Impact of codon 72 Arg > Pro single nucleotide polymorphism in TP53 gene in the risk of kangri cancer: a case control study in Kashmir

Sex Disparities in P53 Regulation and Functions: Novel Insights for Personalized Cancer Therapies

Epidemiological studies have revealed significant sex differences in the incidence of tumors unrelated to reproductive functions, with females demonstrating a lesser risk and a better response to therapy than males. However, the reasons for these disparities are still unknown and cancer therapies are generally sex-unbiased. The tumor-suppressor protein p53 is a transcription factor that can activate the expression of multiple target genes mainly involved in the maintenance of genome stability and tumor prevention. It is encoded by TP53, which is the most-frequently mutated gene in human cancers and therefore constitutes an attractive target for therapy. Recently, evidence of sex differences has emerged in both p53 regulations and functions, possibly providing novel opportunities for personalized cancer medicine. Here, we will review and discuss current knowledge about sexual disparities in p53 pathways, their role in tumorigenesis and cancer progression, and their importance in the therapy choice process, finally highlighting the importance of considering sex contribution in both basic research and clinical practice.

Role of Sex in the Therapeutic Targeting of p53 Circuitry

Sex profoundly affects cancer incidence and susceptibility to therapy, with sex hormones highly contributing to this disparity. Various studies and omics data suggest a relationship between sex and the oncosuppressor p53 circuitry, including its regulators MDM2 and MDM4. Association of this network with genetic variation underlies sex-related altered cancer risk, age of onset, and cancer sensitivity to therapy. Moreover, sex-related factors, mainly estrogenic hormones, can affect the levels and/or function of the p53 network both in hormone-dependent and independent cancer. Despite this evidence, preclinical and clinical studies aimed to evaluate p53 targeted therapy rarely consider sex and related factors. This review summarizes the studies reporting the relationship between sex and the p53 circuitry, including its associated regulators, MDM2 and MDM4, with particular emphasis on estrogenic hormones. Moreover, we reviewed the evaluation of sex/hormone in preclinical studies and clinical trials employing p53-target therapies, and discuss how patients’ sex and hormonal status could impact these therapeutic approaches.

Association of the TP53 rs1042522 C>G polymorphism and hepatoblastoma risk in Chinese children

The TP53 gene encodes an important class of cell cycle and tumor-suppressing factors that play critical roles in maintaining genomic stability. The TP53 Arg72Pro (rs1042522 C>G) polymorphism has been reported to be associated with the risk of several types of adult cancers; however, its risk for pediatric cancers remains unclear. Here, we analyzed the association of the TP53 gene rs1042522 C>G polymorphism with hepatoblastoma (HB) susceptibility in a hospital-based study among Chinese children. A total of 213 HB patients and 958 healthy controls were enrolled in the study. Genotypes were determined by a TaqMan assay, and the strength of the association was assessed by the odds ratios and 95% confidence intervals generated from logistic regression models, adjusted for age, gender, and clinical stage. No significant association between the TP53 rs1042522 C>G polymorphism and HB susceptibility was detected in the main analysis or in stratification analyses of age, gender, and clinical stages. Overall, the TP53 gene rs1042522 C>G polymorphism is not associated with HB susceptibility in the Chinese population, other polymorphisms alone or in combination should be investigated to further clarify HB susceptibility.

Meta-analysis of association between the TP53 Arg72Pro polymorphism and risk of endometriosis based on case-control studies

OBJECTIVE

In the light of the relationship between the TP53 Arg72Pro (rs1042522) polymorphism and the risk of endometriosis remains inclusive or controversial. For better understanding of the effect of TP53 Arg72Pro polymorphism on endometriosis risk, we performed a meta-analysis.

METHODS

The relevant studies were identified through a search of PubMed, Web of Science, EMBASE, Ovid, Springer, China National Knowledge Infrastructure (CNKI), cqvip, Wanfang database, and Chinese Biomedical Literature (CBM) databases up to December, 2014. The association between the TP53 Arg72Pro polymorphism and endometriosis risk was pooled by conducted by odds ratios and 95% confidence intervals.

RESULTS

A total of fifteen case-control studies with 2683 cases and 3335 controls were eventually identified. There was significant association between Arg72Pro polymorphism and endometriosis risk in all of the five models in overall populations (C vs. G: OR=1.32, 95%CI=1.14-1.53, p=0.00; CC vs. GG: OR=1.80, 95%CI=1.28-2.53, p=0.001; GC vs. GG: OR=1.52, 95%CI=1.22-1.88, p=0.00; CC vs.

GC/GG

OR=1.32, 95%CI=1.05-1.66, p=0.016; CC/GC vs. GG: OR=1.59, 95%CI=1.26-2.00, p=0.00). In the sub-group analysis according to ethnicity, the results suggested that TP53 Arg72Pro polymorphism was not associated with endometriosis risk in Caucasians. However, the significant association was found in Asians and Mixed race (MIX) under the five models.

CONCLUSIONS

The results of this meta-analysis suggest that the TP53 Arg72Pro polymorphism can increase the risk of endometriosis, especially among Asians and MIX populations. Considering the limited sample size and ethnicities included in the meta-analysis, further larger scaled and well-designed studies are needed to confirm our results.

Novel medical strategies combating nonmelanoma skin cancer

The incidence of nonmelanoma skin cancer (NMSC) continues to rise, partly because of aging, the frequency of early childhood sunburns, and sporadic extreme recreational sun exposure. A nonsurgical approach to selected cutaneous malignancy could possibly reduce the cost as well as morbidity of surgical treatment for NMSC. There has been growing interest in isolating compounds that could suppress or reverse the biochemical changes necessary for cutaneous malignancies to progress by pharmacologic intervention. By targeting diverse pathways recognized as important in the pathogenesis of nonmelanoma skin cancers, a combination approach with multiple agents or addition of chemopreventative agents to topical sunscreens may offer the potential for novel and synergistic therapies in treating nonmelanoma skin cancer. This preliminary information will expand to include more therapeutic options for NMSC in the future.

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.

Arg72Pro polymorphism of TP53 gene and the risk of skin cancer: a meta-analysis

Background

TP53 gene is one of the most important tumor suppressor genes. We undertook this meta-analysis to explore the association between TP53 Arg72Pro polymorphism and the risk of skin cancer mainly in Caucasians.

Methods

We searched PubMed for case-control studies published up to March 2013. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association.

Results

A total of 5276 skin cancer cases and 5315 controls from 20 studies were included. Overall, no significant association between TP53 Arg72Pro polymorphism and skin cancer was observed in all genetic contrast models (Pro/Pro versus Arg/Arg, Pro/Arg versus Arg/Arg, Pro/Pro + Pro/Arg versus Arg/Arg, Pro/Pro versus Arg/Arg + Pro/Arg, Pro allele versus Arg allele). Similar results were obtained in the stratified analysis by ethnicity and histological types of skin cancer, such as melanoma, squamous cell carcinoma and basal cell carcinoma. Power calculations indicated that some studies were underpowered. No publication bias was found by using the funnel plot and Egger's test.

Conclusions

This meta-analysis indicated that TP53 Arg72Pro polymorphism probably had little association with skin cancer susceptibility mainly in Caucasians. However, larger sample-size studies are required to verify the conclusion as low statistical powers.

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.

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

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.