BCR Gene Research Articles

Heterocyclic Compounds as Bcr-Abl Tyrosine Kinase Inhibitors Against Chronic Myeloid Leukemia

Abstract: Despite significant progress in oncology therapeutics, cancer remains a leading cause of mortality worldwide. Chronic myeloid leukemia, which accounts for 15% of all adult leukemia cases, is characterized by chromosomal abnormalities involving the fusion of the Bcr and Abl genes to form the Bcr-Abl oncogene. Current drug treatment of the disease involves the use of Bcr-Abl tyrosine kinase inhibitors belonging to the first, second, and third generations. However, the toxicity and resistance associated with the use of imatinib, a first-generation Bcr-Abl inhibitor, in cases where the T315I mutation exists, necessitates the need for new tyrosine kinase inhibitors. This review focuses on recent synthetic compounds that exhibit potential as inhibitors of the Bcr-Abl protein which could be utilized in chemotherapy. Herein, we evaluated and summarized 36 studies published in the last few years that reported on newly synthesized and biologically evaluated novel small molecules with different heterocyclic scaffolds as Bcr-Abl tyrosine kinase inhibitors. The intricacy of the structure of newly synthesized compounds and the fact that each compound contains more than one scaffold makes it difficult to infer the potentially active core or scaffold. However, investigating different combined scaffolds enhances the chance of successfully developing novel drug candidates. Overall, the information provided in this review can be beneficial to researchers with an interest in chronic myeloid leukemia and tyrosine kinase inhibitors.

The Unusual Presentation of Bilateral Proptosis Presents a Dilemma in the Case of Juvenile Myelomonocytic Leukemia

AbstractJuvenile myelomonocytic leukemia (JMML) is a myelodysplastic/myeloproliferative neoplasm. It is a rare pediatric neoplasm occurring in early childhood. Herein, we present a case of JMML in a 4-year-old girl admitted for primary complaints of protrusion of eyes and fever for the past 15 days not responding to any medications. With findings of splenomegaly and peripheral blood smear showing severe leukocytosis and increased monocytoid and blast cells, a myelomonocytic series neoplasm was suspected. Abelson (Abl) tyrosine kinase gene break point cluster (Bcr) gene (BCR-ABL1) was found to be negative on fluorescence in situ hybridization (FISH). Taking into consider all these findings, the patient was diagnosed with JMML. Since hematopoietic stem cell transplantation (HSCT) is not offered at our hospital, the patient was referred to another medical facility for the required procedure. This case highlights that bilateral proptosis could be a primary finding in early cases of JMML and should not be missed.

Patched Homolog Gene (PTCHI) as a Reliable Marker for Predicting Imatinib Response in Chronic Phase Chronic Myeloid Leukemia Patients in Correlation with Early Response to First Line of Treatment Imatinib

Abstract Background Chronic myeloid leukaemia BCR-ABL1 + (CML) is a clonal disorder of a pluripotent stem cell. The disease accounts for around 15% of leukaemias and may occur at any age. The diagnosis of CML is rarely difficult and is assisted by the characteristic presence of the Philadelphia (Ph) chromosome. This results from the t (9;22) (q34; q11) translocation between chromosomes 9 and 22, as a result of which part of the oncogene ABL1 is moved to the BCR gene on chromosome 22. and part of chromosome 22 moves to chromosome 9. The abnormal chromosome 22 is the Ph chromosome. Aim of the Work To measure the level of PTCH1 in newly diagnosed CP-CML and to find correlation between the level of PTCH1in those patients and response to first line of treatment; imatinib and other prognostic factors Patients and Methods In our study there are 50 patients newly diagnosed cml recruited from hematology out patients clinic in ain shams university within duration august 2021 –april 2022.We have measured level of PTCH1 protein in newly diagnosed CP-CML and its follow up after 6months Results the studies show that 25% of patients discontinue imatinib due to lack of efficacy. A few years ago, two second-generation tyrosine kinase inhibitors (TKIs), Dasatinib and Nilotinib, were approved for first-line treatment, increasing the options available for patients diagnosed with CP- CML.Currently, the best way to adjust treatment to fit the severity of the disease is by assessing the response at different milestones. One milestone is the BCR-ABL1/ABL1 transcript level at 3 months; a level >10% 3 months after starting treatment has been related to a worse subsequent imatinib response. However, whether a change in therapy is warranted based on this single determination is controversial. Conclusion Patched homolog 1 gene (PTCH1) is marker for predicting first line of treatment imatinib response in chronic myeloid leukemia patients in chronic phase in correlation with response to imatinib. It is detected by PCR and proved to be a reliable marker to detect early imatinib response in chronic myeloid leukemia patients in chronic phase. In our study, we measured level of (PTCH1) in chronic myeloid leukemia patients in chronic phase using ELISA as a cost benefit in comparison to PCR in newly diagnosed cml patients on first line of treatment imatinib then follow up after 6 months. We found that it is a reliable marker, sensitive and specific to detect imatinib response.

