An association between XPC Lys939Gln polymorphism and the risk of bladder cancer: a meta-analysis

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.

Xeroderma Pigmentosum Complementation Group C (XPC): Emerging Roles in Non-Dermatologic Malignancies

Xeroderma pigmentosum complementation group C (XPC) is a DNA damage recognition protein essential for initiation of global-genomic nucleotide excision repair (GG-NER). Humans carrying germline mutations in the XPC gene exhibit strong susceptibility to skin cancer due to defective removal via GG-NER of genotoxic, solar UV-induced dipyrimidine photoproducts. However, XPC is increasingly recognized as important for protection against non-dermatologic cancers, not only through its role in GG-NER, but also by participating in other DNA repair pathways, in the DNA damage response and in transcriptional regulation. Additionally, XPC expression levels and polymorphisms likely impact development and may serve as predictive and therapeutic biomarkers in a number of these non-dermatologic cancers. Here we review the existing literature, focusing on the role of XPC in non-dermatologic cancer development, progression, and treatment response, and highlight possible future applications of XPC as a prognostic and therapeutic biomarker.

Thyroid Cancer: The Quest for Genetic Susceptibility Involving DNA Repair Genes

The incidence of thyroid cancer (TC), particularly well-differentiated forms (DTC), has been rising and remains the highest among endocrine malignancies. Although ionizing radiation (IR) is well established on DTC aetiology, other environmental and genetic factors may also be involved. DNA repair single nucleotide polymorphisms (SNPs) could be among the former, helping in explaining the high incidence. To further clarify the role of DNA repair SNPs in DTC susceptibility, we analyzed 36 SNPs in 27 DNA repair genes in a population of 106 DTCs and corresponding controls with the aim of interpreting joint data from previously studied isolated SNPs in DNA repair genes. Significant associations with DTC susceptibility were observed for XRCC3 rs861539, XPC rs2228001, CCNH rs2230641, MSH6 rs1042821 and ERCC5 rs2227869 and for a haplotype block on chromosome 5q. From 595 SNP-SNP combinations tested and 114 showing relevance, 15 significant SNP combinations (p < 0.01) were detected on paired SNP analysis, most of which involving CCNH rs2230641 and mismatch repair variants. Overall, a gene-dosage effect between the number of risk genotypes and DTC predisposition was observed. In spite of the volume of data presented, new studies are sought to provide an interpretability of the role of SNPs in DNA repair genes and their combinations in DTC susceptibility.

Quantitative assessment of the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk

Previous studies evaluating the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk reported conflicting findings. We searched PubMed and Embase databases up to May 16, 2013 to identify eligible studies on the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk. Finally, a total of seven case-control studies including 3,971 cases of cutaneous melanoma and 5,873 controls were included in the meta-analysis. Statistical analysis was performed with STATA version 11.0. Odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were used to assess the strength of the association. Overall, there was no association between XPC Lys939Gln polymorphism and cutaneous melanoma risk under all five genetic models (Gln vs. Lys: OR = 1.11, 95 % CI = 0.98-1.26, P = 0.10; GlnGln vs. LysLys: OR = 1.26, 95 % CI = 0.98-1.61, P = 0.07; LysGln vs. LysLys: OR = 1.04, 95 % CI = 0.88-1.22, P = 0.64; GlnGln/LysGln vs. LysLys: OR = 1.10, 95 % CI = 0.92-1.31, P = 0.29; GlnGln vs. LysLys/LysGln: OR = 1.19, 95 % CI = 0.99-1.43, P = 0.06). Subgroup analysis in Caucasians showed that there was an obvious association between XPC Lys939Gln polymorphism and cutaneous melanoma risk in Caucasians (GlnGln vs. LysLys/LysGln: OR = 1.12, 95 % CI = 1.00-1.25, P = 0.05). Sensitivity analysis by omitting one study in turns showed that the significance of the pooled ORs was not stable. In addition, there was some evidence of publication bias in the meta-analysis, and meta-analyses of the studies with large sample size did not find the obvious association between XPC Lys939Gln polymorphism and cutaneous melanoma risk in Caucasians. Therefore, there is little evidence for the association between XPC Lys939Gln polymorphism and cutaneous melanoma risk.

