bluuebunny/crossref_metadata_2025 huggingface dataset:
N-acetylcysteine reverses cardiac myocyte dysfunction in a rodent model of behavioral stress
Authors: Chen Fangping , Hadfield Jessalyn M. , Berzingi Chalak , Hollander John M. , Miller Diane B. , Nichols Cody E. , Finkel Mitchell S.
Published: May 2013

Compelling clinical reports reveal that behavioral stress alone is sufficient to cause reversible myocardial dysfunction in selected individuals. We developed a rodent stress cardiomyopathy model by a combination of prenatal and postnatal behavioral stresses (Stress). We previously reported a decrease in percent fractional shortening by echo, both systolic and diastolic dysfunction by catheter-based hemodynamics, as well as attenuated hemodynamic and inotropic responses to the β-adrenergic agonist, isoproterenol (ISO) in Stress rats compared with matched controls (Kan H, Birkle D, Jain AC, Failinger C, Xie S, Finkel MS. J Appl Physiol 98: 77–82, 2005). We now report enhanced catecholamine responses to behavioral stress, as evidenced by increased circulating plasma levels of norepinephrine ( P < 0.01) and epinephrine ( P < 0.01) in Stress rats vs. controls. Cardiac myocytes isolated from Stress rats also reveal evidence of oxidative stress, as indicated by decreased ATP, increased GSSG, and decreased GSH-to-GSSG ratio in the presence of increased GSH peroxidase and catalase activities ( P < 0.01, for each). We also report blunted inotropic and intracellular Ca2+ concentration responses to extracellular Ca2+ ( P < 0.05), as well as altered inotropic responses to the intracellular calcium regulator, caffeine (20 mM; P < 0.01). Treatment of cardiac myocytes with N-acetylcysteine (NAC) (10−3 M) normalized calcium handling in response to ISO and extracellular Ca2+ concentration and inotropic response to caffeine ( P < 0.01, for each). NAC also attenuated the blunted inotropic response to ISO and Ca2+ ( P < 0.01, for each). Surprisingly, NAC did not reverse the changes in GSH, GSSG, or GSH-to-GSSG ratio. These data support a GSH-independent salutary effect of NAC on intracellular calcium signaling in this rodent model of stress-induced cardiomyopathy.
Application of Raman Spectroscopy to Identify Microcalcifications and Underlying Breast Lesions at Stereotactic Core Needle Biopsy
Authors: Barman Ishan , Dingari Narahara Chari , Saha Anushree , McGee Sasha , Galindo Luis H. , Liu Wendy , Plecha Donna , Klein Nina , Dasari Ramachandra Rao , Fitzmaurice Maryann
Published: May 2013

Microcalcifications are a feature of diagnostic significance on a mammogram and a target for stereotactic breast needle biopsy. Here, we report development of a Raman spectroscopy technique to simultaneously identify microcalcification status and diagnose the underlying breast lesion, in real-time, during stereotactic core needle biopsy procedures. Raman spectra were obtained ex vivo from 146 tissue sites from fresh stereotactic breast needle biopsy tissue cores from 33 patients, including 50 normal tissue sites, 77 lesions with microcalcifications, and 19 lesions without microcalcifications, using a compact clinical system. The Raman spectra were modeled on the basis of the breast tissue components, and a support vector machine framework was used to develop a single-step diagnostic algorithm to distinguish normal tissue, fibrocystic change (FCC), fibroadenoma, and breast cancer, in the absence and presence of microcalcifications. This algorithm was subjected to leave-one-site-out cross-validation, yielding a positive predictive value, negative predictive value, sensitivity, and specificity of 100%, 95.6%, 62.5%, and 100% for diagnosis of breast cancer (with or without microcalcifications) and an overall accuracy of 82.2% for classification into specific categories of normal tissue, FCC, fibroadenoma, or breast cancer (with and without microcalcifications). Notably, the majority of breast cancers diagnosed are ductal carcinoma in situ (DCIS), the most common lesion associated with microcalcifications, which could not be diagnosed using previous Raman algorithm(s). Our study shows the potential of Raman spectroscopy to concomitantly detect microcalcifications and diagnose associated lesions, including DCIS, and thus provide real-time feedback to radiologists during such biopsy procedures, reducing nondiagnostic and false-negative biopsies. Cancer Res; 73(11); 3206–15. ©2013 AACR.
Histone Demethylase RBP2 Promotes Lung Tumorigenesis and Cancer Metastasis
Authors: Teng Yu-Ching , Lee Cheng-Feng , Li Ying-Shiuan , Chen Yi-Ren , Hsiao Pei-Wen , Chan Meng-Yu , Lin Feng-Mao , Huang Hsien-Da , Chen Yen-Ting , Jeng Yung-Ming , Hsu Chih-Hung , Yan Qin , Tsai Ming-Daw , Juan Li-Jung
Published: May 2013

