Search

Abstract: Arsenic trioxide (ATO) is presently the most active single agent in the treatment of acute promyelocytic leukemia (APL). In order to explore the molecular mechanism of ATO in leukemia cells with time series, we adopted bioinformatics strategy to analyze expression changing patterns and changes in transcription regulation modules of time series genes filtered from Gene Expression Omnibus database (GSE24946). We totally screened out 1847 time series genes for subsequent analysis. The KEGG (Kyoto encyclopedia of genes and genomes) pathways enrichment analysis of these genes showed that oxidative phosphorylation and ribosome were the top 2 significantly enriched pathways. STEM software was employed to compare changing patterns of gene expression with assigned 50 expression patterns. We screened out 7 significantly enriched patterns and 4 tendency charts of time series genes. The result of Gene Ontology showed that functions of times series genes mainly distributed in profiles 41, 40, 39 and 38. Seven genes with positive regulation of cell adhesion function were enriched in profile 40, and presented the same first increased model then decreased model as profile 40. The transcription module analysis showed that they mainly involved in oxidative phosphorylation pathway and ribosome pathway. Overall, our data summarized the gene expression changes in ATO treated K562-r cell lines with time and suggested that time series genes mainly regulated cell adhesive. Furthermore, our result may provide theoretical basis of molecular biology in treating acute promyelocytic leukemia. [Copyright &y& Elsevier]

Abstract: Tyrosine kinase inhibitors (TKIs), imatinib, nilotinib and dasatinib, are the current treatment of chronic myeloid leukemia (CML). BCR-ABL1 point mutations are the principal cause of resistance to treatment; however other mechanisms could be involved in failure to TKI therapy. LYN is a src kinase protein that regulates survival and responsiveness of tumor cells by a BCR-ABL1 independent mechanism. PTEN tumor suppressor gene is downregulated by BCR-ABL1 in CML stem cells and its deletion is associated with acceleration of disease. In this study we evaluated the expression of LYN, PTEN and the ratio of both genes in 40 healthy donors (HD) and in 139 CML patients; 88 of them resistant to TKI in different phases of disease and 51 in chronic phase classified as optimal responders (OR) to TKI [40 treated with imatinib or nilotinib (OR-IN) and 11 treated with dasatinib (OR-D) therapy]. When we analyzed the gene expression values of LYN, an increase was observed only in advanced stages of the disease, however, when we analyzed the ratio between LYN and PTEN genes, the group of resistant patients in chronic phase in imatinib or nilotinib treatment (CP-IN) also showed a significant increase. Resistant patients treated with dasatinib, a src kinase inhibitor, presented a similar ratio to the observed in HD. In addition, the LYN/PTEN ratio and the LYN expression showed a direct significant correlation with BCR-ABL1 transcript levels in unmutated resistant patients treated with non-src kinase inhibitors. We were able to identify 8/35 (23%) of cases in CP-IN and 4/12 (33%) in accelerated phase and blast phase (AP/BC-IN), in which resistance could be associated with an increase in the ratio of the LYN/PTEN. Our data suggest that the LYN/PTEN expression ratio may be a sensitive monitor of disease progression in unmutated CML patients under imatinib or nilotinib treatment. This ratio could detect cases when resistance is related to altered LYN expression, suggesting that the treatment change to a src kinase inhibitor would be most suitable to overcome resistance. [Copyright &y& Elsevier]

Abstract: RNAi represents a new alternative for treatment of chronic myeloid leukemia (CML) to overcome the difficulties of current drug treatments such as the acquired resistance. However, potent carriers that can overcome delivery barriers to RNAi agents and have therapeutic efficacy especially in difficult-to-transfect CML cells are needed. Here, we explored the use of lipid-modified polyethylenimines (PEI) of low molecular weights (0.6, 1.2 and 2.0kDa) in K562 cells and showed that the delivery efficiency was dependent on the type of lipid used for polymer modification, degree of lipid substitution and polymer molecular weight. Among the lipid-substituted polymers investigated, palmitic acid (PA)-substituted 1.2kDa PEI (~2 lipids/PEI) has proven to be highly efficient in delivering siRNA and silencing of the reporter gene green fluorescent protein (GFP). The silencing efficacy achieved with this polymer was found to be higher than the 25kDa PEI and is similar to commercial reagent Lipofectamine™ 2000. Moreover, when BCR-ABL protein was targeted in K562 cells, a reduction in the corresponding mRNA levels was observed, as well as an induction of early and late stage apoptosis. The results of this study demonstrated that PA-substitutions on low MW polymers could be useful for siRNA delivery in CML cells for therapeutic purposes. [Copyright &y& Elsevier]

Abstract: CUEDC2, a newly reported protein, has been found to be ubiquitously expressed in human tissues and repress NF-κB activity. To study the role of CUEDC2 in chronic myeloid leukemia (CML), we explored the function of CUEDC2 in CML cells through using the CML cell line K562 and its imatinib resistant cells K562/G01. K562 cells expressed a relatively higher level of CUEDC2 compared to K562/G01 cells. Knockdown of CUEDC2 in K562 cells resulted in decreased cell apoptosis after imatinib treatment; when CUEDC2 was overexpressed in K562/G01 cells, imatinib induced more cell apoptosis. By analyzing the activity of NF-κB, the results indicated a negative association between the expression of CUEDC2 and NF-κB signaling pathway in these CML cells. Our data suggested that the expression level of CUEDC2 has an inverse correlation with imatinib resistance and activity of NF-κB signaling pathway in CML cells, CUEDC2 could regulate imatinib sensitivity in CML cells at least partially through NF-κB signaling pathway. [Copyright &y& Elsevier]

Abstract: Hydrogen sulfide-releasing aspirin (HS-ASA) is a novel compound with potential against cancer. It inhibited the growth of Jurkat T-leukemia cells with an IC50 of 1.9±0.2μM whereas that of ASA was >5000μM. It dose-dependently inhibited proliferation and induced apoptosis in these cells, causing a G0/G1 cell cycle arrest. HS-ASA down-regulated β-catenin protein levels and reduced mRNA and protein expression of β-catenin/TCF downstream target genes cyclinD1 and c-myc. Aspirin up to 5mM had no effect on β-catenin expression. HS-ASA also increased caspase-3 protein levels and dose-dependently increased its activity. These effects were substantially blocked by z-VAD-fmk, a pan-caspase inhibitor. [Copyright &y& Elsevier]

Abstract: P-glycoprotein (Pgp) and XIAP co-expression has been discussed in the process of the acquisition of multidrug resistance (MDR) in cancer. Here, we evaluated XIAP and Pgp expression in chronic myeloid leukemia (CML) samples, showing a positive correlation between them. Furthermore, we evaluated the effects of imatinib in XIAP and Pgp expression using CML cell lines K562 (Pgp−) and K562-Lucena (Pgp+). Imatinib increased XIAP and Pgp expression in K562-Lucena cells, while in K562 cells a downregulation of these proteins was observed, suggesting that imatinib induces an increment of MDR phenotype of CML cells that previously exhibit high levels of Pgp/XIAP co-expression. [Copyright &y& Elsevier]