Association between CCND1 and XPC polymorphisms and bladder cancer risk: a meta-analysis based on 15 case-control studies

Perturbations in cell cycle and DNA repair genes might affect susceptibility to cancer. The aim of this meta-analysis is to generate large-scale evidence to determine the degree to which common Cyclin D1 (CCND1) G870A (dbSNP: rs603965) and xeroderma pigmentosum group C (XPC) Ala499Val (dbSNP: rs2228000) polymorphisms are associated with susceptibility to bladder cancer. The electronic databases PubMed, Embase, Web of Science, and CNKI were searched for relevant studies (with an upper date limit of July 25, 2013). The principal outcome measure for evaluating the strength of association was crude odds ratios (ORs) along with their corresponding confidence intervals (95%CIs). We found and reviewed nine case-control studies on CCND1 G870A with a total of 6,823 subjects and seven studies on XPC Ala499Val with a total of 7,674 subjects. Our meta-analysis provides evidence that the variant genotype of CCND1 G870A showed a significant association in the occurrence of invasive bladder tumors in former and current smokers. The XPC Ala499Val polymorphism correlated with significant differences between patients and unaffected subjects, but when the groups were stratified by ethnicity, the magnitude of the overall effect was similar only among Caucasian populations. Results from our meta-analysis support the view that the G870A polymorphism may modulate the risk of bladder cancer in conjunction with tobacco smoking and that the Ala499Val polymorphism may contribute to the susceptibility to bladder cancer in Caucasian populations. Our findings, however, warrant larger well-designed studies to investigate the significance of these two polymorphisms as markers of susceptibility to bladder cancer.

Quantitative assessment of the association between XRCC3 C18607T polymorphism and glioma risk

XRCC3 has an important function in the DNA double-strand break, and XRCC3 C18607T polymorphism is a common polymorphism at exon 7 of the XRCC3 gene. Published data on the association between XRCC3 C18607T polymorphism and glioma risk were inconclusive. Electronic databases of PubMed, and Embase were searched for studies assessing the association between XRCC3 C18607T polymorphism and glioma risk. Pooled odds ratio (OR) and 95 % confidence interval (95 % CI) were calculated to estimate the association. Ten studies with five studies from Caucasians and five studies from Asians were included, including 9,369 subjects. Meta-analysis of total included studies showed that XRCC3 C18607T polymorphism was associated with increased risk of glioma (T vs. C: OR = 1.14, 95 % CI 1.02-1.28, P = 0.02; TT vs. CC: OR = 1.37, 95 % CI 1.03-1.83, P = 0.03; TT vs.

CC/CT

OR = 1.31, 95 % CI 1.00-1.71, P = 0.05; TT/CT vs. CC: OR = 1.12, 95 % CI 1.02-1.22, P = 0.02). Meta-analysis of the five studies from Asians showed that XRCC3 C18607T polymorphism was associated with increased risk of glioma (T vs. C: OR = 1.22, 95% CI 1.09-1.36, P < 0.01; TT vs. CC: OR = 1.89, 95 % CI 1.38-2.57, P < 0.01; TT vs.

CC/CT

OR = 1.78, 95 % CI 1.31-2.40, P < 0.01; TT/CT vs. CC: OR = 1.19, 95 % CI 1.04-1.36, P = 0.01). Meta-analysis of the five studies from Caucasians didn't find the association. In conclusion, the finding from the meta-analysis provides strong evidence for the association between XRCC3 C18607T polymorphism and glioma risk.

Association between NQO1 C609T polymorphism and bladder cancer susceptibility: a systemic review and meta-analysis

There is growing evidence for the important roles of genetic factors in the host's susceptibility to bladder cancer. NAD(P)H:quinone oxidoreductase 1 (NQO1) is a cytosolic enzyme that catalyzes the two-electron reduction of quinoid compounds into hydroquinones. Since the NQO1 C609T polymorphism is linked to enzymatic activity of NQO1, it has also been hypothesized that NQO1 C609T polymorphism may affect the host's susceptibility to bladder cancer by modifying the exposure to carcinogens. There were many studies carried out to assess the association between NQO1 C609T polymorphism and bladder cancer risk, but they reported contradictory results. We conducted a meta-analysis to examine the hypotheses that the NQO1 C609T polymorphism modifies the risk of bladder cancer. Eleven case-control studies with 2,937 bladder cancer cases and 3,008 controls were included in the meta-analysis. Overall, there was no obvious association between NQO1 C609T polymorphism and bladder cancer susceptibility (for T versus C: odds ratio (OR) = 1.12, 95 % confidence interval (95 %CI) 0.99-1.26, P OR = 0.069; for TT versus CC: OR = 1.31, 95 %CI 0.95-1.81, P OR = 0.100; for TT/CT versus CC: OR = 1.06, 95 %CI 0.95-1.18, P OR = 0.304; for TT versus CT/CC: OR = 1.29, 95 %CI 0.94-1.77, P OR = 0.112). After adjusting for heterogeneity, meta-analysis of those left 10 studies showed that there was an obvious association between NQO1 C609T polymorphism and bladder cancer susceptibility (for T versus C: OR = 1.18, 95 %CI 1.06-1.31, P OR = 0.003; for TT versus CC: OR = 1.47, 95 %CI 1.14-1.90, P OR = 0.003; for TT/CT versus CC: OR = 1.16, 95 %CI 1.01-1.34, P OR = 0.036; for TT versus CT/CC: OR = 1.39, 95 %CI 1.10-1.75, P OR = 0.006). There was low risk of publication bias. Therefore, our meta-analysis suggests that NQO1 C609T polymorphism is associated with bladder cancer susceptibility.

