple studies that have determined that patients with GDM have lower selenium levels and that selenium supplementation improves glucose homeostasis in these patients ,33,34,35  0.005) . In a raSelenoproteins are defined by an active selenocysteine residue and, to date, 25 have been described in the literature. Of these, many have been identified in the human placenta, where they play essential roles in maintaining cell function and viability see . Seleniu2O2 but also hydroperoxides in complex lipids [Glutathione peroxidases (GPx) play important roles in oxidative balance and are one of the first and most well characterised groups of selenoproteins. Glutathione peroxidases are part of the glutathione disulphide system that protects cells from oxidative damage by converting hydrogen peroxides into water . There ax lipids . GPx4 hax lipids ,8. GPx6 x lipids .Whilst GPx’s have been identified in a variety of tissues, their roles in the placenta have not been fully characterised. Broadly, GPx was identified to be synthesised by the human placenta both extracellular (eGPx) and cellularly (cGPX) and secreted extracellularly into the maternal circulation . In the Multiple studies have identified that GPx expression is compromised in pre-eclamptic pregnancies in comparison to normotensive pregnancies ,67,68. OThe expression of GPx2 has recently been investigated in developing mouse embryos, where expression of GPx2 mRNA was higher in the extraembryonic tissues than in the embryo ,60. In tGPx3, the extracellular plasma enzyme, has been demonstrated to play a role in maternal–foetal selenium transfer mechanisms, important in pregnancy and birth, in pre-eclampsia and in the growth of large healthy follicles . MaternaGPx4 is found in placental tissue and is vital for embryonic development and male fertility ,36. GPx4Thioredoxin reductases (TrxR) are selenoproteins that are part of a key antioxidant system that regulates oxidative stress. The thioredoxin system is formed by thioredoxin reductase and its associated substrate, the redox active protein thioredoxin, where thioredoxin reductases recycles oxidised thioredoxin at the expense of NADPH ,75,76. IThere are three deiodinases that have been identified across all cell types; however, only DIO2 and DIO3 are expressed in the placenta and may be responsible for the regulation of thyroid hormones that are vital for healthy foetal development . DIO2 isThyroid hormones are required for normal foetal development, and the foetus relies on maternal supply until mid-gestation. The exchange of bioactive molecules between maternal and foetal circulations occurs via transport through the plasma membrane and cytoplasm of placental trophoblast cells, and in the first trimester, foetal levels of thyroid hormone can be 100 times less than those of maternal serum . In healThere is limited evidence on the regulation of selenium in pregnancy in relation to the expression of these DIO enzymes in the human placenta. In some studies, it has been found that mild selenium deficiencies result in partial protection of the thyroid hormone axis and thyroid hormone metabolic pathways. In healthy selenosufficient people and in isolated mild selenium deficiencies, thyroid hormone concentrations were not altered and there was no evidence for impaired activity of these enzymes . It has It has been recognized for some time that SelP is produced by the placenta and with GPx3 is released into both the foetal and maternal circulation, playing an important role in transporting selenium . SelP leThere is limited evidence associating abnormal SelP production with gestational disorders. A study by Altinove et al. in 2015  observedSelenoprotein H (SelH) has a conserved CXXU thioredoxin-like motif and has been shown to have oxidoreductase activity. It is localised to the Golgi and nucleus where it has role in regulating gene expression in response the redox status, antioxidant defences and oxidative stress. The human placenta expresses SelH but little is known of its function in the placenta and whether changes in placental expression are associated with gestational disorders.In a recent series of experiments in our laboratory, we supplemented transformed trophoblast cells, BeWO, Jeg and Swan-7, with sodium selenite or selenomethionine in an attempt to protect cells from oxidative stress induced by rotenone and antimycin . The preThe endoplasmic reticulum is a critical organelle in the secretory pathway and is involved in intracellular protein synthesis and folding, glycosylation, secretion, lipid synthesis and the regulation of intracellular calcium signalling ,93. Prot2+ homeostasis, inflammation, beta cell function, thyroid hormone synthesis and muscle development [Cellular perturbations such as hypoxia, nutrient deprivation, point mutations in secreted proteins, redox changes, loss of calcium homeostasis can cause ER stress . The unfelopment . ER-resi2+) homeostasis [SEPS1 polymorphism in pre-eclamptic and healthy pregnancy controls [SEPS1-105G > A polymorphism was shown to be a significant risk factor for preeclampsia in this population, and genetic variation in SEPS1 gene was strongly associated with circulating levels of TNF-α, IL-6, and IL-1β, suggesting a crucial genetic link in influencing these proinflammatory cytokines [2 = 7.87, p = 0.005) in women with pre-eclampsia, 1.34 times more likely to have the gene in comparison to normal controls, suggesting SEPS1 has a role in protection from pre-eclampsia in that population [SEPS1 polymorphisms in 569 preterm singleton neonates and 673 term neonates, which found that compared with the GG genotype, -105A positive genotypes (GA + AA genotypes) were associated with significantly increased susceptibility to spontaneous preterm birth  [As illustrated in eostasis . Despiteeostasis ,51,97. Aeostasis . A retroytokines . There wSelF was reduced (p < 0.05) within the maternal liver, SelM was significantly reduced (p < 0.05) in all maternal tissues and SelT expression was reduced in the heart (p < 0.05). Another study measured the selenoprotein mRNA expression in the placenta across the maternal and foetal tissues. It was reported that selenoproteins TrxR1, TrxR2, TrxR3, DIO3, SelH, SelI, SelK, SelN, SelO, SelS, SelV and SelW exhibited the highest expression in the middle section of the placenta, whereas GPx1, DIO2, SelM, SelT, and Sel15, exhibited the highest expression levels in foetal-facing placental tissue and GPx4, SelP, SPS2, and DIO1 exhibited a pattern whereby expression was nearly equal in the foetal-facing and middle section, and lower in the maternal facing portion of the placenta [Other selenoproteins that reside in the ER, such as Sep15, SelK, SelM, SelN and SelT, are less studied when it comes to expression in the placenta. A recent study by Hofstee et al. analysed the expression of many of these ER selenoproteins in pregnant mice who were allocated a low-selenium diet in comparison to a control selenium diet . At embrplacenta . FurtherMore specifically, there is limited information on the roles of the other ER-resident selenoproteins. SelK has been demonstrated to participate in oxidation resistance, calcium flux regulation and the ER associated degradation (ERAD) pathway in immune cells; however, not in placenta or trophoblast cells . One stuThe placenta is a highly specialised organ of pregnancy that supports the growth and development of the foetus. It does so by connecting the maternal and foetal circulation to allow for the exchange of gases, nutrients, and waste products. The crucial role of micronutrients in the health of an individual in pregnancy is still under investigation, but there is a body of literature describing the critical role of micronutrient intake during all periods of foetal growth and development. Evidence strongly suggests that where there is an excessive increase or decrease in any nutrient, it has a direct relationship on the development of placental co-morbidities. For many years, selenium has been a micronutrient of interest in pregnancy where deficiencies have been directly linked to an increased chance of developing pregnancy complications such as pre-eclampsia, preterm birth and intrauterine growth restriction . A comprMany studies have implicated the role of oxidative stress in pregnancy pathologies. When antioxidant defences are overwhelmed by reactive oxygen and nitrogen species (RONS), this leads to oxidative insults that damage proteins, lipid and nucleic acids structures. Placental development is an intricate process that is highly dependent on oxygen status. During the first trimester, the placental intervillous space is low in oxygen as trophoblast cells plug the tips of uteroplacental spiral arteries, limiting supply of oxygenated maternal blood . At the The placenta expresses low levels of antioxidants in early pregnancy; therefore, pre-mature maternal foetal circulation and widespread oxidative stress overwhelm cellular homeostasis, leading to placental injury. This is the potential cause of spontaneous first trimester abortions, and insufficient placental perfusion and ischemia reperfusion induced oxidative stress are associated with pre-eclampsia and IUGR . Placent


