Two-dimensional differential gel electrophoresis/analysis of diethylnitrosamine induced rat hepatocellular carcinoma.

Diethylnitrosamine (DEN) is a known carcinogen that can alkylate DNA molecules. In rats, DEN-induced hepatocellular carcinoma (HCC) model is well established. In this study, we used a two-dimensional differential gel electrophoresis (2D-DIGE) system and liquid chromatography/mass spectrometry/mass spectrometry to identify the differential expression protein profiles between the DEN-induced HCC and healthy liver cells. Western blotting and semiquantitative RT-PCR were used to further confirm the results. Seventeen differentially expressed spots were identified in DEN-induced HCC cells. Among all, the most prominent upregulated proteins include the members of the glutathione S-transferase super family, aldo-keto reductase superfamily and proteins involved in the response to oxidative stress. Downregulation was observed in 2 proteins that were known to contribute to hepatic dysfunction. This study provides the first comprehensive protein profiling of the DEN-induced HCC in rats. This model simulates the differential protein expression of human HCC and may be useful for further understanding the mechanism of HCC tumorigenesis.