Expression of Yes-associated protein in gastric adenocarcinoma and effects of Yes-associated protein knockdown on proliferation and metastasis of gastric cancer cells

Abstract

Objective To examine the expression of Yes-associated protein (YAP) in human gastric adenocarcinomas,gastric adenomas and normal gastric mucosa tissues,and further explore the effects and molecular mechanisms of YAP on proliferation and metastasis of gastric cancer cells.Methods The expression of YAP in 78 cases of gastric adenocarcinomas,39 cases of gastric adenomas and 46 cases of normal gastric mucosa tissues was detected by using immunohistochemistry and real-time polymerase chain reaction (PCR).In vitro human gastric cancer SGC-7901 cells were stably transfected with lentivirus-mediated YAP small hairpin RNA (shRNA),and the expression levels of proliferating cell nuclear antigen (PCNA) and metalloproteinase-2 (MMP-2) were detected by using Western blotting.The proliferative activity and metastatic capability of gastric cancer cells were evaluated by methyl thiazol tetrazolium (MTT) and Transwell assays.Results The expression of YAP was observed in 69.23％ gastric adenocarcinoma tissues,and its mRNA expression level in gastric adenocarcinoma (1.74 ± 0.46) was significantly increased as compared with that in normal gastric mucosa (0.33 ± 0.15) and gastric adenoma (0.42 ±0.20).Knockdown of YAP by shRNA could down-regulate the expression of PCNA and MMP-2,and inhibit the proliferation and metastasis of gastric cancer cells.Conclusion YAP is strongly expressed in gastric adenocarcinoma,and knockdown of YAP inhibits proliferation and metastasis of gastric cancer cells. Key words: Gastric carcinoma; Yes-associated protein; Small hairpin RNA; Proliferation; Metastasis