bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivity of B-CLL to Cell Death Induction by Anticancer Drugs Is Independent of the Immunoglobulin Heavy Chain Variable Genes (IgHv) Mutation Status.
Authors: Sturm Isrid , Bosanquet Andrew G. , Hummel Michael , Dorken Bernd , Daniel Peter T. 
Published: April 2020

Abstract
B-type chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease. Unmutated immunoglobulin (Ig) VH genes, i.e. a post-germinal center genotype, are associated with a more aggressive natural course of disease. To explore the impact of Ig variable region hypermutation on response to cytotoxic therapies we analyzed the sensitivities to a panel of cytotoxic modalities by use of the DiSC assay that measures cell death. These data were compared to the Ig VH mutation status in 113 B-CLL patients. 29 patients exhibited IgHV hypermutation (age 66.3±1.8 years, 18 male, 11 female) whereas 84 patients (age 62.2±1.1, 66 male, 18 female) were of pre-germinal center B-cell origin. Hypermutated samples were from Binet stage A in 11 cases (unmutated 12), Binet stage B in 5 cases (14), Binet stage C in 10 cases (44), and in stage A/B in 2 cases (10 cases), Chi-square test p=0.02. 11/29 patients with Ig VH hypermutation and 54 of the 84 of the patients with unmutated B-CLL had received prior chemotherapy. Ig VH hypermutation had no impact in the percentage of surviving cells after 92 hours for ionizing irradiation (IR, 2 Gy by a 137Cs source) (hypermutated, 35.3%±8.2, unmutated 34.2%±4.5). Furthermore, there was no significant difference for the log LC90 values for chlorambucil (Mann-Whitney U test, p=0.22), doxorubicin (p=0.86), fludarabine (p=0.36), and mafosfamide (p=0.49). Interestingly, the log LC90 value for methylprednisolone showed a significant difference and was lower in the unmutated (n=83, mean±SEM 0.8±0.13) as compared to the hypermutated samples(n=29, 1.36±0.2; p=0.038). Conclusions: The mutation status of the IgHV gene segment does not appear to be responsible for differences in the response to various drug treatments in B-CLL. Vice versa, differences in gene expression that were described in hypermutated versus unmutated B-CLL do not seem to impact on drug sensitivity profiles. Thus, both DiSC assay result and VH Gene hypermutation are valuable independent prognostic markers.
Application of Multiplex RT-PCR for Identification of Leukemia Associated Gene Abnormalities.
Authors: Lee Hyun Woo , Jung Youn Mu , Jang Jun Ho , Park Jun Seong , Cho Sung Ran , Choi Jin Hyuk , Lim Ho Yeong , Lee Jong Uk , Kim Hugh C. 
Published: April 2020

Abstract
The best prognostic predictor for acute leukemia is known to be the finding of genetic abnormalities of leukemic cells. Methods for detecting the genetic abnormalities include chromosomal studies for karyotyping, FISH(Fluorescence in situ hybridization) and RT-PCR. However, each methods have limitations i.e. low sensitivity in karyotyping, uncertainty of molecular probe to be used in FISH or RT PCR methods. Multiplex RT-PCR (MRT-PCR) allows simultaneous detection of 28 fusion genes, more than 80 breakpoints and splice variants associated with leukemia. Therefore, this method can be used for detection of molecular abnormality in fresh unknown leukemic cases, as well as for molecular remission in follow-up cases. The aim was to demonstrate whether MRT-PCR system might be successfully used to screen a large number of patients with acute leukemia and compare the result with that of chromosome studies. Frozen bone marrow cells from 78 patients, who were diagnosed with acute leukemia at Ajou university hospital between September 1994 and February 2004, were used for MRT-PCR. In all samples with a known conventional cytogenetic results, we performed MRT-PCR and to compared with conventional cytogenetic study regarding the concordance rate and analyzed discordant cases regarding their types. 