Variant-specific BCR::ABL1 quantification discrepancy in chronic myeloid leukemia.

Accurate quantification of the BCR::ABL1 fusion gene in whole blood is pivotal for the clinical management of chronic myeloid leukemia (CML) patients. The fusion protein encoded by BCR::ABL1 can vary in size, depending on the BCR and/or ABL1 gene breakpoint. The vast majority of CML patients have a p210 BCR::ABL1 fusion gene (M-BCR), which can be attributed to the presence of either e14a2 (b3a2) or e13a2 (b2a2) mRNA transcript junctions. Twenty-five CML samples were analyzed in two different ISO15189-accredited centers that both use an Europe Against Cancer-based quantitative polymerase chain reaction (qPCR) protocol. Reanalysis of the sample set with transcript-specific standard curves and digital droplet PCR (ddPCR) were performed. qPCR quantification revealed a significant (up to 1 log) difference specifically for the e13a2 transcript variant in contrast to e14a2 transcripts (Hodges-Lehman 4.29; p < 0.001). Reanalysis of the sample set with transcript-specific standard curves abolishes the initial transcript-specific difference (Hodges-Lehman 0.003; p = 0.8192). Comparison of transcript-specific qPCR results of both centers with ddPCR, an absolute quantification method, showed a statically significant association, especially in the lower range, indicating the clinical utility of transcript-specific or absolute quantification methods. Our data show that differences between transcript-specific quantification might exist between centers, leading to potential clinical impact on the follow-up of CML patients. The use of transcript-specific standard curves for qPCR quantification, or absolute quantification, can significantly reduce these differences. Specific attention should be applied to the interpretation of quantification differences of CML patients that switch between diagnostic centers.

Distribution of BCR::ABL1 Transcripts in the Different Clinical Phases of Chronic Myeloid Leukemia: Effect on Hematological Parameters and Patient Survival.

Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder characterized by the presence of the Philadelphia chromosome, a product of the reciprocal translocation t(9;22)(q34;q11), in the BCR and ABL genes. These rearrangements in both genes lead to the formation of various fusion mRNA products, with preferential expression of b2a2, b3a2, and other BCR::ABL1 mRNA variants, combined with additional chromosomal abnormalities. Notably, the distribution and frequency of different mRNA variants vary in different populations. However, studies concerning this in Mexico are limited, and the results have been inconclusive. This study therefore aimed to determine the distribution of BCR::ABL1 mRNA variants in different clinical phases of CML and their effect on hematological parameters and patient survival. This study included 33 patients, whose demographic, clinical, and molecular data on BCR::ABL1 mRNA variants and hematological parameters were collected to identify potential associations. A total of 84.8% (n = 28) of patients had BCR::ABL1 translocation and increased platelet and basophil counts. The most frequent mRNA variant was b3a2 (64.3%), followed by b2a2 (28.6%) and e1a2 (3.6%). Concerning the clinical phases of CML, 75.8% (n = 25), 21.2% (n = 7), and 3% (n = 1) of patients were in the chronic, blast, and accelerated phases, respectively. Moreover, the b3a2 mRNA variant was more commonly identified in patients in the chronic phase. No correlation was observed between mRNA variant expression and patient survival. However, b2a2 was indicative of patients with longer survival as well as those treated with imatinib or nilotinib. Additionally, platelet count could be a marker of BCR::ABL1 translocation.