Curcumin and taurine are natural products that have been used in this study evaluating their therapeutic effect on myeloid leukemic cells propagated in vitro. Sixty patients with myeloid leukemia and 30 healthy volunteers were enrolled in the study. All patient groups were admitted to the Medical Oncology Department of the National Cancer Institute, Cairo University. There were statistically significant differences between treated leukemic cells compared to normal mononuclear leukocytes in cell density, interferon-γ and immunophenotypic profile, mainly CD4+, CD8 + and CD25+. This work highlights the possibility of using curcumin and taurine as a potential useful therapy in the management of patients suffering from chronic and acute myeloid leukemias. [ABSTRACT FROM AUTHOR]

Highlights: [•] We show potent inhibition of RET kinase by ponatinib, including gatekeeper-mutant RET. [•] Ponatinib is more potent than FDA-approved vandetanib against RET and overcomes vandetanib-resistant mutant RET. [•] We conclude from our study that ponatinib should be considered as a potential therapeutic option for MEN2 patients. [Copyright &y& Elsevier]

Highlights: [•] SNX-2112 induced apoptosis, necrosis and cell cycle arrest in multidrug-resistant K562/ADR cells. [•] The Bcl-2 family proteins and mitochondria pathway were involved in SNX-2112-induced apoptosis. [•] SNX-2112 induced the activation of caspases cascade in K562/ADR cells. [•] Inactivation of Akt and NF-κB signaling pathways was involved in SNX-2112-induced apoptosis. [•] The expression levels of P-gp and several chaperons related to MDR and apoptosis were decreased. [ABSTRACT FROM AUTHOR]

Abstract: Chronic myeloid leukemia (CML) is a myeloproliferative disease caused by the constitutive tyrosine kinase (TK) activity of the BCR-ABL fusion protein. However, the phenotype of leukemic stem cells (LSC) is sustained by β catenin rather than by the BCR-ABL TK. β catenin activity in CML is contingent upon its stabilization proceeding from the BCR-ABL-induced phosphorylation at critical residues for interaction with the Adenomatous polyposis coli (APC)/Axin/glycogen synthase kinase 3 (GSK3) destruction complex or GSK3 inactivating mutations. Here we studied the impact of β catenin antagonist Chibby (CBY) on β catenin signaling in BCR-ABL1+ cells. CBY is a small conserved protein which interacts with β catenin and impairs β catenin-mediated transcriptional activation through two distinct molecular mechanisms: 1) competition with T cell factor (TCF) or lymphoid enhancer factor (LEF) for β catenin binding; and 2) nuclear export of β catenin via interaction with 14-3-3. We found that its enforced expression in K562 cell line promoted β catenin cytoplasmic translocation resulting in inhibition of target gene transcription. Moreover, cytoplasmic accumulation of β catenin activated the endoplasmic reticulum (ER) stress-associated pathway known as unfolded protein response (UPR). CBY-driven cytoplasmic accumulation of β catenin is also a component of BCR-ABL1+ cell response to the TK inhibitor Imatinib (IM). It evoked the UPR activation leading to the induction of BCL2-interacting mediator of cell death (BIM) by UPR sensors. BIM, in turn, contributed to the execution phase of apoptosis in the activation of ER resident caspase 12 and mobilization of Ca2+ stores. [Copyright &y& Elsevier]

Background: MicroRNAs (miRNAs) have been recognized as one of the key regulatory non-coding RNAs that are involved in a number of basic cellular processes. miRNA expression profiling helps to identify miRNAs that could serve as biomarkers. Next generation sequencing (NGS) platforms provide the most effective way of miRNA profiling, particularly as expression of different isoforms of miRNA (IsomiRs) can be estimated by NGS. Therefore, it is now possible to discern the overall complexity of miRNA populations that participate in gene regulatory networks. It is thus important to consider different isoforms of miRNA as part of total profiling in order to understand all aspects of the biology of miRNAs. Results: Here next generation sequencing data of small RNAs derived from normal peripheral blood mononuclear cells (PBMC) and Chronic myeloid leukemia (CML) patients has been used to generate miRNA profiles using a computation pipeline which can identify isomiRs that are natural variants of mature miRNAs. IsomiR profiles have been generated for all the 5p and 3p miRNAs (previously known as major mature miRNA and minor or miRNA*) and the data has been presented as a composite total miRNA transcriptome. The results indicated that the most abundant isomiR sequence of about 68% miRNAs, did not match the reference miRNA sequence as entered in the miRBase and that there is a definite pattern in relative concentration of different isomiRs derived from same precursors. Finally, a total of 17 potential novel miRNA sequences were identified suggesting that there are still some new miRNAs yet to be discovered. Conclusions: Inclusion of different isoforms provides a detailed miRnome of a cell type or tissues. Availability of miRnome will be useful for finding biomarkers of different cell types and disease states. Our results also indicate that the relative expression levels of different isoforms of a miRNA are likely to be dynamic and may change with respect to changes in the cell or differentiation status. [ABSTRACT FROM AUTHOR]

Extramedullary manifestations of acute myeloid leukemia ( AML) were described as early as the 19th century. However, the incidence, clinical significance and pathobiology of extramedullary AML remain ill defined. We reviewed case reports, retrospective case series, pilot studies and imaging studies of extramedullary leukemia ( EML) to determine its frequency, characteristics, clinical presentation and significance. EML precedes or accompanies development of AML and occurs during or following treatment, even during remission. Although imaging studies are rarely conducted and the true incidence of EML has yet to be verified, authors have reported several estimates based on retrospective and autopsy studies. The incidence of EML in patients with AML of all ages is estimated to be about 9% and EML in children with AML was detected in 40% of patients at diagnosis. The combination of positron emission tomography and computed tomography were the most sensitive and reliable techniques of detecting and monitoring EML. Based on our literature review, the frequency of EML is likely underreported. The well-documented nature of EML in patients with AML suggests that AML can manifest as a solid tumor. The extent to which EML accompanies AML and whether EML is derived from bone marrow are unknown. Furthermore, questions remain regarding the role of the microenvironment, which may or may not facilitate the survival and proliferation of EML, and the implications of these interactions with regard to minimal residual disease, tumor cell quiescence and relapse. Therefore, prospective studies of detection and characterization of EML in patients with AML are warranted. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) represents about 15% of all leukemia cases. Although the incidence of the disease is rather low, the therapeutic progress of the last decade has dramatically changed the evolution of this disease, whose survival considerably increased and in whom we now speak even about cure. The success of the therapy is strongly connected to the precocity of the diagnosis and molecular targeted therapy that implies a close monitoring of the patient. The specific molecular assay, that developed a lot in the last years, became an important tool in the management of these patients, providing the possibility of efficient changing in therapy. The purpose of our study was to identify the characteristics of our CML patients in terms of clinical and biological behavior. We analyzed 21 patients diagnosed between October 2007 and December 2010 and compared the data with a histoncal group of patients, also diagnosed in our department between March 2005 and September 2007. We found a better outcome and overall survival in the study group, due to improved diagnosis and monitoring techniques as well as to better access to therapy. [ABSTRACT FROM AUTHOR]

