Association between the p53 codon 72 Arg/Pro polymorphism and hepatocellular carcinoma risk

Association of p53 codon 72 polymorphism with susceptibility to hepatocellular carcinoma in a Chinese population from northeast Sichuan

The p53 tumor suppressor gene is key in tumor development and progression, and the single nucleotide polymorphism (SNP) of the p53 gene codon 72 (p53Arg/Pro) changes the structure of the protein. In addition, it affects its activity, which may affect cancer risk. The aim of the present study was to investigate the association between p53 codon 72 polymorphism and susceptibility to hepatocellular carcinoma (HCC) in a Chinese population from northeast Sichuan. A total of 342 HCC patients and 347 non-cancer control subjects were recruited, and the polymorphism of p53 codon 72 was measured by TaqMan^® minor groove binder fluorescent quantitative polymerase chain reaction assay. The distribution frequency of p53 sites of arginine (Arg)/Arg, Arg/proline (Pro), Pro/Pro were 18.4, 48.8 and 32.8% in the control group, as compared with 18.7, 49.9 and 31.4% in the case group, which indicated that there was no difference between two groups (χ²=0.14; P=0.93). Upon further stratification with smoking, alcohol consumption, gender and hepatitis B virus (HBV) infection, no risk increasing genotype was identified. However, interactions between p53 codon 72 SNP and smoking, alcohol consumption and HBV infection may increase the risk of HCC [smoking odds ratio (OR), 2.00; 95% confidence interval (CI), 1.21-3.29; alcohol consumption OR, 1.87; 95% CI, 1.08-3.26; HBV infection OR, 1.84; 95% CI, 1.10-3.08]. No significant association was identified between p53 codon 72 polymorphism and HCC, and it may not have an independent effect on the susceptibility to HCC in a Chinese population from northeast Sichuan. However, interaction between genetic factors and environment exposure significantly increased the risk of HCC.

Evaluation of the p53 Arg72Pro polymorphism and its association with cancer risk: a HuGE review and meta-analysis

Codon 72 is a hotspot of polymorphisms in the TP53 gene, which encodes a hub protein in the protein-protein interaction network of p53. It is thus a central player in the apoptotic pathway, preventing cancer. A large number of articles have been published exploring its association with an increased susceptibility to most common cancers. However, these studies have produced inconclusive results, which may be due to their small sample sizes or study designs. To comprehensively evaluate the potential correlation between the TP53 Pro72Arg polymorphism and cancer risk and to better characterize the Pro72Arg polymorphism, we performed a systematic HuGE review and meta-analysis of candidate studies through online resources, according to the proposal of MOOSE and the PRISMA statement. The identified articles were carefully examined according to the inclusion criteria. Pooled odds ratios were calculated on the basis of different genetic models, while heterogeneity was assessed through a chi-based Q-test and I2. After applying the inclusion filters, we obtained a pool of 54 eligible studies, representing 18 718 cases and 21 261 controls. Overall, non-significant cancer risk was observed in all the genetic models but their observed heterogeneity was extremely significant. In subgroup analysis, an increased susceptibility was observed in the case of colorectal cancer, while in cancers of the female reproductive system, significantly increased risk was detected in all the genetic models except the dominant model. In another subgroup analysis, significantly increased cancer risk was observed among Asians in homozygous and recessive models, while in Americans increased cancer risk was observed only in dominant and recessive models. No association was observed in the rest of the populations. In conclusion, pooled subgroup analysis on the basis of ethnicity proved that the TP53 Arg72Pro polymorphism is associated with an increased risk of cancer in Asians and Americans only and is not associated in other populations. It can therefore be concluded that this meta-analysis of available data suggests partial confirmation of the association between the TP53 Arg72Pro polymorphism and cancer risk susceptibility.

Genetic factors, viral infection, other factors and liver cancer: an update on current progress

Primary liver cancer is one of the most common cancers at the global level, accounting for half of all cancers in some undeveloped countries. This disease tends to occur in livers damaged through alcohol abuse, or chronic infection with hepatitis B and C, on a background of cirrhosis. Various cancer-causing substances are associated with primary liver cancer, including certain pesticides and such chemicals as vinyl chloride and arsenic. The strong association between HBV infection and liver cancer is well documented in epidemiological studies. It is generally acknowledged that the virus is involved through long term chronic infection, frequently associated with cirrhosis, suggesting a nonspecific mechanism triggered by the immune response. Chronic inflammation of liver, continuous cell death, abnormal cell growth, would increase the occurrence rate of genetic alterations and risk of disease. However, the statistics indicated that only about one fifth of HBV carries would develop HCC in lifetime, suggesting that individual variation in genome would also influence the susceptibility of HCC. The goal of this review is to highlight present level of knowledge on the role of viral infection and genetic variation in the development of liver cancer.