Abstract 80: Toward best practices for B-cell receptor repertoire profiling

Abstract FDA anticipates that immune cell receptor profiling will become crucial to the Agency’s evaluation of the efficacy and safety of emerging cancer immunotherapies and immunomodulatory drugs by advancing precision medicine and providing orthogonal, functional evidence. High-throughput sequencing of B-cell receptor sequencing (BCR) gene rearrangements and downstream analysis empowers researchers to define the B-cell clonal landscape, as well as identify biomarkers for minimal residual disease (MRD). Although this field has made vast strides over the last decade, it lacks standardized assay controls, adequate sensitivity and specificity in gene mapping/alignment, and appropriately qualified reference data sets, materials, and validation methods. Moreover, detailed comparisons of wet-bench analytical methods or bioinformatic procedures have not appeared. The FDA led B-cell receptor sequencing quality control (BCR-SEQC) consortium is establishing protocols for the development of reference materials and data sets for the evaluation of NGS-based BCR repertoire reconstruction. The consortium is also developing materials for performance bench-marking studies. To this end, we performed whole-genome sequencing, RNAseq, and BCR-seq on 50 B-cell lines to determine the clonotype, full-length transcripts, and expression abundance of BCR genes in each cell line. Two batches of reference materials (DNA, RNA, and cells) were generated from each of nine cell lines that were determined unambiguously to be monoclonal in BCR expression of both heavy and light chains. These materials were distributed to ten companies to test up to 15 BCR-seq products. Our benchmarking studies include six widely-used sequencing technologies. The overarching objectives of this research were to elucidate current capabilities and limitations, address fundamental technical needs, provide reference materials and data sets, and establish actionable best practices for reconstructing B cell receptor repertoires from NGS data. Citation Format: Wenming Xiao, BCR-SEQC consortium. Toward best practices for B-cell receptor repertoire profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 80.

Non-neoplastic B-cell predominant lymphoid proliferations at the organs exposed to external environment mimicking lymphoma: A potential diagnostic pitfall.

Background: Typically, lymphatic tissue proliferative lesions include either benign lesions or lymphoma. However, not all lymphatic lesions can currently be accurately classified into one category, particularly in mucosal areas that are in contact with the external environment.Aims: To explore the morphology, immunophenotype, and molecular changes of Non-neoplastic B-cell predominant lymphoid proliferations (NBPLP) in pathological areas that are exposed to external surroundings which mimicked lymphoma.Methods and Results: 18 cases of Atypical lymphoid hyperplasia (AtLP) were retrieved in this study. The biopsy samples were mucosal samples obtained from areas exposed to external surroundings, including intestines, urethra, cervix, tonsils, and tongue. Microscopically, there is a different level of B cell hyperplasia accompanied by morphological atypia. We categorized the morphology into 4 groups: type A (7/18), type B (3/18), type C (3/18), type D (5/18). Part of the AtLP was found positive for BCR gene rearrangement (6/15), and TCR gene rearrangement (1/4). The follow-up period ranged from 14.2 to 70 months. No evidence of lymphoma was found. Therefore, we diagnosed all of the presented cases as NBPLP. We illustrated the key differential points and provided valuable diagnostic experience on each subtype.Conclusions: Areas exposed to the external environment are commonly exposed to antigen and easily present with AtLP of NBPLP, accompanying with positive IGH rearrangement. Therefore, a comprehensive evaluation of macroscopic, morphology, immunophenotype, and molecular diagnostics is required to prevent the overdiagnosis of lymphoma.

Distinct Pattern of ABL1 Genomic Breakpoints in Chronic Myeloid Leukemia and BCR::ABL1-Positive Acute Lymphoblastic Leukemia: Analysis of 884 Patients with Minor and Major BCR::ABL1 Fusion

