Expression And Clinical Significance Of Sipa1in Gastric Cancer

Objective：To detect the expression of Sipa1（signal-induced proliferation-associated gene1）in gastric cancer and analyze its association with clinicopathological characteristicsand prognosis of patients with gastric carcinoma．To explore the possible funtionmechanism in the cancer proliferation and metastasis of Sipa1gene.Methods:1. The expression levels of Sipa1protein was examined by SPimmunohistochemical technique in122paraffin blocks of the gastric cancer and64normal gastric tissues.2. The expression levels of Sipa1mRNA was examined by real-time PCR in43fresh gastric carcinoma tissues and their corresponding adjacent normal tissues.3. The expression levels of Sipa1protein was examined by western blot infresh gastric carcinoma tissues and their corresponding adjacent normal tissues.4. the patients with gastric carcinoma are follow-up visited by outpatient、hospital、phone、field visit，etc to get information of the patients’ recurrence andmetastasis and death data,and calculate postoperative survival of patients.Results:1. The results of immunohistochemistry staining：To paraffin blocks of thegastric cancer, positive rate of Sipa1protein expression was36.1%,and73.4%ofnormal gastric tissues expressed it, The difference was statistically significant（χ~2numble is23.463，P<0.01P<0.05）. The expression of Sipa1was mainly located in thecytoplasm.2. the relationship between the results of immunohistochemistry staining andclinicopathological characteristics:5-year survival rate of Sipa1protein positive andnegative were38.6%and15.4%respectively. The5-year survival rates of Sipa1-negative patients was significantly lower than the patients with positiveexpression (bilateral log-rank test χ~2=13.626,P<0.01). Sipa1protein had somesignificant connection with tumor differentiation, lymphatic metastasis, invasivedepth, clinical stage（P<0.05）,but not relevant to age,gender,tumor size, areas oftumor,etc（P>0.05）.3. The results of RT-PCR：The△Ct number of Sipa1mRNA expression in gastriccarcinoma tissues was7.94±2.20,and it was5.73±2.25in normal gastric tissuesexpressed.The number of Sipa1mRNA expression in gastric carcinoma tissues is4.62times higher than in normal gastric tissues. The level of Sipa1mRNA expression infresh gastric carcinoma tissues was significantly decreased than that in theircorresponding adjacent normal tissues(t numble is25.28，P<0.01).4. the results of western blot：Sipa1potein expression in gastric carcinomatissues were lower than in normal gastric tissues expressed.Conclusions:1.Down-expression of Sipa1are closely related to the biologic behavior ofgastric carcinoma.2.it is very helpful in evaluating the prognosis gastric carcinoma.