Breakpoint Cluster region-Abelson Murine Leukemia Research Articles

Atypical presentation of chronic myeloid leukemia with e13a2 BCR-ABL1 fusion transcript in a young male

Chronic myeloid leukemia (CML) is usually a disease of the elderly population characterized by a clonal hematopoietic progenitor cell disorder propelled by the product of the breakpoint cluster region-Abelson murine leukemia (BCR-ABL) chimeric gene, known as the Philadelphia chromosome. It occurs due to a balanced reciprocal translocation between the long arms of chromosomes 9 and 22, which codes for tyrosine kinase. The incidence of CML increases with age, and the median age of diagnosis in Western countries is 64 years. The most common finding at presentation is abdominal pain due to splenomegaly which is present in about half of the patients. We present a rare case of CML in the chronic phase where a young 23-year-old male presented with complaints of severe bilateral lower limb bone pain restricting mobility at the hip joint for 1 year. The upper end of the femur showed heterogeneous areas of bone infarct on the technetium 99 m-methylene diphosphonate bone scan. He was treated with imatinib mesylate, and he entered remission within 5 months of starting therapy. This case highlights the atypical presentation of the chronic phase of CML with the e13a2 BCR-ABL fusion transcript in a young patient and the complete recovery achieved with standard therapy.

Frequency of BCR-ABL Gene Translocation in B-ALL Patients Associated with Clinicopathological Parameters

Background: B-Acute Lymphoblastic Leukemia (B-ALL) accounts for 25% of childhood malignancies. Chromosomal abnormalities like translocations lead to the formation of oncogenes, some of which are strong predictors of prognosis and response to anti-leukemic therapy. This study aimed to find out the frequency of BCR-ABL gene translocation in B-ALL patients by fluorescence in situ hybridization (FISH) and its association with their clinicopathological parameters. Methods: Patients (n=150) aged 1-17 years with a confirmed diagnosis of B-ALL were selected. Peripheral blood and/or bone marrow aspirate samples were obtained and Breakpoint cluster region-Abelson murine leukemia viral oncogene (BCR-ABL) translocation by FISH was observed. The patient’s demographics, hemoglobin levels, total leucocytes count, platelet count, FISH results, CNS status and risk stratification were recorded. Data was stratified and the Chi-square test was applied, p-value < 0.05 was considered statistically significant. Results: There were 100 (66.67%) males and 50 (33.33%) females. The average age of the patients was 7.03±4.51 years. The frequency of BCR-ABL translocation in B-ALL was 16(10%). A significant association was found between age and BCR-ABL translocation (p-value <0.05), however, an insignificant association was recorded among gender, Hb levels, TLC, platelet count, CNS status, proposed risk stratification system of B-ALL and BCR-ABL translocation (p-value >0.05). Conclusion: The frequency of BCR-ABL translocation in B-ALL was significantly high in the targeted population. FISH improves detection of the BCR-ABL translocation in either metaphase or interphase cells. Therefore, BCR-ABL expression can be considered as a prognostic approach and assist in effective treatment planning and better management of these children. Keyword: Leukemia; In Situ Hybridization; Fluorescence; Pathology.

8-Hydroxydaidzein Downregulates JAK/STAT, MMP, Oxidative Phosphorylation, and PI3K/AKT Pathways in K562 Cells.