78 samples(40 male and 38 female patients) were analyzed, and there were 59 AML patients and 19 ALL patients. We successfully obtained the mRNA from all frozen samples. In 21 cases with gene abnormalities by chromosome studies most of them (15/21) showed the same abnormalities with MRT-PCR. In 57 patients with normal karyotype by cytogenetic technique, we identified 18 translocations of clinical significance by MRT-PCR method. In 18 discordant cases, there were 4 cases with t(15;17), 4 cases with t(8;21), 3 cases with t(9;22), 2 cases with t(11;19) and 4 others [t(9;11),t(9;9),t(3;11),inv(16)]. Conventional cytogenetics detected 10 cases of good prognostic gene abnormalities [t(15;17),t(8;21),inv(16)], but MRT-PCR method detected 10 additional cases of good prognostic gene abnormalities which might change the treatment paln. The twenty good prognostic cases with MRT-PCR showed better overall survival than others. (median f/u = 10.6 month, p=0.0443) There were 69% concordance rate between cytogenetic technique and MRT-PCR. Furthermore clinically significant translocations were detected by MRT-PCR in 18 of 57 normal karyotype patients, indicating improved sensitivity and prognostic value with MRT-PCR. Further investigations are needed to ascertain the usefulness of MRT-PCR for the screening tool of leukemic gene abnormalities.
Loss of PTEN Expression Induces NF-kB Via PI3K/Akt Pathway Involving Resistance to Chemotherapy in Acute Lymphoblastic Leukemia Cell Lines.
Authors: Gu Lubing , Zhu Ningxi , Findley Harry W. , Zhou Muxiang 
Published: April 2020

Abstract
PTEN is a tumor suppressor gene responsible for downregulating the phosphoinositide 3-kinase (PI3k)/Akt pathway. Loss of PTEN expression frequently occurs in human cancer leading to high Akt activation, which consequently confers neoplastic cell survival and resistance to chemotherapy-induced apoptosis. Here we report a mechanism by which loss of PTEN expression activates the transcription factor NF-kB through the PI3k/Akt pathway that induces activation of the IkBa kinase (IKK). Activation of NF-kB by loss of PTEN expression results in resistance to doxorubicin in acute lymphoblastic leukemia (ALL) cells. Initially, we examined 27 leukemia cell lines derived from children with ALL for the expression of PTEN and constitutive activation of NF-kB to evaluate whether there is a correlation between these two events. We found that 12 of the 27 lines lacked PTEN expression (PTEN-). Of 12 PTEN- ALL lines, 10 lines expressed constitutive NF-kB activation. In contrast, 11 of the 15 PTEN positive (PTEN+) lines were defect of NF-kB activation. Treatment of PTEN- line with PI3k kinase inhibitor Ly294002 caused downregulation of Akt activity accompanied by reduced activation of IKK and inhibition of constitutive NF-kB activation, resulting in increased sensitivity to doxorubicin-induced apoptosis. Similar to treatment with Ly294002, transfection of the PTEN expression plasmid into the PTEN- lines attenuated constitutive activation of both Akt and NF-kB, thereby sensitizing these cells to doxorubicin. These results suggest that both constitutive and inducible activation of NF-kB play an important role in chemotherapy resistance, and that loss of PTEN expression is at least one reason for the constitutive activation of NF-kB in ALL cells.
Single Nucleotide Polymorphisms of DNA Synthetic and Repair Enzymes and Risk of Childhood Acute Lymphoblastic Leukemia.