The BCR::ABL1 fusion gene is a hallmark of chronic myeloid leukemia (CML) but is also found in patients with acute lymphoblastic leukemia (ALL). There are two main breakpoint clusters in BCR - “minor” (between exons 1-2, resulting in p190 fusion protein, prevalent in ALL and scarce in CML) and “Major” (between exons 13-15, resulting in p210 protein). On the ABL1 side, the breakpoints are mostly localized between exons 1-3. Due to large intronic areas where the breakpoints occur, only a few papers have been published focusing on the structure of BCR::ABL1 fusions. Moreover, with a single exception, these studies included only the Major- BCR::ABL1 patients. Here, we focused on the analysis of BCR::ABL1 breakpoints involving CML and ALL, children and adults, and Major and minor forms of fusion. To our knowledge, we present data on the largest cohort of patients with BCR::ABL1 fusion identified at the DNA level described to date. Genomic breakpoints were found in 884 patients with BCR::ABL1+ ALL (n=463) and CML (n=421) by multiplex long distance PCR/Sanger sequencing or by NGS Custom Target Enrichment. The RSS database, MEME software and RepeatMasker were used to search RSS, specific motifs known for mediation of DNA breaks (59 motifs) and interspersed and other types of repeats within particular DNA areas. The uniformity test performed on breakpoint distribution within the minor (n=356) and Major (n=528) BCR areas revealed a non-random pattern (p=2.34e-21 and p=2.56e-10, respectively) with breakpoints accumulated in the second halves of the intron 1 (minor BCR) and intron 13 (Major BCR). Within the ABL1 area, breakpoint sites were distributed more randomly (p=9.28e-03); however, the breakpoint distribution within the ABL1 differed significantly between patients with CML and ALL (p=7.43e-05; see Figure) with higher accumulation of breakpoints near the 5‘ end of the ABL1 intron 1 in CML and near the 3‘ end of the intron 1 in ALL. The difference was not driven by the type of fusion (minor vs. Major BCR) as it was still visible even if only Major BCR::ABL1+ patients were analysed (414 CML and 108 ALL; p=2.28e-03). Comparison between various groups of patients (females vs. males; adults vs. children; various age groups, minor vs. Major BCR fusion [in ALL patients]), did not reveal a significantly distinct breakpoint distribution in any BCR or ABL1 area. Analysis of genomic breakpoints showed that fusions are mostly formed in loci with short homologies (49%; 1-71bp, median=2bp), by blunt end junctions (36%) or by a junction with insertion of random nucleotides (13%; 1-42bp, median=3bp) strongly suggesting NHEJ mechanism of double-strand break repair in vast majority of cases. In 313 patients we compared BCR::ABL1 and the reciprocal ABL1::BCR fusion. Vast majority of the BCR::ABL1 and ABL1::BCR breakpoints (81% and 79% on BCR and ABL1 area, respectively) were located within ±100bp window, showing almost precise reciprocal translocation, with negligible losses/gains of DNA resulting from the fusion. Analysis of the association of breakpoints with DNA motifs and chromatin structure did not reveal any significant association with the localization of breakpoints. In conclusion, we show different breakpoint distribution in ABL1 between CML and BCR::ABL1+ ALL. The double-strand breaks are repaired by NHEJ; however, we have not found any DNA or epigenetic motif, which might be responsible for the breakpoints. Our data suggest that the differences in breakpoint distribution are due to different chromatin accessibility and/or different relative positions of the BCR and ABL1 genes throughout the cell development, reflecting the origin of CML in earlier stages of hematopoiesis compared to ALL. Supported by AZV (NU21-03-00128) and NICR No. LX22NPO5102.

Patient-derived lymphoma spheroids integrating immune tumor microenvironment as preclinical follicular lymphoma models for personalized medicine

BackgroundFollicular lymphoma (FL), the most common indolent non-Hodgkin’s Lymphoma, is a heterogeneous disease and a paradigm of the contribution of immune tumor microenvironment to disease onset, progression, and therapy resistance....

Supremacy of nanoparticles in the therapy of chronic myelogenous leukemia.

The reciprocal translocation of the ABL gene from chromosome 9 to chromosome 22 near the BCR gene gives rise to chronic myelogenous leukemia (CML). The translocation results in forming the Philadelphia chromosome (BCR-ABL) tyrosine kinase. CML results in an increase in the number of white blood cells and alteration in tyrosine kinase expression. CML prognosis includes three stages, namely chronic, accelerated, and blast. The diagnosis method involves a CT scan, biopsy, and complete blood count. However, due to certain disadvantages, early diagnosis of CML is not possible by traditional methods. Nanotechnology offers many advantages in diagnosing and treating cancer. We searched PubMed, Scopus and Google Scholar using the keywords Philadelphia chromosome, bionanotechnology, tyrosine kinase pathway, half-life, passive targeting, and organic and inorganic nanoparticles. The relevant papers and the classical papers in this field were selected to write about in this review. The sensitivity and specificity of an assay can be improved by nanoparticles. Utilizing this property, peptides, antibodies, aptamers, etc., in the form of nanoparticles, can be used to detect cancer at a much earlier stage. The half-life of the drug is also increased by nanoformulation. The nanoparticle-coated drugs can easily escape from the immune system. Depending on their type, nanoparticles can be categorized into organic, inorganic and hybrid. Each type has its advantages. Organic nanoparticles have good biocompatibility, inorganic nanoparticles increase the half-life of the drugs. In this review, we highlight the nanoparticles involved in treating CML.

