Mitotic arrest and JNK-induced proteasomal degradation of FLIP and Mcl-1 are key events in the sensitization of breast tumor cells to TRAIL by antimicrotubule agents

作者：Sanchez Perez T; Ortiz Ferron G; Lopez Rivas A^*

来源：Cell Death and Differentiation, 2010, 17(5): 883-894.

DOI：10.1038/cdd.2009.176

• apoptosis
• TRAIL
• mitotic arrest
• JNK
• cFLIP
• Mcl-1

Breast tumor cells are often resistant to tumor necrosis factor-related apoptosis-inducing ligand (tumour necrosis factor-related apoptosis-inducing ligand (TRAIL)/APO-2 L). Here, we describe the sensitization by microtubule-interfering agents (MIAs) to TRAIL-induced apoptosis in breast tumor cells through a mitotic arrest and c-Jun N-terminal kinase (JNK)-dependent mechanism. MIA treatment resulted in BubR1-dependent mitotic arrest leading to the sustained activation of JNK and the proteasome-mediated downregulation of cellular FLICE-inhibitory protein (cFLIP) and myeloid cell leukemia-1 (Mcl-1) expression. The JNK inhibitor SP600125 abrogated MIA-induced mitotic arrest and downregulation of cFLIP and Mcl-1 and reduced the apoptosis caused by the combination of MIAs and TRAIL. Silencing of cFLIP and Mcl-1 expression by RNA interference resulted in a marked sensitization to TRAIL-induced apoptosis. Furthermore, in FLIP-overexpressing cells, MIA-induced sensitization to TRAIL-activated apoptosis was markedly reduced. In summary, our results show that mitotic arrest imposed by MIAs activates JNK and facilitates TRAIL-induced activation of an apoptotic pathway in breast tumor cells by promoting the proteasome-mediated degradation of cFLIP and Mcl-1. Cell Death and Differentiation (2010) 17, 883-894; doi:10.1038/cdd.2009.176; published online 27 November 2009

• 出版日期2010-5