Open Access Research article

XPD codon 312 and 751 polymorphisms, and AFB1 exposure, and hepatocellular carcinoma risk

Xi Dai Long1*, Yun Ma2, Yun Feng Zhou1, Jin Guang Yao3, Fu Zhi Ban4, Yong Zhi Huang1 and Bing Cheng Huang1

Author Affiliations

1 Department of Pathology, Youjiang Medical College for Nationalities, Baise, Guangxi Zhuang Autonomous Region, PR China

2 Department of Pathology, Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, PR China

3 Department of Medicine, Affiliated Hospital of Youjiang Medical College for Nationalities, Baise, Guangxi Zhuang Autonomous Region, PR China

4 Department of Medical Test, Affiliated Southwest Hospital of Youjiang Medical College for Nationalities, Baise, Guangxi Zhuang Autonomous Region, PR China

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BMC Cancer 2009, 9:400  doi:10.1186/1471-2407-9-400

Published: 17 November 2009

Abstract

Background

Genetic polymorphisms in DNA repair genes may influence individual variation in DNA repair capacity, which may be associated with risk of hepatocellular carcinoma (HCC) related to the exposure of aflatoxin B1 (AFB1). In this study, we have focused on the polymorphisms of xeroderma pigmentosum complementation group D (XPD) codon 312 and 751 (namely Asp312Asn and Lys751Gln), involved in nucleotide excision repair.

Methods

We conducted a case-control study including 618 HCC cases and 712 controls to evaluate the associations between these two polymorphisms and HCC risk for Guangxi population by means of TaqMan-PCR and PCR-RFLP analysis.

Results

We found that individuals featuring the XPD genotypes with codon 751 Gln alleles (namely XPD-LG or XPD-GG) were related to an elevated risk of HCC compared to those with the homozygote of XPD codon 751 Lys alleles [namely XPD-LL, adjusted odds ratios (ORs) were 1.75 and 2.47; 95% confidence interval (CIs) were 1.30-2.37 and 1.62-3.76, respectively]. A gender-specific role was evident that showed an higher risk for women (adjusted OR was 8.58 for XPD-GG) than for men (adjusted OR = 2.90 for XPD-GG). Interestingly, the interactive effects of this polymorphism and AFB1-exposure information showed the codon 751 Gln alleles increase the risk of HCC for individuals facing longer exposure years (Pinteraction = 0.011, OR = 0.85). For example, long-exposure-years (> 48 years) individuals who carried XDP-GG had an adjusted OR of 470.25, whereas long-exposure-years people with XDP-LL were at lower risk (adjusted OR = 149.12). However, we did not find that XPD codon 312 polymorphism was significantly associated with HCC risk.

Conclusion

These findings suggest that XPD Lys751Gln polymorphism is an important modulator of AFB1 related-HCC development in Guangxi population.