A metabolite isolated from fermented soybean, 8-hydroxydaidzein (8-OHD, 7,8,4′-trihydroxyisoflavone, NSC-678112), is widely used in ethnopharmacological research due to its anti-proliferative and anti-inflammatory effects. We reported previously that 8-OHD provoked reactive oxygen species (ROS) overproduction, and induced autophagy, apoptosis, breakpoint cluster region-Abelson murine leukemia viral oncogene (BCR-ABL) degradation, and differentiation in K562 human chronic myeloid leukemia (CML) cells. However, how 8-OHD regulates metabolism, the extracellular matrix during invasion and metastasis, and survival signaling pathways in CML remains largely unexplored. High-throughput technologies have been widely used to discover the therapeutic targets and pathways of drugs. Bioinformatics analysis of 8-OHD-downregulated differentially expressed genes (DEGs) revealed that Janus kinase/signal transducer and activator of transcription (JAK/STAT), matrix metalloproteinases (MMPs), c-Myc, phosphoinositide 3-kinase (PI3K)/AKT, and oxidative phosphorylation (OXPHOS) metabolic pathways were significantly altered by 8-OHD treatment. Western blot analyses validated that 8-OHD significantly downregulated cytosolic JAK2 and the expression and phosphorylation of STAT3 dose- and time-dependently in K562 cells. Zymography and transwell assays also confirmed that K562-secreted MMP9 and invasion activities were dose-dependently inhibited by 8-OHD after 24 h of treatment. RT-qPCR analyses verified that 8-OHD repressed metastasis and OXPHOS-related genes. In combination with DisGeNET, it was found that 8-OHD’s downregulation of PI3K/AKT is crucial for controlling CML development. A STRING protein–protein interaction analysis further revealed that AKT and MYC are hub proteins for cancer progression. Western blotting revealed that AKT phosphorylation and nuclear MYC expression were significantly inhibited by 8-OHD. Collectively, this systematic investigation revealed that 8-OHD exerts anti-CML effects by downregulating JAK/STAT, PI3K/AKT, MMP, and OXPHOS pathways, and MYC expression. These results could shed new light on the development of 8-OHD for CML therapy.

A Multi-disciplinary Approach to Managing Chronic Myelogenous Leukemia Patients on Oral Anticancer Therapy at a Large Academic Medical Center.

Since the discovery of imatinib, an oral breakpoint cluster region-Abelson murine leukemia tyrosine kinase inhibitor, chronic myelogenous leukemia transformed from a hematologic malignancy primarily treated with intravenous chemotherapy to a disease almost solely managed with oral agents. While certainly there are benefits to taking a medication at home, this change in treatment modality also came with unique challenges, including patient adherence, medication acquisition and cost, and toxicity management. Pharmacists are uniquely equipped to assist with educating patients, safe prescribing, and access to medications. Several studies have described the benefits of an integrated oral anticancer medication management program in the ambulatory setting, including improvements in patient adherence, side effect management, patient comprehension, and drug-interaction detection. Pharmacists are also specially trained to assist with medication dose adjustments, relative lab monitoring, and co-pay assistance. Here, we describe the multidisciplinary workflows established to manage oral therapies in chronic myelogenous leukemia patients in a malignant hematology clinic at a large academic medical center. By using the unique talents of the clinic pharmacist, clinic nurse, and specialty retail pharmacy group, patients can be triaged to help ensure the correct skill set is used to optimally care for patients. An acuity-based monitoring structure can improve the ability to reach and safely monitor a large volume of patients.

Hierarchical distribution of somatic variants in newly diagnosed chronic myeloid leukaemia at diagnosis and early follow-up.

There is an emerging body of evidence that patients with chronic myeloid leukaemia (CML) may carry not only breakpoint cluster region-Abelson murine leukaemia viral oncogene homologue 1 (BCR-ABL1) kinase domain mutations (BCR-ABL1 KD mutations), but also mutations in other genes. Their occurrence is highest during progression or at failure, but their impact at diagnosis is unclear. In the present study, we prospectively screened for mutations in 18 myeloid neoplasm-associated genes and BCR-ABL1 KD in the following populations: bulk leucocytes, CD34+ CD38+ progenitors and CD34+ CD38- stem cells, at diagnosis and early follow-up. In our cohort of chronic phase CML patients, nine of 49 patients harboured somatic mutations in the following genes: six ASXL1 mutations, one SETBP1, one TP53, one JAK2, but no BCR-ABL1 KD mutations. In seven of the nine patients, mutations were detected in multiple hierarchical populations including bulk leucocytes at diagnosis. The mutation dynamics reflected the BCR-ABL1 transcript decline induced by treatment in eight of the nine cases, suggesting that mutations were acquired in the Philadelphia chromosome (Ph)-positive clone. In one patient, the JAK2 V617F mutation correlated with a concomitant Ph-negative myeloproliferative neoplasm and persisted despite a 5-log reduction of the BCR-ABL1 transcript. Only two of the nine patients with mutations failed first-line therapy. No correlation was found between the mutation status and survival or response outcomes.

