p53 codon 72 polymorphism is associated with susceptibility to hepatocellular carcinoma in the Turkish population: a case-control study.
ABSTRACT The tumor suppressor p53 gene plays a crucial role in preventing carcinogenesis through its ability to induce cell cycle arrest and apoptosis following DNA damage and oncogene activation. A guanine (G)/cytosine (C) common single nucleotide polymorphism (SNP) at second position of codon 72 in exon 4 of p53 gene determines a arginine (Arg) to proline (Pro) (Arg72Pro) aminoacidic substitution within the proline-rich domain of p53 protein. Arg72 and Pro72 allele are different from a biochemical and biological point of view and many reports suggest that they can modulate individual cancer susceptibility. To determine the association of the p53 Arg72Pro polymorphism with the risk of hepatocellular carcinoma (HCC) development in a Turkish population, a hospital-based case-control study was designed consisting of 119 subjects with HCC and 119 cancer-free control subjects matched for age, gender, smoking and alcohol status. The genotype frequency of the p53 Arg72Pro polymorphism was determined by using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Our data shows that the Pro/Pro genotype of the p53 Arg72Pro polymorphism is associated with increased risk of HCC development in this Turkish population (OR = 3.20, 95% CI: 1.24-8.22, P = 0.02). Furthermore, according to stratified analysis, a significant association was observed between the homozygote Pro/Pro genotype and HCC risk in the subgroups of male gender (OR = 3.01, 95% CI: 1.14-7.97, P = 0.03) and patients with hepatitis B virus (HBV)-related HCC (OR = 4.04, 95% CI: 1.46-11.15, P = 0.007). Because our results suggest for the first time that the Pro/Pro homozygote of p53 Arg72Pro polymorphism may be a genetic susceptibility factor for HCC (especially in the male gender and HBV-infected patients) in the Turkish population, further independent studies are required to validate our findings in a larger series, as well as in patients of different ethnic origins.
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ABSTRACT: Emerging evidence has shown that p53gene participates in human carcinogenesis as tumor suppressors. Polymorphism of p53 gene codon72 arginine (Arg)/proline (Pro) (rs1042522) may influence the function of p53 protein and then affect the processing of carcinogenesis. It has been suggested that p53 codon72 Arg/Pro polymorphism is associated with susceptibility to hepatocellular carcinoma (HCC). However, published results are inconsistent and inconclusive. To examine the validity of the association between the polymorphism and HCC risk, we performed this meta-analysis. We have conducted a search of case-control studies on the associations of p53 codon72 polymorphism with susceptibility to HCC in PubMed, ScienceDirect, BioMed central, Springer, EBSCO, Wanfang databases, and Chinese National Knowledge Infrastructure databases. A total of 15 studies were identified with 3,704 cases and 4,559 controls for codon72 Arg/Pro polymorphism. The result did support a significant genetic association between Pro allele and susceptibility to HCC in all the genetic models. Similarly, subgroup analysis showed significant associations between the Arg/Pro polymorphism and susceptibility to HCC when stratifying by race, gender, source of controls, and hepatitis virus infection status. This meta-analysis suggests that p53 codon72 Arg/Pro polymorphism may be associated with the risk of HCC, especially in subgroup analysis of Asian and Caucasian population, hospital-based population, the female, and the individuals infected with hepatitis virus. However, well-designed studies based on different ethnic groups with larger sample size and more detailed data are needed to confirm these conclusions.Tumor Biology 12/2013; · 2.52 Impact Factor
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ABSTRACT: Previous studies regarding the association of p53 codon 72 Arg/Pro polymorphism with hepatocellular carcinoma (HCC) risk have provided conflicting and inconclusive findings. Thus, a meta-analysis of all currently available publications was performed to address this issue. Eleven individual case-control studies involving a total of 2,718 cases and 3,752 controls were identified after a systematic search of the PubMed, Embase, Web of Science, and Wanfang databases. The strength of the association of p53 codon 72 Arg/Pro polymorphism with HCC risk was estimated by the pooled odds ratio (OR) with its corresponding 95 % confidence interval (95 % CI). Subgroup analyses stratified by ethnicity, source of controls, gender, hepatitis virus infection status, and family history of HCC were also conducted to assess the association. Overall, significantly increased risk of HCC was identified among carriers of the homozygous genotype ProPro (ORProPro vs. ArgArg = 1.38 (95 % CI, 1.03-1.85), P OR = 0.033; ORProPro vs. ArgArg + ArgPro = 1.28 (95 % CI, 1.03-1.59), P OR = 0.026). In subgroup analysis by ethnicity, the pooled results suggested that the p53 codon 72 Arg/Pro polymorphism was associated with an increased risk of HCC in Asians and Caucasians (for Asians, ORProPro vs. ArgArg + ArgPro = 1.17 (95 % CI, 1.02-1.34), P OR = 0.025; for Caucasians, ORProPro vs. ArgArg = 1.65 (95 % CI, 1.07-2.56), P OR = 0.025; ORProPro vs. ArgArg + ArgPro = 1.74 (95 % CI, 1.14-2.66), P OR = 0.010). Subgroup analyses by source of controls and hepatitis virus infection status further demonstrated the significant association, whereas stratification factors involving gender and family history of HCC did not modify the association between p53 codon 72 Arg/Pro polymorphism and HCC risk. This meta-analysis suggests that the p53 codon 72 Arg/Pro polymorphism may play a critical role in the development of HCC, and gender and family history of HCC may not modulate the effect of p53 codon 72 Arg/Pro in HCC risk.Tumor Biology 04/2013; · 2.52 Impact Factor
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ABSTRACT: Growing evidence suggests that the angiotensin-converting enzyme (ACE) and endothelial nitric oxide synthase (eNOS) genes are associated with risk in a wide range of cancers. The objective of this study was to examine whether two DNA polymorphisms at the ACE insertion/deletion (I/D) and the variable number of tandem repeats in NOS intron 4 (4a/4b) were linked to the risk of developing hepatocellular carcinoma (HCC) in a Chinese population. The polymorphisms at ACE I/D and eNOS 4a/4b were genotyped in 293 HCC patients and 384 healthy control subjects using polymerase chain reaction. The frequencies of the D allele (p=0.003, OR=0.72, 95% CI=0.58-0.90) in the ACE gene of HCC patients were significantly different from the healthy controls, and a significantly decreased HCC risk was associated with the DD genotype in both the recessive (p<0.001, OR=0.19, 95% CI=0.11-0.34) and codominant models (p<0.001, OR=0.26, 95% CI=0.14-0.48). This study provided evidence that the ACE I/D polymorphism is associated with HCC, indicating that the ACE I/D polymorphism contributes to HCC progression in the Chinese population.DNA and cell biology 04/2013; · 2.28 Impact Factor