The relapse and resistance to cytarabine (Ara-C) therapy is still a dominating obstacle to the successful clinical treatment of acute myeloid leukemia (AML). Recent studies have shown that dysregulation of miRNAs might modulate the resistance of cancer cells to anticancer drugs; yet, the mechanism is not fully understood. In this study, we showed a significant downregulation of miR-134 in human multidrug-resistant leukemia cells and relapsed/refractory AML patient samples. Overexpression of miR-134 sensitized K562/A02 and HL-60/ADM cells to Ara-C, inhibited cell colony formation, and enhanced the ability of Ara-C to induce apoptosis. Mechanistic analyses revealed that Mnks was a putative target of miR-134, which was inversely correlated with miR-134 expression in human multidrug-resistant leukemia cells and relapsed/refractory AML patient samples. Further investigation showed that miR-134 increased the anti-tumor effects of Ara-C through inhibiting phosphorylation of eukaryotic initiation factor 4E and downregulating Mcl-1 and bcl2, which was independent of p38 and Erk1/2 activation. Taken together, our results demonstrate that miR-134 plays a pivotal role in AML Ara-C resistance through increasing cell sensitivity to Ara-C and promoting apoptosis by targeting Mnks.
BackgroundMyelodysplastic syndromes (MDSs) are a very heterogeneous group of myeloid disorders with high prevalence and risk of developing acute myeloid leukemia. The more accurate risk stratification can provide a better guidance of treatment. The platelet–large cell ratio (P-LCR) is a parameter reported in complete blood cell count tests, and was associated with many diseases, but its role in MDS is not clear.PurposeThis study aims to explore the impact of the P-LCR on the prognosis of patients with MDS, which is of great significance for clinical treatment.MethodsIn the retrospective study, 122 newly diagnosed MDS patients were enrolled. We used the bioinformatics tool X-tile to define a P-LCR threshold of 36.7% to predict prognosis. Patients were divided into P-LCRlow and P-LCRhigh groups, and their characteristics were compared between the two groups.ResultsResults show that the P-LCRlow was associated with worse overall survival (OS) than the P-LCRhigh patients (median OS, 18.53 months versus 25.77 months, p=0.0057), but there were no statistical differences in progression-free survival (PFS) between the two groups (p=0.2001). The results of univariate and multivariate Cox proportional hazard analyses adjusted for gender, bone marrow blast level, platelet count, and International Prognostic Scoring System scores showed that the P-LCR was useful in the evaluation of PFS [hazard ratio (HR) 0.212, 95%CI 0.064–0.702, p=0.011] and OS of MDS (HR 0.464, 95%CI 0.284–0.757, p=0.002).ConclusionThis study is the first report showing that the P-LCR would be a simple and immediately available biomarker for predicting the prognosis of MDS.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.