Association between glutathione S-transferase M1 null variant and risk of bladder cancer in Chinese Han population

Glutathione S-transferase M1 (GSTM1) is one of the most important families of phase II isoenzymes known to detoxify a variety of electrophilic compounds and carcinogens. The GSTM1 null variant is associated with decreased enzyme activity, and it has been assumed to be associated with bladder cancer. The association between the GSTM1 null variant and bladder cancer in the Chinese Han population was unclear owing to the obvious inconsistency from published studies. To quantify the association between the GSTM1 null variant and bladder cancer in the Chinese Han population, we carried out the meta-analysis. We estimated the pooled odds ratio (OR) with its 95% confidence interval (95% CI) to assess the association. Eight studies with a total of 3,887 individuals were finally included into the meta-analysis. Overall, there was an obvious association between the GSTM1 null variant and risk of bladder cancer in the Chinese Han population (OR = 1.61, 95% CI 1.41–1.84, P < 0.001). There was no heterogeneity across those eight studies (I 2 = 0%). The cumulative meta-analyses showed a trend of more obvious association between the GSTM1 null variant and risk of bladder cancer in the Chinese Han population as data accumulated by year. There was no obvious evidence of publication bias in the meta-analysis. In conclusion, the GSTM1 null variant is significantly associated with risk of bladder cancer in the Chinese Han population.

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.

Association between NAD(P)H:quinone oxidoreductase 1 rs1800566 polymorphism and risk of bladder cancer

NAD(P)H

quinone oxidoreductase 1 (NQO1) rs1800566 (Pro187Ser) is a functional polymorphism which leads to a proline-to-serine amino acid substitution at codon 187 in the NQO1 protein and enzyme activity changes. NQO1 rs1800566 polymorphism was implicated to be associated with a risk of bladder cancer, but published studies showed inconclusive results. We performed a meta-analysis of nine publications with a total of 2,661 cases and 2,738 controls on the association between NQO1 rs1800566 polymorphism and risk of bladder cancer. Data were extracted from those included studies, and the pooled odds ratio (OR) with the corresponding 95% confidence interval (95% CI) was calculated to assess the association. We found that there was no association between NQO1 rs1800566 polymorphism and risk of bladder cancer under all four genetic models (Ser vs. Pro, OR = 1.06, 95% CI = 0.97-1.16, P = 0.21, I(2) = 31%; SerSer vs. ProPro, OR = 1.12, 95% CI = 0.89-1.42, P = 0.33, I(2) = 44%; SerSer/ProSer vs. ProPro, OR = 1.08, 95% CI = 0.96-1.21, P = 0.20, I(2) = 27%; SerSer vs. ProPro/ProSer, OR = 1.06, 95% CI = 0.85-1.32, P = 0.59, I(2) = 36%). Meta-analysis of those eight studies from Europeans also showed that there was no association between NQO1 rs1800566 polymorphism and risk of bladder cancer under all four genetic models (Ser vs. Pro, OR = 1.02, 95% CI = 0.93-1.13, P = 0.66, I(2) = 20%; SerSer vs. ProPro, OR = 0.99, 95% CI = 0.75-1.30, P = 0.93, I(2) = 38%; SerSer/ProSer vs. ProPro, OR = 1.04, 95% CI = 0.92-1.17, P = 0.55, I(2) = 6%; SerSer vs. ProPro/ProSer, OR = 0.98, 95% CI = 0.75-1.28, P = 0.87, I(2) = 39%). This meta-analysis suggests that the NQO1 rs1800566 polymorphism is not associated with a risk of bladder cancer. Further studies with larger samples are needed, especially for studies in Asians and Africans.