RESUMO
Background: Breakpoint cluster region-Abelson gene (BCR-ABL) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of patients with chronic myeloid leukemia (CML). However, concern has arisen about the cardiac safety profile of these drugs. Objectives: This study aims to compare long-term risks of adverse cardiovascular and cerebrovascular events (ACE), heart failure or left ventricular ejection fraction (LVEF) < 50%, and venous thromboembolic events (VTE) in patients with CML treated with BCR-ABL TKIs, using data from a large multinational network. Methods: Patients aged ≥ 18 years with CML treated with imatinib, dasatinib, or nilotinib without prior cardiovascular or cerebrovascular disease were included. We used propensity score matching to balance the cohorts. The 5-year cumulative incidences and hazard ratios were calculated. Results: We identified 3,722 patients with CML under treatment with imatinib (n = 1,906), dasatinib (n = 1,269), and nilotinib (n = 547). Patients with imatinib compared to dasatinib showed a higher hazard ratio (HR) for ACE (HR 2,13, 95% CI 1.15-3.94, p = 0.016). Patients with imatinib presented a lower HR than nilotinib for ACE (HR 0.50, 95% CI 0.30-0.83, p = 0.0074). In relation to heart failure or LVEF < 50%, patients with imatinib had a higher HR than dasatinib (HR 9.41, 95% CI 1.22-72.17, p = 0.03), but no significant difference was observed between imatinib and nilotinib (HR 0.48, 95% CI 0.215-1.01, p = 0.064). Conclusion: In this retrospective study with a large number of patients with CML, those treated with nilotinib had a higher 5-year ratio of ACE, while patients with dasatinib showed a lower ratio than patients with imatinib. The ratio of heart failure was higher in patients with imatinib than in patients with dasatinib, but not when compared to nilotinib.
RESUMO
Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm and was the first neoplastic disease associated with a well-defined genotypic anomaly - the presence of the Philadelphia chromosome. The advances in cytogenetic and molecular assays are of great importance to the diagnosis, prognosis, treatment, and monitoring of CML. The discovery of the breakpoint cluster region (BCR)-Abelson murine leukemia (ABL) 1 fusion oncogene has revolutionized the treatment of CML patients by allowing the development of targeted drugs that inhibit the tyrosine kinase activity of the BCR-ABL oncoprotein. Tyrosine kinase inhibitors (known as TKIs) are the standard therapy for CML and greatly increase the survival rates, despite adverse effects and the odds of residual disease after discontinuation of treatment. As therapeutic alternatives, the subsequent TKIs lead to faster and deeper molecular remissions; however, with the emergence of resistance to these drugs, immunotherapy appears as an alternative, which may have a cure potential in these patients. Against this background, this article aims at providing an overview on CML clinical management and a summary on the main targeted drugs available in that context.
RESUMO
In this work, we analyzed the association between RUNX1 gene expression and the accessibility of BCR3, one of RUNX1 gene breakpoint regions involved in the chromosomal translocation (8;21), a frequent translocation in treatment-related acute myeloid leukemia patients. To this end, we evaluate DNA damage generation induced by in vitro etoposide treatment of KG-1 and Colo320 cells. Our results show that treatment using clinical doses of etoposide for 24 h induces the generation of DNA double strand breaks in the BCR3 of RUNX1 gene in KG-1 cells, but not in Colo320 cells, even though both cell lines express RUNX1 gene. These findings suggest that chromatin accessibility and DNA damage generation at the BCR3 due to treatment with etoposide, is independent of RUNX1 gene expression.
RESUMO
BACKGROUND: RUNX1 gene, a master regulator of the hematopoietic process, participates in pathological conditions as a partner for several genes in chromosomal translocations. One of the most frequent chromosomal translocations found in acute myeloid leukemia patients is the t(8;21), in which RUNX1 and ETO genes recombine. In RUNX1 gene, the DNA double-strand breaks that originate the t(8;21) are generated in the intron 5, specifically within three regions designated as BCR1, BCR2, and BCR3. To date, what determines that these regions are more susceptible to DNA double-strand breaks is not completely clear. In this report, we characterized RUNX1 intron 5, by analyzing DNase-seq and ChIP-seq data, available in the ENCODE Project server, to evaluate DNaseI hypersensitivity and the presence of the epigenetic mark H3K4me3 in 124 and 51 cell types, respectively. RESULTS: Our results show that intron 5 exhibits an epigenetic mark distribution similar to known promoter regions. Moreover, using the online tool YAPP and available CAGE data from the ENCODE Project server, we identified several putative transcription start sites within intron 5 in regions BCR2 and BCR3. Finally, available EST data was analyzed, identifying a novel uncharacterized long non-coding RNA, which is expressed in hematopoietic cell lines as shown by RT-PCR. Our data suggests that the core promoter of the novel long non-coding RNA locates within the region BCR3. CONCLUSION: We identified a novel long non-coding RNA within RUNX1 intron 5, transcribed from a promoter located in the region BCR3, one of the chromosomal breakpoints of RUNX1 gene.