The retinoblastoma binding protein RBP2 (KDM5A) is a histone demethylase that promotes gastric cancer cell growth and is enriched in drug-resistant lung cancer cells. In tumor-prone mice lacking the tumor suppressor gene RB or MEN1, genetic ablation of RBP2 can suppress tumor initiation, but the pathogenic breadth and mechanistic aspects of this effect relative to human tumors have not been defined. Here, we approached this question in the context of lung cancer. RBP2 was overexpressed in human lung cancer tissues where its depletion impaired cell proliferation, motility, migration, invasion, and metastasis. RBP2 oncogenicity relied on its demethylase and DNA-binding activities. RBP2 upregulated expression of cyclins D1 and E1 while suppressing the expression of cyclin-dependent kinase inhibitor p27 (CDKN1B), each contributing to RBP2-mediated cell proliferation. Expression microarray analyses revealed that RBP2 promoted expression of integrin-β1 (ITGB1), which is implicated in lung cancer metastasis. Mechanistic investigations established that RBP2 bound directly to the p27, cyclin D1, and ITGB1 promoters and that exogenous expression of cyclin D1, cyclin E1, or ITGB1 was sufficient to rescue proliferation or migration/invasion, respectively. Taken together, our results establish an oncogenic role for RBP2 in lung tumorigenesis and progression and uncover novel RBP2 targets mediating this role. Cancer Res; 73(15); 4711–21. ©2013 AACR.
Radioresistant Cancer Cells Can Be Conditioned to Enter Senescence by mTOR Inhibition
Authors: Nam Hae Yun , Han Myung Woul , Chang Hyo Won , Lee Yoon Sun , Lee Myungjin , Lee Hyang Ju , Lee Byoung Wook , Lee Hee Jin , Lee Kyung Eun , Jung Min Kyo , Jeon Hyesung , Choi Seung-Ho , Park Neung Hwa , Kim Sang Yoon , Kim Seong Who
Published: May 2013

Autophagy is frequently activated in radioresistant cancer cells where it provides a cell survival strategy. The mTOR inhibitor rapamycin activates autophagy but paradoxically it also enhances radiosensitivity. In this study, we investigated the mechanisms of these opposing actions in radiation-resistant glioma or parotid carcinoma cells. Radiation treatment transiently enhanced autophagic flux for a period of 72 hours in these cells and treatment with rapamycin or the mTOR inhibitor PP242 potentiated this effect. However, these treatments also increased heterochromatin formation, irreversible growth arrest, and premature senescence, as defined by expression of senescence-associated β-galactosidase activity. This augmentation in radiosensitivity seemed to result from a restoration in the activity of the tumor suppressor RB and a suppression of RB-mediated E2F target genes. In tumor xenografts, we showed that administering rapamycin delayed tumor regrowth after irradiation and increased senescence-associated β-galactosidase staining in the tumor. Our findings suggest that a potent and persistent activation of autophagy by mTOR inhibitors, even in cancer cells where autophagy is occurring, can trigger premature senescence as a method to restore radiosensitivity. Cancer Res; 73(14); 4267–77. ©2013 AACR.
Integration of High-Resolution Methylome and Transcriptome Analyses to Dissect Epigenomic Changes in Childhood Acute Lymphoblastic Leukemia
Authors: Busche Stephan , Ge Bing , Vidal Ramon , Spinella Jean-François , Saillour Virginie , Richer Chantal , Healy Jasmine , Chen Shu-Huang , Droit Arnaud , Sinnett Daniel , Pastinen Tomi
Published: May 2013

B-cell precursor acute lymphoblastic leukemia (pre-B ALL) is the most common pediatric cancer. Although the genetic determinants underlying disease onset remain unclear, epigenetic modifications including DNA methylation are suggested to contribute significantly to leukemogenesis. Using the Illumina 450K array, we assessed DNA methylation in matched tumor-normal samples of 46 childhood patients with pre-B ALL, extending single CpG-site resolution analysis of the pre-B ALL methylome beyond CpG-islands (CGI). Unsupervised hierarchical clustering of CpG-site neighborhood, gene, or microRNA (miRNA) gene-associated methylation levels separated the tumor cohort according to major pre-B ALL subtypes, and methylation in CGIs, CGI shores, and in regions around the transcription start site was found to significantly correlate with transcript expression. Focusing on samples carrying the t(12;21) ETV6–RUNX1 fusion, we identified 119 subtype-specific high-confidence marker CpG-loci. Pathway analyses linked the CpG-loci–associated genes with hematopoiesis and cancer. Further integration with whole-transcriptome data showed the effects of methylation on expression of 17 potential drivers of leukemogenesis. Independent validation of array methylation and sequencing-derived transcript expression with Sequenom Epityper technology and real-time quantitative reverse transcriptase PCR, respectively, indicates more than 80% empirical accuracy of our genome-wide findings. In summary, genome-wide DNA methylation profiling enabled us to separate pre-B ALL according to major subtypes, to map epigenetic biomarkers specific for the t(12;21) subtype, and through a combined methylome and transcriptome approach to identify downstream effects on candidate drivers of leukemogenesis. Cancer Res; 73(14); 4323–36. ©2013 AACR.
Bone Marrow–Derived CD11b+Jagged2+ Cells Promote Epithelial-to-Mesenchymal Transition and Metastasization in Colorectal Cancer
Authors: Caiado Francisco , Carvalho Tânia , Rosa Isadora , Remédio Leonor , Costa Ana , Matos João , Heissig Beate , Yagita Hideo , Hattori Koichi , da Silva João Pereira , Fidalgo Paulo , Pereira António Dias , Dias Sérgio
Published: May 2013

Timely detection of colorectal cancer metastases may permit improvements in their clinical management. Here, we investigated a putative role for bone marrow–derived cells in the induction of epithelial-to-mesenchymal transition (EMT) as a marker for onset of metastasis. In ectopic and orthotopic mouse models of colorectal cancer, bone marrow–derived CD11b(Itgam)+Jagged2 (Jag2)+ cells infiltrated primary tumors and surrounded tumor cells that exhibited diminished expression of E-cadherin and increased expression of vimentin, 2 hallmarks of EMT. In vitro coculture experiments showed that the bone marrow–derived CD11b+Jag2+ cells induced EMT through a Notch-dependent pathway. Using neutralizing antibodies, we imposed a blockade on CD11b+ cells' recruitment to tumors, which decreased the tumor-infiltrating CD11b+Jag2+ cell population of interest, decreasing tumor growth, restoring E-cadherin expression, and delaying EMT. In support of these results, we found that peripheral blood levels of CD11b+Jag2+ cells in mouse models of colorectal cancer and in a cohort of untreated patients with colorectal cancer were indicative of metastatic disease. In patients with colorectal cancer, the presence of circulating CD11b+Jag2+ cells was accompanied by loss of E-cadherin in the corresponding patient tumors. Taken together, our results show that bone marrow–derived CD11b+Jag2+ cells, which infiltrate primary colorectal tumors, are sufficient to induce EMT in tumor cells, thereby triggering onset of metastasis. Furthermore, they argue that quantifying circulating CD11b+Jag2+ cells in patients may offer an indicator of colorectal cancer progression to metastatic levels of the disease. Cancer Res; 73(14); 4233–46. ©2013 AACR.
Vitronectin–αvβ3 Integrin Engagement Directs Hypoxia-Resistant mTOR Activity and Sustained Protein Synthesis Linked to Invasion by Breast Cancer Cells
Authors: Pola Carolina , Formenti Silvia C. , Schneider Robert J.
Published: May 2013

