p53 Suppression of Arsenite-Induced Mitotic Catastrophe Is Mediated by p21^CIP1/WAF1

Abstract

Arsenic trioxide, an acute promyelocytic leukemia chemotherapeutic, may be an efficacious treatment for other cancers. Understanding the mechanism as well as genetic and molecular characteristics associated with sensitivity to arsenite-induced cell death is key to providing effective chemotherapeutic usage of arsenite. Arsenite sensitivity correlates with deficient p53 pathways in multiple cell lines. The role of p53 in preventing arsenite-induced mitotic arrest-associated apoptosis (MAAA), a form of mitotic catastrophe, was examined in TR9-7 cells, a model cell line with p53 exogenously regulated in a tetracycline-off expression system. Arsenite activated G 1 and G 2 cell cycle checkpoints independently of p53, but mitotic catastrophe occurred preferentially in p53 inhibit cyclin B/CDC2 by CDC2 tyrosine-15 phosphorylation and direct binding, respectively. CDC2-Y15-P was transiently elevated in arsenite-treated p53 (ϩ) cells but persisted in p53 (Ϫ) cells. Arsenite induced p53-S15-P and p21 CIP1/WAF1 only in p53 (ϩ) cells. P21 CIP1/WAF1 -siRNA-treated p53 (ϩ) cells were similar to p53(Ϫ) cells in mitotic index and cell cycle protein levels. p53-inducible proteins GADD45␣ and 14-3-3 are capable of inhibiting cyclin B/CDC2 but did not play a p53-dependent role in mitotic escape in TR9-7 cells. The data indicate that p53 mediates cyclin B/CDC2 inactivation and mitotic release directly via p21 CIP1/WAF1 induction.

Sensitivity to sodium arsenite in human melanoma cells depends upon susceptibility to arsenite-induced mitotic arrest

“…Our previous studies and those of others have demonstrated that arsenite-induced apoptosis is associated with arrest in mitosis (States et al, 2002;Taylor et al, 2006;McCollum et al, 2003;Huang et al, 2000;Ling et al, 2002). Therefore, we examined cell cycle distribution with flow cytometry and mitotic index analysis.…”

“…SK-Mel-3 cells treated with high concentrations of arsenite alone and at lower concentrations of arsenite in combination with either BSO or MK571 accumulated in the S-phase compartment ( Figure 6A). We previously observed an arsenite-induced accumulation of fibroblasts with Sphase DNA content that was subsequently found not to consist of S-phase cells but rather degenerating G 2 cells (Taylor, McNeely, Miller, Lehmann, McCabe, Jr., and States, 2006). To examine if a similar phenomenon was occurring in the SK-Mel-3 cells, cultures were treated for flow cytometric analysis as before with the exception that they were pulsed with 10 µM 5-bromo-2'-deoxyuridine (BrdU) for 1 h prior to harvest at 12 and 24 h to specifically label the S-phase cells.…”

“…Assays were performed as described previously (Taylor et al, 2006). Briefly, 2,500 to 5,000 cells were seeded per well in 96-well plates and allowed to attach overnight.…”

Harnessing the complexity of DNA-damage response pathways to improve cancer treatment outcomes

“…Mitotic catastrophe (MC) has been reported as a prominent response to different anticancer drugs that affect cytoskeletal components and include microtubule toxins (Tounekti et al, 1993;Lock and Stribinskiene, 1996;Torres and Horwitz, 1998;Taylor et al, 2006), radiotherapy (Streffer et al, 1986;Falkvoll, 1990;Zolzer et al, 1995;Bhattathiri et al, 1998;Widel et al, 1999) and chemotherapy (Yashige et al, 1999). Cell cycle checkpoint inhibitors in combination with DNA-damaging agents enhance MC by inducing 'mitotic slippage'.…”

Subhepatotoxic exposure to arsenic enhances lipopolysaccharide-induced liver injury in mice

“…For example, arsenic delays progression through each cell cycle phase, and also causes an arrest at the G 1 /S and G 2 /M transitions (McCabe, Jr. et al, 2000;McCollum et al, 2005;McNeely et al, 2006;Taylor et al, 2006). Furthermore, Suzuki and Tsukamoto (2006) demonstrated that acute arsenic exposure impaired the normal proliferative response in rat liver after partial hepatectomy.…”