Abstract: The monitoring of minimal residual disease (MRD) through low sensitivity real-time (RT) polymerase chain reaction (PCR) analysis of BCR-ABL transcripts allows early detection of chronic myeloid leukemia (CML) relapse after allogeneic hematopoietic stem cell transplantation (HSCT). The introduction of more sensitive techniques, such as RT quantitative (Q)-PCR, may lead to an overestimation of the risk of CML relapse. In this study, we reviewed the results of peripheral blood RT Q-PCR in CML patients who underwent allogeneic HSCT from 1983 to 2007. In our laboratory, RT Q-PCR analysis was routinely performed since 2002. Eighty-seven of 189 patients had available RT Q-PCR data; 63 patients had at least 3 RT Q-PCR analyses assessable. Fifty-two of 63 patients (83%) had, at least once, detectable transcript levels, but with an BCR-ABL/ABL ratio <.1% defined as .1% confirmed by the finding of Ph+ cells in bone marrow. No patients with persistent undetectable transcripts relapsed (P = .19). Relapse did not correlate with the number of occurrences of

Abstract: Imatinib is a highly effective drug for the treatment of chronic myeloid leukemia (CML) that targets the BCR–ABL kinase. However, a number of patients have CML that is resistant to Imatinib treatment. In this report, we developed AGM130 as a potential therapeutic drug for Imatinib-resistant CML treatment. The AGM130 compound is derived from Indirubin, which is an ingredient of Danggui Longhui Wan and known as a cyclin-dependent kinase (CDK) inhibitor. The water solubility of AGM130 is more enhanced than that of the original form of Indirubin, which has very poor water solubility. Our data showed that the AGM130 compound efficiently decreased the viability of CML-derived K562 cells. Moreover, this compound also efficiently decreased the viability of Imatinib-resistant K562 cells in in vitro and in vivo systems. In addition, like Indirubin, AGM130 also inhibited phosphorylation of retinoblastoma protein (Rb), which is a major substrate of CDK. Conclusively, our data suggest that AGM130 is a strong candidate for treating Imatinib-resistant CML. [Copyright &y& Elsevier]

The introduction of tyrosine kinase inhibitors (TKIs) for chronic myeloid leukemia (CML) led to a dramatic change in the role of allogeneic stem cell transplantation (SCT) with a rapid decline in the number of patients receiving SCT in first chronic phase (CP1). We evaluated 68 consecutive patients in all phases of CML (male/female = 39:29, 27 in CP1), who received SCT from related/unrelated donors (related/unrelated = 23:45) under myeloablative or reduced intensity conditioning (MAC/RIC = 45:23). Forty-eight patients (71 %) received TKIs pre-SCT, 20 patients post-SCT (29 %). Overall survival (OS) of CP1 patients achieved a plateau of 85 % at 10 months. Relapse-free survival (RFS) of CP1 patients was 85 % at 1 and 2 years, and 81 % at 5 years. Multivariate analysis showed adverse OS and RFS for patients transplanted >CP1 (hazard ratio (HR) = 6.61 and 4.62) and those who had grade III-IV aGvHD (HR = 2.45 and 1.82). Patients with advanced CML had estimated OS of 65 and 47 %; and RFS of 41 and 32 % at 1 and 2 years respectively. Therefore, for patients with advanced CML phases, allogeneic SCT provides an acceptable chance of cure. Transplant research should focus on improving conditioning regimens and post-SCT management for this subgroup of CML patients. [ABSTRACT FROM AUTHOR]

Backgroud: Cancer stem cells (CSCs) are proposed to persist in tumors as a distinct population and cause relapse and metastasis by giving rise to new tumors. Development of specific therapies targeted at CSCs holds hope for the improvement of survival and quality of life of cancer patients, especially for sufferers of metastatic disease. This is particularly true in chronic myeloid leukemia (CML). Methods: In this study, we isolated fetal liver kinase-1-positive (Flk1) cells carrying the BCR/ABL fusion gene from the bone marrow of Philadelphia chromosome-positive (Ph) patients with stem cells property. We examined their biological characteristics as well as immunological function and further detected the possible molecular mechanism involved in the leukemia genesis. Results: We showed that CML patient-derived Flk1CD31CD34 MSCs had normal morphology, phenotype and karyotype but appeared impaired immunomodulatory function. The capacity of Flk1CD31CD34 MSCs from CML patients to inhibit T lymphocyte activation and proliferation was impaired in vitro. CML patient-derived MSCs have dampening immunomodulatory functions, suggesting that the dysregulation of hematopoiesis and immune response might originate from MSCs rather than HSCs. These Ph putative CML hemangioblast upregulated TGF-β1 and resultantly activated matrix metalloproteinase-9 (MMP-9) to enhance s-KitL and s-ICAM-1 secretion, which activated c-kit HSCs from the quiescent state to proliferative state. Further studies showed that phosphatidylinositol-3 kinase (PI3K)/Akt/nuclear factor (NF)-κB signaling pathway was involved in CML pathogenesis. Conclusions: Flk1CD31CD34 MSCs that express BCR/ABL leukemia oncogene are CSCs of CML and they play a critical role in the progression of CML through PI3K/Akt/NF-κB/MMP-9/s-ICAM-1/s-KitL signaling pathway beyond HSCs. [ABSTRACT FROM AUTHOR]

Abstract: Chronic myeloid leukemia (CML) is associated with overexpression of BCR-ABL1, a nonreceptor tyrosine kinase critical for malignant transformation. We investigated whether non-coding microRNAs (miRNAs) targeting BCR-ABL1 mRNA contribute to the pathogenesis of CML. Indeed, miR-30a targeted BCR-ABL1 and was underexpressed in bone marrow from CML patients. In K562 leukemia cells, overexpression of miR-30a reduced ABL1 and BCR-ABL1 protein expression, decreased proliferation, and arrested cell cycle progression between G1 and S. These findings strongly suggest that miR-30a acts as a tumor suppressor by downregulating ABL1 and BCR-ABL1 expression. Upregulation of miR-30a in hematopoietic cells may have therapeutic efficacy against CML. [Copyright &y& Elsevier]

A proportion of patients with somatic variants show resistance or intolerance to TKI therapy, indicating additional mutations other than BCR∷ABL1 may lead to TKI treatment failure or disease progression. We retrospectively evaluated 151 CML patients receiving TKI therapy and performed next-generation sequencing (NGS) analysis of 22 CML patients at diagnosis to explore the mutation spectrum other than BCR∷ABL1 affecting the achievement of molecular responses. The most frequently mutated gene was ASXL1 (40.9%). NOTCH3 and RELN mutations were only carried by subjects failing to achieve a major molecular response (MMR) at 12 months. The distribution frequency of ASXL1 mutations was higher in the group that did not achieve MR4.0 at 36 months (p = 0.023). The achievement of MR4.5 at 12 months was adversely impacted by the presence of >2 gene mutations (p = 0.024). In the analysis of clinical characteristics, hemoglobin concentration (HB) and MMR were independent factors for deep molecular response (DMR), and initial 2GTKI therapy was better than 1GTKI in the achievement of molecular response. For the scoring system, we found the ELTS score was the best for predicting the efficacy of TKI therapy and the Socal score was the best for predicting mutations other than BCR∷ABL.

