Genetic variations in nucleotide excision repair pathway genes and hepatoblastoma susceptibility

The etiology of hepatoblastoma is largely unknown due to the rarity of this disease. Nucleotide excision repair (NER), a versatile system in repairing DNA damage, is highly implicated in carcinogenesis. However, it remains unclear whether single nucleotide polymorphisms (SNPs) of genes in the NER pathway are related to hepatoblastoma risk. A total of 313 Chinese children diagnosed with hepatoblastoma and 1446 controls were recruited from seven hospitals across China. TaqMan assay was adopted to genotype 19 SNPs in NER pathway genes including ERCC1, XPA, XPC, XPD, XPF and XPG. Of them, only two SNPs in XPC gene predisposed to hepatoblastoma risk. The XPC rs2607775 polymorphism significantly contributed to hepatoblastoma risk (dominant model: adjusted OR = 1.44, 95% CI = 1.01-2.05, P = .046). However, XPC rs1870134 conferred a significantly decreased risk of hepatoblastoma in recessive model (adjusted OR = 0.50, 95% CI = 0.26-0.98, P = .042). Stratified analysis revealed that rs2607775 CG/GG genotype, rs1870134 CC genotype and four to five risk genotypes were associated with the risk of hepatoblastoma under certain subgroups. The significant relationships were confirmed by haplotype analyses and false-positive report probability analyses. In addition, expression quantitative trait locus analysis suggested that rs2607775 G increased expression of XPC mRNA. Collectively, our discover a promising candidate XPC gene as a biomarker for the risk of hepatoblastoma.