Anterior temporal lobectomy (ATL) is the most common surgical treatment for drug-resistant temporal lobe epilepsy (TLE). Right ATL has been reported to reduce facial memory ability in patients with TLE, as indicated by poor performance on the Warrington Recognition Memory Test for Faces (RMF), which is commonly used to evaluate visual memory in these patients. However, little is known about whether patients with TLE exhibit difficulties in identifying faces in daily life after ATL. The aim of this study was to investigate facial memory ability and self-awareness of face identification difficulties in patients with TLE after ATL. Sixteen patients with TLE after right ATL, 14 patients with TLE after left ATL, and 29 healthy controls were enrolled in this study. We developed the multiview face recognition test (MFRT), which comprises a learning phase  and a recognition phase . Facial memory abilities were examined in all participants using the MFRT and RMF, and self-awareness of difficulties in face identification was evaluated using the 20-item prosopagnosia index (PI20), which has been widely used to assess developmental prosopagnosia. The MFRT performance in patients with TLE after ATL was significantly worse than that in healthy controls regardless of the resected side, whereas the RMF scores in patients with TLE were significantly worse than those in healthy controls only after right ATL. The MFRT performance in patients with TLE after both left and right ATL was more influenced by working memory load than that in healthy controls. The PI20 scores revealed that patients with TLE after left ATL were aware of their difficulties in identifying faces. These findings suggest that patients with TLE not only after right ATL but also after left ATL might have difficulties in face identification. Epilepsy is one of the most frequent chronic neurological disorders –4. DespiNaturally, facial memory can be influenced by facial perception processing . PreviouIn the real world, it is rare to be confronted by so many faces. In addition, people do not always recognize faces from the front, and hairstyles and clothes can change every day. Furthermore, one previous study showed that many participants were able to identify individuals in a modified RMF that removed all internal facial feature information . AlthougSeveral previous studies have reported that patients with focal hippocampal damage due to anoxia or encephalitis have impaired higher-order visuospatial perception and recognition, including unknown faces, when working memory demand is slightly increased , 37. In The main aims of this study were to investigate facial memory ability and self-awareness of face-identifying difficulties in patients with TLE after ATL. Our hypothesis is that (1) not only right TLE patients but also left TLE patients after ATL exhibit deficits in identifying unknown faces if they see the faces at different angles or the faces are partially hidden; (2) the deficits will become more severe when working memory load increases; and (3) not only right TLE patients but also left TLE patients after ATL are aware of face identification difficulties in their daily life. For these purposes, we developed a new test to assess facial memory that not only uses frontal face images but also oblique face images and those covered with noise. In addition, the test required participants to learn only one or three unknown faces to investigate the alteration of facial memory ability due to working memory load and to better reflect situations encountered in daily life. Moreover, we assessed face identification difficulties in daily life using a validated self-assessment questionnaire. We selected the 20-item prosopagnosia index (PI20), which has been confirmed to be correlated with the Cambridge Face Memory Test scores . It is iThe ethics committees of the Tohoku University Hospital approved this study. Written informed consent was obtained from all participants after they had been given a detailed description of the study.Thirty consecutive patients with drug-resistant TLE who underwent unilateral ATL at Tohoku University Hospital or National Center of Neurology and Psychiatry Hospital were enrolled in this study. The inclusion criteria were as follows: (1) 1 year or more after surgery; (2) ≥ 16 years old; (3) a Performance Intelligence Quotient index on the Wechsler Adults Intelligence Scale-III (WAIS-III) of ≥ 70; (4) a native Japanese speaker; and (5) a best-corrected Snellen acuity ≥ 20/50. The exclusion criteria were as follows: (1) concurrent extratemporal lesions on MRI and (2) no history of neurological or psychiatric disease other than TLE-related conditions.Of the 30 patients, ATL with amygdalohippocampectomy was performed in 24 patients . The antero-inferior temporal lobe was removed by up to 35 mm on the dominant side and 45 mm on the nondominant side from the tip of the temporal lobe, and then the inferior horn of the lateral ventricle was opened. The amygdala was aspirated subpially to the level of the anterior choroidal artery or optic tract. The mesial and basal temporal structures, including the hippocampus, entorhinal and perirhinal cortex, and anterior part of the parahippocampal and fusiform gyrus, were removed en bloc and further aspirated to the level of the superior colliculus in the anterior–posterior direction. ATL with amygdalectomy was performed in four patients . One of the remaining two patients underwent left ATL with multiple hippocampal transactions, and the other patient underwent left ATL preserving both the amygdala and hippocampus. One patient had a cerebral infarction adjacent to the resected brain area in the right temporal lobe immediately after right ATL. The lateral and basal temporal areas resected in the patients with ATL are demonstrated in Postoperative seizure outcome was evaluated using Engel’s classification. Of the patients with right ATL (right ATL group), 11 (68.8%) had achieved seizure freedom (Class I), two had rare seizures (Class II), two had a worthwhile improvement (Class III), and one had no change (Class IV) 1 year after surgery. Of the patients with left ATL (left ATL group), 10 (71.4%) had achieved seizure freedom (Class I), two had rare seizures (Class II), one had a worthwhile improvement (Class III), and one had no change (Class IV). The right ATL and left ATL groups did not differ from each other in age at onset, disease duration, or seizure outcome. The demographic data are summarized in Twenty-nine healthy controls (HCs) matched for age and sex were recruited from the local community through advertisements. Participants with any history of neurological or psychiatric disease and/or impaired visual acuity (a best-corrected Snellen acuity that was poorer than 20/50) were excluded. Although there was no significant difference in handedness among both the ATL groups and the HC group, the averages of education years in patients after left and right ATL groups were significantly lower than those in the HC group .In the present study, all neuropsychological tests, including standardized and developed tests, were administered to the patients after ATL. There was no significant difference in the mean intervals from ATL to assessment between the right and left ATL groups . All patients underwent the following standardized neuropsychological tests: the WAIS-III for verbal capacities, visuoconstructive functions, working memory, and cognitive speed ; the WecIn addition, to evaluate retrograde facial memory and familiar face recognition ability, we developed a famous face identification task in which participants were presented with 20 faces of Japanese actors, athletes, or politicians . Participants were required to provide both the first and last names of the famous individuals. If they could not correctly name the famous person, they were asked to provide the information about the famous person. These tests yield two scores: the naming score, which is the number of total correct responses , and the recognition score, which is calculated by adding the number of total correct responses to the number of total correct but insufficient responses (a participant correctly answers either the first or last name or correctly provides one or more pieces of information about the famous person). Each score ranges from 0 to 20. The famous face identification task was administered to all participants.3 on frontal face images. Selected examples of face stimuli are shown in We collected 144 nonfamous Japanese faces  for test stimuli, of which 60 were drawn from the face database of the Advanced Telecommunications Research Institute International Inc. and the others were obtained from local volunteers. A 10-point rating of facial emotional valence was assessed in each face image by 10 healthy volunteer raters . Sixty neutral face images were selected in order from the average emotional valences closest to 5.5 points. The average emotional valence of the selected male and female face images was 4.70 (SD = 0.40) points and 4.89 (SD = 0.59) points, respectively. There was no significant difference in valence between the male and female face images (p = 0.150). Hair-removed frontal and oblique [left—30 degrees] views of each face