Abstract
Mitotic catastrophe (MC) is a newly identified type of anticancer mechanism for multidrug resistance (MDR) prevention. However, the long cellular death process resulting from MC is not beneficial for anticancer treatment. BZML is a novel colchicine-binding site inhibitor which can overcome MDR by inducing MC; however, BZML-induced MC cells underwent a long cellular death process. Thus, to improve anticancer therapies based on drug-induced MC, BZML-induced MC was served as a model to further study the underlying molecular mechanisms in the process of MC. Here, BZML could induce p53-dependent senescence in A549/Taxol cells, a MDR cell line. This senescence was a secondary effect of MC in overcoming MDR. During MC, BZML-induced destruction of protein-degradation system contributed not only to an increase of p53 protein but also to the accumulation of survivin in nucleus of A549/Taxol cells. Importantly, the nuclear accumulation of survivin was not the inducer but the result of BZML-induced MC, and it promoted the survival of senescent cells. Moreover, it provided additional vulnerability and critical opportunities for sequentially applied therapies. Further, targeting survivin with YM155 accelerated the death of MC cells by timely eliminating therapy-induced senescent cells and strengthening the efficiency of BZML in overcoming MDR in A549/Taxol cells. Collectively, nuclear accumulation of survivin delayed cellular death during MC by promoting the survival of BZML-induced senescent A549/Taxol cells. Moreover, "one-two punch" approach to cancer treatment based on combination therapy with YM155 for survivin suppression might be a new strategy for potentiating MC to overcome MDR.