Overexpression of methionine adenosyltransferase II alpha (MAT2A) in gastric cancer and induction of cell cycle arrest and apoptosis in SGC-7901 cells by shRNA-mediated silencing of MAT2A gene.

The aim of this study was to clarify the methionine adenosyltransferase II alpha (MAT2A) expression pattern and to explore its potential role in gastric cancer. Quantitative real-time PCR was performed to examine MAT2A mRNA expression in 20 cases of gastric cancer tissues and corresponding non-tumor tissue samples. Immunohistochemistry was conducted to detect MAT2A protein expression in 91 gastric cancer tissues. Moreover, the stable cell lines transfected with the small hairpin RNA (shRNA) targeting MAT2A mRNA plasmids were established and the biological characteristics of these cells were examined. The expression levels of MAT2A mRNA in gastric cancer tissues were significantly higher than those in corresponding non-tumor tissues. High-level MAT2A expression was observed in 40.7% (37 of 91 cases), and correlated with tumor classification (P=0.012), lymph node metastasis (P=0.001) and poor tumor differentiation (P=0.011) of gastric cancer patients. Additionally, the MAT2A expression level was significantly decreased in the transfected cells with MAT2A specific shRNA expression plasmid pGCsi-H1-792. The stable transfected cancer cells exhibited a decrease in growth ability and an increase in the incidence of spontaneous apoptosis and the percentage of the G1 phase. Our data suggest that MAT2A plays an important role in gastric cancer development and progression.