Therapeutic drug monitoring of imatinib in patients of chronic myeloid leukemia – Chronic phase

Introduction: Tyrosine kinase inhibitor is recommended for the initial management of chronic phase chronic myeloid leukemia (CP CML) based on the more favorable balance of toxicity and long-term disease control. Background: Mean trough plasma Imatinib Mesylate (IM) levels are detected to be significantly higher in patients with a complete cytogenetic response or major molecular response (MMR). Methodology: The primary objective of the study was to correlate the IM drug levels with MMR on two different occasions at least 3 months apart and to study the variation in the plasma trough levels of IM during the treatment with standard dose for at least 12 months. Results: After exclusion, 30 patients of CML-CP in MMR, on standard dose over a period of 2 years were finally analyzed. The mean IM plasma levels (IPLs) of the first sample for all patients were 1722 ± 566 ng/ml (IPL-1) with a corresponding mean molecular response (MR) 0.0257 ± 0.0279 breakpoint cluster region-abelson murine leukemia (BCR-ABL) IS % (MR-1). The mean IPLs of the second sample for all patients were 1549 ± 375 ng/ml (IPL-2) with a corresponding mean MR 0.0143 ± 0.0184 BCR-ABL IS % (MR-2). Area under the receiver operating characteristic curve for IPL-1 was 0.565 and IPL-2 was 0.639. For IM level at second point of 1800 ng/ml, the specificity for predicting MMR was 81.8% and sensitivity was 31.6%. Conclusion: Monitoring of trough IM plasma concentrations may become the part of standard management of CML patients.

In vivo, ex vivo and in vitro dasatinib activity in chronic lymphocytic leukemia.

Dasatinib inhibits the breakpoint cluster region-Abelson murine leukemia 1 (BCR-ABL1) gene along with other kinases known to be overexpressed and abnormally active in patients with chronic lymphocytic leukemia (CLL). The current study used primary leukemic cells obtained from 53 patients with CLL that were treated with dasatinib. A 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay and Annexin V staining was performed to assess the cytotoxic effects of dasatinib treatment. The XTT assay revealed that the median cytotoxicity of dasatinib was 8.30% (range, 0.00–77.89%). Due to high dispersion of dasatinib activity, patients were divided into sensitive (n=27; 50.94%; median cytotoxicity, 22.81%) and resistant groups (n=26; 49.06%; median cytotoxicity, 0.00%). A median cytotoxicity of 8.30% was selected as a cut off value. Using Annexin V staining and flow cytometry on exemplary sensitive and resistant CLL samples, it was revealed that 17.71 and 1.84% of cells were apoptotic, respectively. The current study presented a case of a patient with concomitant occurrence of CLL and chronic myeloid leukemia (CML) with a major molecular response after dasatinib treatment. A simultaneous reduction of circulating CLL cells indicated in vivo anti-CLL activity induced by dasatinib. After an in vitro culture of the patient's mononuclear cells with subsequent dasatinib treatment, a higher percentage of CLL cells undergoing apoptosis was obsevered when compared with untreated samples (38.19 vs. 21.99%, respectively). Similarly, the percentage of CLL apoptotic cells (ΔΨmlow) measured by chloromethyl-X-rosamine was higher after incubation with dasatinib (7.28%) than in the negative control (2.86%). In conclusion, dasatinib induced antileukemic effects against CML and CLL cells. The results of the current study indicated that dasatinib may induce apoptosis ex vivo, in vitro and in vivo in CLL.