This study aims to evaluate the possibility of tyrosine kinase inhibitors (TKIs) discontinuation in chronic myeloid leukemia (CML) patients who obtained sustained deep molecular response (DMR) and to explore the prognostic role of NK cells in treatment-free remission (TFR). Sixty CML patients who discontinued TKI treatment were enrolled, and we also investigated the immune profiles in 27 CML patients after TKI cessation. Of the 60 patients, the estimated TFR rate was 60.8% [95% CI: 49.5-74.8%] at 12 months. Patients who had longer TKI duration, major molecular response, and DMR maintenance time had a significantly higher TFR rate. And a higher percentage of NKG2A + NK cells and NKG2A + CD56 bright CD16 - NK cells were independent prognostic factors of TFR in multivariate analysis. These results indicate the practicality of the cessation of TKIs and patients with stable NK cell counts accompanied by higher cytotoxicity and increased killing capacity are more inclined to get sustained treatment-free survival.

Objective: To investigate the concerns of adult patients with chronic myeloid leukemia (CML) in the chronic phase receiving tyrosine kinase inhibitor (TKI) therapy in China. Methods: A cross-sectional questionnaire including 23 issues of concern was filled by patients with CML nationwide from August to September 2021. The results were compared with those from 2015 to 2016. Results: Data from 952 questionnaires were analyzed. The five most concerned issues were "TKI-related adverse effects and management" (66%) , "stopping TKI therapy" (46%) , "CML risk assessment" (46%) , "TKI dose reduction" (42%) , and "restrictions in daily life activities" (41%) . Compared with the results from 2015 to 2016, patients paid more attention to "TKI-related adverse effects and management" , "monitoring" , and "interpretation of laboratory reports" (all P <0.01) . Concerns of "TKI reimbursement policies" , "price reduction of TKIs" , and issues related to generic TKIs decreased significantly (all P <0.01) . Multivariate analysis showed that female patients ( OR =1.8, 95% CI 1.4-2.5, P <0.001) , elderly patients ( OR =1.0, 95% CI 1.0-1.0, P <0.001) , or patients with bachelor's degree or higher ( OR =1.8, 95% CI 1.3-2.4, P <0.001) were more concerned with "TKI dose reduction" than others. Patients with a bachelor's degree or higher ( OR =1.6, 95% CI 1.2-2.2, P =0.002) paid more attention to "CML risk assessment" , whereas those currently receiving a second- or third-generation TKI therapy ( OR =1.9, 95% CI 1.3-2.6, P <0.001) were more concerned about "TKI resistance" . Conclusion: Patients with CML paid the most attention to "TKI-related adverse effects and management" , "stopping TKI therapy" , "CML risk assessment" , "TKI dose reduction" , and "restrictions in daily life activities" . Patients' sociodemographic covariates and treatment status were associated with their concerns.

Signal transducers and activators of transcription (STAT) proteins are latent cytoplasmic transcription factors that affect several cellular processes including cell growth, proliferation, differentiation, and survival. Following phosphorylation, STATs are activated, and their upregulated expressions increase in malignancies with playing a role in the development of leukemia. In this study, transfection of K-562 cells with either unmodified or chemically modified anti-STAT3, -STAT5A, -STAT5B siRNAs for duration of 12 days, determining gene silencing at mRNA and protein levels, evaluating apoptosis rate, and detecting JAK/STAT pathway members' gene expression profiles via array method were aimed. Quantitative RT-PCR and Western blot assays indicated that STAT expressions were downregulated both at mRNA and protein levels, and TUNEL assay showed that leukemic cell apoptosis was induced due to inhibition of STATs. Array analysis resulted with decreases in signal transducer, phosphorylation inducer, and oncogene expressions, whereas increased expressions in STAT inhibitor and apoptosis inducer genes were observed. These results point out that siRNA application could constitute a new and alternative curative method for supporting therapy of CML-diagnosed patients in the future. [ABSTRACT FROM AUTHOR]

The approval of dasatinib and nilotinib for first line treatment of chronic myeloid leukemia (CML) in chronic phase (CP) opened new therapeutic options. However, their role in this setting is yet undefined and additionally recent landmark studies have laid ground to re-discuss which response milestones are relevant for treatment guidance. Thus, updated data on these issues at last year's ASH meeting were expected to potentially hint to what the new management standards might be. This short review briefly summarizes the respective evidence for (a) the outcome predictive value of early and deep molecular responses, (b) the superiority of second generation tyrosine kinase inhibitors (TKIs) to imatinib with regard to cytogenetic and molecular response rates, (c) the (yet) lacking proof of a survival benefit of second generation TKIs and (d) the role of new TKIs and alternative treatment strategies. Chronic myeloid leukemia (CML) has become a paradigm for targeted medicine; however, despite their impressive therapeutic success, TKIs offer disease control rather than disease eradication. The development of second generation TKIs broadened therapeutic options and consecutively disease management recommendations focused on response monitoring to guide change of treatment upon patient's individual failure to respond. This short review will focus on ASH updates on second generation TKIs in first line treatment, potential future definitions of response milestones, and briefly on new TKIs and alternative TKI treatment concepts. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) represents a rare myeloproliferative disease among children where allogeneic stem cell transplantation (SCT) remains the curative gold standard. However, the impressive early cytogenetic and molecular responses achieved by tyrosine kinase inhibitors [TKIs (imatinib, nilotinib, and dasatinib)] as first-line or even sole treatment in adults, has led to their increasing use also among children. Due to limited data regarding long-term results of TKIs and especially those of second generation in pediatric cohorts, we would like to add clinical information in this rare series of patients by reporting on four children with CML over a 10-year period, focusing on TKIs, dose escalations and clinical responses. [ABSTRACT FROM AUTHOR]