The tumor microenvironment is a crucial player in the ability of cancer cells to acquire the ability to survive under the hypoxic environment and promote migration and invasion. Translational regulation is an essential part of cancer development and progression. Protein synthesis consumes considerable cellular metabolic energy and is therefore highly regulated, in turn controlling tumor cell proliferation and survival in extreme tumor–host conditions. Protein synthesis is typically downregulated by hypoxia, impairing cell proliferation and migration. Here, we show that breast cancer cells expressing integrin αvβ3, when engaging the extracellular matrix (ECM) protein vitronectin, strongly upregulate both mTOR activity and cap-dependent mRNA translation, which overrides their inhibition by hypoxia and facilitates tumor cell invasion. Interaction of vitronectin with integrin αvβ3 results in the continued activation of the kinase mTOR despite hypoxia through a mechanism that is dependent on integrin-linked kinase but is independent of focal adhesion kinase. Continuous activation of mTOR despite hypoxia involves release of translation initiation factor eIF4E from its repressor protein 4E-BP1, which is required for vitronectin-mediated tumor cell invasion. As integrin αvβ3 is associated with breast cancer cell invasion and metastasis to bone, we propose that the interaction with specific ECM proteins can influence cancer cell invasion, in part, by hyperactivation of mTOR, thereby promoting and sustaining protein synthesis under hypoxic conditions. Cancer Res; 73(14); 4571–8. ©2013 AACR.
Genetic Ablation of the Fatty Acid–Binding Protein FABP5 Suppresses HER2-Induced Mammary Tumorigenesis
Authors: Levi Liraz , Lobo Glenn , Doud Mary Kathryn , von Lintig Johannes , Seachrist Darcie , Tochtrop Gregory P. , Noy Noa
Published: May 2013

The fatty acid–binding protein FABP5 shuttles ligands from the cytosol to the nuclear receptor PPARβ/δ (encoded for by Pparδ), thereby enhancing the transcriptional activity of the receptor. This FABP5/PPARδ pathway is critical for induction of proliferation of breast carcinoma cells by activated epidermal growth factor receptor (EGFR). In this study, we show that FABP5 is highly upregulated in human breast cancers and we provide genetic evidence of the pathophysiologic significance of FABP5 in mammary tumorigenesis. Ectopic expression of FABP5 was found to be oncogenic in 3T3 fibroblasts where it augmented the ability of PPARδ to enhance cell proliferation, migration, and invasion. To determine whether FABP5 is essential for EGFR-induced mammary tumor growth, we interbred FABP5-null mice with MMTV-ErbB2/HER2 oncomice, which spontaneously develop mammary tumors. FABP5 ablation relieved activation of EGFR downstream effector signals, decreased expression of PPARδ target genes that drive cell proliferation, and suppressed mammary tumor development. Our findings establish that FABP5 is critical for mammary tumor development, rationalizing the development of FABP5 inhibitors as novel anticarcinogenic drugs. Cancer Res; 73(15); 4770–80. ©2013 AACR.
Efficacy of the Specific Endothelin A Receptor Antagonist Zibotentan (ZD4054) in Colorectal Cancer: A Preclinical Study
Authors: Haque Samer-ul , Dashwood Michael R. , Heetun Mohammed , Shiwen Xu , Farooqui Noreen , Ramesh Bala , Welch Hazel , Savage Felicity J. , Ogunbiyi Olagunju , Abraham David J. , Loizidou Marilena
Published: May 2013

Endothelin 1 (ET-1) is overexpressed in cancer, contributing to disease progression. We previously showed that ET-1 stimulated proliferative, migratory, and contractile tumorigenic effects via the ETA receptor. Here, for the first time, we evaluate zibotentan, a specific ETA receptor antagonist, in the setting of colorectal cancer, in cellular models. Pharmacologic characteristics were further determined in patient tissues. Colorectal cancer lines (n = 4) and fibroblast strains (n = 6), isolated from uninvolved areas of colorectal cancer specimens, were exposed to ET-1 and/or ETA/B receptor antagonists. Proliferation (methylene blue), migration (scratch wounds), and contraction (gel lattices) were assessed. Receptor distribution and binding characteristics (Kd, Bmax) were determined using autoradiography on tissue sections and homogenates and cytospun cells, supported by immunohistochemistry. Proliferation was inhibited by ETA (zibotentan > BQ123; P < 0.05), migration by ETB > ETA, and contraction by combined ETA and ETB antagonism. Intense ET-1 stromal binding correlated with fibroblasts and endothelial cells. Colorectal cancer lines and fibroblasts revealed high density and affinity ET-1 binding (Bmax = 2.435 fmol/1 × 106 cells, Kd = 367.7 pmol/L; Bmax = 3.03 fmol/1 × 106 cells, Kd = 213.6 pmol/L). In cancer tissues, ETA receptor antagonists (zibotentan; BQ123) reduced ET-1 binding more effectively (IC50: 0.1–10 μmol/L) than ETB receptor antagonist BQ788 (∼IC50, 1 mmol/L). ET-1 stimulated cancer-contributory processes. Its localization to tumor stroma, with greatest binding/affinity to fibroblasts, implicates these cells in tumor progression. ETA receptor upregulation in cancer tissues and its role in tumorigenic processes show the receptor's importance in therapeutic targeting. Zibotentan, the most specific ETA receptor antagonist available, showed the greatest inhibition of ET-1 binding. With its known safety profile, we provide evidence for zibotentan's potential role as adjuvant therapy in colorectal cancer. Mol Cancer Ther; 12(8); 1556–67. ©2013 AACR.
Genetic and Chemical Targeting of Epithelial-Restricted with Serine Box Reduces EGF Receptor and Potentiates the Efficacy of Afatinib
Authors: Zhang Manchao , Taylor Christopher E. , Piao Longzhu , Datta Jharna , Bruno Paul A. , Bhave Sanjay , Su Tizhi , Lang James C. , Xie Xiujie , Teknos Theodoros N. , Mapp Anna K. , Pan Quintin
Published: May 2013

