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Requirement of a functional spindle checkpoint for arsenite‐induced apoptosis
Author(s) -
Wu YiChen,
Yen WenYen,
Yih LingHuei
Publication year - 2008
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.21861
Subject(s) - mad2 , spindle checkpoint , mitosis , microbiology and biotechnology , cell cycle checkpoint , g2 m dna damage checkpoint , spindle apparatus , apoptosis , biology , cancer research , mitotic exit , cell cycle , chemistry , cell , cell division , anaphase , biochemistry
To understand the potential influence of spindle checkpoint function in response to arsenic trioxide (ATO)‐induced apoptosis observed in cancer cell lines, we examined the correlation between activation of the spindle checkpoint and susceptibility to ATO‐induced apoptosis in 10 cancer cell lines lacking functional p53. The ability to functionally activate the spindle checkpoint in each cancer cell line was assessed by the induction of mitotic arrest after Taxol treatment. Bromodeoxyuridine (BrdU) pulse‐chase analysis of Taxol‐treated cell lines with low mitotic arrest showed that they were not arrested at mitosis but divided abnormally, confirming that spindle checkpoint activation was impaired in these cell lines. Our results demonstrate that apoptosis was significantly induced by ATO in cancer cell lines with functional activation of the spindle checkpoint and substantial induction of mitotic arrest. Cell lines with negligible mitotic arrest exhibited little ATO‐induced apoptosis. However, no such correlation was observed following treatment of cells with camptothecin, a topoisomerase I inhibitor. Furthermore, attenuation of the spindle checkpoint function by small interfering RNA‐mediated silencing of BubR1 and Mad2 in cancer cells that were susceptible to ATO‐induced mitotic arrest and apoptosis greatly reduced the induction of mitotic arrest and apoptosis by ATO and increased the formation of micronuclei or multinuclei in survived cells. The marked correlation between ATO‐induced mitotic arrest and apoptosis indicates that the induction of apoptosis by ATO was highly dependent on the functional activation of the spindle checkpoint in cancer cells lacking normal p53 function. J. Cell. Biochem. 105: 678–687, 2008. © 2008 Wiley‐Liss, Inc.