Association of HLA-G 3′ UTR 14-bp Insertion/Deletion Polymorphism with Hepatocellular Carcinoma Susceptibility in a Chinese Population

The 14-bp insertion/deletion (indel) polymorphism located in the 30 UTR of the human leukocyte antigen-G (HLA-G) gene plays a role in several autoimmune and chronic inflammatory diseases. HLA-G expression is associated with hepatocellular carcinoma (HCC) prognosis, especially in early stage, with high expression independently associated with shortened overall survival and increased tumor recurrence. In the present study, we carried out a case-control study in a Chinese population (318 cases and 599 controls) to estimate the susceptibility to HCC associated with the 14-bp indel polymorphism. Logistic regression analysis showed that the heterozygote and the homozygote 14-bp ins/ins confer a lower risk of HCC (adjusted OR = 0.75, 95% CI: 0.57-1.01, p = 0.061; OR = 0.54, 95% CI: 0.30-0.98, p = 0.031, respectively). Hepatitis B virus (HBV) stratification analysis showed that the associations were stronger in the HBV-positive population. Immunohistochemical analysis further showed that HLA-G expression in HCC tissues with 14-bp del/del genotype was more prominent than for heterozygous and 14-bp ins/ins genotype (p < 0.01). Taken together, our results suggested that the HLA-G 14-bp indel polymorphism may be a marker for genetic susceptibility to HCC in Chinese populations. Further studies from different populations with larger sample size are warranted to validate our findings.