Glutathione S-Transferase P1 Correlated with Oxidative Stress in Hepatocellular Carcinoma

BACKGROUND Glutathione-S-transferase P1 (GSTP1) is an important phase II enzyme that can protect cells from oxidative stress in various human cancers. However, few clinical studies were undertaken on the relationship between GSTP1 and oxidative stress in hepatocellular carcinoma (HCC). The present study was therefore aimed to evaluate the potential associations between GSTP1 and oxidative stress in HCC patients. METHODS The GSTP1 expression in peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry from 38 HCC patients and 38 chronic hepatitis B (CHB) patients. The GSTP1 mRNA level in PBMCs was determined by real-time quantitative polymerase chain reaction. Enzyme-linked-immunosorbent-assay (ELISA) was performed to measure the oxidative stress status, including plasma levels of malondialdehyde (MDA), xanthine oxidase (XOD), reduced glutathione hormone (GSH) and glutathione-S-transferases (GST). RESULTS Significantly decreased GSTP1 protein expression was found in HCC patients than in CHB patients (P<0.05). The GSTP1 mRNA expression of HCC patients was also decreased compared with CHB patients (P<0.05). MDA and XOD levels were significantly higher in HCC patients than in CHB patients, while plasma GSH and GST levels were statistically lower in HCC patients than in CHB patients. GSTP1 expression level was correlated with plasma levels of MDA (P<0.01), XOD (P = 0.01) and GSH (P< 0.01), GST (P< 0.01). CONCLUSION We demonstrated that the reduced GSTP1 expression might contribute to oxidative stress in the development of HCC from CHB.