OBJECTIVE
To explore the correlation between single nucleotide polymorphisms (SNPs) of interleukin-28B (IL-28B) gene and the susceptibility to primary hepatocellular carcinoma (HCC).
METHODS
A total of 300 histologically confirmed HCC cases (from November 2001 to April 2010) and 310 healthy controls with no history of chronic hepatitis B or hepatocellular carcinoma (2009-2010) were selected from a hospital in Guilin and a hospital in Beijing for this case-control study.139 HCC patients in the case group had complete clinical tracking data. All the subjects were Han Chinese, with no age or gender restrictions.2 ml peripheral blood samples were drawn from each subject with informed consent. SNP of rs12972991, rs4803223, rs8099917 and rs12979860 four loci in IL-28B gene were analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF).
RESULTS
The frequencies of C allele at rs12972991, G allele at rs8099917 and G allele at rs4803223 were 6.7% (40/598), 7.9% (47/598) and 10.0% (59/588) respectively in case group; all higher than the corresponding frequencies in control group, separately 2.9% (18/618), 4.1% (25/616) and 3.6% (21/608). The differences were statistically significant (χ2=9.542, 7.858, 20.736, P values all<0.05). The above alleles could increase the risk of HCC, and the OR (95%CI) values were separately 1.67 (1.13-2.46), 1.49 (1.08-2.06) and 2.91 (1.79-4.72). The genotype frequencies of AC+CC at rs12972991, GT+GG at rs8099917, GA+GG at rs4803223 were 13.0% (39/299), 14.7% (44/299) and 19.0% (56/296) respectively in case group; while the frequencies were lower in control group, separately 5.8% (18/309), 8.1% (25/308) and 6.6% (20/304). The differences were statistically significant (χ2=9.319, 6.557, 20.948, P values all<0.05). These genotypes may increase the risk of HCC, and the adjusted OR (95%CI) values were 2.24 (1.31-3.83), 1.81 (1.14-2.88) and 2.90 (1.78-4.70), respectively. The stratified analysis of the clinical data indicated that the frequency of genotype GA+GG at rs4803223 was 50.0% (13/26) in patients of tumor thrombosis in portal vein (TTPV), higher than the frequency of genotype AA (21.1%, 23/109). The difference was statistically significant (χ2=8.965, P=0.003).
CONCLUSION
The results suggested that IL-28B gene polymorphisms was correlated to the susceptibility to HCC in Chinese Han ethnic population. Among them, GA + GG genotype at rs4803223 could increase the risk of TTPV in HCC patients.