Biomaterial Database

p21 is necessary for the p53-mediated G1 arrest in human cancer cells. 1995

T Waldman, and K W Kinzler, and B Vogelstein

Johns Hopkins Oncology Center, Baltimore, Maryland 21231, USA.

DNA-damaging agents induce a p53-dependent G1 arrest that may be critical for p53-mediated tumor suppression. It has been suggested that p21WAF1/CIP1, a cdk inhibitory protein transcriptionally regulated by p53, is an effector of this arrest. To test this hypothesis, an isogenic set of human colon adenocarcinoma cell lines differing only in their p21 status was created. The parental cell line underwent the expected cell cycle changes upon induction of p53 expression by DNA damage, but the G1 arrest was completely abrogated in p21-deficient cells. These results unambiguously establish p21 as a critical mediator of one well-documented p53 function and have important implications for understanding cell cycle checkpoints and the mechanism(s) through which p53 inhibits human neoplasia.

UI	MeSH Term	Description	Entries
D003110	Colonic Neoplasms	Tumors or cancer of the COLON.	Cancer of Colon,Colon Adenocarcinoma,Colon Cancer,Cancer of the Colon,Colon Neoplasms,Colonic Cancer,Neoplasms, Colonic,Adenocarcinoma, Colon,Adenocarcinomas, Colon,Cancer, Colon,Cancer, Colonic,Cancers, Colon,Cancers, Colonic,Colon Adenocarcinomas,Colon Cancers,Colon Neoplasm,Colonic Cancers,Colonic Neoplasm,Neoplasm, Colon,Neoplasm, Colonic,Neoplasms, Colon
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D016158	Genes, p53	Tumor suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53.	Genes, TP53,TP53 Genes,p53 Genes,Gene, TP53,Gene, p53,TP53 Gene,p53 Gene
D016193	G1 Phase	The period of the CELL CYCLE preceding DNA REPLICATION in S PHASE. Subphases of G1 include "competence" (to respond to growth factors), G1a (entry into G1), G1b (progression), and G1c (assembly). Progression through the G1 subphases is effected by limiting growth factors, nutrients, or inhibitors.	First Gap Phase,G1a Phase,G1b Phase,Gap Phase 1,First Gap Phases,G1 Phases,G1a Phases,G1b Phases,Gap Phase, First,Gap Phases, First,Phase 1, Gap,Phase, First Gap,Phase, G1,Phase, G1a,Phase, G1b,Phases, First Gap,Phases, G1,Phases, G1a,Phases, G1b
D016213	Cyclins	A large family of regulatory proteins that function as accessory subunits to a variety of CYCLIN-DEPENDENT KINASES. They generally function as ENZYME ACTIVATORS that drive the CELL CYCLE through transitions between phases. A subset of cyclins may also function as transcriptional regulators.	Cyclin
D050759	Cyclin-Dependent Kinase Inhibitor p21	A cyclin-dependent kinase inhibitor that mediates TUMOR SUPPRESSOR PROTEIN P53-dependent CELL CYCLE arrest. p21 interacts with a range of CYCLIN-DEPENDENT KINASES and associates with PROLIFERATING CELL NUCLEAR ANTIGEN and CASPASE 3.	CDK2-Associated Protein 20 kDa,CDKN1 Protein,CDKN1A Protein,Cdk-Interacting Protein 1,Cdk2 Inhibitor Protein,Cell Cycle Regulator p21,Cyclin Kinase Inhibitor p21,Cyclin-Dependent Kinase Inhibitor 1A Protein,Senescent Cell-Derived Inhibitor Protein 1,p21 Cell Cycle Regulator,p21 Cyclin Kinase Inhibitor,CDK2 Associated Protein 20 kDa,Cdk Interacting Protein 1,Cyclin Dependent Kinase Inhibitor 1A Protein,Cyclin Dependent Kinase Inhibitor p21,Senescent Cell Derived Inhibitor Protein 1