Authors: Pakakasama Samart , Sirirat Thanasan , Kajanachumpol Saowanee , Chaunsumrit Ampaiwan , Hongeng Suradej 
Published: April 2020

Abstract
Although the outcome of children with acute lymphoblastic leukemia (ALL) has been improving, the origin of this disease is still unknown. It is likely that individual genetic susceptibility and environmental exposure play a role in carcinogenesis. To maintain normal hematopoiesis, DNA synthesis and repair systems need to be intact. Folate metabolism, producing purines and pyrimidines, is the source of nucleotides while base excision and nucleotide excision repair enzymes, i.e. XRCC1 and XPD, have important roles in protection of DNA damage. Single nucleotide polymorphisms (SNPs) of enzymes involving these processes alter their enzymatic structures and functions. We hypothesized that SNPs of folate metabolic enzymes including methylenetetrahydrofolate reductase (MTHFR 677 C&gt;T; 1298 A&gt;C), methionine synthase (MS 2756 A&gt;G), and tandem repeats of thymidylate synthase (TS 2R or 3R) and of DNA repair enzymes (XRCC1 26304 C&gt;T; 27466 G&gt;A; 28152 G&gt;A and XPD 23591 G&gt;A; 35931 A&gt;C) could effect the risk of ALL in children. We performed genotyping of these SNPs in 108 ALL and 317 normal controls by using PCR RFLP method. Genotype frequencies of folate metabolic enzymes SNPs were not different between cases and controls. However, TS 2R allele showed a trend to decrease risk of ALL (OR=0.66; 95% CI 0.41–1.07). We observed a 4.5 fold reduction in the risk of ALL in individuals with the XRCC1 26304 TT genotype (OR=0.22; 95% CI 0.5–0.96). XRCC1 26304 T allele showed a protective effect to this disease (OR=0.67; 95% CI 0.47–0.97). In contrast, individuals with XRCC1 28152 A allele had an increased risk of ALL (OR=1.67; 95% CI 1.2–2.33) compared to those with G allele. XRCC1 28152 GA and GA+AA genotypes were significantly higher among patients with ALL compared to controls (OR=2.17; 95% CI 1.37–3.45 and OR=2.18; 95%CI 1.38–3.42). No association between genotype or allele frequencies of both XPD SNPs and risk of ALL was shown in this study. In conclusion, our data demonstrated that SNPs of DNA repair enzymes (XRCC1 26304 C&gt;T and 28152 G&gt;A) but not folate-dependent DNA synthetic enzymes may influence risk of childhood ALL.
Akt/PKB Activation-Induced Cytoplasmic Mislocalization of p27Kip1 Protein Is Mediated by Jab1 Shuttling in Human Myeloid Leukemia Cells.
Authors: Min Yoo-Hong , Eom Ju In , Choi Ae Jin , Lee Jee Young , Kim Jin Seok , Lee Seung Tae , Cheong June-Won 
Published: April 2020

Abstract
We previously demonstrated the cytoplasmic mislocalization of p27Kip1 protein was highly correlated with constitutive Akt/PKB phosphorylation and poor prognosis in primary acute myeloid leukemia. However, mechanism involved in the Akt/PKB-mediated nuclear export of p27Kip1 in leukemia cells is not fully understood. Jun activation domain-binding protein 1 (Jab1)/CSN5 is the fifth component of the COP9 signalosome complex, which is involved in modulating signal transduction, ubiquitin-proteasome pathway, and nuclear transport. We examined the effects of Akt/PKB activation on the phosphorylation and localization of p27Kip1 protein in relation to Jab1 shuttling in K562 leukemia cells. Akt/PKB activation did not affect the phosphorylation at threonine 187 residue (T187) of p27Kip1 protein in K562 cells. However, the phosphorylation of p27Kip1 at the serine 10 (S10) and threonine T157 (T157) residue was markedly increased in the constitutively active Akt/PKB cDNA-transfected K562 (Myr-Akt/PKB-K562) cells. In the Myr-Akt/PKB-K562 cells, the S10- and T157-phosphorylated form of p27Kip1 localized almost exclusively to the cytoplasm. Leptomycin-B (LMB) pretreatment of Myr-Akt/PKB-K562 cells led to restoration of S10- and T157-phosphorylated p27Kip1 to the nucleus, indicating that Akt/PKB activation-induced cytoplasmic translocation of S10- and T157-phosphorylated p27Kip1 was mediated by CRM1-dependent pathway. We found that Akt/PKB activation did not alter the total cellular levels of Jab1 protein. However, Jab1 protein was exclusively localized to the cytoplasm in the Myr-Akt/PKB-K562 cells, whereas it was preferentially localized to the nucleus in the dominant negative Akt/PKB cDNA-transfected K562 cells. In Myr-Akt/PKB-K562 cells pretreated with LMB, the localization of the Jab1 was essentially nuclear. Jab1 silencing led to an accumulation of S10- and T157-phosphorylated p27Kip1 to the nucleus in the Myr-Akt/PKB-K562 cells, which was accompanied by a prominent decrease in the cytoplasmic level of p27Kip1. Taken together, we demonstrate that Akt/PKB activation-induced cytoplasmic mislocalization of S10- and T157-phosphorylated p27Kip1 protein is mediated by Jab1 shuttling in human myeloid leukemia cells. Apart from our understanding of the mechanism implicated in the regulation of phosphorylation and localization of p27Kip1 protein in leukemia cells, all these data might suggest possibilities for designing leukemia therapy since it should be possible to restore the function of a misplaced p27Kip1 protein.