Imatinib and GNF-5 Exhibit an Inhibitory Effect on Growth of Hepatocellar Carcinoma Cells by Downregulating S-phase Kinase-associated Protein 2.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is one of the leading causes of cancer-related deaths worldwide. Imatinib and GNF-5 are breakpoint cluster region-Abelson murine leukemia tyrosine kinase inhibitors which have been approved for the treatment of chronic myeloid leukemia and various solid tumors. However, the effect and underlying mechanisms of imatinib and GNF-5 in HCC remain poorly defined. In this study, we investigated the anticancer activity and underlying mechanisms of imatinib and GNF-5 in HepG2 human hepatocarcinoma cells. Cell proliferation and anchorage-independent colony formation assays were done to evaluate the effects of imatinib and GNF-5 on the growth of HepG2 cells. The cell cycle was assessed by flow cytometry and verified by immunoblot analysis. Gene overexpression and knockdown assays were conducted to evaluate the function of S-phase kinase-associated protein 2 (Skp2). Imatinib and GNF-5 significantly inhibited the growth of HepG2 cells. Imatinib and GNF-5 induced G0/G1 phase cell cycle arrest by downregulating Skp2 and upregulating p27 and p21. Overexpression of Skp2 reduced the effect of imatinib and GNF-5 on HepG2 cells. Knockdown of Skp2 suppressed the proliferation and induced G0/G1 phase arrest. Furthermore, knockdown of Skp2 enhanced the effect of imatinib and GNF-5 on growth of HepG2 cells. In conclusion, imatinib and GNF-5 effectively suppress HepG2 cell growth by inhibiting Skp2 expression. Skp2 promotes the cell proliferation and reverse G0/G1 phase cell cycle arrest and it represents a potential therapeutic target for HCC treatment.

Point: Is there a best duration of deep molecular response to achieve therapy-free remission in chronic myeloid leukaemia?

Point: Is there a best duration of deep molecular response to achieve therapy-free remission in chronic myeloid leukaemia?

Novel HDAC inhibitor MAKV-8 and imatinib synergistically kill chronic myeloid leukemia cells via inhibition of BCR-ABL/MYC-signaling: effect on imatinib resistance and stem cells

BackgroundChronic myeloid leukemia (CML) pathogenesis is mainly driven by the oncogenic breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (BCR-ABL) fusion protein. Since BCR-ABL displays abnormal constitutive tyrosine kinase activity, therapies using tyrosine kinase inhibitors (TKis) such as imatinib represent a major breakthrough for the outcome of CML patients. Nevertheless, the development of TKi resistance and the persistence of leukemia stem cells (LSCs) remain barriers to cure the disease, justifying the development of novel therapeutic approaches. Since the activity of histone deacetylase (HDAC) is deregulated in numerous cancers including CML, pan-HDAC inhibitors may represent promising therapeutic regimens for the treatment of CML cells in combination with TKi.ResultsWe assessed the anti-leukemic activity of a novel hydroxamate-based pan-HDAC inhibitor MAKV-8, which complied with the Lipinski’s “rule of five,” in various CML cells alone or in combination with imatinib. We validated the in vitro HDAC-inhibitory potential of MAKV-8 and demonstrated efficient binding to the ligand-binding pocket of HDAC isoenzymes. In cellulo, MAKV-8 significantly induced target protein acetylation, displayed cytostatic and cytotoxic properties, and triggered concomitant ER stress/protective autophagy leading to canonical caspase-dependent apoptosis. Considering the specific upregulation of selected HDACs in LSCs from CML patients, we investigated the differential toxicity of a co-treatment with MAKV-8 and imatinib in CML versus healthy cells. We also showed that beclin-1 knockdown prevented MAKV-8-imatinib combination-induced apoptosis. Moreover, MAKV-8 and imatinib co-treatment synergistically reduced BCR-ABL-related signaling pathways involved in CML cell growth and survival. Since our results showed that LSCs from CML patients overexpressed c-MYC, importantly MAKV-8-imatinib co-treatment reduced c-MYC levels and the LSC population. In vivo, tumor growth of xenografted K-562 cells in zebrafish was completely abrogated upon combined treatment with MAKV-8 and imatinib.ConclusionsCollectively, the present findings show that combinations HDAC inhibitor-imatinib are likely to overcome drug resistance in CML pathology.

