Induction of centrosome amplification during arsenite-induced mitotic arrest in CGL-2 cells.
Arsenite-induced mitotic abnormalities result in mitotic death in several cancer cell lines. However, how arsenite induces these effects is not known. We have previously shown that arsenite induces mitotic arrest, mitotic abnormalities, and mitotic death in CGL-2 cells. To further delineate the mechanism of action of arsenite, we examined its effect on centrosome duplication and the possible link between centrosome dysregulation and arsenite-induced mitotic death. Immunofluorescence staining of gamma-tubulin revealed that centrosome amplification was induced in arsenite-arrested mitotic cells but not in nocodazole-arrested cells. When S phase-enriched cells were treated with arsenite, they progressed into and arrested at mitosis and then formed supernumerary centrosomes. A further increase in arsenite-induced centrosome amplification was seen during the prolonged mitotic arrest. The arsenite-induced supernumerary centrosomes might result from uneven fragmentation of centrosome, overexpression of pericentriolar materials, and inhibition of centrosomal coalescence during mitosis. Furthermore, termination of mitotic arrest by treatment of arsenite-arrested mitotic cells with cyclin-dependent kinase 1 inhibitors or by suppression of spindle checkpoint function by small interfering RNA-mediated silencing of BubR1 or Mad2 markedly reduced the induction of centrosome amplification and mitotic death in arsenite-treated cells. These results indicate that centrosome amplification is induced in arsenite-arrested mitotic CGL-2 cells in a spindle checkpoint-dependent manner and is involved in the induction of arsenite-induced mitotic death.
Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China.
Ling-Huei
LH
Yih
Yun-Yu
YY
Tseng
Yi-Chen
YC
Wu
Te-Chang
TC
Lee
D017209:Apoptosis / Q000187:drug effects; D018053:Arsenites / Q000494:pharmacology*; D016203:CDC2 Protein Kinase / Q000037:antagonists & inhibitors; D018385:Centrosome / Q000187:drug effects* / Q000502:physiology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis / Q000187:drug effects; D008941:Spindle Apparatus / Q000187:drug effects
D018053:Arsenites; D016203:CDC2 Protein Kinase; C015001:arsenite