were generated using FaceGen software (Singular Inversion). We removed the facial blemishes manually using Adobe Photoshop CS 6.0 and Adobe Illustrator CS 5.1. All face images were transformed into grayscale with a black background. Noise-masked face images were created by overlaying black-and-white visual noise of spatial frequencies of 1/fParticipants sat in front of a personal laptop computer . The computer was placed in an easily viewable and operable position. The participants were instructed both verbally and in written instructions. Each trial of the test consisted of a learning phase and a recognition phase. During the learning phase, participants were asked to remember frontal face images that were displayed on a screen for 5 s. This presentation time and the angle of face (oblique face image) was defined based on a pilot study in 7 healthy volunteer subjects  so that the total accuracy rate of the MFRT became approximately 80%. We varied the numbers of frontal face images displayed (one or three images) . In the We found significant differences in the scores between each time interval between the learning and recognition phases , both in the one-image and three-image blocks in the HC group . As showTo assess patients’ insight into their own facial recognition abilities, we used the PI20 , which iOne-way ANOVA and post hoc Bonferroni tests were used for between-group comparisons in the Warrington Recognition Memory Test scores (words and faces), and Welch’s t-test was used to compare the other neuropsychological test scores, except for the recognition score of the famous face identification task and the MFRT scores, between the left and right ATL groups. A three-way repeated measures ANOVA was used to analyze between-group differences  in the MFRT scores for the three stimulus conditions  and between the two working memory loads (Memory: one image or three images). The Kruskal–Wallis test and a post hoc Mann–Whitney U-test with Bonferroni correction were used to compare the recognition score of the famous face identification task and PI20 scores between the three groups.Statistical analyses were performed using IBM SPSS statistics software , and the threshold for statistical significance was set at p < 0.05.2 = 0.396). Post hoc pairwise comparisons with Bonferroni correction revealed that the mean naming score of the famous face identification task score in the left ATL group was significantly lower than that in the right ATL (p = 0.050) and HC groups (p < 0.001). In contrast, there were no significant differences in the median recognition scores of the famous face identification task among the three groups . The mean scores of the Warrington Recognition Memory Test for words  = 5.87, p = 0.005, η2 = 0.173) and for faces  = 6.67, p = 0.003, η2 = 0.192) were significantly different among the three groups. Post hoc pairwise comparisons with Bonferroni correction revealed that the Warrington Recognition Memory Test for words score in the left ATL group was significantly lower than that in the HC group (p = 0.003), whereas there were no such significant differences between the right ATL and HC groups (p = 0.791) or between the left and right ATL groups (p = 0.126). In contrast, the RMF score in the right ATL group was significantly lower than that in the HC group (p = 0.002), and there were no such significant differences between the left ATL and HC groups (p = 1.000) or between the left and right ATL groups (p = 0.105).The neuropsychological assessment results are summarized in 2 = 0.032) for the MFRT scores. However, the interactions between Group and Memory  = 7.54, p = 0.001, η2 = 0.212) and between View and Memory  = 10.15, p < 0.001, η2 = 0.270) were significant. There was no significant interaction between Group and View  = 1.17, p = 0.153, η2 = 0.058). The main effects of Group  = 6.66, p = 0.003, η2 = 0.192), View  = 14.66, p < 0.001, η2 = 0.348), and Memory  = 307.91, p < 0.001, η2 = 0.844) were significant. According to post hoc pairwise comparisons with Bonferroni correction, the mean MFRT scores of the left and right ATL groups were significantly worse than those of the HC group . There was no significant difference in the mean MFRT scores between the left and right ATL groups (p = 1.000). In addition, the mean scores for oblique view and noise-masked view trials were significantly worse than those for the frontal view trial . There was no significant difference in the mean MFRT score between oblique view and noise-masked view trials (p = 0.852). Moreover, the mean MFRT score in the three-image tasks was significantly lower than that in the one-image tasks (p < 0.001).The MFRT results are summarized in 2 = 0.066), whereas the simple main effect of Group in the three-image tasks  = 8.62, p < 0.001, η2 = 0.235) was significant. In contrast, the simple main effect of Memory was significant in each group  = 77.52, p < 0.001, η2 = 0.581; right ATL group: F  = 142.97, p < 0.001, η2 = 0.720; HC group: F  = 95.27, p < 0.001, η2 = 0.624). Post hoc Bonferroni contrast analysis tests revealed that the mean MFRT scores in the left and right ATL groups were significantly worse than those in the HC group on the three-image tasks . There was no significant difference in the mean MFRT scores between the left and right ATL groups on the three-image tasks (p = 0.927). In addition, the mean MFRT score on the three-image tasks was significantly worse than that on the one-image tasks in each group .In the interaction between Group and Memory, there was no significant simple main effect of Group in the one-image tasks  = 1.97, p = 0.149, η2 = 0.291; three-image tasks: F  = 11.12, p < 0.001, η2 = 0.288). Furthermore, simple main effects of Memory were also significant for each view  = 99.39, p < 0.001, η2 = 0.640; oblique view: F  = 126.23, p < 0.001, η2 = 0.693; noise-masked view: F  = 223.72, p < 0.001, η2 = 0.800). Post hoc Bonferroni contrast analysis tests revealed that the mean MFRT score for the oblique view was significantly worse than those for the frontal view and noise-masked view on the one-image tasks . In addition, the mean MFRT scores for the oblique view and noise-masked view were significantly worse than those for the frontal view on the three-image tasks . There was no significant difference in mean MFRT scores between the oblique view and noise-masked view on the three-image tasks (p = 0.868). Moreover, the mean MFRT score on the three-image tasks was significantly worse than that on the one-image tasks for each view .In the interaction between View and Memory, simple main effects of View in both the one-image and three-image tasks were significant  = 11.31, p < 0.001, ηThe PI20 results are shown in We investigated facial memory ability and self-awareness of face identification difficulties in patients with TLE after ATL using MFRT and PI20. The major findings were as follows: (1) the MFRT performance in patients with TLE after ATL was significantly worse than that in HCs regardless of the resected side; and (2) the PI20 score was higher in patients with TLE after left ATL but was not higher in patients with TLE after right ATL than in HCs.As previous studies have demonstrated, RMF performance was normal in TLE patients after left ATL in the current study , 22. On The discrepancy between the RMF and MFRT results in the TLE patients after left ATL is likely to have arisen from differences between the two tests. The RMF stimuli contained abundant noninternal facial feature information, such as hairline and clothes, whereas the MFRT stimuli were hair-removed. Given that the face images used in the MFRT contain less nonfacial feature information, the clues for learning and recognizing face images were more limited than in the RMF. In addition, the MFRT requires participants to recognize face images that are different from the learned face images. We suggest that this requires the ability to complement or compensate for incomplete face images. However, the TLE patients after left ATL exhibited good facial memory performance, despite the less informative face images on the one-image tasks. The poor performance on the MFRT in the TLE patients after left ATL only became obvious on the three-image tasks. These findings indicate that difficulties in learning or remembering less informative face images in TLE patients after left ATL were accompanied by an increased working memory load, which is coincident with one of our hypotheses.Previous studies of patients with focal hippocampal damage due to anoxia or encephalitis, amnestic mild cognitive impairment, or Alzheimer’s disease and functional MRI studies have indicated that the hippocampus plays a crucial role in higher-order visuospatial working memory , 42, 43.In addition, a previous study reported that patients with medial temporal lobe lesions that were involved in not only the hippocampus but also the perirhinal cortex, which was involved in almost all patients after ATL in the present study, showed impaired discrimination of unfamiliar faces presented from differing viewpoints . MoreoveThe PI20 scores in patients with TLE after left ATL were higher than those in the HC group. This finding could not be predicted from the results