Molecular characterization of Glaesserella parasuis strains circulating in North American swine production systems

BackgroundGlaesserella parasuis is the causative agent of Glässer’s disease in pigs. Serotyping is the most common method used to type G. parasuis isolates. However, the high number of non-typables (NT) and low discriminatory power make serotyping problematic. In this study, 218 field clinical isolates and 15 G. parasuis reference strains were whole-genome sequenced (WGS). Multilocus sequence types (MLST), serotypes, core-genome phylogeny, antimicrobial resistance (AMR) genes, and putative virulence gene information was extracted.ResultsIn silico WGS serotyping identified 11 of 15 serotypes. The most frequently detected serotypes were 7, 13, 4, and 2. MLST identified 72 sequence types (STs), of which 66 were novel. The most predominant ST was ST454. Core-genome phylogeny depicted 3 primary lineages (LI, LII, and LIII), with LIIIA sublineage isolates lacking all vtaA genes, based on the structure of the phylogenetic tree and the number of virulence genes. At least one group 1 vtaA virulence genes were observed in most isolates (97.2%), except for serotype 8 (ST299 and ST406), 15 (ST408 and ST552) and NT (ST448). A few group 1 vtaA genes were significantly associated with certain serotypes or STs. The putative virulence gene lsgB, was detected in 8.3% of the isolates which were predominantly of serotype 5/12. While most isolates carried the bcr, ksgA, and bacA genes, the following antimicrobial resistant genes were detected in lower frequency; blaZ (6.9%), tetM (3.7%), spc (3.7%), tetB (2.8%), bla-ROB-1 (1.8%), ermA (1.8%), strA (1.4%), qnrB (0.5%), and aph3''Ia (0.5%). ConclusionThis study showed the use of WGS to type G. parasuis isolates and can be considered an alternative to the more labor-intensive and traditional serotyping and standard MLST. Core-genome phylogeny provided the best strain discrimination. These findings will lead to a better understanding of the molecular epidemiology and virulence in G. parasuis that can be applied to the future development of diagnostic tools, autogenous vaccines, evaluation of antibiotic use, prevention, and disease control.

The Role of BCR-ABL Gene on Chronic Myeloid Leukemia: An Overview

The Breakpoint Cluster Region is a protein encoded by the BCR gene with its partially discovered function to generate instructions for producing a protein and also to encode serine/threonine kinase protein. There are three Breakpoint cluster regions; major (M-bcr) which is high in CML patients, minor (m-bcr) with a 1-2% contribution in the CML, and micro (μ-bcr) which is very rare in the case of CML. The ABL1 encodes for the ABL1 protein which can function as a tyrosine kinase. The translocation of the ABL gene on chromosome 9 at the band 34 to the BCR gene on chromosome 22 at band 11 leads to the fusion of the BCR-ABL gene which is responsible for Chronic Myeloid Leukemia (CML), Acute Myeloid Leukemia (AML), and Acute Lymphoblastic Leukemia (ALL). Chromosome 22 with this hybrid gene called a Philadelphia chromosome codes for a BCR-ABL protein that enhances the activity of tyrosine kinase thereby activating numerous signaling pathways. If there is a translocation of BCR to chromosome 9, which will cause the emergence of the ABL-BCR gene (9q+). [1][4][5][6] The role of the BCR-ABL gene in CML is to increase the growth and proliferation of myeloid cells, avoid apoptosis, increase c-independent growth, induce aberrations in the cytoskeletons, etc.

