Survivin Suppression Strengthens BZML-induced Mitotic Catastrophe to Overcome Multidrug Resistance by Removing Senescent A549/Taxol Cells

Abstract

Background: Mitotic catastrophe (MC) of cancer cells induced by BZML, a novel colchicine-binding site inhibitor, exerts a significant advantage in overcoming multidrug resistance (MDR) in NSCLC. However, the long cellular death process resulting from MC is not beneficial for anticancer treatment. Here, we study the mechanisms underlying MC occurrence and development to promote the development of anticancer therapies based on drug-induced MC.Methods: Cellular senescence was confirmed by morphological features, SA-β-Gal and C12FDG staining. Cell cycle analysis and Hoechst 33342 staining were used to detect MC. Relevant signal transduction pathways and protein location were detected by qRT-PCR, westren blot and immunofluorescence. The half-life of proteins was evaluated using the protein synthesis inhibitor cycloheximide. Flow cytometry, MTT assay, crystal violet staining, Hoechst 33342 staining and cell division detection were performed to determine the effects of BZML and/or YM155 on cell fate. Results: We found that BZML induced p53-dependent cellular senescence in A549/Taxol cells, but not in A549, H1299 and MDA-MB-231 cells. Interestingly, BZML-induced senescence was a secondary effect of MC. In addition, the destruction of the protein-degradation system induced by BZML contributed not only to an increase in p53 protein but also to the accumulation of survivin in the nucleus of A549/Taxol cells. However, in A549 cells, the overexpression of survivin had no effect on apoptosis resistance against BZML and failed to promote BZML-induced MC. The inhibition of survivin did not prevent MC occurrence. Unexpectedly, targeting survivin with YM155 accelerated the death of the MC cells by eliminating senescent cells and strengthening the efficiency of BZML in overcoming the MDR of A549/Taxol cells.Conclusions: Our data suggest that nuclear accumulation of survivin can delay cellular death during MC by promoting the survival of senescent BZML-treated A549/Taxol cells. Further, depending on the dose sequence, combination therapy with YM155 to inhibit survivin might be a new strategy for potentiating BZML-induced MC to overcome MDR during cancer treatment.