| Objective:The genetic expression of tumor has an significant effect on the prognosis of gastric cancer patients. This study not only commits to determine the expression of COUP-TFII and observe the performance of the biological characteristics in gastric cancer cells by regulating the expression level of COUP-TFII, but also to discuss the relevance between COUP-TFII and the prognosis of gastric cancer patients.Methods: 1. The m RNA and protein expression level of COUP-TFII gene in 34 cases of gastric cancer tissues and normal mucosa were detected respectively by the fluorescent quantitative polymerase chain reaction(PCR), Western-blot and immunohistochemistry.2. By the fluorescent quantitative PCR and Western-blot, the expression level of COUP-TFII in 3 gastric cancer cell lines and normal mucosa cell line were detected respectively.3. Construction of recombinant plasmid carrying with the gene COUP-TFII, infected MGC-803 cell with lentivirus vector and obtained stable expressed COUP-TFII gene of gastric cancer cell lines. A variety of cell function experimental, such as MTT assay, Transwell cell migration and invasion assay, Nude mice tumor metastasis experiments in vivo, respectively was used to detect the impact of biological characteristics in overpression COUP-TFII gene of gastric cancer cell.4. Through transfecting si RNAs into GES-1 cells, the expression level of COUP-TFII gene was down-regulated. The knockdown cell line was obstained and used for detect the impact of biological characteristics.5. The relationship between the expression level of COUP-TFII gene and either clinic pathological parameters or overall survival of patients are also analyzed in this study.Results: 1. The fluorescent quantitative PCR, Western-blot detection showed that the expression of COUP-TFII m RNA and protein in the gastric carcinoma is significantly lower than normal gastric mucosa tissues of 34 cases(P<0.05)and 19 cases(P<0.01) respectively. Also, Immunohistochemical shows that the positive expression rate of COUP-TFII in gastric cancer tissues(11/19) is lower than normal gastric mucosa tissues(P<0.01).2. The expression level of COUP-TFII mRNA and protein in 3 gastric cancer cell lines(SGC-7901、BGC-823、MGC-803) and normal gastric mucosa cell line(GES-1) was detected by the fluorescent quantitative PCR and Western-blot. Compared with GES-1, the expression level of COUP-TFII was low in all gastric cell lines, especially the MGC-803 was the lowest(P<0.001).3. Obtained the stable expressed COUP-TFII gene in gastric cancer cell line(MGC-803/COUP-TFII), Transwell migration and invasion assay indicated that the mobility and invasioness were evidently receded in MGC-803/COUP-TFII group(P<0.001). MTT assay showed that the ability of proliferation in MGC-803/COUP-TFII was significantly weaker against the MGC-803 and MGC-803/CTRL group(P<0.001). The number of hepatic metastasis in MGC-803/COUP-TFII group was less than MGC-803/CTRL group in nude mice tumor metastasis experiments in vivo(P<0.001). 4. After down-regulating COUP-TFII gene in GES-1, the the ability of proliferation(P<0.01), migration(P<0.01) and invasion(P<0.001) of GES-1 were enhanced in different extent.5. The analysis of the clinical pathological parameters in 80 gastric pateints from oncomine database suggested that the expression level of COUP-TFII in gastric cancer was not relevant to the patient’s sex, age and grade as there is no statistically significance(P>0.05), however, it has related with the clinical stage(P<0.01). The kaplan-Meier plot showed that high levels of COUP-TFII improved overall survival in patients with gastric cancer.Conclusion: 1. A different expression of COUP-TFII between the gastric cancer tissue and gastric mucosa tissue showed that COUP-TFII had an effect on the tumorigenesis of gastric cancer. And the low-expression of COUP-TFII in gastric cancer tissue led to lack of the ability of tumor suppression.2. The expression level of COUP-TFII in 3 gastric cancer cell lines was lower than gastric mucosa tissue, especially the MGC-803 was the lowest. It indicated that MGC-803 was the most appropriate candidate for overexpression. Similarly, GES-1 was used for knockdown.3. The significantly lack of the ability of invasion, migration and metastasis in overexpression cell line and the enhanced above capacity in GES-1 showed that COUP-TFII had impact on the invasioness, mobility, proliferation and metastasis of gastric cancer.4. The high expression level of COUP-TFII could improve the prognosis in patients with gastric cancer, since it had no relation with the patient’s sex, age and grade. But The high expression level of COUP-TFII was significantly related to patient’s clinical stage and overall survival. |
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