WDR4 gene polymorphisms increase hepatoblastoma susceptibility in girls

Hepatoblastoma, originating from hepatoblasts, is the most common hepatic malignancy. WD repeat domain 4 (WDR4) is a subunit of RNA N(7)-methylguanine (m7G) methyltransferase complex. Recently, WDR4 has shown oncogenic potential in various adult cancers, but its roles in pediatric cancers have not been reported. We performed a case-control study (313 cases vs. 1446 controls) to investigate whether genetic variants in the WDR4 gene influence hepatoblastoma susceptibility in the Chinese Han nationality. We first determine the genotypes of five WDR4 gene polymorphisms (rs2156315 C>T, rs2156316 C>G, rs6586250 C>T, rs15736 G>A, rs2248490 C>G) in participants, using the Taqman assay. And then, an unconditional logistic regression analysis was performed to assess the association between WDR4 gene polymorphisms and hepatoblastoma risk. Overall, we did not find any polymorphism significantly associated with the risk of developing hepatoblastoma. Instead, the stratified analysis revealed that the co-existence of 2-5 risk genotypes increased hepatoblastoma risk by 2.23 folds in girls (adjusted odds ratio=2.23, 95% confidence interval=1.17-4.23, P=0.014). In conclusion, our results demonstrate that single selected polymorphisms were too weak to exert a significant effect on the whole study population. However, in combination, two or more WDR4 gene polymorphisms significantly conferred increased hepatoblastoma risk in girls. Our findings may encourage more genetic association studies to discover significant polymorphisms in the WDR4 gene for hepatoblastoma.