The treatment of chronic myeloid leukemia (CML) was revolutionized by the introduction of the targeted tyrosine kinase inhibitor (TKI) imatinib mesylate. Later, to improve efficacy and tolerability, the more potent TKIs dasatinib and nilotinib were evaluated in CML. Clinicians comparing the clinical efficacy of TKIs face considerable challenges, including the variable treatment histories of patients receiving second-line therapy. The aim of this review is to highlight the pitfalls and possible solutions for comparing efficacy across disparate CML trials. Comparison of efficacy across trials is aided by careful consideration of possible confounding factors, including treatment history, definitions of imatinib intolerance or resistance, and BCR-ABL mutational status at baseline. However, methods exist to improve the comparability of data from different trials, yielding a more clinically and statistically meaningful inter-trial comparison. [ABSTRACT FROM AUTHOR]

Optimal responses during imatinib therapy are commonly defined following the European LeukemiaNet (ELN) recommendations. Achievements of these optimal responses have not, however, been comprehensively tested as response-related prognostic factors using single center data sets. We evaluated the parameters using long-term (median 63 months) outcomes from 363 chronic phase chronic myeloid leukemia patients treated with imatinib as frontline therapy at our center. Intention-to-treat analysis showed comparable rates of complete cytogenetic response (86 %), major molecular response (MMR, 54 %), and complete molecular response (MR, 8 %). Estimated overall survival, progression-free survival, and event-free survival at 7 years were 94, 88 and 84 %, respectively. Achievement of recommended optimal response at 6 months (major cytogenetic response) and 12 months (complete cytogenetic response) yielded significantly better overall, progression-free, and event-free survival. However, achievement of recommended optimal response at 18 months (MMR) provided marginal benefit only in event-free survival. Most ELN criteria were predictive of long-term outcomes, with the exception of the clinical significance of achieving MMR at 18 months. Treatment adherence in the early treatment period was one of the important independent predictors of favorable long-term outcome. Durable cytogenetic and molecular responses were maintained in a majority of patients treated with optimal dose intensity. [ABSTRACT FROM AUTHOR]

Abstract: Nilotinib is a rationally designed tyrosine kinase inhibitor with improved specificity and binding affinity for BCR-ABL compared with imatinib. Nilotinib is approved in patients with imatinib-resistant and -intolerant Philadelphia chromosome-positive chronic myeloid leukemia (CML), as well as in patients with newly diagnosed CML. Nilotinib is generally well tolerated, with mild and manageable side effects, and is associated with some adverse events that require management to insure patient adherence to therapy and optimal treatment outcomes. The objectives of this article are to review the clinical management of the most frequent of these adverse events and to guide physicians in helping their patients maintain adherence and achieve optimal outcomes with nilotinib therapy. [Copyright &y& Elsevier]

Background: The so-called Philadelphia (Ph) chromosome is present in more than 90% of chronic myeloid leukemia (CML) cases. It results in juxtaposition of the 5′ part of the BCR gene on chromosome 22 to the 3′ part of the ABL gene on chromosome 9. Since the majority of CML cases are currently treated with Imatinib, variant rearrangements in general have no specific prognostic significance, although the mechanisms involved in resistance to therapy have yet to be investigated. The T315I mutation within the abl-gene is the most frequent one associated with resistance to tyrosine kinase inhibitors. Results: This study evaluated a Ph chromosome positive CML case resistant to imatinib mesylate. A dic(17;18), loss of TP53 gene, co-expression of b2a2 and b3a2 fusions transcript and a T315I mutation were found. Conclusions: We reported here a novel case of a Ph chromosome positive CML with a secondary abnormality [dic(17;18)], resulting to Glivec resistance but good response to nilotinib. The dic(17;18) might be a marker for poor prognosis in CML. Our finding indicated for an aggressive progression of the disease. The patient died under the treatment due to unknown reasons. [ABSTRACT FROM AUTHOR]

Background: Resistance to tyrosine kinase inhibitors (TKIs) remains a challenge in management of patients with chronic myeloid leukemia (CML). A better understanding of the BCR-ABL signalling network may lead to better therapy. Findings: Here we report the discovery of a novel downstream target of BCR-ABL signalling, PRL-3 (PTP4A3), an oncogenic tyrosine phosphatase. Analysis of CML cancer cell lines and CML patient samples reveals the upregulation of PRL-3. Inhibition of BCR-ABL signalling either by Imatinib or by RNAi silencing BCR-ABL reduces PRL-3 and increases cleavage of PARP. In contrast, the amount of PRL-3 protein remains constant or even increased in response to Imatinib treatment in drug resistant cells expressing P210 T315I. Finally, analysis with specific shRNA shows PRL-3 involvement in the proliferation and self-renewal of CML cells. Conclusions: These data support a role for PRL-3 in BCR-ABL signalling and CML biology and may be a potential therapeutic target downstream of BCR-ABL in TKI resistant mutant cells. [ABSTRACT FROM AUTHOR]

Recently novel treatment modalities has focused on targeted therapies. Tyrosine kinases represent a good target for cancer treatment since they are involved in transferring phosphate groups from ATP to tyrosine residues in specific substrate proteins transducing intracellular signals engaged in the many mechanisms, playing an important role in the modulation of growth factors signaling that are strongly related to carcinogenesis. Deregulation of tyrosine kinases activity was also found in hematological malignancies, particularly overexpression of tyrosine kinases was observed in chronic myeloid leukemia or acute lymphoblastic leukemia. Herein we show that tyrosine kinase inhibitors have revolutionized hematology malignancies therapy in a very short period of time and they still remain one of the most interesting anticancer compounds that could give a hope for cure and not only long-lasting complete remission. This manuscript summarizes current view on the first generation tyrosine kinase inhibititor - imatinib, second generation - dasatinib, nilotinib and bosutnib as well as new generation tyrosine kinase inhibititors - ponatinib and danusertib in hematooncology [ABSTRACT FROM AUTHOR]

Objective: The Philadelphia (Ph) chromosome, consisting of the t(9;22)(q34;q11) translocation, is observed in ~90% of patients with chronic myeloid leukemia (CML). Variant Ph translocations are observed in 5%-10% of CML patients. In variant translocations 3 and possibly more chromosomes are involved. Herein we report 6 CML patients with variant Ph translocations. Materials and Methods: Bone marrow samples were examined using conventional cytogenetic meth ods. Fluorescence in situ hybridization (FISH) with whole-chromosome paints and BCR-ABL 1D probes were used to confirm and/or complement the findings, and identify rearrangements beyond the resolution of conventional cytogenetic methods. Results: Variant Ph translocations in the 6 patients were as follows: t(7;22)(p22;q11), t(9;22;15) (q34;q11;q22), t(15;22)(p11;q11), t(1;9;22;3)(q24;q34;q11;q21), t(12;22)(p13;q11), and t(4;8;9;22) (q11;q13;q34;q11). Conclusion: Among the patients, 3 had simple and 3 had complex variant Ph translocations. Two of the presented cases had variant Ph chromosomes not previously described, 1 of which had a new complex Ph translocation involving chromosomes 1, 3, 9, 22, and t(1;9;22;3)(q24;q34;q11;q21) apart from a clone with a classical Ph, and the other case had variant Ph translocation with chromosomes 4, 8, 9, and 22, and t(4;8;9;22)(q11;q13;q34;q11) full complex translocation. Number of studies reported that some patients with variant Ph translocation were poor responders to imatinib. All of our patients with variant Ph translocations had suboptimal responses to imatinib, denoting a poor prognosis also. Variant Ph translocations may be important as they are associated with prognosis and therapy for CML patients. [ABSTRACT FROM AUTHOR]