EGF receptor (EGFR) is elevated in more than 90% of head and neck squamous cell carcinoma (HNSCC). However, a majority of patients with HNSCC do not respond to anti-EGFR therapeutics. Insensitivity to EGFR inhibitors may be due to kinase-independent actions of EGFR and/or activation of Her2. Strategies to reduce EGFR and Her2 protein levels in concert may be an optimal approach to enhance the efficacy of current anti-EGFR molecules. In this study, knockdown of epithelial-restricted with serine box (ESX) decreased EGFR and Her2 promoter activity, expression, and levels. ESX was elevated in primary HNSCC tumors and associated with increased EGFR and Her2. Genetic ablation of ESX decreased EGFR and Her2 levels and enhanced the antiproliferative effects of EGFR/Her2 tyrosine kinase inhibitors (TKI), lapatinib and afatinib. Biphenyl isoxazolidine, a novel small-molecule ESX inhibitor, reduced EGFR and Her2 levels and potentiated the antiproliferative efficacy of afatinib. Single-agent biphenyl isoxazolidine retarded the in vivo tumorigenicity of CAL27 cells. Importantly, the combination of biphenyl isoxazolidine and afatinib was significantly superior in vivo and resulted in a 100% response rate with a 94% reduction in tumor volume. Targeting EGFR/Her2 levels with an ESX inhibitor and EGFR/Her2 kinase activity with a TKI simultaneously is a highly active therapeutic approach to manage HNSCC. Our work provides evidence to support the further development of ESX inhibitors as an adjuvant to enhance the response rate of patients with HNSCC to current anti-EGFR/Her2 therapeutics. Mol Cancer Ther; 12(8); 1515–25. ©2013 AACR.
Impact of Tumor HER2/ERBB2 Expression Level on HER2-Targeted Liposomal Doxorubicin-Mediated Drug Delivery: Multiple Low-Affinity Interactions Lead to a Threshold Effect
Authors: Hendriks Bart S. , Klinz Stephan G. , Reynolds Joseph G. , Espelin Christopher W. , Gaddy Daniel F. , Wickham Thomas J.
Published: May 2013

Numerous targeted nanotherapeutics have been described for potential treatment of solid tumors. Although attention has focused on antigen selection and molecular design of these systems, there has been comparatively little study of how cellular heterogeneity influences interaction of targeted nanoparticles with tumor cells. Antigens, such as HER2/ERBB2, are heterogeneously expressed across different indications, across patients, and within individual tumors. Furthermore, antigen expression in nontarget tissues necessitates optimization of the therapeutic window. Understanding the performance of a given nanoparticle under different regimens of antigen expression has the ability to inform patient selection and clinical development decisions. In this work, HER2-targeted liposomal doxorubicin was used as a model-targeted nanoparticle to quantitatively investigate the effect of HER2 expression levels on delivery of doxorubicin to the nucleus. We find quantitatively greater nuclear doxorubicin delivery with increasing HER2 expression, exhibiting a threshold effect at approximately 2 × 105 HER2 receptors/cell. Kinetic modeling indicated that the threshold effect arises from multiple low-affinity interactions between the targeted liposome and HER2. These results support previous data showing little or no uptake into human cardiomyocytes, which express levels of HER2 below the threshold. Finally, these results suggest that HER2-targeted liposomal doxorubicin may effectively target tumors that fall below traditional definitions of HER2-positive tumors, thereby expanding the potential population of patients that might benefit from this agent. Mol Cancer Ther; 12(9); 1816–28. ©2013 AACR.
B56γ Tumor-Associated Mutations Provide New Mechanisms for B56γ-PP2A Tumor Suppressor Activity
Authors: Nobumori Yumiko , Shouse Geoffrey P. , Wu Yong , Lee Kyu Joon , Shen Binghui , Liu Xuan
Published: May 2013

The hetero-trimeric PP2A serine/threonine phosphatases containing the regulatory subunit B56, and in particular B56γ, can function as tumor suppressors. In response to DNA damage, the B56γ subunit complexes with the PP2A AC core (B56γ-PP2A) and binds p53. This event promotes PP2A-mediated dephosphorylation of p53 at Thr55, which induces expression of p21, and the subsequent inhibition of cell proliferation and transformation. In addition to dephosphorylation of p53, B56γ-PP2A also inhibits cell proliferation and transformation by a second, as yet unknown, p53-independent mechanism. Here, we interrogated a panel of B56γ mutations found in human cancer samples and cell lines and showed that these mutations lost B56γ tumor-suppressive activity by two distinct mechanisms: one is by disrupting interactions with the PP2A AC core and the other with B56γ-PP2A substrates (p53 and unknown proteins). For the first mechanism, due to the absence of the C catalytic subunit in the complex, the mutants are unable to mediate dephosphorylation of any substrate and thus failed to promote both the p53-dependent and -independent tumor-suppressive functions of B56γ-PP2A. For the second mechanism, the mutants lacked specific substrate interactions and thus partially lost tumor-suppressive function, i.e., either the p53-dependent or p53-independent contingent upon which substrate binding was affected. Overall, these data provide new insight into the mechanisms of tumor suppression by B56γ.

