| BACKGROUND AND AIMS: China has always been a high incidence of primary liver cancer. It is one of the common malignant tumor in clinic. More than 50% of all new cases in the world happened in china each year. Pathologically, primary liver cancer was classified into two types, hepatocellular carcinoma and cholangiocellular carcinoma,while hepatocellular carcinoma is one of common pathological type, the proportion is about 75%. Though in recent years, with the deepening of the scientific and technological progress and research, we get a lot of new discoveries and new breakthrough, clinical treatment of primary liver cancer after long-term survival without obvious improvement. Fbxw7(F-box and WD repeat domain- containing 7, Fbw7) also called cdc4, one of the most important conponent of SCF ubiquitin ligase,which can identificate the substrates. Fbxw7 can recognize the phosphorylated substrates through specific recognition site,and combined with it to degradation by the ubiquitin proteasome system.recent studies have found that Fbxw7 plays an very important role in many important signaling pathway by degradation key moleculars. Fbxw7 is an important tumor suppressor genes.It is found that Fbxw7 can inhibite the tumor proliferation,differentiation,drug resistance etc. in many different tumors. This study was aim to find the role of Fbxw7 in the development of liver cancer.First, we want to find Fbxw7 expression in liver cancer and the correlation of the expression level and clinical prognosis.then by exogenous expression Fbxw7 to understand its fuction in liver cancer by vivo and vitro.finally,to find the mechanism of signaling pathway changes.RESEARCH METHODS: 1. By the Real- time PCR and Western blot method to detect Fbxw7 expression level in human liver cancer tissue and hepatocellular carcinoma cell lin;Through the Real- Time PCR method to detect Fbxw7 different subtypes distribution in liver cancer. 2. Use the tissue microarray to observe Fbxw7 expression by immunohistochemical staining, combination with the patient’s prognosis and the pathological data to have correlation analysis. 3. To establish cell lines of exogenous overexpression of Fbxw7, testing the liver cancer cell proliferation and clone formation, migriation, invasion and stemness. 4. By the method of si-RNA,we establish exogenous fbxw7 interference, observe its effect on liver cancer cell proliferation,metastasis, invasion etc. 5. Through the subcutaneous tumor-burdened model and tail vein injection of pulmonary metastasis model, study Fbxw7 function in vivo. 6. Use different inflammatory factors stimulation, testing Fbxw7 influence to different inflammatory signaling pathways. 7. To detect Fbxw7 influence of TGF-beta/smad pathway, the changes of upstream and downstream of the signaling pathways.RESULTS: 1. Most of the patients with liver cancer tissues Fbxw7 expression level is lower than the tissue adjacent to carcinoma, and tumor emboli in the organization Fbxw7 expression level is extremely low, most Fbxw7 alpha subtype expression in liver tissue. 2. The patients with higher Fbxw7 expression level indicate the better prognosis, to the contrary, lower expression Fbxw7 has correlation with AFP and tumor capsule and TNM classification. 3. Over expression Fbxw7 in hepatocellular carcinoma cell line can reduce cancer cell proliferation, and the amount of cell clone formation and the number of migriation and invasion. 4. By interference Fbxw7 in hepatocellular carcinoma cell line, cell proliferation was increased, so as to the number of migriation and invasion.5. Overexpression of Fbxw7 reduces the volume and the weight of liver cancer of the liver cells in the body, and also can significantly reduce the number of cells in the pulmonary metastasis of liver cancer. 6. Overexpression of Fbxw7 can reduce the reaction of inflammatory signaling pathways, and can significantly reduce the EMT related gene expression. 7. Fbxw7 can inhibit TGF- beta upstream and downstream signaling pathways, affecting the liver cancer cells ability of migriation and invasion.CONCLUSIONS: This study by exogenous Fbxw7 differential expression in vivo and in vitro found that Fbxw7 can negative regulating liver cancer cell proliferation and clone formation, transfer, and stemness ability,Fbxw7 of TGF- beta signal pathways through upstream and downstream of the negative control and promote the degradation of Slug, involved in regulating the cancer metastasis and invasion.In addition, the expression level of Fbxw7 is negatively related to the postoperative survival of patients and clinical prognosis, suggest it can be a prognostic factor of liver cancer. |
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