Skip Navigation

Publication Detail

Title: Exit from arsenite-induced mitotic arrest is p53 dependent.

Authors: McNeely, Samuel C; Xu, Xiaogiang; Taylor, B Frazier; Zacharias, Wolfgang; McCabe Jr, Michael J; States, J Christopher

Published In Environ Health Perspect, (2006 Sep)

Abstract: Arsenic is both a human carcinogen and a chemotherapeutic agent, but the mechanism of neither arsenic-induced carcinogenesis nor tumor selective cytotoxicity is clear. Using a model cell line in which p53 expression is regulated exogenously in a tetracycline-off system (TR9-7 cells) , our laboratory has shown that arsenite disrupts mitosis and that p53-deficient cells [p53(-)], in contrast to p53-expressing cells [p53(+)], display greater sensitivity to arsenite-induced mitotic arrest and apoptosis.Our goal was to examine the role p53 plays in protecting cells from arsenite-induced mitotic arrest.p53(+) and p53(-) cells were synchronized in G2 phase using Hoechst 33342 and released from synchrony in the presence or absence of 5 microM sodium arsenite.Mitotic index analysis demonstrated that arsenite treatment delayed exit from G2 in p53(+) and p53(-) cells. Arsenite-treated p53(+) cells exited mitosis normally, whereas p53(-) cells exited mitosis with delayed kinetics. Microarray analysis performed on mRNAs of cells exposed to arsenite for 0 and 3 hr after release from G2 phase synchrony showed that arsenite induced inhibitor of DNA binding-1 (ID1) differentially in p53(+) and p53(-) cells. Immunoblotting confirmed that ID1 induction was more extensive and sustained in p53(+) cells.p53 promotes mitotic exit and leads to more extensive ID1 induction by arsenite. ID1 is a dominant negative inhibitor of transcription that represses cell cycle regulatory genes and is elevated in many tumors. ID1 may play a role in the survival of arsenite-treated p53(+) cells and contribute to arsenic carcinogenicity.

PubMed ID: 16966095 Exiting the NIEHS site

MeSH Terms: Apoptosis/drug effects*; Apoptosis/physiology; Arsenites/toxicity*; Benzimidazoles/pharmacology; Cell Cycle/drug effects*; Cell Cycle/physiology; Cells, Cultured; Dose-Response Relationship, Drug; G2 Phase/drug effects; G2 Phase/physiology; Genes, p53/drug effects*; Genes, p53/physiology; Humans; Inhibitor of Differentiation Protein 1/metabolism; Kinetics; Microarray Analysis; Mitosis/drug effects*; Mitosis/physiology; RNA, Messenger/metabolism; Sodium Compounds/toxicity; Time Factors

Back
to Top