Malic enzyme 1 (ME1) is a potential oncogene in gastric cancer cells and is associated with poor survival of gastric cancer patients

Background and objective: Gastric cancer is one of the most common cancers worldwide. However, the mechanisms associated with this disease are still not clear. Malic enzyme 1 (ME1) is a metabolic enzyme that is overexpressed in various cancers. Here, we examined whether it is involved in gastric cancer. Methods: ME1 expression was knocked down in the gastric cancer cell line SGC7901. Cell growth and migration were measured using a real-time microelectronic cell sensor system. Cell invasion was measured using a Transwell assay. Cell cycle analysis was also performed to examine cell cycle arrest. A gastric cancer tissue microarray of gastric cancer was stained using immunohistochemistry. ME1 expression levels were also statistically analysed. Results: ME1 knockdown in gastric cancer SGC7901 cells significantly inhibited cell proliferation, migration, and invasion. Cell cycle arrest was induced in the G2 phase. Further, ME1 expression was significantly correlated with gastric cancer patient prognosis based on both univariable and multivariable survival analysis. No significant difference was found between ME1 expression in gastric cancer tissues and that in adjacent tissues. Conclusion: Our results provide evidence that ME1 is a key factor for gastric cancer. ME1 might be pro-oncogenic during both the development and migration of gastric cancer; it also might be related to gastric cancer patient survival.