Expression Of CDK5RAP3 In Human Gastric Cancer And Its Effect On Cell Proliferation And Invasion

Objective: To detect the expression of CDK5RAP3 in human gastric cancer and adjacent non-cancerous tissues. To analyze the possible relationship between CDK5RAP3 expression and clinicopathological parameters. To study the effect of knockdown of CDK5RAP3 protein on the ability of gastric cancer cell lines proliferation and invasion in vitro. Methods: 1. Retrospective study, were collected from January to July of 2014 in Fujian Medical University Union Hospital, clinical data and gastric cancer tissues and their corresponding adjacent non-cancerous tissues of 108 cases patients who were treated radical gastrectomy. Western blot was used to detect the expression level of CDK5RAP3 in gastric cancer tissues and its’ adjacent non-cancerous tissues. 2. The association of CDK5RAP3 expression with clinicopathological parameters was statistically analyzed by chi-square test. 3. 43 cases of gastric cancer tissues and adjacent non-cancerous tissues paraffin-embedded specimens were collected from Fujian Medical University Union Hospital with detailed clinicopathological parameters between October 2009 and September 2007. The immunohistochemical SP was performed to evaluate the expression level of CDK5RAP3. 4. Knockdown the level of CDK5RAP3 in MGC-803 cells by using the specific shRNA. 5. CCK8 assay, colony formation assay were used to study the effect of down-regulating CDK5RAP3 on gastric cancer cell proliferation in vitro. 6. Transwell invasion assay to detect the ability of invasion of gastric cancer cell with low expression of CDK5RAP3 in vitro. Results:1. Western blot results showed that: Thirty-five patients(32.41%) showed high expression in tumor tissues, while 73 of 108 patients(67.59%) showed high expression in non-tumor adjacent tissues.CDK5RAP3 protein relative expression intensity in gastric cancer tissues(0.6010±0.06796)was significantly lower than its adjacent non-cancerous tissues(0.9809±0.1331),the difference was statisticly significant(p<0.05). 2. The lower expression of CDK5RAP3 protein in gastric cancer was associated with depth of invasion and pTNM stage. 3. Immunohistochemistry found that CDK5RAP3 protein can express in gastric cancer tissues and adjacent non-cancerous tissues. The immunostaining for CDK5RAP3 was mainly located in the cytoplasm of tumor cells. Further analysis showed that CDK5RAP3 staining was positive in 19(44.19%) gastric cancer tissues and 34(79.07%) of noncancerous tissues(P < 0.05). 4. Transfcction lead to the expression of CDK5RAP3 decreased significantly in CDK5RAP3-siRNA transfected cells when compared with that in Mock-transfeted cells(P<0.05). 5. CCK8 assay, colony formation assay showed that: Knockdown of CDK5RAP3 expression significantly increased cell proliferation and colony formation in MGC-803 cells. 6. Transwell invasion assay showed that: Knockdown of CDK5RAP3 expression significantly increased cell invasion in MGC-803 cells. Conclusions:CDK5RAP3 expression in gastric cancer tissue is lower than tissue adjacent to carcinoma significantly, and the abnormal expression of CDK5RAP3 may be related to carcinogenesis and the development of gastric cancer. Knockdown of CDK5RAP3 could increase gastric cancer cell proliferation and invasion in vitro.