Implications: This study further indicates the importance of B56γ-PP2A in tumorigenesis. Mol Cancer Res; 11(9); 995–1003. ©2013 AACR.
Unraveling the Role of FOXQ1 in Colorectal Cancer Metastasis
Authors: Abba Mohammed , Patil Nitin , Rasheed Kabeer , Nelson Laura D. , Mudduluru Giridhar , Leupold Jörg Hendrik , Allgayer Heike
Published: May 2013

Malignant cell transformation, invasion, and metastasis are dependent on the coordinated rewiring of gene expression. A major component in the scaffold of these reprogramming events is one in which epithelial cells lose intercellular connections and polarity to adopt a more motile mesenchymal phenotype, which is largely supported by a robust transcriptional machinery consisting mostly of developmental transcription factors. This study demonstrates that the winged helix transcription factor, FOXQ1, contributes to this rewiring process, in part by directly modulating the transcription of TWIST1, itself a key mediator of metastasis that transcriptionally regulates the expression of important molecules involved in epithelial-to-mesenchymal transition. Forced expression and RNA-mediated silencing of FOXQ1 led to enhanced and suppressed mRNA and protein levels of TWIST1, respectively. Mechanistically, FOXQ1 enhanced the reporter activity of TWIST1 and directly interacted with its promoter. Furthermore, enhanced expression of FOXQ1 resulted in increased migration and invasion in colorectal cancer cell lines, whereas knockdown studies showed the opposite effect. Moreover, using the in vivo chicken chorioallantoic membrane metastasis assay model, FOXQ1 significantly enhanced distant metastasis with minimal effects on tumor growth.

Implications: These findings reveal FOXQ1 as a modulator of TWIST1-mediated metastatic phenotypes and support its potential as a biomarker of metastasis. Mol Cancer Res; 11(9); 1017–28. ©2013 AACR.
HDAC6 and SIRT2 Regulate the Acetylation State and Oncogenic Activity of Mutant K-RAS
Authors: Yang Moon Hee , Laurent Gaelle , Bause Alexandra S. , Spang Robert , German Natalie , Haigis Marcia C. , Haigis Kevin M.
Published: May 2013

Activating point mutations in K-RAS are extremely common in cancers of the lung, colon, and pancreas and are highly predictive of poor therapeutic response. One potential strategy for overcoming the deleterious effects of mutant K-RAS is to alter its posttranslational modification. Although therapies targeting farnesylation have been explored, and have ultimately failed, the therapeutic potential of targeting other modifications remains to be seen. Recently, it was shown that acetylation of lysine 104 attenuates K-RAS transforming activity by interfering with GEF-induced nucleotide exchange. Here, the deacetylases HDAC6 and SIRT2 were shown to regulate the acetylation state of K-RAS in cancer cells. By extension, inhibition of either of these enzymes has a dramatic impact on the growth properties of cancer cells expressing activation mutants of K-RAS. These results suggest that therapeutic targeting of HDAC6 and/or SIRT2 may represent a new way to treat cancers expressing mutant forms of K-RAS.

Implications: This study suggests that altering K-RAS acetylation is a feasible approach to limiting tumorigenic potential. Mol Cancer Res; 11(9); 1072–7. ©2013 AACR.
Complications of Acute Stroke and the Occurrence of Early Seizures
Authors: Pezzini Alessandro , Grassi Mario , Del Zotto Elisabetta , Giossi Alessia , Volonghi Irene , Costa Paolo , Poli Loris , Morotti Andrea , Gamba Massimo , Ritelli Marco , Colombi Marina , Padovani Alessandro
Published: May 2013

Background: Seizures are common neurological consequences of stroke. Although a number of factors including stroke severity on admission, cortical involvement, and stroke subtype have been consistently associated with post-stroke seizures, the effect that medical and neurological complications of stroke, occurring in the very acute phase, might have on such a risk has never been adequately explored. In the present study we aimed at determining the extent to which complications within the first week of stroke influence the risk of early seizures (ES). Methods: Data of consecutive patients with first-ever acute stroke included in the Brescia Stroke Registry were analyzed. ES (≤7 days) were recorded and correlated with demographic data, disease characteristics, risk factors, and prespecified medical and neurological stroke complications in a multivariate path analysis model. Results: 516 patients with first-ever acute stroke were eligible for inclusion in the present study. Of them, 436 patients had ischemic stroke (IS) [64 (14.6%) with hemorrhagic transformation (HT)] and 80 had intracerebral hemorrhage (ICH). Twenty patients (3.9%) developed ES. Patients with ES had a higher burden of complications compared with those without (30 vs. 4.2%, for patients with >6 complications). Lesion type, stroke complications, and lesion site were directly related to the risk of seizure occurrence (OR, 0.24; 95% CI, 0.07-0.80 for IS vs. ICH; OR, 1.57; 95% CI, 1.21-2.01 for any increase of 1 in the number of complications; OR, 0.15; 95% CI, 0.04-0.56 for subcortical lesions vs. cortical lesions). Complications appeared also to mediate the indirect effect of lesion type on the occurrence of ES (OR, 0.75; 95% CI, 0.60-0.94). No significant difference on the risk of ES was observed when HT and ICH were compared. The total effect of lesion type was 0.25 × 0.75 = 0.18, corresponding to (1-0.18) = 82% lower risk of ES for IS as compared to ICH. Conclusion: Although major determinants of ES are nonmodifiable, preventable and treatable medical and neurologic complications within the first week of stroke increase the risk of ES and mediate the effect of established predictors on the propensity to post-stroke epilepsy. Future epidemiologic studies aimed at investigating post-stroke seizures should include precise information on these complications.
European Consensus Guidelines on the Management of Neonatal Respiratory Distress Syndrome in Preterm Infants - 2013 Update
Authors: Sweet David G. , Carnielli Virgilio , Greisen Gorm , Hallman Mikko , Ozek Eren , Plavka Richard , Saugstad Ola D. , Simeoni Umberto , Speer Christian P. , Vento Maximo , Halliday Henry L.
Published: May 2013

