Identification of the Differential Expression Profiles of Serum and Tissue Proteins During Rat Hepatocarcinogenesis

The pathogenesis of hepatocellular carcinoma is complex and not fully known yet. This study aims to screen and identify the differentially expressed proteins in peripheral blood and liver tissue samples from rat hepatocellular carcinoma and to further clarify the pathogenesis and discover the specific tumor markers and molecular targets of hepatocellular carcinoma. The hepatocellular carcinoma model of Wistar rats were induced by chemical carcinogen. The serum and liver tissue samples were obtained after induction for 2, 4, 8, 14, 18, and 21 weeks. The results showed that the clusterin (IPI00198667), heat shock protein a8 (IPI00208205), and N-myc downstream-regulated gene-2 (IPI00382069) being closely related to hepatocarcinogenesis were eventually identified from the 30 different proteins. As the time progressed, the serum levels of clusterin and heat shock protein a8 increased gradually during induced liver cancer in rats. However, the serum N-myc downstream-regulated gene 2 level in induced liver cancer in rats underwent biphasic changes, and the serum N-myc downstream-regulated gene 2 level decreased at the 8th week, increased at the 14th week, and then decreased significantly. Statistical difference occurred in protein expression of clusterin and heat shock protein a8 in liver tissues at the different time points. In the liver tissues, the N-myc downstream-regulated gene 2 level decreased gradually at the 8th week, increased gradually at the 14th week, and then decreased significantly after 14 weeks. The study demonstrated that heat shock protein a8, clusterin, and N-myc downstream-regulated gene 2 participated in the process of abnormal cell division, proliferation, and carcinogenesis of liver cells during hepatocarcinogenesis.