title: Association between p21 Ser31Arg polymorphism and cancer risk: a meta-analysis.
abstract: P21 (CDKN1A), a key cell cycle regulatory protein that governs cell cycle progression from G1 to S phase, can regulate cell proliferation, growth arrest, and apoptosis. The Ser31Arg polymorphism is located in the highly conserved region of p21 and may encode functionally distinct proteins. Although many epidemiological studies have been conducted to evaluate the association between the p21 Ser31Arg polymorphism and cancer risk, the findings remain conflicting. This meta-analysis with 33 077 cases and 45 013 controls from 44 published case-control studies showed that the variant homozygous 31Arg/Arg genotype was associated with an increased risk of numerous types of cancers in a random-effect model (homozygote comparison: OR = 1.17, 95% CI = 0.99 to 1.37, P = 0.0002 for the heterogeneity test; recessive model comparison: OR = 1.16, 95% CI = 1.01 to 1.33, P = 0.0001 for the heterogeneity test). Stratified analysis revealed that increased cancer risk associated with the 31Arg/Arg genotype remained significant in subgroups of colorectal cancer, estrogen-related cancer, Caucasians, population-based studies, studies with matching information or a larger sample size. Heterogeneity analysis showed that tumor type contributed to substantial between-study heterogeneity (recessive model comparison: Χ(2) = 21.83, df = 7, P = 0.003). The results from this large-sample sized meta-analysis suggest that the p21 31Arg/Arg genotype may serve as a potential marker for increased cancer risk.
authors: Department of Epidemiology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. qwei@mdanderson.org.
authors: Hongxia
authors: H
authors: Ma
authors: Ziyuan
authors: Z
authors: Zhou
authors: Sheng
authors: S
authors: Wei
authors: Qingyi
authors: Q
authors: Wei
mesh_terms: D044466:Asian People / Q000235:genetics; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics*; D005787:Gene Frequency; D018740:Genetic Heterogeneity; D005838:Genotype; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012307:Risk Factors; D044465:White People / Q000235:genetics
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21