Quantitative assessment of the association between TP53 Arg72Pro polymorphism and bladder cancer risk

Genetic Polymorphisms Involved in Bladder Cancer: A Global Review

Bladder cancer (BC) has been associated with genetic susceptibility. Single peptide polymorphisms (SNPs) can modulate BC susceptibility. A literature search was performed covering the period between January 2000 and October 2020. Overall, 334 articles were selected, reporting 455 SNPs located in 244 genes. The selected 455 SNPs were further investigated. All SNPs that were associated with smoking and environmental exposure were excluded from this study. A total of 197 genes and 343 SNPs were found to be associated with BC, among which 177 genes and 291 SNPs had congruent results across all available studies. These genes and SNPs were classified into eight different categories according to their function.

Bladder Cancer Genetic Susceptibility. A Systematic Review

Background:

The variant/gene candidate approach to explore bladder cancer (BC) genetic susceptibility has been applied in many studies with significant findings reported. However, results are not always conclusive due to the lack of replication by subsequent studies.

Objectives:

To identify all epidemiological investigations on the genetic associations with BC risk, to quantify the likely magnitude of the associations by applying metaanalysis methodology and to assess whether there is a potential for publication/reporting bias.

Methods:

To address our aims, we have catalogued all genetic association studies published in the field of BC risk since 2000. Furthermore, we metaanalysed all polymorphisms with data available from at least three independent case-control studies with subjects of Caucasian origin analyzed under the same mode of inheritance.

Results:

The characterization of the genetic susceptibility of BC is composed of 28 variants, GWAS contributing most of them. Most of the significant variants associated with BC risk are located in genes belonging to chemical carcinogenesis, DNA repair, and cell cycle pathways. Causal relationship was also provided by functional analysis for GSTM1-null, NAT2-slow, APOBEC-rs1014971, CCNE1-rs8102137, SLC14A1-rs10775480, PSCA-rs2294008, UGT1A-rs1189203, and TP63-rs35592567.

Conclusions:

Genetic susceptibility of BC is still poorly defined, with GWAS contributing most of the strongest evidence. The systematic review did not provide evidence of further genetic associations. The potential public health translation of the existing knowledge on genetic susceptibility on BC is still limited.

TP53 Arg72Pro polymorphism (rs1042522) and risk of endometriosis among Asian and Caucasian populations

This study was conducted to investigate the association between TP53 Arg72Pro polymorphism (rs1042522) and risk of endometriosis. Studies were retrieved from Pubmed, Embase and HuGENet, and four models [dominant (AA+AG vs. GG), recessive (AA vs. AG+GG), co-dominant (AA vs. AG, AA vs. GG) and allele analysis (A vs. G), combined with odds ratios (OR) and 95% confidence intervals (CI)], were applied to evaluate this association. Fourteen eligible studies from eight countries were included. The pooled analysis identified a significant association between TP53 Arg72Pro polymorphism (rs1042522) and risk of endometriosis [dominant: OR 0.746, 95% CI 0.585-0.952, I(2)=59%; recessive: OR 0.650, 95% CI 0.510-0.829, I(2)=73%; co-dominant (GG vs. GC): OR 0.676, 95% CI 0.637-0.851, I(2)=67%; co-dominant (GG vs. CC): OR 0.564, 95% CI 0.395-0.806, I(2)=74%; allele analysis: OR 0.762, 95% CI 0.654-0.888, I(2)=71%]. In the subgroup analysis, the same positive associations were found among Asians. After removing studies that did not satisfy Hardy-Weinberg equilibrium, significant correlations were confirmed in both the pooled analysis and the Asian subgroup. Three bioinformatic methods (TagSNP calculations, functional prediction and linkage disequilibrium analysis) were used to determine the importance of TP53 Arg72Pro polymorphism (rs1042522), and suggested that this locus may be equally important regardless of ethnicity. In conclusion, TP53 Arg72Pro polymorphism (rs1042522) was positively associated with risk of endometriosis, particularly among Asians. However, its potential role in Caucasians should not be ignored.

p53 Status correlates with the risk of recurrence in non-muscle invasive bladder cancers treated with Bacillus Calmette-Guérin: a meta-analysis

Objective

Published studies have yielded inconsistent results on the relationship between p53 status and the prognosis of non-muscle invasive bladder cancer (NMIBC) treated with Bacillus Calmette–Guérin (BCG) intravesical therapy. Therefore, we performed a meta-analysis to evaluate the prognostic value of p53 in NMIBC treated with BCG.

Methods

We systematically searched for relevant literature in PubMed, EMBASE, CNKI, and Chinese Wanfang databases. Hazard ratios (HRs) with 95% confidence intervals (CIs) were combined as the effect size (ES) across studies for recurrence-free survival (RFS) and progression-free survival (PFS).

Results

A total of 11 studies, consisting of 1,049 participants, met the criteria. Overall, there was no clear relationship between p53 status and RFS or PFS for NMIBC patients treated with BCG (HR: 1.40, 95% CI: 0.91-2.16; HR: 1.37, 95% CI: 0.90-2.09, respectively). Obvious heterogeneity was observed across the studies (I² = 69.5%, P = 0.001; I² = 44.7%, P = 0.081, respectively). In stratified analysis by region, p53 overexpression was a predictor of poor RFS in Asian populations (HR: 1.57, 95% CI: 1.08-2.27). In addition, after excluding the studies that possibly contributed to the heterogeneity by the Galbraith plot, the overall association for RFS became statistically significant (HR: 1.38 95% CI: 1.08-1.77) without evidence of heterogeneity (I² = 0.0%, P = 0.499).

Conclusion

This meta-analysis suggests that p53 overexpression in NMIBC patients treated with BCG may be associated with RFS, especially in Asian populations. Because of the heterogeneity and other limitations, further studies with rigid criteria and large populations are still warranted to confirm our findings.

Association between the cytotoxic T-lymphocyte antigen 4 +49A/G polymorphism and bladder cancer risk

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a potent immunoregulatory molecule that suppresses antitumor response by downregulating T cell activation. The most studied CTLA-4 +49A/G polymorphism has been associated with various cancers risks. However, little is known about the association between CTLA-4 +49A/G polymorphism and bladder cancer risk. A hospital-based case-control study was conducted in 300 patients with bladder cancer and 300 healthy controls matched with age and sex. The CTLA-4 +49A/G polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism. Patients with bladder cancer had a significantly lower frequency of CTLA-4 +49GG genotype [odds ratio (OR) = 0.44, 95 % confidence interval (CI) = 0.23, 0.85; P = 0.01] and G allele (OR = 0.73, 95 % CI = 0.56, 0.96; P = 0.02) than healthy controls. When stratifying by the stage, grade, and histological type of bladder cancer, we found no statistical association. This is the first study to highlight the significant association between CTLA-4 +49A/G polymorphism and bladder cancer risk. Additional studies are needed to confirm this finding.