ACCUMULATED LABORATORY DATA IN B12 VITAMIN BLOOD LEVEL TIME DEPENDENCY STUDIES IN PATIENTS WITH MYELOMA, LYMPHOCYTIC LEUKEMIA AND MYELOBLASTIC LEUKEMIA IN LATVIA

Vitamin B12 blood level in patients with myeloma (C90 - International Classification of Diseases (ICD-10)), lymphocytic leukemia (C91) and myeloblastic leukemia (C92) prior and after the diagnosis and also BCR-ABL (fusion gene from breakpoint cluster region BCR gene and tyrosine-protein kinase ABL1 (Abelson murine leukemia) gene) tests for C92 patients were studied.Clinical records of 20 C92 patients in Riga East University Hospital were complemented with 6987 B12 clinical test data accumulated in E Gulbis laboratory (EGL) for 7451 patients over 20 years period. BCR-ABL and B12 dynamics for 11 patients with sufficient number of BCRABL and B12 tests were studied.Oracle Cloud with pseudonymized data replica from more than 350 000 000 original EGL clinical test data was used. The data were selected by online analytical processing and SQL built in tools and then used in offline analysis and visualization.Annually there are 107, 189 and 91 confirmed cases of C90, C91 and C92 in Latvia. EGL has 30% more C90-92 patients, due to suspected but later unconfirmed cases. Out of 7451 patients 1386 had one B12 test, two- 548, three and more- 864. The patients with diagnosis fluctuating between C90, C91 and C92 were excluded from the study. The data for the time period of 10 years before and after the first diagnosis were analyzed.Results. Methods and tools for data extraction and analysis from large amount of archived clinical test data were developed and applied. High and very high B12 level was observed for 53% of C92 patients starting from 3 years prior to diagnosis. For C90 and C91 patients B12 level changes around the diagnosis date were also observed although the effect was considerably smaller. Analysis of 11 selected patient data with clinical records showed timewise correlation between B12 and BCR-ABL for 3 of the patients.

Clonal evolution analyses of a chronic myeloid leukemia patient with hematopoietic stem cell transplantation based on deep sequencing

BackgroundThe Philadelphia (Ph) chromosome is the hallmark chromosome aberration in chronic myeloid leukemia (CML), which confers the cancer phenotype of the disease. However, how the Ph chromosome forms and the genetic clonal evolution structure after targeted Ph treatment are still unclear.MethodsIn this study, we performed genome sequencing and clonal evolution analyses in a series of bone marrow specimens and skin biopsy from a CML patient who had received hematopoietic stem cell transplantation from her sister, then relapsed (lymphoid blast crisis), and received Ph-targeted therapy.ResultsThe Ph chromosome was the “driver” clonal change in the original CML and the relapse. Both the patient and her sister had micro-deletions in the BCR gene region; however, the patient had a frameshift BRIP1 mutation that may account for the malfunctioning homologous recombination DNA repair of the BCR gene region and formation of the Ph chromosome.ConclusionWe found that the BCR-ABL1 translocation was the driving force of the patient’s CML and relapse. The malfunctioning double-strand DNA break repair caused by the BRIP1 mutation could be the cause of Ph chromosome formation in the patient.

Downregulation of Stearoyl-CoA Desaturase 1 (SCD-1) Promotes Resistance to Imatinib in Chronic Myeloid Leukemia.

Chronic myeloid leukemia (CML) is a malignant hematopoietic stem cell disease resulting in the fusion of BCR and ABL genes and characterized by the presence of the reciprocal translocation t(9;22)(q34;q11). BCR-ABL, a product of the BCR-ABL fusion gene, is a structurally active tyrosine kinase and plays an important role in CML disease pathogenesis. Imatinib mesylate (IMA) is a strong and selective BCR-ABL tyrosine kinase inhibitor. Although IMA therapy is an effective treatment, patients may develop resistance to IMA therapy over time. This study investigated the possible genetic resistance mechanisms in patients developing resistance to IMA. We did DNA sequencing in order to detect BCR-ABL mutations, which are responsible for IMA resistance. Moreover, we analyzed the mRNA expression levels of genes responsible for apoptosis, such as BCL-2, P53, and other genes (SCD-1, PTEN). In a group of CML patients resistant to IMA, when compared with IMA-sensitive CML patients, a decrease in SCD-1 gene expression levels and an increase in BCL-2 gene expression levels was observed. In this case, the SCD-1 gene was thought to act as a tumor suppressor. The present study aimed to investigate the mechanisms involved in IMA resistance in CML patients and determine new targets that can be beneficial in choosing the effective treatment. Finally, the study suggests that the SCD-1 and BCL-2 genes may be mechanisms responsible for resistance.