Aim. This is a case report of a 51 year old male with marked splenomegaly, basophilia, severe thrombocytopenia, anemia and high SFKL phosphorylation downstream of Bcr-Abl, investigated for association of the e6a2 BCR-ABL fusion gene and marked basophilia. The treatment strategy implications in patients with Philadelphia positive CML are described. Methods. RT-PCR and sequencing were carried out on the peripheral blood leukocytes to detect the type of BCR-ABL transcript. The BCR-ABL mutational status was assessed using sequencing of the RT-PCR products. The in vitro test of sensitivity to TKIs was based on detecting inhibited phosphorylation of the Crkl and Phospho-Src family kinases (SFK, Tyr416) using immunodetection. Results. The cytogenetics revealed 90% of Ph+ (Philadelphia) cells in the bone marrow aspirate with no additional clonal chromosomal abnormalities at diagnosis. This correlated with an accelerated phase of the CML. Sequencing analysis of reverse transcribed and PCR amplified BCR-ABL transcript revealed a rare e6a2 fusion, with no evidence for Bcr-Abl kinase domain mutation. Western blot analysis showed high phosphorylation (activation) of Crkl and the Src family of kinases (P-SFK). In vitro test of sensitivity of the patients' leukemic cells to imatinib demonstrated sensitivity of Bcr-Abl tyrosine kinase to imatinib, as assessed by a decrease in phosphorylated Crkl and the disappearance of P-SFK, suggesting that P-Src reflects only the Bcr-AbL-dependent Src activity. The initial treatment strategy was reduced imatinib and search for an unrelated hematopoietic stem cell donor (according to the ELN recommendations). The patient was allografted with peripheral stem cells from an HLA- identical male donor but on day +70 graft failure occurred. He was allografted again with the peripheral stem cells from an HLA-identical female donor, engrafted on day +15 and showed 100% donor chimerism with no evidence of the e6a2 BCR-ABL fusion transcript on day +30. Conclusion. The clinical disease course in patients with the rare e6a2 BCR-ABL transcript variant is aggressive. This may be the result of increased kinase activity due to partial loss of the guanine exchange factor/dbl-like domain which mediates the interaction with several Ras-like G-proteins involved in cell proliferation, signal transduction, and cytoskeletal organization. For the above reasons, these patients should receive stem cell transplant immediately after a short course of treatment with imatinib/ dual Src/Abl kinase inhibitor or they should be registered in clinical trials with experimental agents. [ABSTRACT FROM AUTHOR]

Abstract: Nonadherence has been shown to be frequent amongst chronic myeloid leukemia (CML) patients prescribed imatinib, which results in reduced clinical response and increased healthcare costs. However, little is known about the reasons why CML patients frequently do not take their imatinib as prescribed. The current study explored CML patients’ experience of taking, or not taking, imatinib therapy through in-depth interviews with twenty-one patients. Their adherence had been previously measured using a medication events monitoring device. The interviews were recorded, transcribed and analysed in accordance with established techniques. Patients revealed a variety of reasons for their nonadherence. Major themes that emerged from the data were the intentional and unintentional reasons for nonadherence. Furthermore, as a result of information received from health care professionals, several patients felt inappropriately reassured that their nonadherence would not have a detrimental effect on their clinical response. Factors that seemed to favour adherence were finding ways to deal with side effects and using prompts as reminders to take the medicine. This study forms a basis on which to build future adherence research and may help to develop interventions designed to ensure that patients with CML and other cancers adhere optimally to their oral drugs treatment. [Copyright &y& Elsevier]

Circadian clock genes use transcriptional-translational feedback loops to control circadian rhythms. Recent studies have demonstrated that expression of some circadian clock genes displays daily oscillation in peripheral tissues including peripheral blood and bone marrow. Circadian rhythms regulate various functions of human body, and the disruption of circadian rhythm has been associated with cancer development and tumor progression. However, the direct links between aberrant circadian clock gene expression and human disorders remain largely unknown. In this study, comparisons were made between the expression profiles of 9 circadian clock genes from peripheral blood mononuclear cells (PBMCs) and polymorphonuclear cells (PMNs) from 18 healthy volunteers. Peripheral blood (PB) total leukocytes from 54 healthy volunteers and 95 patients with chronic myeloid leukemia (CML) were also investigated. Similar expression profiles of all 9 circadian clock genes were observed in PBMCs and PMNs of healthy individuals. In PB total leukocytes of healthy individuals, the daily pattern of PER1, PER2, PER3, CRY1, CRY2, and CKIε expression level peaked at 0800 h, and BMAL1 peaked at 2000 h. Daily pattern expression of these 7 genes was disrupted in newly diagnosed pre—imatinib mesylate—treated and blast crisis—phase patients with CML. Partial daily pattern gene expression recoveries were observed in patients with CML with complete cytogenetic response and major molecular response. The expression of CLOCK and TIM did not show a time-dependent variation among the healthy and patients with CML. These results indicate a possible association of the disrupted daily patterns of circadian clock gene expression with the pathogenesis of CML. [ABSTRACT FROM PUBLISHER]

BACKGROUND: The current study was conducted to compare simultaneously obtained bone marrow (BM) cytogenetics (CTG), peripheral blood (PB) and BM fluorescence in situ hybridization (FISH), and quantitative real-time polymerase chain reaction (Q-PCR) for BCR-ABL1 in monitoring response to treatment with tyrosine kinase inhibitors and homoharringtonine (HHT) in patients with chronic myeloid leukemia (CML). METHODS: PB and BM FISH (n = 112 samples) and/or Q-PCR (n = 132 samples) for BCR-ABL1 were simultaneously obtained in 70 patients with Philadelphia chromosome-positive (Ph+) CML in chronic (68%), accelerated (16%), and blast phase (16%) before the initiation of therapy and during the course of treatment with imatinib (IM) (n = 40 patients), dasatinib (n = 20 patients), nilotinib (n = 4 patients), bosutinib (n = 18 patients), or HHT (n = 4 patients) for patients with newly diagnosed (n = 13 patients), IM-sensitive (n = 34 patients), IM-resistant (n = 30 patients), or IM-intolerant (n = 9 patients) disease. Eighteen patients were found to have Ph+ variants or karyotypic abnormalities in addition to the Ph+. RESULTS: Excellent correlations (r) were observed between PB and BM FISH (r = 0.95) and PB and BM Q-PCR (r = 0.87), as well as BM CTG and PB FISH (r = 0.89) and PB Q-PCR (r = 0.82). This correlation was not affected by the presence of the Ph+ variant or additional chromosomal abnormalities, the presence of ABL1 kinase domain mutations, phase of the disease, or treatment. CONCLUSIONS: PB FISH and Q-PCR appear to be reliable methods with which to monitor response to modern therapy in patients with all phases of CML. [ABSTRACT FROM AUTHOR]

