HLA-G genetic variants and hepatocellular carcinoma: a meta-analysis

Human leukocyte antigen (HLA)-G is a key tolerogenic molecule mainly expressed in the placenta and is crucial for implantation of the embryo and immunological tolerance of the fetus during pregnancy. However, under pathological conditions, such as cancer or viral infections, HLA-G can be expressed in other tissues. The gene coding for HLA-G (HLA-G, chromosome 6p21.3) presents numerous polymorphisms, some of them influencing its expression. One of the most studied, is the 14 bp ins/del (rs371194629) situated at the 3'-UTR of the gene. The insertion is thought to stabilize HLA-G mRNA. Different studies have analyzed the role of rs371194629 in hepatic injury, with either hepatotropic virus infection (i.e., HBV or HCV) or hepatocellular carcinoma (also induced by viral infection). Results from these studies are heterogeneous, differing with ethnicity and population age, and the role of rs371194629 is unclear. For these reasons, we decided to perform a meta-analysis of these results, concluding that the 14-bp ins/del polymorphism does not significantly contribute to hepatic injury.