Arsenic Trioxide (ATO) Downregulates the Expression of the AML1/MDS1/EVI-1 (AME) Oncoprotein and Induces Differentiation and Apoptosis in AME-Leukemic Cells.
Authors: Shackelford David , Waxman Samuel , Ren Ruibao 
Published: April 2020

Abstract
Arsenic is an ancient drug, used for many centuries to treat a broad range of ailments including cancer but was largely abandoned in the early 20th century. In the 1990s arsenic trioxide (ATO) was rediscovered as an effective treatment for patients suffering from acute promyelocytic leukemia (APL). ATO has been shown to specifically target the fusion protein resulting from the t(15;17) translocation, PML/RARα, and subsequently stimulate differentiation and apoptosis of APL cells both in vitro and in vivo. The success in using ATO as a targeted therapy for APL underscores the importance of matching the right drug to patients with appropriate molecular targets. We previously reported that expression of the AML1/MDS1/EVI1 (AME) transcription factor fusion protein [a product of the human t(3;21)(q26;q22) translocation found as a secondary mutation in some cases of chronic myelogenous leukemia during the blast phase and in some patients with de novo and therapy-related myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML)] in mouse bone marrow cells by retroviral transduction impaired hematopoiesis and eventually induced an AML in mice. Our results established a causal role of AME in t(3;21)-positive myeloid malignancies. We went on to examine whether ATO could target AME. We found that ATO treatment downregulated forced-expressed AME protein in Bosc23 (a cell line derived from human 293 kidney cell line) and BM6-4 cells, a primary myeloid blast cell line derived from bone marrow of a mouse with AME-induced AML, in a dose dependent manner (within therapeutic relevant dosage range). We also found that ATO inhibited proliferation of BM6-4 cells, induced these cells to differentiate into macrophages and induced apoptosis in a dose dependent manner. Our results suggest that ATO could be used as a targeted therapy for t(3;21)-positive MDS and AML. The in vivo effect of ATO in the AME mouse model and mechanism of ATO-induced AME downregulation is under investigation. Such research may extend ATO therapy to other hematological malignancies and help to identify new therapeutic targets for human cancer.
Fibroblast Growth Factor Receptor-1 Expression and Signaling in Acute Myeloid Leukemia.
