ABSTRACT. Transforming growth factor-beta 1 (TGF-β1), a member of the transforming growth factor beta family, functions as a multi-functional cytokine and plays a key role in cellular growth, proliferation, and differentiation. The 509 C/T polymorphism in the TGF-β1 gene has been implicated in the outcome of hepatitis C virus (HCV) infection; however, little is known regarding the relationship between TGF-β1 gene mutations and the development of hepatocellular carcinoma (HCC) in HCV-infected patients. The aim of the study was to evaluate the effect of the TGF-β1 polymorphisms 509 C>T on the occurrence of HCC in patients chronically infected with HCV in a Chinese Han population. The results showed that HCC patients had a higher frequency of the TGF-β1 -509 TT genotype distribution of the TGF-β1 -509 polymorphism and a lower frequency of the CC genotype. Serum TGF-β1 levels were significantly higher in patients with the TT genotype than in those with the CC genotype. In this study, we confirmed that the TGF-β1 polymorphism 509 C>T is associated with the risk of HCC in HCV-infected patients.

ABSTRACT. MicroRNAs (miRNAs) are key regulators of gene expression and play an important role in the development and progression of various diseases including esophageal squamous cell carcinoma (ESCC). In this study, we determined whether a polymorphism at the miR-214 binding site in the 3'-untranslated region (3'-UTR) of the methylenetetrahydrofolate reductase gene (MTHFR) is associated with susceptibility to ESCC. A total of 448 ESCC cases and 460 genderand age-matched subjects were recruited for the study. The genotypes of the rs114673809 single nucleotide polymorphism (SNP) were determined by polymerase chain reaction sequencing. Associations between genotypes of MTHFR rs114673809 and ESCC risk were determined using logistic regression analyses. In the recessive model, when the MTHFR rs114673809 GG homozygote genotype was used as the reference group, the GA genotype was not associated with the risk of ESCC (GA vs GG: OR = 1.261, 95%CI = 0.960-1.657, P = 0.110), but the AA genotype was associated with increased risk of ECSS (AA vs GG: OR = 1.752, 95%CI = 1.076-2.853, P = 0.027). Additionally, the rs114673809 A allele carriers also showed a 1.286-fold increased ESCC risk compared with those carrying the rs114673809 G allele genotype. Furthermore, we observed a significant increase in plasma homocysteine levels in ESCC cases carrying the AA genotype relative to ESCC cases carrying the GG genotype. Our data demonstrate that a polymorphism at the miR-214 binding site in the 3'-UTR of MTHFR is an ESCC susceptibility SNP in the Chinese population.