Abstract
Previous studies have indicated that complex interactions among viral, environmental and genetic factors lead to hepatocellular carcinoma (HCC). To identify susceptibility alleles for hepatitis B virus (HBV)-related HCC, the present study conducted a pilot two-phase genome-wide association study (GWAS) in 660 Han Chinese individuals. In phase 1, a total of 500,447 single-nucleotide polymorphisms (SNPs) were genotyped in 50 HCC cases and 50 controls using Affymetrix GeneChip 500k Array Set. In phase 2, 1,152 SNPs were selected from phase 1 and genotyped in 282 cases and 278 controls using the Illumina GoldenGate platform. The prior probability of HCC in control subjects was assigned at 0.01, and false-positive report probability (FPRP) was utilized to evaluate the statistical significance. In phase 1, one SNP (rs2212522) showed a significant association with HCC (P(allele)=5.23×10(-8); OR(allele)=4.96; 95% CI, 2.72-9.03). In phase 2, among 27 SNPs with unadjusted P(allele)<0.05, 9 SNPs were associated with HCC based on FPRP criteria (FPRP <0.20). The strongest statistical evidence for an association signal was with rs2120243 (combined OR(allele)=1.76; 95% CI, 1.39-2.22; P=2.00×10(-6)), which maps within the fourth intron of VEPH1. The second strongest statistical evidence for an association was identified for rs1350171 (combined OR(allele)=1.66; 95% CI, 1.33-2.07; P=6.48×10(-6)), which maps to the region downstream of the FZD4 gene. The other potential susceptibility genes included PCDH9, PRMT6, LHX1, KIF2B and L3MBTL4. In conclusion, this pilot two-phase GWAS provides the evidence for the existence of common susceptibility loci for HCC. These genes involved various signaling pathways, including those associated with transforming growth factor β, insulin/phosphoinositide 3 kinase, Wnt and epidermal growth factor receptor. These associations must be replicated and validated in larger studies.