Association between polymorphisms in tumor suppressor genes and oncogenes and risk of hepatocellular carcinoma: a case-control study in an HCC epidemic area within the Han Chinese population

Data concerning the risk of hepatocellular carcinoma (HCC) and specific single nucleotide polymorphisms (SNPs) in an HBV-free population are currently limited. Therefore, we performed a case-control study to investigate the association between SNPs and the risk of HCC in individuals without chronic HBV infection. A total of 160 Han Chinese patients with HCC and an identical number of healthy controls were enrolled in this study. rs1042522, rs10814325, rs17401966, and rs2279744 genotypes were determined using matrix-associated laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS). CG and GG genotypes in rs1042522 and heterozygote and homozygote in rs2279744 were significantly associated with an elevated risk of HCC. Homozygous mutation of rs1081432 conferred a 2.68-fold risk of HCC (95% CI 1.35-5.34); however heterozygosity was not statistically significant. rs17401966 heterozygosity or homozygosity was not significantly associated with a increased risk of HCC. Several polymorphisms associated with a significantly increased risk of HCC were identified. These may serve as biomarkers in evaluating HCC risk in the general population.

Association between murine double minute 2 T309G polymorphism and risk of liver cancer

During the past decade, a number of studies were published to evaluate the association between murine double minute 2 (MDM2) T309G polymorphism and risk of liver cancer. However, the association between MDM2 T309G polymorphism and risk of liver cancer was still unclear owing to the conflicting results from those published studies. An undated meta-analysis of all eligible studies was carried out to comprehensively assess the association. The pooled odds ratio (OR) with 95 % confidence interval (95% CI) was used to evaluate the association between MDM2 T309G polymorphism and risk of liver cancer. Finally, ten studies with a total of 2,243 cases and 3,471 controls were finally included into the meta-analysis. Overall, there was an association between MDM2 T309G polymorphism and risk of liver cancer (G vs. T: OR=1.39, 95% CI 1.17-1.64, P<0.001; GG vs. TT: OR=1.87, 95% CI 1.34-2.62, P<0.001; GG/GT vs. TT: OR=1.61, 95 % CI 1.24-2.08, P<0.001). Subgroup analysis in Europeans showed that there was also an association between MDM2 T309G polymorphism and risk of liver cancer in Europeans (G vs. T: OR=1.81, 95% CI 1.45-2.27, P<0.001; GG vs. TT: OR=3.26, 95% CI 1.99-5.32, P<0.001; GG/GT vs. TT: OR=2.20, 95% CI 1.58-3.07, P<0.001). Subgroup analysis in Asians showed that there was also an association between MDM2 T309G polymorphism and risk of liver cancer in Asians (G vs. T: OR=1.27, 95% CI 1.06-1.52, P=0.010; GG vs. TT: OR=1.59, 95% CI 1.11-2.27, P=0.011; GG/GT vs. TT: OR=1.41, 95% CI 1.07-1.87, P=0.016). The meta-analysis provides a strong evidence for the association between MDM2 T309G polymorphism and risk of liver cancer.

The NQO1 C609T polymorphism and hepatocellular carcinoma risk

NAD(P)H quinine oxidoreductase 1 (NQO1) enzyme plays a crucial role in the protection against oxidative stress. The polymorphism of NQO1 C609T has been implicated in the development of hepatocellular carcinoma (HCC). However, the findings were inconsistent due to different ethnicity, sample size, and source of controls in individual studies. To better estimate the association of NQO1 C609T polymorphism with HCC risk, we performed a meta-analysis of all currently available studies on the susceptibility to HCC. The meta-analysis included three independent studies with a total of 1, 595 subjects. The association was assessed under five different gene models. The overall analysis suggested that the variant allele and genotypes were significantly related to increased risk of HCC (ORT vs. C = 1.47, 95 % CI 1.07-2.00, P OR = 0.016; ORTT vs. CC = 2.06, 95 % CI 1.06-3.98, P OR = 0.032; ORTC vs. CC = 1.33, 95 % CI 1.06-1.67, P OR = 0.012; ORTT + TC vs. CC = 1.46, 95 % CI 1.19-1.81, P OR < 0.001; ORTT vs. CC + TC = 1.62, 95 % CI 1.25-2.09, P OR < 0.001). Stratified analyses in Asians and hospital-based case-control studies further demonstrated the significant correlation. Sensitivity analysis confirmed the reliability of these findings. Our study firstly shows that individuals carrying the NQO1 C609T variant allele and genotypes are more susceptible to HCC, particularly for Asians.