RET Gene Fusions in Malignancies of the Thyroid and Other Tissues.

Following the identification of the BCR-ABL1 (Breakpoint Cluster Region-ABelson murine Leukemia) fusion in chronic myelogenous leukemia, gene fusions generating chimeric oncoproteins have been recognized as common genomic structural variations in human malignancies. This is, in particular, a frequent mechanism in the oncogenic conversion of protein kinases. Gene fusion was the first mechanism identified for the oncogenic activation of the receptor tyrosine kinase RET (REarranged during Transfection), initially discovered in papillary thyroid carcinoma (PTC). More recently, the advent of highly sensitive massive parallel (next generation sequencing, NGS) sequencing of tumor DNA or cell-free (cfDNA) circulating tumor DNA, allowed for the detection of RET fusions in many other solid and hematopoietic malignancies. This review summarizes the role of RET fusions in the pathogenesis of human cancer.

Tryptase: A novel prognostic biomarker in chronic myeloid leukemia

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm characterized by the presence of the Philadelphia chromosome. It is treated with tyrosine kinase inhibitor agents targeted against the breakpoint cluster region-Abelson murine leukemia 1 fusion transcript. Disease risk stratification at diagnosis of chronic-phase (CP) CML is done using Sokal, Hasford, and EUTOS scores which use basophilia as a major component. However, basophil counts can be both variable and inaccurate. The serum tryptase level is being studied as a novel biomarker which represents the total basophil compartment. Tryptase, deriving its name from trypsin-like activity commonly expressed by mast cells, and also by immature basophils of patients suffering from various myeloid and leukemic disorders, has a role in tumor proliferation. Patients with seemingly low-normal levels of basophils and raised tryptase levels progress further in disease despite treatment. There is a recent interest in the role of serum tryptase as a prognostic marker in CML-CP.

Comparison of BCR-ABL Transcript Variants Between Patients With Chronic Myeloid Leukaemia and Leukaemia Cell Lines.

Chronic myeloid leukaemia (CML) is a myeloproliferative disorder characterized by the presence of breakpoint cluster region-Abelson murine leukemia (BCR-ABL1) gene fusion as a hallmark that is expressed as two major transcripts b2a2 and b3a2. The aim of this study was to compare the BCR-ABL transcripts in the blood cells of patients with CML, and in chemoresistant and chemosensitive CML cell lines to validate their use as a good method to elucidate CML biology. Twelve patients with CML and CML cell lines (K562, K562-LUCENA and FEPS) were analyzed by real-time polymerase chain reaction to evaluate gene expression of BCR-ABL transcripts. All patients had the same expression levels of b2a2 and b3a3 transcripts, however, CML cell lines presented only b3a2 expression. There were no significant differences in absolute b3a2 expression between patients and CML cell lines. CML cell lines provide a good in vitro alternative in that they have the same BCR-ABL expression as patients.

Pharmacovigilance evaluation of the relationship between impaired glucose metabolism and BCR-ABL inhibitor use by using an adverse drug event reporting database.

