Quantitative assessment of the association between MTHFR rs1801131 polymorphism and risk of liver cancer.

Methylenetetrahydrofolate reductase (MTHFR) is one of the most important enzymes for folate metabolism which plays a key role in cell metabolism. MTHFR rs1801131 (A1298C) polymorphism can decrease in vitro MTHFR enzyme activity and has been hypothesized to be associated with liver cancer risk. This study aimed to quantify the strength of the association between MTHFR rs1801131 polymorphism and liver cancer risk by performing a meta-analysis. We searched the PubMed and Wanfang databases for studies relating on the association between MTHFR rs1801131 polymorphism and risk of liver cancer. Seven studies with 2,030 cases of liver cancer and 3,096 controls were finally included into the meta-analysis. Meta-analysis of a total of seven studies showed that the homozygote genotype CC of MTHFR rs1801131 polymorphism was significantly associated with decreased risk of liver cancer (for CC versus AA: odds ratio (OR) = 0.65, 95% confidence interval (CI) 0.47-0.89, P = 0.007; for CC versus AA + AC: OR = 0.65, 95% CI 0.48-0.89, P = 0.006). Subgroup by race showed that the homozygote genotype CC of MTHFR rs1801131 polymorphism was significantly associated with decreased risk of liver cancer in Asians (CC versus AA: OR = 0.64, 95% CI 0.46-0.90, P = 0.010; for CC versus AA + AC: OR = 0.63, 95% CI 0.45-0.88, P = 0.007). However, the association in Caucasians was still unclear owing to the limited data available now. Thus, Asian individuals with the homozygote genotype CC of MTHFR rs1801131 polymorphism are significantly associated with decreased risk of liver cancer. The association in Caucasians needs further studies.

Protective effects of ursodeoxycholic acid against immune-mediated liver fibrosis in rats.

BACKGROUND/AIMS: Ursodeoxycholic acid (UDCA), a natural component of bile, has been synthesized to treat cholestatic liver diseases such as primary biliary cirrhosis. Broad biochemical changes in UDCA-treated patients suggest beneficial effects of UDCA beyond stimulating hepatobiliary secretion and possible efficacy of the medicine in treating cirrhosis of other causes. The aim was to explore the potential benefit of UDCA in controlling immune-mediated hepatic fibrosis. METHODOLOGY: We applied the rat experimental model of liver fibrosis induced by intraperitoneal injection of porcine serum. UDCA was administered orally during the course of the serum injections. RESULTS: Compared with the untreated group, the rats treated with UDCA ended with significantly higher body weight, lower liver weight, and lower spleen weight. The treated groups also demonstrated less severe liver fibrosis, with significantly lowered hepatic expression of type I and type III collagens, in terms of both mRNA and proteins. Moreover, serum levels of hyaluronic acid (HA), laminin (LN), type IV collagen (C IV), and type III procollagen (PC III) were also lower in the UDCA-treated animals. CONCLUSION: UDCA deters development of immune-mediated liver fibrosis by inhibiting the expression of collagen and other extracelluar matrix components.

Effect of ursodeoxycholic acid on TGF beta1/Smad signaling pathway in rat hepatic stellate cells.

BACKGROUND: Hepatic fibrosis is the key stage of the pathological progress from hepatic injury to cirrhosis. Ursodeoxycholic acid (UDCA) has been known as having significant clinical therapeutic effects on chronic liver diseases. Our research aimed to study the effect of UDCA on the signaling pathway of transforming growth factor beta1 (TGFbeta1)/Smad and discuss its possible molecular mechanisms of inhibiting hepatic fibrosis. METHODS: Rat hepatic stellate cells were cultured in vitro and randomly assigned to 4 groups. Group A was control group, with only DMEM culture medium applied, and groups B, C, D were experimental groups, with different doses of UDCA (1.0 mmol/L, 0.5 mmol/L and 0.25 mmol/L respectively) added into their DMEM culture medium for further culture of 24 hours and 48 hours. The protein expressions of TGFbeta1, TGF type I receptor, Smad3, Smad4 and Smad7 were measured by Western blotting, as well as the expressions of TGFbeta1, Smad3, Smad7 and cAMP response element (CREB) binding protein (CBP) mRNA by real-time PCR. SPSS 11.5 statistical package was adopted for data analyses. RESULTS: Compared with control group, the mRNA expressions of TGFbeta1 in the high and middle UDCA dose groups for 24 hours and 48 hours significantly decreased (P < 0.05), the protein expressions of TGFbeta1 in the two above groups for 48 hours and in the high dose group for 24 hours significantly decreased (P < 0.05). The protein and mRNA expressions of Smad3 in each UDCA dose group for 24 hours and 48 hours significantly decreased, with significant difference among different UDCA dose groups and between that of 24 hours and 48 hours observed (P < 0.05). The protein and mRNA expressions of Smad7 in the high and middle UDCA dose groups for 24 hours and 48 hours significantly increased. The CBP mRNA expression in each UDCA dose group for 24 hours and 48 hours significantly decreased (P < 0.05), with significant difference among different UDCA dose groups observed (P < 0.05). CONCLUSION: UDCA could curb the development of hepatic fibrosis through affecting the signaling pathway of TGFbeta1/Smad by inhibiting the expressions of TGFbeta1, Smad3 and CBP and increasing the expression of Smad7.