of the RMF, since the RMF scores in patients with TLE after left ATL were not different from those of HCs in both the current and previous studies , 22. We In the present study, the performance of the patients with TLE after right ATL on both the RMF and MFRT was significantly lower than that of the HC participants. This finding is coincident with previous studies and our hypothesis –25. It iAlthough there was no significant difference in the mean visual memory index of the WMS-R between the TLE patients after right ATL and after left ATL, the mean intelligence quotient index of the WAIS-III in the TLE patients after right ATL tended to be lower than that after left ATL. The mean level of performance intelligence in the TLE patients after right ATL was not abnormal. However, it was possible that the performance on the MFRT in these patients was influenced by their intelligence.Surprisingly, the PI20 scores in the patients with TLE after right ATL were not higher than those in the HC participants. The TLE patients after right ATL did not seem to be aware of face identification impairment in their daily life, despite their significantly reduced objective unfamiliar face identification task performance. One possible explanation for this finding is that patients with TLE after right TLE might have anosognosia for visual memory impairment. Previous studies have demonstrated that very few TLE patients are aware of their significant memory decline after right ATL , 48. SawOur study has several limitations. First, we did not validate the developed neuropsychological tests, including the MFRT, famous face identification task, and Japanese version of RMF. We did not evaluate test-retest reliability for these neuropsychological tests. Therefore, we could not conclude whether the differences in performance on these neuropsychological tests among the TLE patients and HC participants were evident. In addition, as mentioned above, the recognition scores of the famous face identification task we created demonstrated a ceiling effect in the TLE patients and HC participants. Unfortunately, it is highly likely that we could not reliably detect deficits in famous face recognition in patients after right ATL.Second, we did not implement neuropsychological tests, including the MFRT and PI20, before surgery. Thus, we could not investigate whether the MFRT performance in the patients with TLE was reduced due to ATL or whether stronger awareness of difficulties in face recognition in daily life was derived from a left ATL.Third, we only evaluated facial memory ability. However, in patients with hippocampal damage, impaired higher-order visuospatial perception or recognition has been observed when working memory demand is increased, even though face stimuli were not used –40. TherFinally, some TLE patients did not undergo PI20 before either or both MFRT and RMF were implemented. Therefore, the results of MFRT and/or RMF could affect the PI20 scores in these patients. Moreover, the PI20 score is influenced by various factors, including memory function and face perception. The daily demand for face recognition in social life may be altered by occupation and/or household . EnvironIn conclusion, our results suggest that the ability to remember faces with less internal and/or external information is impaired when visuospatial working memory load increases in patients with TLE who underwent ATL, regardless of the resected side. However, validation of the MFRT is necessary to confirm our findings. In the future, we aim to investigate memory of not only unfamiliar but also familiar faces and related multiaspect information about patients with TLE before and after ATL to elucidate whether ATL affects facial memory ability, which could help improve the quality of life and surgical outcome of ATL in patients with TLE.S1 Table(DOCX)Click here for additional data file.S2 Table(PDF)Click here for additional data file.S3 Table(PDF)Click here for additional data file.


The mitogen-activated protein kinase (MAPK) family is an important bridge in the transduction of extracellular and intracellular signals in different responses at the cellular level. Within this MAPK family, the p38 kinases can be found altered in various diseases, including cancer, where these kinases play a fundamental role, sometimes with antagonistic mechanisms of action, depending on several factors. In fact, this family has an immense number of functionalities, many of them yet to be discovered in terms of regulation and action in different types of cancer, being directly involved in the response to cancer therapies. To date, three main groups of MAPKs have been identified in mammals: the extracellular signal-regulated kinases (ERK), Jun N-terminal kinase (JNK), and the different isoforms of p38 . In this review, we highlight the mechanism of action of these kinases, taking into account their extensive regulation at the cellular level through various modifications and modulations, including a wide variety of microRNAs. We also analyze the importance of the different isoforms expressed in the different tissues and their possible role as biomarkers and molecular targets. In addition, we include the latest preclinical and clinical trials with different p38-related drugs that are ongoing with hopeful expectations in the present/future of developing precision medicine in cancer.  Currently, a large part of the resources allocated to global health are being directed towards the study and prevention of cancer, as it is one of the main causes of death worldwide . As a reThanks to these efforts, it has been possible to relate the appearance of various types of cancer with the mutational state of some important genes. By identifying certain molecular patterns that do not function properly, it would be possible to successfully intervene with different therapies aimed at correcting or blocking these alterations involved in the development and survival of tumor cells . SpecifiIn 1991, the sequences of the first MAPKs studied in mammals  were revealed, identifying them as member enzymes of this newly discovered specific family of protein kinases . MAPKs aMAPK signal transduction pathways are ubiquitous and highly conserved regulatory mechanisms in eukaryotic cells which promote coordinated and integrated responses to numerous stimuli through protein kinase-type receptors, leading to important cellular physiological effects. MAPKs phosphorylate target substrates at Ser or Thr residues, followed by a Pro residue, suggesting limited specificity . This spIn recent years, the cross-interaction of the JNK and p38 families has been studied in greater depth, elucidating their dual role in different types of cancer, depending in many cases on the cellular context and the specific individual . Both thIn this review, we highlight the broad functionalities of the different components of the p38 MAPK molecular signaling pathway, considering the role of even the less known p38 isoforms, in the development of numerous cancer-related processes, highlighting their dual role in multiple tumor types and their great viability as cancer biomarkers or potential therapeutic agents.MAPK14, MAPK11, MAPK12, and MAPK13, which code for p38α, p38β, p38γ, and p38δ, respectively [MAPK14 is expressed in almost all cellular types, whereas the other isoforms are expressed in specific tissues. For example, p38β is mainly found in the brain, p38γ is expressed in skeletal muscles, and p38δ is observed in kidneys, the pancreas, the small intestine, and testis [Four genes with high sequence homology have been identified that code for MAPK/p38: ectively , with p3ectively . p38α/MAd testis . In gened testis . It has d testis ; howeverd testis . It shoud testis . TherefoThe great complexity of the p38 MAPK pathway lies in addition to its mechanism of action, in its regulation at various levels by activators and inhibitors of different natures.In mammals, p38 isoforms are activated in response to different stresses produced in the cellular environment as well as the liberation of inflammatory cytokines such as interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-α) in processes of oxidative stress during UV radiation exposition, hypoxic conditions, or during ischemia . As with the other MAPK families, the p38 pathway involves the canonical cascade activation of certain small proteins of the Rho GTPase family, such as Rac or Cdc42, which are upstream of the MAPK module discussed above . Some ofOn the other hand, there is a noncanonical p38 activation pathway. This occurs, for example, in T cells, where p38 can be activated by T-cell receptor (TCR)-mediated phosphorylation at a Tyr323 residue by the 70-kDa protein kinase ζ-chain-associated protein kinase (ZAP70) .As mentioned before, the p38 module is also bound by scaffolding proteins that play a crucial role in the specificity of its signaling. These proteins do not possess catalytic activity themselves, but regulate the activity of the p38 cascade by promoting the conformational changes necessary for its activation and controlling its cellular localization . p38 activation occurs by dual phosphorylation at Thr180 and Tyr182 residues located in the activation