We describe a young man who presented with neurological signs and symptoms, and with a paraspinal soft tissue mass involving the vertebral body at T4. The patient was treated with dexamethasone prior to neurosurgical decompression and debulking. Biopsy showed features of a small B-cell lymphoma possibly of follicle center cell origin. The patient achieved complete remission with radiotherapy. However, he experienced relapse 10 months later with a soft tissue mass close to and involving the posteroinferior aspect of the sternum. Biopsy of the recurrent lesion showed features of B lymphoblastic leukemia/lymphoma. The first biopsy was revisited to demonstrate the lymphoblastic immunophenotype of the lesional cells. The 'indolent' appearance of the cells in the first biopsy was attributable to treatment with dexamethasone prior to the biopsy. [ABSTRACT FROM AUTHOR]

STAT proteins are cytoplasmic transcription factors that are involved in the regulation of numerous cellular activities such as cell growth, differentiation, and survival. In this study, we aimed to identify the expression pattern of STAT genes in imatinib-sensitive and -resistant K562 cells, and further, to reveal the effects of STAT5A siRNA knockdown on cell growth and apoptosis induction. The XTT cell proliferation assay showed that both sensitive and resistant K562 cells were sensitized to imatinib upon transfection with STAT5A siRNA. Caspase-3 enzyme activity was increased significantly in both cells. These results may open up new opportunities to overcome chemotherapeutic resistance in leukemia. [ABSTRACT FROM AUTHOR]

Copyright of Der Onkologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the recent changes in the indication to allogeneic stem cell transplantation (SCT) in chronic myeloid leukemia (CML), we retrospectively analyzed 1,716 patients with different CML stages who received an allograft from related ( n = 767) or unrelated donors ( n = 938) within the German Registry of Stem Cell Transplantation (DRST) from 1998 to 2004. Myeloablative conditioning was performed in 724/871 cases (83%), dose-reduced conditioning in 147/871 (17%). Annual transplantations were decreasing from 357 to 98 (28%) in the period of study, but the proportion of advanced cases was increasing from 32% (112/346) to 53% (50/94) of all SCTs. Stage of disease, intervals from diagnosis, and patients’ age were independent prognostic parameters, while peripheral stem cells and unrelated transplantation seemed equal to bone marrow/related transplantation. This study demonstrates that allo-SCT still has an important role in advanced CML, which emphasizes the need for optimized transplantation strategies for these high-risk patients. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) is a lethal hematological disorder caused by the p210Bcr−Abl oncogene. Previous studies have suggested that p210Bcr−Abl transformation contributes to homing and retention defects, typical of immature myeloid cells in CML, by attenuating chemotactic response to stromal-derived factor-1α (SDF-1α). As Rho family GTPases are key regulators of the cytoskeleton and have been previously found to interact with p210Bcr−Abl, this study aimed to determine whether p210Bcr−Abl signaling affects SDF-1α chemotaxis through Rho GTPase signaling. We found that SDF-1α stimulated Cdc42 GTPase activation in myeloid progenitor 32D, but not in p210Bcr−Abl-transformed (32Dp210) cells. In fact, the basal level of active Cdc42 was elevated in 32Dp210 cells and mononuclear cells isolated from bone marrow of CML patients. Inhibition of p210Bcr−Abl kinase activity decreased basal Cdc42 activity and restored SDF-1α-induced Cdc42 and migration responses. Transduction of active Tat-Cdc42V12 abolished this reconstituted chemotactic response. As Cdc42 is particularly important in cytoskeletal remodeling and directional sensing, these results suggest that sustained activation of Cdc42 GTPase through p210Bcr−Abl tyrosine kinase signaling in CML cells contributes to defects in SDF-1α-chemotactic response due to desensitization of the actin polarization signal required for directional migration. [ABSTRACT FROM AUTHOR]

The mechanism that is responsible for mature neutrophil overproduction in the chronic phase (CP) of chronic myeloid leukemia (CML), a neoplastic disease of hematopoietic stem cells carrying a constitutively active tyrosine kinase BCR–ABL, remains obscure. In this study, microarray analysis revealed that c-Jun, a monopoiesis-promoting transcription factor, was downregulated in CML neutrophils. BCR–ABL directly inhibited c-Jun expression, as c-Jun downregulation in primary CML neutrophils and in the CML blast cell lines, KCL22 and K562, was reversed by the tyrosine kinase inhibitor imatinib. We established a myeloid differentiation model in KCL22 cells using zinc-inducible CCAAT/enhancer-binding protein (C/EBP)α (KCL22/α). Myeloid differentiation was observed in C/EBP-induced KCL22/α cells. Imatinib-induced c-Jun upregulation promoted the monocytic differentiation of KCL22/α cells. c-Jun knockdown in KCL22/α cells by a short interfering RNA redirected their differentiation from the monocytic to the neutrophilic lineage, even after imatinib treatment. A blockade of PI3K-Akt signaling with an Akt inhibitor upregulated c-Jun and induced the monocytic differentiation of KCL22, K562, and C/EBP-induced KCL22/α cells. Thus, BCR–ABL downregulates c-Jun expression by activating the PI3K-Akt pathway during CML-CP, thereby allowing C/EBPs to promote neutrophil differentiation. [ABSTRACT FROM AUTHOR]

Here we demonstrated that the ‘loss of function’ of not-rearranged c-ABL in chronic myeloid leukemia (CML) is promoted by its cytoplasmic compartmentalization bound to 14-3-3 sigma scaffolding protein. In particular, constitutive tyrosine kinase (TK) activity of p210 BCR-ABL blocks c-Jun N-terminal kinase (JNK) phosphorylation leading to 14-3-3 sigma phosphorylation at a critical residue (Ser186) for c-ABL binding in response to DNA damage. Moreover, it is associated with 14-3-3 sigma over-expression arising from epigenetic mechanisms (promoter hyper-acetylation). Accordingly, p210 BCR-ABL TK inhibition by the TK inhibitor Imatinib mesylate (IM) evokes multiple events, including JNK phosphorylation at Thr183, p38 mitogen-activated protein kinase (MAPK) phosphorylation at Thr180, c-ABL de-phosphorylation at Ser residues involved in 14-3-3 binding and reduction of 14-3-3 sigma expression, that let c-ABL release from 14-3-3 sigma and nuclear import, and address BCR-ABL-expressing cells towards apoptotic death. Informational spectrum method (ISM), a virtual spectroscopy method for analysis of protein interactions based on their structure, and mathematical filtering in cross spectrum (CS) analysis identified 14-3-3 sigma/c-ABL binding sites. Further investigation on CS profiles of c-ABL- and p210 BCR-ABL-containing complexes revealed the mechanism likely involved 14-3-3 precluded phosphorylation in CML cells. [ABSTRACT FROM AUTHOR]

