Abstract: Objective To detecte the expression of the difference proteins of the human hepatoma carcinoma cell line 7402 ,7721 and adjacent liver cell 7701 before and after the treatment of the adenovirus-thymidine kinase/gancyclovir( ADV-TK/GCV)system,further elucidating the mechanism of the suicide gene system ADV-TK/GCV on hepatoma cells. Methods Peptide mass fingerprinting ( PMF)and two-dimensional electrophoresis analysis were used to test the expression of the difference proteins of the human hepatoma cell lines 7402 ,7721 and the adjacent liver cell line 7701 before and after the treatment of the ADV-TK/GCV system;moreover,we observed the cell pathological morphology changes after the treatment with Hematein Eosin( HE),one of the routine methods of pathology. We also used the electron-microscopy to detect the expression port,distribution and quantity of cytokeratin 18 (CK18)of dosing group and control group with immunohistochemistry. Results 7721 and 7701 were sensitive to ADV-TK/GCV system. The expression of many proteins of the human hepatoma cell lines 7402,exhibited differences after the disposal method of suicide gene drugs,the expression of CK18 was upregulated obviously by comparative analysis. Cellular morphology changed significantly by HE. Cells in the control group were mostly spindle-shaped and nucleoli were obvious,while most cells in dosing group died. The volume of residual cell was small,round,and hyperchromatic. Electron microscopy observations showed that the control abundant organelles,accidentally saw cell apoptosis. Dosing group of cell organelle were oedematous obviously,microfilament increased and throughout around the nucleus,apoptosis phenomenon was obvious. The immunocytochemistry showed that the expression of CK18 of the control group was equally distributed in the cytoplasm and cell membrane,but the expression of CK18 of the treatment group increased and was uneven distribution,mainly concentrated in the membrane surrounding the cytoplasm,some of which were circular distribution. Conclusion After the suicide gene system ADV-TK/GCV played a role,protein expression of the sensitive line 7402 showed differences,which suggested the expression of CK18 upregulated memorably,the distribution presented differences and caused changes in the morphology.

Key words: liver neoplasms, differentially expressed proteins, keratins