Objective: To detect the expression profile of NDRG1 gene in different tissues and cell lines and explore the relationship of NDRG 1 with liver tissue differentiation and hepatocarcinogenesis. Methods: The expression profiles of NDRG 1 in hepatocellular carcinoma (HCC) tissues, paired noncancerous liver (PNL) tissues, adult normal liver (NL) tissues, baby mouse liver tissues and fetal liver tissues in different developmental stages and cultured cell lines were performed using RT PCR and Northern Blot analysis. Results: Expression of NDRG 1 was significantly up regulated in HCC tissues compared to that of NL tissues and PNL tissues, however, the expressions of NDRG1 in NL and PNL tissues showed no evident difference. In ten cell lines, the highest expression was in the 293T human kidney cell line, the next one in liver cell L02, and the lowest one in the undifferentiated HLE cell line. Expression of NDRG1 in liver tissues enhanced with the development of the baby mouse and human fetus. Conclusion: NDRG 1 is probably related to the liver cell differentiation and is highly expressed in the specific stage of the differentiation. However, it could not be recognized as a marker of differentiation. The high expression of NDRG 1 in HCC indicates that HCC is not just distributed to a simple de differentiation. Much more study is necessary in understanding the comprehensive relationship of the disorder proliferation and differentiation of HCC and the related genes.

Objective: To study the biological effects of the novel gene LAPTM4B high expressed in hepatocellular carcinoma on cell proliferation and tumorigenesis of NIH3T3 cells. Methods: Eukaryotic expression plasmid pcDNA3 TM4B was constructed and transfected into mouse NIH3T3 cell line using Lipofectamin 2000 mediating gene transfer technique. Monoclonal transfected cells with high expression of LAPTM4B gene were identified and selected by RT-PCR, Northern blot and Western blot method. Cell surface morphology was detected by scanning electronic microscopy (SEM). The cell attachment /spreading on various matrices was examined. The cell growth curves were measured by acid phosphatase method. Cell cycle was detected by flow cytometry (FCM). The expression level of Cyclin E protein was examined using Western blot. Results: The cell surface of the LAPTM4B transfected cells showed abundant tube/finger like microvilli, which were distinguished significantly from the MOCK cells. The cell attachment/spreading of transfected cells increased on fibronectin, matrigel and laminin. The growth rate of transfected cells was faster than that of the MOCK cells. FCM analysis indicated that the amount of the transfected cells in S phase was increased significantly. Cyclin E protein expression of transfected cells was much higher than that of the MOCK cell. The serum dependence of transfected cells was decreased. The fibrosarcoma was formed at a tumorigenic rate of 50% in NIH mice inoculated with LAPTM4B transfected cells.Conclusion: LAPTM4B gene promotes the cell proliferation by involving in the regulation of cell cycle control and causes tumorigenesis of NIH3T3 cells, indicating that it plays important roles in tumorigenesis.