Emerging Effects of Sepantronium Bromide (YM155) on MOLT-4 Cell Line Apoptosis Induction and Expression of Critical Genes Involved in Apoptotic Pathways

Targeting BIRC5 as a therapeutic approach to overcome ASXL1-associated decitabine resistance

Hypomethylating agents (HMAs) are widely employed in the treatment of myeloid malignancies. However, unresponsive or resistant to HMAs occurs in approximately 50 % of patients. ASXL1, one of the most commonly mutated genes across the full spectrum of myeloid malignancies, has been reported to predict a lower overall response rate to HMAs, suggesting an essential need to develop effective therapeutic strategies for the patients with HMA failure. Here, we investigated the impact of ASXL1 on cellular responsiveness to decitabine treatment. ASXL1 deficiency increased resistance to decitabine treatment in AML cell lines and mouse bone marrow cells. Transcriptome sequencing revealed significant alterations in genes regulating cell cycle, apoptosis, and histone modification in ASXL1 deficient cells that resistant to decitabine. BIRC5 was identified as a potential target for overcoming decitabine resistance in ASXL1 deficient cells. Furthermore, our experimental evidence demonstrated that the small-molecule inhibitor of BIRC5 (YM-155) synergistically sensitized ASXL1 deficient cells to decitabine treatment. This study sheds light on the molecular mechanisms underlying the ASXL1-associated HMA resistance and proposes a promising therapeutic strategy for improving treatment outcomes in affected individuals.

Effects of YM155 on the proliferation and apoptosis of pulmonary artery smooth muscle cells in a rat model of high pulmonary blood flow-induced pulmonary arterial hypertension

INTRODUCTION

Proliferation and apoptosis of pulmonary artery smooth muscle cells (PASMCs) play an important role in the occurrence and development of pulmonary arterial hypertension (PAH). The purpose of this study was to investigate the effects of survivin inhibitor YM155 on the proliferation and apoptosis of PASMCs in rats with PAH induced by high pulmonary blood flow.

METHODS

Thirty male Sprague-Dawley (SD) rats were randomly divided into control, model, and YM155 intervention groups. A rat model of PAH induced by high pulmonary blood flow was established, and it was confirmed by assessments of right-ventricular pressure (RVP) and right ventricular hypertrophy index (RVHI). Immunohistochemical staining and western blot analysis were used to detect the expression of survivin, and the proliferation and apoptosis of PASMCs. Lastly, the effects of in vivo treatment of YM155 were tested.

RESULTS

The increased expression of survivin mRNA and protein were observed in the model group, accompanied by pulmonary arteriolar wall thickening, lumen stenosis, and perivascular inflammatory cell infiltration. Elevated expression of survivin and pulmonary vascular remodeling were significantly mitigated after YM155 treatment. Specifically, the YM155 intervention group had a significantly lower PASMC proliferation rate and a higher PASMC apoptotic rate.

CONCLUSION

YM155 suppressed PASMC proliferation and promoted PASMC apoptosis by inhibiting survivin expression and thereby reducing pulmonary vascular remodeling in high pulmonary blood flow-induced PAH in vivo.