loop, therefore one way to de-phosphorylate these sites is by the actuation of phosphatases at several levels, acting also upstream of dephosphorylate MAP2Ks. Within this group are members of the dual specificity phosphatases (DUSP) family of phosphatases, which includes MAPK phosphatases (MKP). Notably, these phosphatases are activated even by stimuli that activate p38 . DUSP4 iMicroRNAs (miRNAs) are small, conserved noncoding RNAs that act at the post-transcriptional level, inducing the silencing of complementary mRNA targets once the Argonaute proteins assemble in miRNA-induced silencing complexes (miRISCs) . Most ofOn the other hand, the p38 MAPK pathway has been also involved in cervical cancer through the miR-409-3p/CDK8 axis . In gliaThese findings suggest that miRNAs may become the main regulators of the long-term specificity and sensitivity of p38 and other signaling pathways. However, since there are numerous identified miRNAs that regulate the p38 MAPK pathway in different tumor models with different consequences, its use as biomarkers or therapeutic targets is still far from being readily applied in clinical practice.MAPK p38 can be found in both the cytoplasm and the nucleus, and its location determines its signaling specificity . p38 is In response to inducers of DNA damage, such as radiotherapy or chemotherapy used in cancer treatment, the nuclear localization of p38 depends on its phosphorylation, but does not depend on its own kinase activity . Since pThe p38 substrates include other protein kinases and transcription factors, 55% of which are found in the nucleus . Most ofIn conclusion, most studies have suggested that p38 regulates the inhibitors or activators of transcription, in addition to chromatin modulation, favoring or not the transcription of many genes implicated in different cellular processes .On the other hand, the cytosolic substrates of p38 include proteins with antiproliferative functions such as p57Kip2 and cyclin D1/3, and apoptotic functions such as Bax and BimEL. Moreover, p38 can regulate cell survival by phosphorylation of caspase-3 and caspase-8  Figure .There is strong evidence for a role of p38α as a tumor suppressor, mainly mediated by the negative regulation of the cell cycle and the activation of apoptosis. Moreover, the induction of terminal differentiation is involved in its role as a tumor suppressor . HoweverAs we know, uncontrolled proliferation is a characteristic process in cancer, and the p38 MAPK pathway plays a key role in regulating cell cycle progression at different points by mechanisms that can depend on transcription machinery. In addition, it can modulate antagonic cellular programs for cell survival, differentiation, or cell death induction, resulting in significant effects on the progression of several types of cancers .HRAS, functioning as an anti-tumor defense mechanism by inducing p53 phosphorylation [As discussed before, p38α can negatively regulate cell cycle progression at the G1/S and G2/M transitions by different processes, such as the downregulation of cyclins and the upregulation of cyclin-dependent kinase (CDK) inhibitors, as well as the modulation of the tumor suppressor p53 . p38 MAPrylation . This furylation . This efrylation . Howeverrylation . These orylation . It has A quiescent state known as cancer dormancy, induced by p38α through inflammatory and antiapoptotic signals, such as the liberation of IL-6 cytokine, has been also suggested as a mechanism involved in drug resistance. This different activity of p38α could be relevant for tumor suppression, leading to more differentiated and less transformed cells in cancer cell lines, such as in renal carcinoma or colon cancer . Ultimately, it is likely that the different effects of p38α pathway activation depends on cell type differences, along with the duration, quality, and intensity of the stimulus and its communication and interaction with other signaling pathways.MAPK11 in keratinocytes could promote a decrease in c-Myc expression [On the other hand, it has been shown that p38β could be involved in cell proliferation, thanks to its relationship with integrin-αv, as it maintains cell proliferation in keratinocytes by controlling the translation of c-Myc FAK, p38β, and p90RSK1. Therefore, it has been shown that either chemical inhibition or genetic interference of p38β pression .MAPK13 gene [The analysis of the expression of p38γ and p38δ in both cell lines and patient samples indicate that they have pro- and antioncogenic roles in tumor development and outcome . For exaK13 gene ,70.Chronic inflammation plays a key role in cancer development by promoting cancer survival, along with angiogenesis and cell invasion and metastasis. Studies have shown that these processes are controlled by the p38 MAPK pathway, as that these enzymes regulate the activity and expression of some inflammatory mediators such as different proteases and cytokines that contribute to cancer development and progression .The tumor microenvironment (TME) is the collection of cells , molecules (such as cytokines and chemokines), and blood vessels that surround and feed a tumor. In addition, the stroma, which dynamically supports the TME, is formed by the extracellular matrix, a different type of cells, including fibroblasts, infiltrated immune cells, and histological structures such as the blood vessels or connective tissue  Figure .It has been shown that p38α regulates the activation of cyclooxygenase 2 (COX2), which has a proinflammatory activity that has significant effects on cancer progression, such as nonmelanoma skin cancer, breast cancer, or glioma ,74,75. IIn addition, p38α, by other independent mechanisms, can induce the expression of metalloproteinases, which are involved in matrix formation, remodeling, or degradation by metastatic cancer cells, with the participation of the vascular endothelial growth factor A (VEGF-A), which facilitates the tumor survival through angiogenesis induction. For tumor growth, the formation of new vessels close to the cells is indispensable, a process known as angiogenesis . AngiogeImportantly, the downstream activator of p38: MKK6 may or may not have metastatic effects, depending on the experimental model ,88. FinaOn the other hand, there is evidence that p38α may have tumor suppressor functions through genetic studies that have identified that MKK4 (a MAP2K shared by both the JNK pathway and p38) may have a relevant role in this type of process. Thus, loss-of-function alleles for MKK4 were found in some types of cancer such as lung, breast, colon, prostate, and even pancreatic cancer; however, there are also studies indicating that this loss could also promote tumorigenesis ,91.The tumor suppressor activity of p38α has been studied in relation to the occurrence of the overexpression of several negative modulators of p38 MAPK signaling in various human tumor types, such as the phosphatases PPM1D and DUSP26 ,92,93 anBy studying the expression of p38γ and p38δ in knock-out mouse models and mouse cancer models, the tumor suppressor role of these isoforms in mouse embryonic fibroblasts has been demonstrated, such that their deficiency could increase cell migration and metalloproteinase-2 secretion, thereby modifying cell contact inhibition. Furthermore, decreased expression of p38γ in K-Ras-transfected fibroblasts resulted in increased cell proliferation and tumorigenesis in trials conducted both in vitro and in vivo . The proCross signaling between pathways plays a crucial role in cell regulation, depending on the cellular context. As noted above, the JNK and p38 MAPK pathways share several upstream regulators, therefore there are many stimuli that can activate both pathways at the same time . In someTherefore, most studies support the idea that therapeutic inhibition of the p38 MAPK pathway must depend on the cellular context, cancer type, and tumor stage, as well as the intensity and duration of the signal, together with cross signaling between MAPK pathways.Early detection and diagnosis of cancer is crucial for the survival of cancer patients. Tumor biomarkers are crucial in reflecting molecular differences between certain types of cancers, sometimes enabling detection at an early stage—a consequent advantage in improving a patient’s prognosis. Therefore, many studies have focused on the discovery of new biomarkers targeting the MAPK pathway and, in this sense, the p38α isoform is one of the most studied; however, in recent years, isoforms p38β, p38γ, and p38δ have been recognized with a potential role in cancer diagnosis.The p38γ isoform is associated with invasion, clinical stage, metastasis, and chemosensitivity. Some studies have shown that overexpression of this isoform is associated with a poor prognosis in patients with cellular hepatocarcinoma  and may MAPK13 gene [It has been shown that p38δ is overexpressed in cholangiocarcinoma, invasive human cutaneous squamous cell carcinoma (SCC), head and neck SCC, and prostate cancer ,109,110.K13 gene ,111,112.K13 gene . In addiK13 gene . Thus, tK13 gene . MAPK11 gene expression in specific female tissue cancers has been determined with in-silico studies [The p38β is an isoform that has been recently