Breakpoint cluster region‐Abelson murine leukemia (BCR‐ABL) inhibitors markedly improve the prognosis of chronic myeloid leukemia. However, high treatment adherence is necessary for successful treatment with BCR‐ABL inhibitors. Therefore, an adequate understanding of the adverse event profiles of BCR‐ABL inhibitors is essential. Although many adverse events are observed in trials, an accurate identification of adverse events based only on clinical trial results is difficult because of strict entry criteria or limited follow‐up durations. In particular, BCR‐ABL inhibitor‐induced impaired glucose metabolism remains controversial. Pharmacovigilance evaluations using spontaneous reporting systems are useful for analyzing drug‐related adverse events in clinical settings. Therefore, we conducted signal detection analyses for BCR‐ABL inhibitor‐induced impaired glucose metabolism by using the FDA Adverse Event Reporting System (FAERS) and Japanese Adverse Drug Event Report (JADER) database. Signals for an increased reporting rate of impaired glucose metabolism were detected only for nilotinib use, whereas these signals were not detected for other BCR‐ABL inhibitors. Subgroup analyses showed a clearly increased nilotinib‐associated reporting rate of impaired glucose metabolism in male and younger patients. Although FAERS‐ and JADER‐based signal detection analyses cannot determine causality perfectly, our study suggests the effects on glucose metabolism are different between BCR‐ABL inhibitors and provides useful information for the selection of appropriate BCR‐ABL inhibitors.

Mutations in the breakpoint cluster region-Abelson murine leukemia 1 gene in Brazilian patients with chronic myeloid leukemia

IntroductionMutations in the breakpoint cluster region-Abelson murine leukemia 1 gene are the leading cause of resistance to treatment with tyrosine kinase inhibitors in chronic myeloid leukemia patients. Mutations have been detected throughout the extension of the kinase domain of this gene and it is important to investigate their positions because there may be a difference in clinical relevance. ObjectiveTo evaluate mutations in the transcripts of the BCR-ABL1 gene in Brazilian patients with chronic myeloid leukemia under tyrosine kinase inhibitor treatment in the Hospital de Clínicas of the Universidade Federal do Paraná. MethodsThis retrospective observational cross-sectional study analyzed mutation data of BCR-ABL1 gene transcripts. Three hundred and thirty peripheral blood samples from 193 patients were evaluated with the search for mutations being achieved by Sanger sequencing. ResultsSixteen mutation types were identified in 48/193 (24.87%) patients with T315I (20.83%) being the most common. Furthermore, four polymorphisms (T240T, K247R, E275E and Y275Y) were identified. The highest incidence of mutations (19/53: 35.85%) occurred in the P-loop of the tyrosine kinase domain, whereas no mutation was found in the A-loop. In 43/48 (89.58%) patients only one mutation was found and more than one mutation was found in 5/48 (10.42%). The simultaneous presence of two mutations (E189G/V299L and E255K/T315I) was observed in 2/5 patients while the different mutations were seen in sequential samples of the other three patients (Y253Y/T315I, T315I/E255K and E255K/T315I). ConclusionsThis molecular characterization contributed to the identification of the resistance profile to tyrosine kinase inhibitors in Brazilian patients, thus enabling the use of adequate therapeutic strategies in a timely manner.

Side effects and medication adherence of tyrosine kinase inhibitors for patients with chronic myeloid leukemia in Taiwan

Nonadherence is common in patients with chronic myeloid leukemia (CML) and leads to treatment failure and poor outcomes. Side effects due to treatment are also common in patients with CML. However, no study has investigated the link between side effects and medication adherence for patients with CML in Taiwan. Therefore, the aim of our study was to explore the influence of side effects on medication adherence in Taiwanese patients with CML.CML in chronic-phase patients treated with breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 tyrosine kinase inhibitors were recruited. We designed a questionnaire to collect baseline patient information, medication adherence (measured using the 8-item Morisky Medication Adherence Scale), and side effects. Clinical outcomes were assessed by the 3-month early molecular response rate and the 12-month major molecular response rate. Statistical comparisons of different parameters between adherent and nonadherent groups were conducted.Fifty-eight patients were enrolled in this study, and 31% of them had poor adherence. The lack of information about treatment and medication was the major reason for poor medication adherence. Patients who were younger and unmarried were prone to poor adherence. The occurrence of side effects carried no statistically significant influence on adherence. Poor adherence resulted in a poor treatment response (lower 3-month early molecular response rate and lower 12-month major molecular response rate).Poor adherence is common in Taiwanese patients with CML. The main reason for a decrease in the adherence rate is the lack of comprehensive information about treatment and medication, particularly in young and single population. The next urgent step is to educate patients about their treatment and management of side effects to improve adherence and treatment outcome for patients with CML in Taiwan.