Despite recent advances in the perinatal management of neonatal respiratory distress syndrome (RDS), controversies still exist. We report updated recommendations of a European Panel of expert neonatologists who developed consensus guidelines after critical examination of the most up-to-date evidence in 2007 and 2010. This second update of the guidelines is based upon published evidence up to the end of 2012. Strong evidence exists for the role of antenatal steroids in RDS prevention, but it is still not clear if the benefit of repeated courses on respiratory outcomes outweighs the risk of adverse outcomes in the short and long term. Many practices involved in preterm neonatal stabilization at birth are not evidence based, including oxygen administration and positive pressure lung inflation, and they may at times be harmful. Surfactant replacement therapy is crucial in the management of RDS but the best preparation, optimal dose and timing of administration at different gestations is not completely clear. In addition, use of very early continuous positive airway pressure (CPAP) has altered the indications for prophylactic surfactant administration. Respiratory support in the form of mechanical ventilation may be lifesaving but can cause lung injury, and protocols should be directed at avoiding mechanical ventilation where possible by using non-invasive respiratory support such as CPAP. For babies with RDS to have best outcomes, it is essential that they have optimal supportive care, including maintenance of normal body temperature, proper fluid management, good nutritional support, appropriate management of the ductus arteriosus and support of the circulation to maintain adequate tissue perfusion.
The Surfactant System Protects Both Fetus and Newborn
Authors: Hallman Mikko
Published: May 2013

Surfactant complex and its individual components decrease surface tension, silence inflammatory responses, bind and destroy air-borne microbes, facilitate phagocytosis by alveolar macrophages and bind endogenous and exogenous molecules. Surfactant components generally decrease harmful inflammatory responses. New exogenous surfactants and new indications for surfactant therapy remain to be studied. At term the pool of human surfactant from developing airways extends to the amniotic cavity and to the gastrointestinal tract. Preterm labor-inducing inflammatory ligands (interleukin-1 or lipopolysaccharide) cause a robust induction of surfactant complex and lower the risk of respiratory distress syndrome (RDS). The effect of antenatal glucocorticoid therapy is complementary. According to transgenic experiments or genetic evidence in humans, surfactant proteins A, D or C (SP-A, SP-D, SP-C), expressed in fetal tissue, influence the onset of term or preterm labor. After birth, the surface tension-reducing and the inflammation-silencing effects of exogenous and endogenous surfactant are complementary. Surfactant proteins influence the genetic predisposition of RDS, bronchopulmonary dysplasia (BPD) and airway infections in early infancy. Moderate to severe BPD has a strong genetic predisposition. Deleterious mutations of SP-B, ABCA3 or SP-C cause congenital interstitial lung disease that mimics the phenotype of established severe BPD. I propose that lung surfactant protects both the fetus and the newborn. Surfactant ameliorates inflammatory responses that are harmful to the mother, fetus and infant. In chorioamnionitis, inflammatory ligands are carried from the fetal membranes to the alveolar space via amniotic fluid and developing airways. They induce surfactant synthesis and secretion. Surfactant ameliorates severe inflammatory responses in fetal compartments and promotes spontaneous preterm birth.
Validation of FLAIR Hyperintense Lesions as Imaging Biomarkers to Predict the Outcome of Acute Stroke after Intra-Arterial Thrombolysis following Intravenous Tissue Plasminogen Activator
Authors: Chung Jong-Won , Kim Kyeong Joon , Noh Won-Young , Jang Myung Suk , Yang Mi Hwa , Han Moon-Ku , Kwon O-Ki , Jung Cheolkyu , Kim Jae Hyoung , Oh Chang Wan , Lee Ji Sung , Lee Juneyoung , Bae Hee-Joon
Published: May 2013