Gfi1b is a transcriptional repressor that is essential for erythroid cells and megakaryocytes, but is also expressed in hematopoietic stem cells and early myeloid progenitors. The chromosomal localization of the Gfi1b gene at 9q34 and its functional homology with the proto-oncogene Gfi1 were suggestive for a role of Gfi1b in malignant transformation and myeloid leukemia. We show here that the expression of Gfi1b is strongly elevated in CML and AML patients compared to normal healthy controls and that imatinib, a drug widely used to treat CML, further enhances Gfi1b expression in patients even after remission. Our data suggest that Gfi1b may be an important factor to establish or maintain myeloid leukemia and myeloproliferative diseases and that, high expression levels of Gfi1b might be associated with the emergence of Philadelphia chromosome negative myeloid malignancies after imatinib withdrawal or after the development of imatinib resistance. [ABSTRACT FROM AUTHOR]

Abstract: The heat shock protein 90 (Hsp90) plays a crucial role in the stability of several proteins that are essential for malignant transformation. Hsp90 is therefore an interesting therapeutic target for cancer therapy. In this paper, we investigated whether an oxidative stress generated during ascorbate-driven menadione redox cycling (ascorbate/menadione), affects Hsp90 leading to the degradation of some critical proteins and cell death. Unlike 17-AAG, which inhibits Hsp90 but enhances Hsp70 levels, ascorbate/menadione-treated cells present an additional Hsp90 protein band of about 70kDa as shown by Western blot analysis, suggesting Hsp90 cleavage. This Hsp90 cleavage seems to be a selective phenomenon since it was observed in a large panel of cancer cell lines but not in non-transformed cells. Antibodies raised against either the N-terminus or the C-terminus domains of Hsp90 suggest that the site of cleavage should be located at its N-terminal part. Furthermore, antibodies raised against either the α- or the β-Hsp90 isoform show that Hsp90β is cleaved while the α isoform is down-regulated. We have further shown that different Hsp90 client proteins like Bcr-Abl (a chimerical protein expressed in K562 leukemia cells), RIP and Akt, were degraded when K562 cells were exposed to an oxidative stress. Both Hsp90 cleavage and Bcr-Abl degradation were observed by incubating K562 cells with another H2O2-generating system (glucose/glucose oxidase) and by incubating KU812 cells (another leukemia cell line) with ascorbate/menadione. Due to the major role of Hsp90 in stabilizing oncogenic and mutated proteins, these results may have potential clinical applications. [Copyright &y& Elsevier]

The neurological complications are frequent in patients with hematological syndromes such as: myeloproliferative diseases, malignant diseases of lymphoid cells, plasmocytic diseases, transfusion biology and therapy, bone marrow and stem cell transplantation, disorders of the platelet and vessel wall, disorders of coagulation and thrombosis, hypoproliferative anemias, hemoglobinopathies, megaloblastic anemias, hemolytic anemias and acute blood loss, aplastic anemia, myelodysplasia and related bone marrow syndrome. We proposed a synthetic review in two parts of the neurological complications in hemato-oncologic diseases that are present not only in relation with hematological disease itself, but in relation with systemic and intrathecal chemotherapy, radiotherapy and stem cell transplantation during the course and follow-up of the hemato-oncologic patient. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) in Asia has an incidence rather lower than in Western countries yet tends to afflict a younger population. As in the West, imatinib mesylate (IM, Glivec) has supplanted busulphan, hydroxyurea and interferon-α as first-line treatment. Its use has resulted in a dramatic decline in the number of hematopoietic stem cell transplantations (HSCT) performed. Although it is expensive, IM induces a complete cytogenetic response in 60–90% of newly diagnosed patients, and up to 10% for those in blastic phase. The standard dose of 400 mg is well tolerated by most patients, although adverse events have been observed, including drug-induced cytopenia. Through the Glivec International Patient Assistance Program, the majority of CML patients has access to IM and can expect prolonged survival, even in the absence of HSCT. However, just as in Western countries, resistance to imatinib has emerged in Asian countries. They will require the novel tyrosine kinase inhibitors (dasatinib, nilotinib) becoming available through either clinical trials or market approval. This review examines the available data on CML in China, Hong Kong, India, the Philippines, Singapore, South Korea, Taiwan and Thailand. [ABSTRACT FROM AUTHOR]

Abstract: Single nucleotide polymorphism (SNP) serve as frequent genetic markers along the chromosome. They can, however, have important consequences for individual susceptibility to disease and reactions to medical treatment. Also, genetics of the human phenotype variation could be understood by knowing the functions of these SNPs. Currently, a vast literature exists reporting possible associations between SNPs and diseases. It is still a major challenge to identify the functional SNPs in a disease related gene. In this work, we have analyzed the genetic variation that can alter the expression and the function in chronic myeloid leukemia (CML) by ABL1 gene through computational methods. Out of the total 827 SNPs, 18 were found to be non-synonymous (nsSNPs). Among the 30 SNPs in the untranslated region, 3 SNPs were found in 5′ and 27 SNPs were found in 3′ untranslated regions (UTR). It was found that 16.7% nsSNPs were found to be damaging by both SIFT and PolyPhen server. UTR resource tool suggested that 6 out of 27 SNPs in the 3′ UTR region were functionally significant. The two major mutations that occurred in the native protein (1OPL) coded by ABL1 gene were at positions 159 (L→P) and 178 (G→S). Val (6), Ala (7) and Trp (344) were found to be stabilizing residues in the native protein (1OPL) coded by ABL1 gene. Even though all the three residues were found in the mutant protein 178 (G→S), only two of them Val (6) and Ala (7) were acting as stabilizing residue in another mutant 159 (L→P). We propose from the overall results obtained in this work that, both the mutations 159 (L→P) and 178 (G→S) should be considered important in the chronic myeloid leukemia caused by ABL1 gene. Our results on this computational study will find good application with the cancer biologist working on experimental protocols. [Copyright &y& Elsevier]

Deletions of the CDKN2A/B tumor suppressor locus and of the IKAROS and PAX5 genes that promote B-lineage development occur frequently in lymphoid, but not myeloid leukemias initiated by the BCR-ABL tyrosine kinase. Why is this the case, and how do these genetic lesions contribute to an aggressive disease that fails to durably respond to targeted kinase inhibitors? [ABSTRACT FROM AUTHOR]