Silencing MASTL Inhibits Cell Proliferation and Migration of Gastric Cancer MGC-803 Cells Via Suprressing AKT, mTOR, p38 Signal Pathways

Abstract

Background: Microtubule-associated serine/threonine kinase (MASTL) functions to regulate chromosome condensation and mitotic progression. Emerging reports showed that aberrant MASTL expression is commonly implicated in various human cancers and act as an oncogene. This study aimed to discover the potential significance of MASTL in gastric cancer, and to uncover relevant mechanisms. Methods: Lentivirus MASTL-shRNA was constructed and infected into MGC-803 cells to analysis its influences on cell proliferation by Green fluorescent protein (GFP)-based cellomics and colony formation assay, cell invasion and migration by transwell assay, apoptosis and cell cycle by flow cytometry detection, respectively. Nude mice and fluorescence imaging were used to characterize the regulation of tumor growth in vivo. Affymetrix mRNA microarray assay combined KEGG enrichment analysis were used to screen relevant molecules related to MASTL silencing. Finally，several aberrantly expressed genes were validated by quantitative reverse transcription PCR(RT-qPCR)and western blot detection. Results: Silencing MASTL significantly inhibited cell proliferation, migration and invasion, arrested cell cycle at G1 stage. Silencing MASTL reduced tumor growth in nude mice, and fluorescence imaging indicated that the total radiant efficiency of mice in the Lv-shMAST group was markedly reduced compared with in mice in the Lv-shCtrl group in vivo. Affymetrix mRNA microarray assay revealed that 124 genes upregulated, 167 genes downregulated. RT-qPCR and western blotting validation showed that cyclin dependent kinase 6(CDK6), bone morphogenetic protein 2(BMP2), snail family transcriptional repressor 2(SNAI2), phosphorylation-mechanistic target of rapamycin kinase (p-mTOR), phosphorylation-AKT serine/threonine kinase (p-AKT) and phosphorylation-p38 kinase (p-p38) are downregulated, and cyclin dependent kinase inhibitor 1A (CDKN1A) is upregulated. Conclusions: Silencing MASTL could significantly inhibit cell growth, migration ability, induce apoptosis, arrest cell cycle at G1 stage, and the mechanisms of which were mediated via inactivation of mTOR, AKT, p38 signal pathways.