XPG Asp1104His polymorphism increases colorectal cancer risk especially in Asians

Abstract

Xeroderma pigmentosum group G (XPG) protein is a pivotal element of the nucleotide excision repair pathway. XPG gene single nucleotide polymorphisms (SNPs) have been shown to confer colorectal cancer (CRC) susceptibility. In this study, we further investigated the role of Asp1104His (rs17655 G > C) in XPG on CRC risk. We genotyped the rs17655 G > C polymorphism in Chinese population comprising 1019 CRC cases and 1036 cancer-free controls. We also performed a meta-analysis to further assess the association. Overall, no significant association was detected between the rs17655 G > C and the risk of CRC. Stratified analysis also revealed no significant association. To further elucidate the association of the rs17655 with CRC susceptibility, we conducted a meta-analysis by including qualified publications and the current study. The meta-analysis results demonstrated that rs17655 G > C was associated with an increased CRC risk (CG vs. GG: OR = 1.14, 95% CI = 1.01-1.28; CC/CG vs. GG: OR = 1.12, 95% CI = 1.01-1.24; C vs. G: OR = 1.06, 95% CI = 1.01-1.11). In subgroup analysis, the significant association between the rs17655 C allele and CRC risk was found in Asians and hospital-based subgroups. Taken together, our results suggested that the XPG rs17655 G > C polymorphism is a low-penetrance susceptibility locus for CRC. Further studies are warranted to validate these findings.

Keywords: Asp1104His; Colorectal cancer; XPG; polymorphism; susceptibility.

Figure 1

Forest plot for the CRC susceptibility associated with the rs17655 G > C polymorphism under allele comparison model. The horizontal lines represent the study-specific ORs and 95% CIs, respectively. The diamond represents the pooled results of OR and 95% CI.

Figure 2

Forest plot for the CRC susceptibility associated with the rs17655 G > C polymorphism stratified by ethnicities under allele comparison model. The horizontal lines represent the study-specific ORs and 95% CIs, respectively. The diamond represents the pooled results of OR and 95% CI.

Figure 3

Forest plot for the CRC susceptibility associated with the rs17655 G > C polymorphism stratified by design under allele comparison model. The horizontal lines represent the study-specific ORs and 95% CIs, respectively. The diamond represents the pooled results of OR and 95% CI.

Figure 4

Forest plot for the CRC susceptibility associated with the rs17655 G > C polymorphism stratified by HWE under allele comparison model. The horizontal lines represent the study-specific ORs and 95% CIs, respectively. The diamond represents the pooled results of OR and 95% CI.