title: Influence of p53 and p21Waf1 expression on G2/M phase arrest of colorectal carcinoma HCT116 cells to proteasome inhibitors.
abstract: Ubiquitin-mediated protein degradation in vertebrates has been implicated in cell cycle control. In this report we explored the effects of proteasome inhibitors (MG132, lactacystin and ALLN) on cell cycle distribution. Colorectal carcinoma HCT116 cells were treated with proteasome inhibitor MG132. The results showed that MG132 inhibited cell proliferation in a dose-dependent manner. MG132 arrested HCT116 cells at G2/M phase, which was associated with drug-induced blockade of p53 degradation and/or induction of p53-related gene expression along with the accumulation of cyclin B, cyclin A and p21. MG132 treated HCT116 (wild-type) had a similar cell cycle distribution as the MG132 treated HCT116 (p53-/-) and HCT116 (p21-/-) cells, suggesting that p53 and p21 may not be essential for MG132-induced G2/M phase arrest. The release experiments from nocodazole-induced mitotic phase cells indicated that MG132 inhibits the proliferation of HCT116 cells via arrest in the G2 phase. In addition, when HCT116 cells were exposed to combination of sodium butyrate and MG132 enhanced cell growth inhibition and induction of apoptosis were observed.
authors.affiliation: Department of Immunology, School of Medicine, Keimyung University, Taegu 700-712, South Korea.
authors.forename: On Hee
authors.initials: OH
authors.lastname: Kim
authors.forename: Jun Hee
authors.initials: JH
authors.lastname: Lim
authors.forename: Kyung Jin
authors.initials: KJ
authors.lastname: Woo
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Ing-Nyol
authors.initials: IN
authors.lastname: Jin
authors.forename: Sang Tae
authors.initials: ST
authors.lastname: Han
authors.forename: Jong-Wook
authors.initials: JW
authors.lastname: Park
authors.forename: Taeg Kyu
authors.initials: TK
authors.lastname: Kwon
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D002087:Butyrates / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism*; D003546:Cysteine Endopeptidases; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D016195:G2 Phase / Q000187:drug effects*; D006801:Humans; D007976:Leupeptins / Q000494:pharmacology; D008938:Mitosis / Q000187:drug effects*; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors; D046988:Proteasome Endopeptidase Complex; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D014452:Ubiquitins / Q000378:metabolism
chemical_list: D002087:Butyrates; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D015853:Cysteine Proteinase Inhibitors; D007976:Leupeptins; D009097:Multienzyme Complexes; D016159:Tumor Suppressor Protein p53; D014452:Ubiquitins; C067713:lactacystin; D020169:Caspases; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; D000111:Acetylcysteine