incorporated in cancer studies and showed an interesting role in cancer development. For example, this isoform has been proposed as a key target of the Pokémon proto-oncogene, a transcription factor involved in tumorigenesis and metastasis in liver cells . Further studies . Finally studies .The p38 pathway is a pleiotropic cascade with different actions in the proper functioning or otherwise of cells in the body, such as in response to growth factors or stress, during carcinogenesis or metastasis. For this reason, p38 plays a fundamental role in the approach to conventional cancer therapies, such as radiotherapy or chemotherapy and targeted treatments, using certain small molecules that act as inhibitors of key steps in the signaling pathway, although they can induce resistance from the first dose due to the positive selection of those tumor cells that are able to compensate the specific target pathway.A large percentage of patients are treated with ionizing radiation for cancer. The effect of exposure to this radiation on both normal and tumor tissues has been extensively studied in recent years. The early effects of chemotherapy result in the induction of apoptotic cell activation, with excessive secretion of proinflammatory cytokines because of this process, as well as the increased recruitment of blood cells and platelets, the activation of coagulation systems, and increased vascular permeability . The molFor example, it has been shown that, in human dermal microvascular endothelial cells, radiation-induced apoptosis is largely mediated by p38  and thisApoptosis is a mechanism of cell death in response to anticancer agents and, as mentioned before, p38 plays a key role in this process, modulating the chemotherapeutic response to both conventional and targeted therapies. P38 has been implicated in cell apoptosis that is mediated by cis-platinum and 5-fluorouracil (5-FU) in breast and colon cancer cell lines  and has P38 contributes to chemotherapeutic resistance in several tumor types, e.g., in response to doxorubicin, cis-platinum, or other agents that target DNA damage, as p38 will promote cell survival of p53-deficient cancer cells through MK2-mediated cell cycle arrest ,129. In Antiestrogen tamoxifen is a key treatment for hormone-sensitive breast cancers, and the activation of the p38 pathway is related to resistance and poor prognosis . HoweverIn terms of p38γ-related drugs, it has been shown that this isoform can regulate the signal transduction of drugs targeting DNA topoisomerase II α, which represent an important class of antitumor drugs in the clinic, thus enhancing their therapeutic activity . However, it has been shown that the role of the p38 pathway in the response to chemotherapy depends on the type of tumor, since each tumor microenvironment also participates in the neoplasia. The involvement of this pathway in tumor development involves several cell types within the tumor microenvironment, as discussed before. Thus, several p38 inhibitors have been shown to inhibit cancer progression by halting processes such as angiogenesis, for example, in an in vivo experimental model of prostate cancer , as wellIn addition, genotoxic, ROS-generating drugs such as doxorubicin induce the liberation of IL-6 from endothelial cells in a mechanism that depend on p38 activation, contributing to the induction of senescence in tumor-associated stromal cells ,138. TheAll these studies demonstrate the viability of therapy directed against the p38 pathway as a target for cancer, and are summarized in the following section. There are many clinical trials evaluating the role of p38 as a biomarker and target for different diseases, with a considerable percentage dedicated to cancer treatment, where p38 is considered a promising target, either using p38-specific inhibitors alone or in combination with other chemotherapeutic agents  Table 1Table 1.However, one cannot overlook the fact that p38 is involved in many biological activities, and its inhibition could lead to unwanted and unknown side effects, therefore efforts are currently focused on discovering agents that specifically target p38 or a component of the pathway that is deregulated and is the trigger for a particular disease. For example, small peptides are being developed that target VEGFR-2, thereby inhibiting the activation of p38 by VEGF, and thus inhibiting p38-dependent angiogenic effects . In this regard, it has also been shown that the combination of p38 inhibitors with conventional chemotherapy drugs could be a promising approach in antitumor therapy. One of the most prominent is the p38α and p38β inhibitor LY2228820/Ralimetinib, which has antiangiogenic effects in vitro and in vivo  and has Because of the involvement of p38α in proinflammatory cytokine production and cytokine receptor signaling, the development of a large number of small p38α MAPK inhibitor molecules is ongoing . These hMoreover, treatment resistance should be considered in cancer therapy, and attempts should be made to limit it. Thus, the inhibition of the p38 pathway has been shown to limit resistance to irinotecan in colon adenocarcinoma . HoweverAlmost all clinical trials to date have failed and therefore no compound has yet been approved, which has been due to systemic side effects on the heart, liver, or nervous system , which cTherefore, efforts should focus on gaining a better understanding of the contribution of p38 to the development of cancer and other diseases, both at the cellular and organismal level, to develop better compounds that specifically target the different components of this MAPK signaling pathway to improve responses to treatment and reduce the drawbacks of conventional inhibitors.MAP kinases are involved in the response of cancer cells to a wide range of stimuli, both external and internal. In the last 25 years, many important advances have been made in our understanding of the regulation and functionality of the p38 MAPK pathway. Due to genomic and proteomic strategies, the different components of the p38 MAPK pathway have been identified that could play a key role in oncogenic processes when they are altered, making them potential targets for the development of antitumor drugs. However, these strategies have been hampered by the activation of compensatory pathways in cancer cells and the high degree of crossover and dual functionality that exists between the other different MAPK families (ERK and JNK), thus giving rise to a strong resistance to the most common treatments. These kinases are highly regulated at various levels, where numerous miRNAs have been described as interfering in different steps of signaling. However, numerous reports have shown that the use of miRNA as biomarkers or drug targets has been unsuccessful due to differences in the methodology of the studies, the lack of standard methods for normalization, the different miRNA processing, and the inability to discriminate among closely related miRNAs, among others.Given the latest advances in gene therapy, it is not impossible to think that cancer, which can be defined as a disease caused by different genetic predispositions, could be fought by modifying certain aberrations in the genome or by inducing certain tumor suppressor genes, a revolutionary process also known as epigenome editing. This would be possible thanks to the CRISPR-Cas9 method that could inhibit oncogenes such as the p38γ gene in some tumors, which could be a promising cancer therapeutic strategy . SeveralIt should be noted that immunotherapy has become an important cancer treatment in recent years. These include immunosuppressants that target PD-1 on T cells and PD-L1 on tumor cells. The aim of this antitumor therapy is to activate CD8+ T cells so that they can kill tumor cells specifically. However, when this occurs, there are immune checkpoints aimed at preventing these processes, resulting in immunosuppression and consequent immune escape from tumors . It has However, a better understanding of the contribution of p38 to disease at both the cellular and organismal levels is needed and can be achieved by better defining the specific functions of this signaling pathway in specific tumors. In addition, future therapies may also involve collateral cancer processes such as directly related as angiogenesis or the tumor microenvironment modulation. Moreover, the existence of several isoforms that have been located at different levels of expression depending on the tissues and the degree of tumorigenicity opens the door to explore new diagnostic strategies based on the different expression and/or activity of these peculiar kinases. Recent studies have shown that the differentiation and quantification of individual alternative isoforms could improve insights into cancer diagnosis and outcome. However, there are limitations in the traditional methods used for determining isoforms, such as the level of transcription, low level of expression, and cross-linking of activity.Nevertheless, there is no doubt that, in the coming years, the development of new drugs targeting p38 will be able to improve therapeutic efficacy in diseases such as cancer in a successful way, in view of favoring a medicine of greater precision.