The BCR-ABL inhibitor nilotinib influences phenotype and function of monocyte-derived human dendritic cells.

In chronic myeloid leukemia (CML), the translocation t(9;22) results in the fusion protein BCR-ABL (breakpoint cluster region-abelson murine leukemia), a tyrosine kinase mediating oncogenic signaling which is successfully targeted by treatment with BCR-ABL inhibitors like imatinib. However, BCR-ABL inhibitors may also affect antitumor immunity. For instance, it was reported that imatinib impairs the function of dendritic cells (DCs) that play a central role in initiating and sustaining T cell responses. Meanwhile, second generation BCR-ABL inhibitors like nilotinib, which inhibits BCR-ABL with enhanced potency have become standard of treatment, at least in patients with BCR-ABL kinase domain mutations. In this study we analyzed the influence of therapeutic concentrations of nilotinib on human monocyte-derived DCs and compared its effects to imatinib. We found that both tyrosine kinase inhibitors (TKI) comparably and significantly impaired differentiation of monocytes to DCs as revealed by curtated downregulation of CD14 and reduced upregulation of CD1a and CD83. This was only partially restored after withdrawal of the TKI. Moreover, both TKI significantly reduced activation-induced IL-12p70 and C-C motif chemokine ligand (CCL) 3 secretion, while divergent TKI effects for CCL2 and CCL5 were observed. In contrast, only nilotinib significantly impaired the migratory capacity of DCs and their capacity to induce T-cell immune responses in MLRs. Our results indicate that imatinib and nilotinib may differ significantly with regard to their influence on antitumor immunity. Thus, for future combinatory approaches and particularly stop studies in CML treatment, choice of the most suitable BCR-ABL inhibitor requires careful consideration.

Imatinib derivatives as inhibitors of K562 cells in chronic myeloid leukemia

Imatinib was the first representative of the class of Breakpoint cluster region-Abelson murine leukemia viral oncogene homolog (BCR-ABL) tyrosine kinase inhibitors used for the treatment of chronic myeloid leukemia. Second-generation and third-generation drugs have been introduced in this therapy, affording increased patient survival. However, all BCR-ABL tyrosine kinase inhibitors have been shown to induce resistance, necessitating a search for new therapeutic options. The sunitinib, another tyrosine kinase inhibitor used in the treatment of renal cell carcinoma and gastrointestinal stromal tumors is an isatin derivative. Isatin nucleus is highly versatile for the preparation of new substances, and several tyrosine kinase inhibitors examples have been obtained using it. This work aimed to design, synthesize, and biological evaluation of new compounds using the K562 cell line, which constitutively expresses the active BCR-ABL enzyme. Three new series of imatinib derivatives have been planned from the imatinib, and all have a phenylaminopyrimidine group as the main pharmacophore. Sunitinib was used as a structural prototype to planning the series 1 (8a–e) of hybrids between sunitinib and imatinib. Series 2 and 3 are 2-oxo-2-phenyacetamide and 2,2-difluoro-2-phenylacetamide derivatives, respectively. Isatins were used as the starting materials for all series. Compounds were synthesized using simple methodologies and were obtained in high purities. The compounds were tested against K562 cells, and four showed a reduction in cell viability, with EC50 values ranging from 0.37 to 2.02 μM, some of which are close to the imatinib standard (0.21 µM).