The role of transport channels in the mechanism of action of the synergistic triple combination, carvacrol-cuminaldehyde-vancomycin, against vancomycin-resistant Enterococcus faecium

BackgroundNovel antimicrobials with new mechanisms of action are critical to circumvent emerging antimicrobial resistant microorganisms (AMR), such as vancomycin resistant Enterococcus faecium (VanREF). Previous research demonstrated, with transcriptomic analysis and phenotypic assays, that the essential oil components (EOCs) carvacrol (CARV) (1.98 mM) and cuminaldehyde (CA) (4.20 mM) with the antibiotic vancomycin (Van) (0.022 µM), restored the susceptibility of VanREF. This finding suggested that an envelope damage has occurred. Several transport channel-related genes were also differentially expressed including bcr, ecfA1, ecsA-1, yloB and nhaC_2, indicating they could contribute to the mechanism of action of the triple combination CARV-CA-Van. PurposeThe aim of this study was to elucidate the role of transport channels in the antimicrobial mechanism of action of CARV and CA with Van. MethodsThe expression levels of bcr, ecfA1, ecsA-1, yloB and nhaC_2 were established using qPCR under the effect of the triple combination, and in the presence of 1 mM calcium or 0.1 mM EDTA (channel blocker) over time. ResultsSignificant (p ≤ 0.05) changes in expression of yloB and bcr genes were observed at 10 and 30 min, and of ecfA1, ecsA-1 and nhaC_2 at later time points (120 and 360 min). Adding Ca2+ to the combination induced significant changes in the expression of yloB (from -5.67 to -50-fold, +3.68 to -4.4-fold, -1.8 to +6.6-fold and +1.32 to +3.08-fold at 10, 30, 60 and 120 min, respectively). Instead, the addition of EDTA significantly changed the expression of bcr (from -13.5 to -1.11-fold, +15.3 to -1.06-fold, +15.71 to -10-fold at 10, 120 and 360 min, respectively). Since that Ca2+ participates in the stability of bacterial cell wall and EDTA blocks efflux pumps, the current findings suggest the involvement of the efflux system in the mechanism of action of the three-drug combination. ConclusionOverall, the findings of this study suggest the involvement of transportation channels in the mechanism of action of the CARV-CA-Van combination against VanREF.

Asciminib (Scemblix): A third-line treatment option for chronic myeloid leukemia in chronic phase with or without T315I mutation.

To review the pharmacology, efficacy, safety, dosing and administration, and place in therapy of asciminib, an oral tyrosine kinase inhibitor (TKI) used as a third-line treatment option for Philadelphia chromosome-positive chronic myeloid leukemia (CML) in chronic phase. CML is a rare cancer caused by a chromosomal translocation that forms a fusion of the BCR and ABL1 genes on chromosomes 22 and 9. Until recently, patients for whom first-line treatment options failed were treated with TKIs that bind to the adenosine triphosphate-binding site on BCR-ABL1. However, because of similar mechanisms of action, there continues to be an unmet need in patients for whom at least 2 TKIs have failed or those with a T315I mutation unable to tolerate ponatinib. In October 2021, the Food and Drug Administration approved asciminib (Scemblix), the first TKI specifically targeting the ABL1 myristoyl pocket (STAMP) via allosteric binding, as a third-line option for patients with chronic-phase (CP)-CML. Asciminib received accelerated approval due to meeting its primary endpoint at week 24, demonstrating a major molecular response rate of 25.5% for patients on asciminib compared to 13.2% for those receiving bosutinib. In addition, patients on asciminib achieved a higher rate of complete cytogenetic response at 40.8% compared to a rate of 24.2% for bosutinib. Clinicians prescribing asciminib should monitor for increased levels of pancreatic enzymes, hypertension, cardiovascular toxicity including ischemic and thromboembolic conditions, and decreased numbers of neutrophils and platelets, as these may require treatment interruption, dose reduction, or treatment discontinuation. Asciminib is a unique targeted TKI that provides clinicians with an additional third-line and beyond treatment option for adults with CP-CML regardless of mutation status as well as a second TKI treatment option for patients harboring a T315I mutation.