RB1 gene was the first tumor suppressor gene cloned from humans by studying genetic lesions in families with retinoblastoma. Children who inherit one defective copy of the RB1 gene have an increased susceptibility to retinoblastoma. Several years after the identification of the human RB1 gene, a targeted deletion of Rb was generated in mice. Mice with one defective copy of the Rb gene do not develop retinoblastoma. In this manuscript, we explore the different roles of the Rb family in human and mouse retinal development in order to better understand the species-specific difference in retinoblastoma susceptibility.The RB1 was acutely inactivated in the developing human fetal retina, p107 was not upregulated in a compensatory manner.We found that the Rb family of proteins  are expressed in a dynamic manner during mouse retinal development. The primary Rb family member expressed in proliferating embryonic retinal progenitor cells in mice is p107, which is required for appropriate cell cycle exit during retinogenesis. The primary Rb family member expressed in proliferating postnatal retinal progenitor cells is Rb. p130 protein is expressed redundantly with Rb in postmitotic cells of the inner nuclear layer and the ganglion cell layer of the mouse retina. When Rb is inactivated in an acute or chronic manner during mouse retinal development, p107 is upregulated in a compensatory manner. Similarly, when p107 is inactivated in the mouse retina, Rb is upregulated. No changes in p130 expression were seen when p107, Rb or both were inactivated in the developing mouse retina. In the human retina, RB1 was the primary family member expressed throughout development. There was very little if any p107 expressed in the developing human retina. In contrast to the developing mouse retina, when RB1 loss, but mice require both Rb and p107 gene inactivation.We propose that intrinsic genetic compensation between Rb and p107 prevents retinoblastoma in Rb- or p107-deficient mice, but this compensation does not occur in humans. Together, these data suggest a model that explains why humans are susceptible to retinoblastoma following  The timing of cell cycle exit is coordinated with cell-fate specification and differentiation in the developing central nervous system (CNS) to ensure that the appropriate number of neurons and glia are generated in the correct proportion. If too many neural progenitor cells exit the cell cycle during the early stages of development, then the overall number of cells is reduced, and the ratio of cell types shifts ,2.Rb1 thymidine ([3H]thy) with p107  was significantly higher than that in stage-matched wild-type retinas . The mean proportion of p107+ cells in the P2 Rb-/- retinas (7.3% ± 1.1%) was also significantly higher than that in age-matched wild-type retina . The proportion of p107+ cells was lower than that of Rb+ cells, because there are fewer proliferating retinal progenitor cells at P2 than at E13.5 . To. ToRb allls Fig. . Those d to p107  were simRb inactivation [Rb at P3. Even though the majority (~ 95%) of cells in the P3 retina are postmitotic [Rb has been acutely inactivated are susceptible to deregulated proliferation. A similar experiment in which all proliferating retinal progenitor cells in the P3 retina were labeled with [3H]thy for 24 h prior to acute Rb inactivation showed the same result  after acute p107 inactivation , but one copy of p107 in Chx10-Cre;RbLox/-; p107+/- retinas is haploinsufficient to regulate proliferation. Specifically, in retinal progenitor cells, two copies of the p107 gene are required to compensate for loss of Rb, but only one copy of Rb is required to compensate for loss of p107.TUNEL assay results revealed no difference in the proportion of apoptotic cells in dk2 Fig.  and Sfrprp2 Fig. . TogetheRb;p107-deficient retinas thy-. If a retinal progenitor cell is more susceptible to deregulated proliferation after acute Rb inactivation, then we would predict that the majority of BrdU+ cells would be [3H]thy+. If both retinal progenitor cells and postmitotic cells divide after acute Rb inactivation, then the proportions of BrdU+, [3H]thy- cells and BrdU+, [3H]thy+ cells will reflect the proportions of postmitotic cells and mitotic cells in the starting population, respectively.The developmental studies and clonal analyses described above suggest that reciprocal compensation between Rb and p107 prevents deregulated retinal progenitor cell proliferation and retinoblastoma. However, we have shown that p107 compensation also occurs at P3 when the majority (93%) of cells are postmitotic Fig. . Therefothy Fig. , inactivtmitotic . If a po3H]thy+ cells  ectopically dividing cells were BrdU+, thy demonstrated that p107 is downregulated as cells exit the cell cycle. There were no defects in cell-fate specification or differentiation in p107-deficient retinas; thus, we propose that p107 primarily regulates retinal progenitor cell proliferation in the embryonic retina. Rb is expressed in postnatal retinal progenitor cells and differentiating neurons and glia. Consistent with a role in cell-fate specification or differentiation, Rb was expressed throughout the cell cycle and continued to be expressed as cells entered G0. In the absence of Rb, immature cells persist in the ONL and rod photoreceptors failed to form, a finding that indicates that Rb regulates the developmental processes in this specific sublineage.Immunostaining, in situ hybridization, real-time RT-PCR and immunoblot analyses revealed that p107 is expressed primarily in proliferating retinal progenitor cells of the embryonic mouse retina. Pulse-labeling with thy-labeling experiments, we predict that Rb and p130 are redundant in newly postmitotic cells of the INL and GCL. It is not known if p130 is required for terminal cell cycle exit in the developing retina, for maintaining cells in the postmitotic state or both.Our data suggest that Rb and p107 share the same role in regulating mouse retinal progenitor cell proliferation but the role of Rb is unique in rods. An extensive genetic analysis of p130 is beyond the scope of this manuscript, but based on our expression studies and [3H]thy-labeled dissociated cells and immunoblotting); these approaches provided the same overall picture of the dynamic changes in the expression of the Rb family during seven stages of mouse retinal development. Spencer and colleagues provided a more limited data set with internal inconsistencies. For example, immunostaining was done on samples from just three stages of mouse retinal development , and in situ hybridization was carried out for Rb but not for p107 or p130. Their real-time RT-PCR and immunoblotting data show high levels of p107 expression in the embryonic retinas, but no p107+ nuclei are detected in their immunostained sections. Clearly, all expression data are limited by the reagents being used. For example, it is possible that the Rb, p107 and p130 expression patterns in our study or that of Spencer and colleagues are broader than reported due to the limited sensitivity of the antibodies used. We have attempted to minimize such limitations by combining several independent approaches such as in situ hybridization, immunostaining, real time RT-PCR and dissociated cell staining. Nontheless, we anticipate that the retinal expression pattern of the Rb family will be further refined as new reagents become available.A recent study published by Spencer and colleagues characterized the expression of the Rb family in developing mouse retina and adult human retina . Our datThe Rb family proteins are expressed in a dynamic manner during mouse retinal development. We show here that p107 is expressed in proliferating retinal progenitor cells in the embryonic retina and is downregulated as cells exit the cell cycle and undergo terminal differentiation. Around birth, the expression of p107 tapers off, and that of Rb takes it place in proliferating retinal progenitor cells. Rb expression persists in postmitotic differentiating neurons and glia of the mouse retina. The p130 protein is expressed in the late postnatal period of mouse retinal development. As cells exit the cell cycle, they upregulate p130, and its expression persists in postmitotic differentiating cells of the INL and GCL. Based on the expression pattern alone, one might predict that proliferation would be deregulated in p107-deficient embryonic retinas and Rb-deficient postnatal retinas. However, we report here that when p107 is inactivated, Rb is upregulated in a compensatory manner in the embryonic retina. Similarly, when Rb is inactivated, p107 is upregulated in a compensatory manner in the postnatal retina. There is no evidence for compensation by p130 in either Rb- or p107-deficient retinas.p107 in this process. We show here that two copies of p107 are required for efficient compensation of Rb loss, but only one copy of Rb is required to compensate for p107 loss. This may indicate that there are different mechanisms for Rb and p107 gene compensation or that retinal progenitor cells exhibit different sensitivities to Rb and p107 protein levels. One intriguing possibility is that p107 haploinsufficiency for compensation may reflect the differential binding of Rb and p107 to different E2F family members.One of the interesting features of the compensation that we uncovered in this study is the haploinsufficiency of p107 is an E2F-responsive gene; therefore, the mechanisms for p107 compensation most likely involve a direct feedback loop thy labeling we used in our study compared to the BrdU labeling used by Chen et al. Alternatively, it could reflect the non-cell-autonomous effect of broad Rb inactivation in Pax6-Cre;RbLox/Lox; p107-/- retinas examined by Chen et al. compared with the more restricted mosaic Rb inactivation in Chx10-Cre;RbLox/-; p107-/- retinas that we investigated thy  or 10 μM BrdU for 1 h at 37°C. For these pulse-labeling experiments, retinas