Background: Intravenous tissue plasminogen activator (tPA) given within 4.5 h of symptom onset is accepted as the standard treatment of ischemic stroke. Persistent occlusion of cerebral arteries despite intravenous thrombolysis and unremitting neurologic deficits lead us to consider additional intra-arterial approaches. The aim of this study was to elucidate the potential of fluid-attenuated inversion recovery (FLAIR) MRI performed during or immediately after intravenous thrombolysis for predicting clinical outcomes of subsequent intra-arterial thrombolysis. Methods: With a prospective stroke registry database of patients hospitalized in our institution from January 2004 to February 2010, we identified ischemic stroke patients with the following conditions: (1) presentation within 2.5 h of onset, (2) treated with intravenous tPA based on brain CT, (3) persistent occlusion on subsequent MRI/MR angiography, including a FLAIR sequence, and (4) eventually treated with intra-arterial thrombolysis. Demographic, clinical and laboratory findings including initial National Institutes of Health Stroke Scale (NIHSS), follow-up NIHSS at the 7th day or discharge, modified Rankin scale (mRS) score at 3 months, and symptomatic hemorrhagic transformation were captured. FLAIR images were reviewed by 2 investigators blinded to clinical information independently and dichotomized into the absence and presence of FLAIR change within the diffusion-restriction lesions. Results: Of the 57 patients who met these conditions, FLAIR-hyperintense lesions (FHL) were observed in 32 (56.1%). The FHL-negative group was 69.1 ± 12.1 years old on average and the FHL-positive group 67.3 ± 11.0 years old. In both groups, hypertension was the most common vascular risk factor, cardioembolic stroke was the most common subtype, and distal middle cerebral artery was the most common site of occlusion. The incidence of symptomatic hemorrhagic transformation was 4.0% in the FHL-negative group and 9.4% in the FHL-positive group (p = 0.62). NIHSS scores of 0-1 on the 7th day of hospitalization or at discharge were observed in 36% of the FHL-negative group and in 9.4% of the FHL-positive group; mRS scores of 0-1 at 3 months was 32% in the FHL-negative group and 21% in the FHL-positive group. An ordinal logistic regression analysis showed that the presence of FHL was associated with higher 7-day NIHSS scores (adjusted for relevant covariates) but not with higher 3-month mRS scores. Conclusions: This study suggests that the FHL might be used as imaging biomarker to predict outcomes for additional intra-arterial thrombolysis in patients treated with intravenous tPA.
Asymptomatic Cerebral Microbleeds in Adult Patients with Moyamoya Disease: A Prospective Cohort Study with 2 Years of Follow-Up
Authors: Sun Wen , Yuan Cuiping , Liu Wenhua , Li Yongkun , Huang Zhixin , Zhu Wusheng , Li Min , Xu Gelin , Liu Xinfeng
Published: May 2013

Objective: Risk factors for cerebral microbleeds (CMBs) in moyamoya disease (MMD) remain unknown, and whether the presence or distribution of CMBs is related to the subsequent hemorrhagic events needs to be confirmed. This study aimed to investigate the relationship between intracranial vascular morphology and the incidence/distribution patterns of CMBs as well as to determine the outcome in adult patients with MMD. Methods: Eighty-five consecutive adult patients with MMD were prospectively evaluated by 3.0-tesla high-intensity susceptibility-weighted magnetic resonance imaging and catheter-based digital subtraction angiography from June 2009 to January 2012. The differences in intracranial angiography (Suzuki stages, posterior cerebral artery stages, and angiographic features of the anterior choroidal and posterior communicating arteries) and clinical parameters (age, gender, hemorrhagic onset, antiplatelet treatment, systolic/diastolic blood pressure, diabetes, and plasma fibrinogen) among various CMB distribution patterns were analyzed with multinomial logistic regression. Moreover, after a median follow-up of 23 months, the relationship between CMB distribution patterns and subsequent intraventricular hemorrhage was also analyzed with Kaplan-Meier survival analysis and a Cox proportional hazards model. Results: Forty-five female and 40 male patients were finally enrolled in the study with an average age of 41.4 ± 12.7 years. Thirty-one CMB foci were detected in 24 (28.2%) patients. Most of the lesions (n = 22, 71.0%) were located in the region of deep and periventricular white matter (DPWM). Dilation and extension of anterior choroidal and posterior communicating arteries (AChA-PComA) was found to be an independent risk factor associated with the CMBs located in DPWM (p = 0.045; odds ratio 3.39, 95% CI 1.03-11.19). Patients with DPWM CMBs showed a statistically higher likelihood of subsequent intraventricular hemorrhage compared to patients without CMB foci and with CMBs in other regions (p = 0.014) during the follow-up period. Multivariable analysis suggested that DPWM CMBs were independent predictors of subsequent intraventricular hemorrhage (p = 0.028; hazard ratio 5.53, 95% CI 1.20-25.41). Conclusions: Dilation and extension of AChA-PComA is a determinant of CMBs involved in DPWM. CMBs in DPWM are probably predictors of subsequent intraventricular hemorrhage.
Necessity of Education for Oral Contraceptive Use in Korea: Results from the Fourth Korean National Health and Nutrition Examination Survey 2007-2009
Authors: Lee Jung-Yun , Park Sang Min , Ko Young-Jin , Song Yong-Sang
Published: May 2013

Background/Aims: To compare the prevalence of contraindications to oral contraceptive (OC) use between OC users and nonusers and to identify high-risk groups related to contraindications to OC use among OC users. Methods: This health-interview survey is part of the Fourth Korean National Health and Nutrition Examination Survey 2007-2009. Of 13,561 women who participated in the survey, 672 were OC users and 3,720 were OC nonusers. The adjusted proportions of contraindications to OC use were measured according to the current OC use status. Factors associated with contraindications to OC use among OC users were identified using multivariate analysis. Results: The prevalence of contraindications to OC use was higher in OC users than in OC nonusers (12.6 vs. 7.8%, p < 0.001). The adjusted proportion of women who were smokers and aged ≥35 years was greater in OC users than in OC nonusers (5.8 vs. 1.9%, p < 0.001). Among OC users, the 40-50 age group, lower education level, and a BMI ≥25 had higher odds of having contraindications. Conclusion: Education programs for OC use are urgently required to improve knowledge about correct use of and contraindications to OC use.
Intravenous Pamidronate Treatment in Children with Moderate-to-Severe Osteogenesis Imperfecta Started under Three Years of Age
Authors: Alcausin M.B. , Briody J. , Pacey V. , Ault J. , McQuade M. , Bridge C. , Engelbert R.H.H. , Sillence D.O. , Munns C.F.
Published: May 2013