Authors: Karajannis Matthias A. , Vincent Loïc , Zhang Fan , Shmelkov Sergey V. , Cheung Joseph , Bohlen Peter , Zhu Zhenping , Kussie Paul , Sun Haijun , Rafii Shahin 
Published: April 2020

Abstract
Fibroblast growth factor receptors (FGFRs) are tyrosine kinase receptors affecting cell proliferation, motility and survival. Fibroblast growth factor 2 (FGF2, basic FGF) represents the prototype FGFR ligand. Expression of FGFRs has been demonstrated in a subset of acute myeloid leukemias (AMLs) and FGF2 is overexpressed in the bone marrow of AML patients. The role of FGF/FGFR signaling in AML however is controversial, and downstream signaling cascades activated by FGFR1 are not known. Therefore, we hypothesized that subsets of primary acute leukemic cells may express functional FGFR1 mediating survival and proliferation of leukemic cells. We examined the role of the FGF/FGFR axis in primary AML blasts isolated from a 74 year old male (designated R81). Using RT-PCR we showed that FRFR1 was expressed in leukemic cells. To assess whether FGF2 stimulates FGFR1 signaling, R81 blasts were incubated in serum free medium with and without 20 ng/ml of FGF2 and/or a with 10 μg/ml of neutralizing monoclonal antibody to FGFR1. Viable cells were counted at 48 and 96 hours with trypan blue exclusion (see figure). The results show that FGF2 stimulates growth and/or survival of R81 AML blasts and this effect is abrogated by FGFR1 antibodies. Specifically, FGF2 induced a two-fold increase in the proliferation of leukemic blasts after 48 hours. To identify downstream signaling pathways involved in FGFR1 signaling, proliferation and survival of FGF2-treated R81 cells were examined in the presence or absence of selective PI3 kinase and MAP kinase inhibitors, LY-294002 and PD098059, respectively. The results indicated that FGF2 signaling exerts its proliferative and pro-survival effects primarily through PI3 kinase activation. In summary, we show that FGF/FGFR1 signaling plays a role in a subset of AMLs and may be blocked by a FGFR1 specific antibody. Currently, we are further elucidating the mechanisms involved in FGFR signaling and its effects on cell proliferation, migration, and apoptosis. In addition, animal experiments are underway to assess a possible therapeutic role of anti-FGFR antibodies for the treatment of FGFR-positive AML in murine xenotransplant models.
Figure Figure
TPCK Induces Apoptosis in Human Acute Myeloid Leukemia U-937 Cells.
Authors: Mazar Julia , Lichtenstein Alexandra , Katz Leora , Shpilberg Ofer , Levi Itai , Nathan Ilana 
Published: April 2020

Abstract
Many types of antitumor therapy in general and AML in particular exert their effect by activating apoptosis. Apoptosis of AML cells can be induced by cytostatic drugs, corticosteroids, and radiation. Recently, the role of different proteases as possible targets for chemotherapy was described. N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), a chymotrypsin-like protease (CLP) inhibitor was shown to exert a dual effect on leukemic cells: proapoptotic and antiapoptotic. In the present study the mechanism of its proapoptotic effect was addressed. It was found that the CLP inhibitors, TPCK and 3,4 dichloroisicoumarine induced apoptosis in a time- and concentration-dependent manner. Apoptosis was accompanied by a decrease in mitochondrial membrane potential, cytochrome c release, caspase-3 (but not caspase-8) activation, PS flip-flop (measured by Annexin-V staining followed by flow cytometry analysis) and chromatin condensation, but not fragmentation (detected by acridine orange/ethidium bromide staining).
All apoptotic processes induced by TPCK were completely inhibited by cycloheximide. The ability of cycloheximide to inhibit TPCK-induced cell death suggests that protein synthesis plays a role in TPCK-induced apoptosis. Additionaly, the proapoptotic effect of TPCK was abolished by elimination of glucose from the medium. The data supports the role of mitochondria in this process.
In the present study the apoptotic pathway driven by inhibition of CLP was demonstrated. Moreover, these findings suggest possible ways of preventing the proapoptotic activity of TPCK and thereby enhancimg its antiapoptotic action.
Analysis of Cytokine Profiling in Hepatitis-Associated Aplastic Anemia.
Authors: Lu Jun , Wong Susan , Basu Atanu , Young Neal S. , Brown Kevin E. 