TP53 and MDM2 gene polymorphisms, gene-gene interaction, and hepatocellular carcinoma risk: evidence from an updated meta-analysis

Background

The association between TP53 R72P and/or MDM2 SNP309 polymorphisms and hepatocellular carcinoma (HCC) risk has been widely reported, but results were inconsistent. To clarify the effects of these polymorphisms on HCC risk, an updated meta-analysis of all available studies was conducted.

Methods

Eligible articles were identified by search of databases including PubMed, Cochrane Library, EMBASE and Chinese Biomedical Literature database (CBM) for the period up to July 2013. Data were extracted by two independent authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Metaregression and subgroup analyses were performed to identify the source of heterogeneity.

Results

Finally, a total of 10 studies including 2,243 cases and 3,615 controls were available for MDM2 SNP309 polymorphism and 14 studies containing 4,855 cases and 6,630 controls were included for TP53 R72P polymorphism. With respect to MDM2 SNP309 polymorphism, significantly increased HCC risk was found in the overall population. In subgroup analysis by ethnicity and hepatitis virus infection status, significantly increased HCC risk was found in Asians, Caucasians, Africans, and HCV positive patients. With respect to TP53 R72P polymorphism, no significant association with HCC risk was observed in the overall and subgroup analyses. In the MDM2 SNP309–TP53 R72P interaction analysis, we found that subjects with MDM2 309TT and TP53 Pro/Pro genotype, MDM2 309 TG and TP53 Arg/Pro genotype, and MDM2 309 GG and TP53 Pro/Pro genotype were associated with significantly increased risk of developing HCC as compared with the reference MDM2 309TT and TP53 Arg/Arg genotype.

Conclusions

We concluded that MDM2 SNP309 polymorphism may play an important role in the carcinogenesis of HCC. In addition, our findings further suggest that the combination of MDM2 SNP 309 and TP53 Arg72Pro genotypes confers higher risk to develop HCC. Further large and well-designed studies are needed to confirm this association.

The association between polymorphism of P53 Codon72 Arg/Pro and hepatocellular carcinoma susceptibility: evidence from a meta-analysis of 15 studies with 3,704 cases

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.

The association between polymorphism of P53 codon 72 Arg/Pro and hepatocellular carcinoma susceptibility: evidence from a meta-analysis of 15 studies with 3704 cases

BACKGROUND

Emerging evidence has shown that p53gene participates in human carcinogenesis as tumor suppressors. Polymorphism of p53 gene codon 72 Arg/Pro (rs1042522) may influence the function of p53 protein and then affect the processing of carcinogenesis. It has been suggested that p53 codon 72 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.

METHODOLOGY/PRINCIPAL FINDINGS

We have conducted a search of case-control studies on the associations of p53 codon 72 polymorphism with susceptibility to HCC in PubMed, ScienceDirect, Bio-Med central, Springer-link, EBSCO, Wanfang databases and Chinese National Knowledge Infrastructure (CNKI) databases. A total of 15 studies were identified with 3704 cases and 4559 controls for codon 72 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.

CONCLUSIONS/SIGNIFICANCE

This meta-analysis suggests that p53 codon 72 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.

Significant association between MTHFR C677T polymorphism and hepatocellular carcinoma risk: a meta-analysis

Previous studies investigated the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and hepatocellular carcinoma risk, but the impact of MTHFR C677T polymorphism on hepatocellular carcinoma was still unclear, owing to the obvious inconsistence from those studies. This study aimed to quantify the strength of the association between MTHFR C677T polymorphism and hepatocellular carcinoma risk by performing a meta-analysis. We searched the PubMed and Wanfang databases for studies on the association between MTHFR C677T polymorphism and hepatocellular carcinoma risk. We estimated the pooled odds ratios (ORs) with their 95% confidence intervals (95% CIs) to assess the association. Fifteen studies with 8,625 participants were finally included into the meta-analysis. Meta-analyses of total 15 studies suggested that MTHFR C677T polymorphism was significantly associated with an increased risk of hepatocellular carcinoma under two main genetic models (for TT versus CC, OR = 1.19, 95% CI 1.03-1.37, P = 0.016; for TT versus CT/CC, OR = 1.14, 95% CI 1.01-1.28, P = 0.032). Subgroup meta-analyses suggested that MTHFR C677T polymorphism was associated with an increased risk of hepatocellular carcinoma in Asians, but not in Caucasians. Thus, individuals with homozygote genotype TT of MTHFR C677T have obviously increased risk of hepatocellular carcinoma.