Objective: Evaluate clinical outcome of early cyclic intravenous pamidronate treatment in children with moderate-to-severe osteogenesis imperfecta (OI), commenced before three years of age. Methods: A retrospective review of 17 patients with moderate-to-severe OI. Development, anthropometry, fracture history, bone mineral density (BMD) and biochemistry were collected at baseline, 12 and 24 months. Results: Four had OI type I, eleven had type III, one OI-FKBP10 type and one OI type V. Mean age at start of pamidronate was 14 ± 11 months. Pamidronate ranged from 6 to 12 mg/kg/year. No adverse reaction apart from fever and vomiting was noted. Long bone fracture decreased from a mean of 10.4/year to 1.2/year after 12 months and 1.4/year after 24 months (p = 0.02). Lumbar spine age- and height-matched BMD Z-scores increased (p < 0.005). Sixteen with vertebral compression fractures at baseline all showed improved vertebral shape (p < 0.001). Concavity index, likewise, improved (p < 0.005). Motor milestones compared to historical data show earlier attainment in rolling over, crawling, pulling to stand and walking independently but not sitting. Conclusion: Cyclic intravenous pamidronate, started under 3 years of age in children with moderate-to-severe OI, was well tolerated and associated with an increase in lumbar spine BMD, reduced fracture frequency, vertebral remodelling and attainment of motor milestones at an earlier age.
Use of Diagnostic Laparoscopy in a Patient with Gastric Pneumatosis and Portal Venous Gas
Authors: Shah Nilay R. , Dossick Deborah S. , Madura James A. , Heppell Jacques P.
Published: May 2013

Gastric pneumatosis is a radiographic finding that represents a spectrum of conditions ranging from benign disease to abdominal sepsis and death. Along with portal venous gas, it is generally considered an ominous sign prompting emergent operative intervention. We report a rare case showing that diagnostic laparoscopy can be used to confirm or refute full thickness ischemic necrosis and that conservative management can be considered in some patients, recognizing the possibility of a benign process.
Angiotensin-(1–7) Dose-Dependently Inhibits Atherosclerotic Lesion Formation and Enhances Plaque Stability by Targeting Vascular Cells
Authors: Yang Jian Min , Dong Mei , Meng Xiao , Zhao Yu Xia , Yang Xiao Yan , Liu Xiao Ling , Hao Pan Pan , Li Jing Jing , Wang Xu Ping , Zhang Kai , Gao Fei , Zhao Xue Qiang , Zhang Ming Xiang , Zhang Yun , Zhang Cheng
Published: May 2013

Objective—

To test the hypothesis that chronic infusion of angiotensin-(1–7) [Ang-(1–7)] may dose-dependently inhibit atherosclerotic lesion formation by targeting vascular smooth muscle cells and a large dose of Ang-(1–7) may stabilize mature plaque by targeting macrophages.

Approach and Results—

In vivo, the effects of Ang-(1–7) on atherogenesis and plaque stability were observed in ApoE
−/−
mice fed a high-fat diet and chronic angiotensin II infusion. In vitro, the effects of Ang-(1–7) on vascular smooth muscle cells’ proliferation and migration, and macrophage inflammatory cytokines were examined. Ang-(1–7) dose-dependently attenuated early atherosclerotic lesions and inhibited vascular smooth muscle cells’ proliferation and migration via suppressing extracellular regulated protein kinase/P38 mitogen-activated protein kinase and janus kinase/signal transducers and activators of transcription activities and enhancing smooth muscle 22α and angiotensin II type 2 receptor expression. Ang-(1–7) treatment resulted in high contents of collagen and vascular smooth muscle cells, and low contents of macrophages and lipids in carotid mature plaques. Ang-(1–7) lowered the expression levels of proinflammatory cytokines and activities of matrix metalloproteinases in mature plaques.

Conclusions—

Ang-(1–7) treatment inhibits early atherosclerotic lesions and increases plaque stability in ApoE
−/−
mice, thus providing a novel and promising approach to the treatment of atherosclerosis.
Oxidative Stress–Mediated Thrombospondin-2 Upregulation Impairs Bone Marrow–Derived Angiogenic Cell Function in Diabetes Mellitus
Authors: Bae Ok-Nam , Wang Jie-Mei , Baek Seung-Hoon , Wang Qingde , Yuan Hong , Chen Alex F.
Published: May 2013

Objective—

Circulating angiogenic cells play an essential role in angiogenesis but are dysfunctional in diabetes mellitus characterized by excessive oxidative stress. We hypothesize that oxidative stress–mediated upregulation of thrombospondin-2 (TSP-2), a potent antiangiogenic protein, contributes to diabetic bone marrow–derived angiogenic cell (BMAC) dysfunction.

Approach and Results—

BMACs were isolated from adult male type 2 diabetic db/db mice and control db/+ (C57BLKS/J) mice. In Matrigel tube formation assay, angiogenic function was impaired in diabetic BMACs, accompanied by increased oxidative stress and nicotinamide adenine dinucleotide phosphate oxidase activity. BMAC angiogenic function was restored by overexpression of dominant negative Rac1 or by overexpression of manganese superoxide dismutase. TSP-2 mRNA and protein were both significantly upregulated in diabetic BMACs, mediated by increased oxidative stress as shown by a decrease in TSP-2 level after overexpression of dominant negative Rac1 or manganese superoxide dismutase. Silencing TSP-2 by its small interfering RNA in diabetic BMACs improved BMAC function in tube formation, adhesion, and migration assays. Notably, the upregulation of TSP-2 was also found in BMACs from streptozotocin-induced type 1 diabetic mice, and normal BMACs with high glucose treatment. let-7f, a microRNA which has been related to endothelial angiogenic function, is found to play key role in TSP-2 increase, but let-7f did not directly interact with TSP-2 mRNA.

Conclusions—

The upregulation of TSP-2 mediated by increased oxidative stress contributes to angiogenesis dysfunction in diabetic BMACs.