Effects of Vinblastine and Vincristine on the function of chronic myeloid leukemic cells through expression of A20 and CYLD.

Chronic myelogenous leukemia (CML) is characterised by the translocation of regions of the BCR and ABL genes, leading to the fusion gene BCR-ABL forming the Philadelphia (Ph) chromosome. Vinblastine (Vinb) and Vincristine (Vinc) are Vinca alkaloids and frequently used in combination chemotherapy in leukemias and lymphomas. Deubiquitinating enzyme (DUB) genes such as A20, Otubain 1 and CYLD are known as inhibitors of functional activation of immune cells mediated through the NF-κB/STAT pathway. Little is known about the regulatory role of Vinb/Vinc on the function of CML cells and the contribution of the DUBs to those effects. In the end, the gene expression profile was determined by quantitative RT-PCR, physiological properties of CML cells by flow cytometry and cytokine production by ELISA. As a result, inactivated expression of the DUBs A20, CYLD, Otubain 1 and Cezanne and enhanced activation of CD11b+ and CD4T cells were observed in CML patients. Importantly, Vinc enhanced the expression of A20 and CYLD and inhibited the proliferation and survival of CML (K562) cells. The effects were abolished in the presence of A20 siRNA, while cell proliferation only depended on the presence of CYLD. In conclusion, the up-regulation of A20 by Vinc could involve inhibitory effects on the proliferation and survival of K562 cells. The events might contribute to the anticancer effect of Vinc on A20-sensitive CML cells.

Expression of deubiquitinase genes and inflammatory response in myeloid leukemia

Myeloid leukemia (ML) is a cancer of the blood that begins when cells of the myeloid lineage uncontrollably change and grow. Acute myeloid leukemia (AML) is a disorder of rapid, uncontrolled growth of immature myeloid cells in the blood and bone marrow. Chronic myeloid leukemia (CML) is characterized by the aberrant proliferation of myeloid cells and driven by the translocation of regions of the BCR and ABL genes to form the Philadelphia (Ph) chromosome. The deubiquitinase enzymes (DUBs) including A20, OTUB1, OTUB2, and Cezanne play important roles in inhibiting NF-κB activation in response to various stimuli. Cytokines including tumor necrosis factor-alpha (TNF-α), IL-6, and IL-1β are released from immune cell activation triggered by antigenic stimulation. To this end, blood samples of 20 AML and 62 CML patients and the control group consisting of 37 healthy individuals were used to examine the mRNA expression of A20, OTUB1, OTUB2 and Cezanne genes by using quantitative RT-PCR and determine IL-6, TNF-α and IL-1β concentrations by using ELISA. As a result, the mRNA level of OTUB1 was significantly decreased in both AML and CML patients compared to that in healthy individuals, however, no difference in the transcriptional expression of OTUB2 among AML and CML patients and control group was detected. Unlike the levels of OTUB1 and OTUB2, the expressions of A20 and Cezanne in CML, but not in AML patients were significantly lower than healthy individuals. For serum cytokine analysis of the study groups, in AML and CML samples, IL-6 and TNF-α concentrations significantly increased in comparison with the control group, however, IL-1β level was similar among CML, AML patients and healthy individuals. In conclusion, this study revealed the different DUB involvement in the pathogenesis of ML, suggesting further investigations on gene polymorphisms and their functions linked to biological properties of leukemia cells.

Three atypical BCR/ABL transcripts detected simultaneously in a Philadelphia-positive acute lymphoblastic leukemia patient showing resistance to tyrosine kinase inhibitors.

The Philadelphia (Ph) chromosome with a BCR/ABL fusion gene is a characteristic feature ofchronic myeloid leukemia (CML) and partial acute lymphoblastic leukemia (ALL) patients, with different breakpoints of the BCR and ABL genes. Here, we report the case of a Ph-positive ALL patient with poor prognosis in whom simultaneous different BCR/ABL transcripts named e1a3, e1a4, and e1a5 were detected by RNA-seq analysis but not traditional RT-PCR. To our knowledge, this is the first report to describe coexistence of different atypical BCR-ABL transcripts in the same patient and that traditional TKI therapy may not overcome the poor prognosis. This finding will bring new challenges in diagnosis and monitoring for minimal residual disease.