were dissected at four stages of development  and exposed to the label for various durations  to allow retinal progenitor cells to progress through the cell cycle. The p27Kip1 protein, which is upregulated at G1/G0, was used as an internal control  into the eye. Electroporation consisted of five 50-μsec pulses of 80 V each separated by 950-μsec recovery periods. As a control, retinas were electroporated with a plasmid lacking Cre. For explant cultures, the DNA was purified and resuspended in HBSS at 1 μg/μL.Electroporation consisted of five pulses of 25 V for 50 μsec each with 950-μsec recovery periods. For FACS purification of electroporated cells, retinas were dissociated as described previously ,43, resu® software (Applied Biosystems). TaqMan® probes were synthesized with 5'-FAM and 3'-BHQ. RNA was prepared using Trizol, and cDNA was synthesized using the Superscript system . Samples were analyzed in duplicate and normalized to Gapdh, Gpi1 and Mmt2 expression levels.Real-time RT-PCR experiments were performed using the ABI 7900 HT Sequence Detection System . Primers and probes were designed using Primer Express33P-labeled or DIG-labeled probes at the same specific activity and total mass). Hybridization was carried out at 60°C overnight, and the slides were washed in a series of SSC washes. The sections were then counterstained with a nuclear dye (Sytox green or PI) and dehydrated prior to immersion in autoradiographic emulsion. Exposure was carried out for 1 week before the blots were developed.For immunoblot analysis, retinas of C57Bl/6 mice were dissected at the following seven stages of development: E14.5, E17.5, P0, P3, P6, P12 and adult. Retinas were sonicated in RIPA with protease and phosphatase inhibitors  to clear the lysate. The debris was pelleted, and the concentration of each lysate was determined using a Bradford assay . Lysate (30 μg) was loaded onto each lane and transferred to nitrocellulose. Each antibody was used at a dilution of 1:1000, and HRP-conjugated secondary antibodies were used at 1:5000. The Amersham ECL system  was used to detect antibody binding per the manufacturer's instructions. For in situ hybridization, retinas from each stage of development were rapidly dissected, fixed for 1 h in 4% paraformaldehyde, cryoprotected in 30% sucrose/PBS and embedded in OCT before freezing on dry ice. Cryosections (14-μm thick) were cut, mounted on slides and dried. Tissue was rehydrated in and treated briefly with proteinase K. Slides were then acetylated in acetic anhydride/0.1 M TEA and dehydrated using an alcohol series. Prehybridization was carried out with formamide/SDS hybridization solution, and the riboprobes were added . Eyes were transported in RPMI medium on wet ice. Retinas were isolated and divided into 8 radial sections. Each section was placed on a polycarbonate filter and maintained in explant culture medium, as described previously for mouse retinas ,25,37. B4, embedded, sectioned and viewed by transmission EM.Bright-field and single-cell fluorescent images were obtained using a Zeiss Axioplan-2 fluorescent microscope with the Zeiss AxioCam digital camera. Fluorescent images of tissue sections were obtained using a Leica TCSNT confocal microscope. For EM, animals were anesthetized with avertin until a loss of deep tendon reflexes. Transcardial perfusion was performed with carboxygenated Ames Medium supplemented with 40 mM glucose to clear the vasculature, followed by perfusion with Sorenson's phosphate buffer (pH 7.2) containing 2% EM-grade paraformaldehyde and 1% EM-grade glutaraldehyde. Eyes were then harvested; a slit was made in the cornea to aid in diffusion; and the tissue was placed in 3% glutaraldehyde in Sorenson's phosphate buffer overnight. Tissue was washed with 0.2 M cacodylate buffer in 5% sucrose, post-fixed in 1% OsORetroviruses and retinal culture procedures have been extensively described elsewhere ,37,43.3H]-thymidine pulse-labeling experiment. All authors contributed to the preparation of the manuscript.SD carried out in situ hybridization for mouse and human Rb family genes and performed the square wave electroporation and FACS experiments on human and mouse retinae. BS analyzed the mouse retinae from the different genetic combinations of Rb and p107 deficient mice and performed the reciprocal compensation experiments. BS also assisted with single cell immunostaining and scoring and performed the real time RT-PCR these samples. RM developed and characterized the RB1 siRNA and performed the immunoblot experiments. DJ performed all EM analysis. MD performed the immunostaining of the Rb family in human and mouse retinae and performed the [Expression of the Rb, p107 and p130 during the cell cycle in retinal progenitor cells.Click here for fileHuman fetal retinal explant cultures.Click here for fileRb in the developing retina.Effects of acute inactivation of Click here for filep107 in the Rb-deficient retinae during development.Acute inactivation of Click here for fileExpression of Proliferation and Differentiation Markers in P0 Retinae Lacking Rb and/or p107.Click here for fileExpression of Proliferation and Differentiation Markers in P6 Retinae Lacking Rb and/or p107.Click here for fileExpression of Proliferation and Differentiation Markers in P12 Retinae Lacking Rb and/or p107.Click here for fileExpression of Proliferation and Differentiation Markers in P30 Retinae Lacking Rb and/or p107.Click here for fileClone composition and distribution from in vivo lineage analysis.Click here for fileAntibodies used for immunofluorescence on adult tissue.Click here for file


The p53 gene is one of the best studied tumour suppressor genes. Recently we performed mutation analysis on the p53 gene in a large number of bone and soft tissue sarcomas, and found that approximately one-third of the sarcomas have some type of DNA alteration at the p53 locus . However, the expression of the p53 protein resulting from these alterations still remains to be clarified. In this study, p53 expression in the sarcoma tissues was analysed immunohistochemically using antibody PAb421 (Oncogene Science) and its relationship to DNA alterations was examined. Of 113 tumours, 29 (25.7%) showed positive staining for the p53 protein. These included 19 of 67 osteosarcomas, five of 20 chondrosarcomas, four of 11 malignant fibrous histiocytomas (MFHs) and one Ewing's sarcoma. In chondrosarcomas, most of the p53-positive tumours belonged to highly malignant and atypical tumour types , suggesting a role for p53 mutation in the progression of cartilaginous tumours. All the cases with a missense mutation showed strongly positive staining, while no immunoreactivity was observed in the remaining three-quarters with DNA alterations including gross rearrangement, frame-shift mutation, nonsense mutation or mutation at splicing site except in one case. These results demonstrated the dominance of the p53 mutations with null protein expression in bone and soft tissue sarcomas, showing a unique characteristic of these types of tumours compared with other malignancies such as colon carcinomas.


Recent data suggest that the function of p53 might also play a role in the regulation of organismal lifespan. Increased p53 activity leads to lifespan shortening in mice, while apparent reduction of p53 activity in flies leads to lifespan extension. Although the mechanism by which p53 regulates lifespan remains to be determined, these findings highlight the possibility that careful manipulation of p53 activity during adult life may result in beneficial effects on healthy lifespan.As guardian of the genome the tumor suppressor p53 controls a crucial point in protection from cellular damage and response to stressors. Activation of p53 can have beneficial (DNA repair) or detrimental (apoptosis) consequences for individual cells. In either case activation of  It has long been known that mice that are deficient for p53 are prone to develop tumors and die prematurely , surprisingly did not live longer than controls. Even more astonishing, instead of living longer, the mice with constitutively hyperactive p53 (through incorporation of a shortened form of p53 into the p53 tetramer), actually died earlier than their wild-type counterparts.Why does increased tumor protection not translate into longer lifespans for these animals? Several markers of aging, including muscle loss, osteoporosis, skin atrophy and defects in wound healing, were found to be greatly accelerated in mice with hyperactive p53. No markers of accelerated aging were found in the other two models, leading to the speculation that, rather than increased p53 activity per se, altered functionality of the p44(p24)/p53 complex might explain those premature aging phenotypes , but no Recently, a form of programmed cell death has been described that shares features of both apoptosis and necrosis and has subsequently been termed necroptosis (An alternative to losing important functionality in the brain by permanent cell loss would be to functionally disable or alter cells without actually killing them. In fibroblasts, replicative senescence constitutes such a pathway . ImportaFinally, p53 has been demonstrated to activate apoptosis in a transcription-independent manner through interaction with the pro-apoptotic Bcl-2 family member Bax , which cIn light of the fact that Dmp53 transcriptional profile changes during fly development, it might also be possible that Dmp53 function changes, exchanging function as a transcriptional regulator to that of a signaling pathway modulator through direct interaction. It is conceivable that p53 influences biological events other than apoptosis through these direct protein–protein interactions, which might be a major mechanism in the adult fly. Interestingly, two-hybrid analysis has revealed protein interaction partners of Dmp53 that are involved in a variety of processes, including DNA repair and metabolism (