ABSTRACT
BACKGROUND: Recently, some people believed that the mechanisms of primary hepatic carcinoma might be caused by poor differentiation or disdifferentiation of hepatic stem cells. Studies on hepatic stem cells are in the early stage at present, and the theory of "stem cell origins" of human primary hepatic carcinoma deserves further verification. OBJECTIVE: To investigate the activation, distribution, origin and immunological expression characteristics of hepatic stem cells in different histopathologic types of primary hepatic carcinoma. DESIGN: Observational comparative study. SETTING: Tumor Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University of Chinese PLA. PARTICIPANTS: Experiments were performed at the Laboratory of Tumor Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University of Chinese PLA from September 2003 to July 2004. We took 94 cases of hepatic cellular cancer, 12 cases of intrahepatic cholangiocellular carcinoma and 10 cases of mixed hepatocarcinoma paraffin-embedded tissue blocks as research objects, with 5 cases of liver cirrhosis and 4 cases of normal liver as experimental control. These materials were collected from the archive of the Department of Pathology of Daping Hospital. Primary hepatic carcinoma tissues and corresponding adjacent liver tissues were obtained from patients who had undergone surgery for the removal of their tumors. All the patients were not treated by chemotherapy or radiotherapy before the operation. They had signed the informed consent. Main Antibodies were bought from Santa Cruz Company.METHODS: The histological and immunohistochemical characteristics were examined by haematoxylin and eosin staining and immunohistochemistry (SP method), including mouse antihuman cytokeratin 19 monoclonal antibody, mouse antihuman cytokeratin 7 monoclonal antibody, mouse antihuman cytokeratin 8&&18 monoclonal antibody, mouse antihuman c-kit monoclonal antibody, mouse antihuman Thy-1 monoclonal antibody, mouse antihuman alpha fetoprotein monoclonal antibody. MAIN OUTCOME MEASURES: Expression of immunological markers of hepatic stem cells in different histopathologic types. RESULTS: Immunological markers of hepatic stem cells expressed variously in different histopathologic types of primary hepatic carcinoma. Hepatic stem cells differentiated into hepatoma carcinoma cells in all the types. The highest expression rate of hepatic stem cell immunophenotype was found in the mixed hepatocarcinoma (P < 0.05). Immunophenotypes of hepatic stem cells were negative in normal group and cirrhosis group. CONCLUSION: Hepatic stem cells of varied differentiations and origins existed in different histopathologic types of primary hepatic carcinoma.
ABSTRACT
Objective To investigate the expression of microRNA-224 in HepG2 cells and analyze its target genes to reveal its role in the carcinogenesis of hepatoma. Methods The genes with differential expression in HepG2 cells and LO2 cells were obtained by gene expression microarray analysis. The up-regulated target genes of microRNA-224 were predicted by bioinformatics method, and their functions were analyzed. Results Compared with LO2 cells, microRNA-224 was highly expressed in HepG2 cells. A total of 264 target genes of microRNA-224 were predicted, including genes involved in cell cycle, signal transduction, cell differentiation, proliferation and apoptosis. Conclusions MicroRNA-224 is highly expressed in HepG2 cells. MicroRNA-224 plays an important role in the carcinogenesis of hepatoma via regulating the expression of its target genes directly or indirectly.