Prognostic significance of micro RNA 150 marker in BCR-ABL positive chronic myeloid leukaemia patients on imatinib mesylate

Background: Micro-RNAs control gene expression by destabilizing targeted transcripts and inhibiting their translation. In chronic myeloid leukaemia (CML), abnormal expressions of miRNAs have been described. The current treatment for newly diagnosed cases of CML is imatinib mesylate which produces rapid haematological responses. It is currently impossible to predict whether a patient will develop resistance to imatinib mesylate. This makes identification of predictors of resistance to imatinib an important goal in management of patients with CML. MicroRNA expression patterns can be used to predict outcome which can be remission or relapse. This study therefore, was set to assess the possible use of microRNA 150 for prognostication.Methods: Fifty peripheral blood samples previously collected from CML patients who were being treated with imatinib mesylate and stored in the refrigerator at +4°C were analyzed for the expression of microRNAs 150. Total RNA was extracted from guanidium isothiocynate (GITC) lysate of the blood samples using RNeasy mini spin column. The total RNA was converted to complimentary DNA by random hexamer priming using Murine Moloney Leukaemia Virus Reverse Transcriptase. Real time Multiplex PCR was used for detecting Breakpoint Cluster Region-Abelson Murine Leukaemia (BCR-ABL) transcript type.Results: The patients’ samples showed an expression of miRNA-150. Correlation of BCR-ABL ratio with miRNA-150 was done and the Spearman correlation coefficient (Rho) between BCR-ABL1 and miRNA-150 was 0.442 (p = 0.001; CI = 0.18-0.65) showing that there was a positive correlation between BCR-ABL1 and miRNA-150. The coefficient of determination was 20% (CI = 3-42%), which implies that about 20% of BCR-ABL1 ratio could be accounted for by the miRNA-150 values.Conclusions: Therefore, once patients who are on imatinib achieve molecular remission of the CML, the miRNA-150 can be useful in predicting outcome which could be relapse or complete molecular remission but is weak at diagnosis in predicting such outcome.

Sequencing myeloproliferative leukemia exon 10 mutations in iranian patients with breakpoint cluster region-abelson murine leukemia viral oncogene homolog 1-negative myeloproliferative neoplasm

Context: Breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (BCR-ABL1)-negative myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF), are distinguished by the dysregulated Janus kinase (JAK)-signal transducer and activator of transcription functionality, abnormal hematopoiesis, and spontaneous proliferation. Moreover, a mutation in JAK2V617F as well as myeloproliferative leukemia (MPL) mutations have been reported in these patients, which could be important in the pathogenesis of diseases. MPL plays a role in the development of megakaryocytes and platelets as well as self-renewal of hematopoietic stem cells. Aims: The aim of the present study was to investigate the frequency of MPL mutations in patients with BCR-ABL1-negative MPNs. Settings and Design: This study was a cross-sectional study conducted as an analytical, descriptive review. Subjects and Methods: This study was performed on 54 newly diagnosed patients with BCR-ABL1-negative MPN (PV, ET, and PMF) who referred to Shafa Hospital, Ahvaz, Iran. Five milliliter whole blood was drawn from these patients; JAK2V617Fmutation and mutations in exon 10 of MPL gene were investigated using polymerase chain reaction and DNA sequencing techniques following the isolation of mononuclear cells from the blood.Statistical Analysis: All the data were presented as mean ± standard deviation and were analyzed by SPSS. Results: JAK2V617Fmutation was present in 33 patients, among whom there were 6 ET (35.3%), 7 PMF (41.2%), and 20 PV cases (100%). MPLW515 L/Kmutation was found in only one case of PMF, which was negative for JAK2V617Fmutation. The prevalence of these mutations was 1.8%, and the patient had splenomegaly with lower white blood cell counts and hemoglobin concentration than normal. Conclusions: Based on the results, MPL mutations rarely occur in patients with MPN. These mutations could be co-expressed with JAK2 mutations and might be helpful for detecting MPN patients with no BCR-ABL1 translocation or JAK2V617Fmutation.