Knockdown of KREMEN2 inhibits tumor proliferation and metastasis in gastric cancer.

Abstract

e16555 Background: KREMEN2 is an important regulator of classical Wnt/β-catenin signaling pathway. However, the relationship between KREMEN2 and gastric cancer is not clear. The aim of this study was to explore the regulatory role of KREMEN2 in the tumorigenesis and metastasis of gastric cancer. Methods: We measured the protein level of KREMEN2 in 156 gastric adenocarcinoma, 40 metastatic gastric adenocarcinoma, 8 marginal and 4 normal tissues using tissue microarray. The differences in KREMEN2 expression were tested with Mann-Whitney U test. The relationship between KREMEN2 expression and pathologic data was determined with Pearson’s correlation analysis. The mRNA and protein level in cultured cell lines were detected by qRT-PCR and western blotting, respectively. Lentivirus was transfected by repressing KREMEN2. Cell viability was determined by the MTT assay. Apoptosis and cell cycle distribution were detected using flow cytometry. The cell migration was investigated by wound healing and transwell assay. Antibody array was performed to explore the underlying molecule mechanism. In vivo, Xenograft assay was established using nude mice to explore the role of KREMEN2 in gastric cancer cell and bioluminescence was observed via an in vivo imaging system. Results: It was demonstrated that, compared to para-cancerous tissues, KREMEN2 was significantly up-regulated in gastric cancer tissues, and was positively correlated with the pathological grade of gastric cancer patients. Given that KREMEN2 is abundantly expressed in most tested gastric cancer cell lines, KREMEN2 knockdown cell models were established and further used to construct mice xenograft model. After knocking down KREMEN2, the proliferation of gastric cancer cells was inhibited both in vivo and in vitro. At the same time, knockdown of KREMEN2 induced apoptosis, cell cycle arrest at G2/M phase and inhibition of migration in gastric cancer cells in vitro. Mechanistically, we found that knockdown of KREMEN2 suppressed PI3K/Akt pathway. Conclusions: Therefore, we revealed that the overexpression of KREMEN2 in gastric cancer may promote the carcinogenesis and metastasis of gastric cancer by activating the PI3K/Akt pathway.