Published: April 2020

Abstract
In hepatitis-associated aplastic anemia (HAA), bone marrow failure follows an acute attack of seronegative hepatitis. Aplastic anemia (AA) is also associated with orthotopic liver transplantation for non-A, non-B, non-C hepatitis in young patients. Although the etiology of HAA is unknown, a clinical response to immunosuppressive therapy is observed in most clinical cases. The liver is the potential initial target organ of the immune response. We have previously determined the T-cell repertoire in the liver and peripheral blood lymphocytes in patients with HAA (Lu et al. Blood. 2004 Jun 15;103(12):4588–93). An antigen-driven T-cell expansion was implicated in the acute stage before bone marrow failure. In the present study, we measured serum cytokine levels in 22 HAA serum samples. Only interleukin (IL)-10 levels showed a significant increase compared to healthy controls (p&lt;0.02); IFN-γ , TNF-α and IL-1, 2, 4, 5, 6, 8, 12 levels showed no significant difference. To further characterize the immune response in the liver, we performed RNAse protection assays and realtime PCR for RNA transcripts. In 4 HAA liver samples, 2 demonstrated increased IFN-γ by RNAse protection; TNF-α , IL-2, 3, 4, 5, 10, 15 transcripts were not different compared to transcript levels in 4 hepatitis B and/or C livers and 2 fulminant hepatitis (FH) samples. To confirm our preliminary data, we characterized the cytokine profile including CD4, CD8, CD69, TNF-α , IFN-γ and interleukins and compared them among the hepatitis B/C, FH and HAA liver samples by quantitative PCR for RNA transcripts. In 10 HAA liver samples, CD8 transcripts were increased and the CD4/CD8 ratio was decreased, but there was no significant difference between HAA and hepatitis B/C (p&gt;0.05), confirming the important role of cellular immunity in HAA. IFN-γ transcripts were significantly overexpressed in both HAA and FH samples compared to hepatitis B/C samples (p&lt;0.05), but without a difference between HAA and FH. CD69 transcripts were reduced in HAA but not significantly lower than in hepatitis B/C (p&lt;0.05). There were no difference of TNF-α transcripts among HAA, hepatitis and FH samples (p&gt;0.05). In summary, our data confirm that enhanced cellular immunity (increased IFN-γ level) is implicated in the pathogenesis of HAA, similar to that observed in the bone marrow of idiopathic AA, and in contrast to other liver diseases such as chronic hepatitis B/C. Quantitation of IFN-γ levels in acute hepatitis samples might be a predictive marker for the development of bone marrow failure after liver transplantation following seronegative hepatitis and FH.
A Small Number of PNH-Type Cells Predict Good Prognosis in Patients with Aplastic Anemia.
Authors: Sugimori Chiharu , Mochizuki Kanako , Yamazaki Hirohito , Feng Xingmin , Nakao Shinji 
Published: April 2020

Abstract
To determine the clinical significance of a minor population of glycosylphosphatidylinositol-anchored membrane protein-negative (GPI-AP−) cells in acquired aplastic anemia (AA), we quantified CD55− CD59− granulocytes and red blood cells (RBCs) in peripheral blood from 122 patients with recently diagnosed AA and correlated numbers of GPI-AP− cells and responses to immunosuppressive therapy (IST). The highly sensitive flow cytometry detected 0.005% to 23.1% of GPI-AP− cells in 68.0% of AA patients. Sixty-eight of 83 (91%) patients with an increased ratio of GPI-AP− cells (PNH+) responded to antithymocyte globulin (ATG) + cyclosporin (CsA) therapy, whereas 18 of 39 (48%) without such an increase (PNH−) responded. Failure-free survival rates were significantly higher (64%) among PNH+ than PNH− patients (12%) at 5 years (Figure) although overall survival rates were comparable between the groups. Numbers of GPI-AP− and GPI-AP+ cells increased in parallel among most PNH+ patients who responded to IST, suggesting that these cells are equally sensitive to immune attack. These results indicate that a minor population of GPI-AP− cells represents a reliable marker of a positive IST response and a favorable prognosis among patients with AA. Furthermore, immune attack against hematopoietic stem cells that allows PNH clonal expansion might occur only at the onset of AA.
Figure Figure