The expression and significance of MCM7 protein in hepatocellular carcinoma tissues of human, rat and tree shrew

Objective: To test the expression of Minichromosome maintenance complex component 7(MCM7) protein in hepatocellular carcinoma(HCC) of different species including human, rat and tree shrew (tupaia) by cross-species oncogenomics approach, and to investigate the relationship between the expression of MCM7 and the development of hepatocellular carcinoma and its clinical significance. Methods: Western blot and Immunohistochemistry were applied to detect the expression levels of MCM7 protein in HCC tissues,corresponding HCC-adjacent liver tissues and normal liver tissues collected from different species including human, rat and tree shrew, respectively. The clinicopathologic factors were also analyzed with the results of Immunohistochemistry. Results: Western blot analysis showed that the expression of MCM7 protein in HCC tissues of human and rat were higher than that in corresponding HCC-adjacent liver tissues and normal liver tissues, respectively and significantly (P<0.05). However, the expression of MCM7 protein in HCC tissues of tree shrew were also higher than that in corresponding HCC-adjacent liver tissues and normal liver tissues, but no significant difference was found among three types of tissues (P>0.05).There was also no significant difference between HCC-adjacent liver tissues and normal liver tissues in three species (P>0.05). Immunohistochemical analysis showed that MCM7 protein was mainly expressed in nucleus of HCC cells, and the positive rate of MCM7 protein in HCC tissues of human, rat and tree shrew were significantly higher than that in corresponding HCC-adjacent liver tissues and normal liver tissues, respectively (P<0.05). However, no significant difference was found between HCC-adjacent liver tissues and normal liver tissues (P>0.05). Moreover, the protein level of MCM7 was intimately related to patient's HCC stage, extrahepatic metastases and postoperative recurrence (P<0.05). Conclusion: MCM7 protein might play a pivotal role in hepatocarcinogenesis. In addition, it was probably related to patient's HCC stage, extrahepatic metastases and postoperative recurrence. It seems very likely that MCM7 may be applied as a new molecular target in HCC prevention and treatment.