2,6-DMBQ is a novel mTOR inhibitor that reduces gastric cancer growth in vitro and in vivo
Xueyin Zu, Xiaoli Ma, Xiaomeng Xie, Bingbing Lu, Kyle Vaughn Laster, Kangdong Liu, Zigang Dong, Dong Joon Kim
Abstract
BACKGROUND: Fermented wheat germ extract has been reported to exert various pharmacological activities, including anti-oxidant, anti-cell growth and cell apoptosis in various cancer cells. Although 2,6-dimethoxy-1,4-benzoquinone (2,6-DMBQ) is a benzoquinone compound and found in fermented wheat germ extract, its anticancer effects and molecular mechanism(s) against gastric cancer have not been investigated. METHODS: Anticancer effects of 2,6-DMBQ were determined by MTT, soft agar, cell cycle and Annexin V analysis. Potential candidate proteins were screened via in vitro kinase assay and Western blotting. mTOR knockdown cell lines were established by lentiviral infection with shmTOR. The effect of 2,6-DMBQ on tumor growth was assessed using gastric cancer patient-derived xenograft models. RESULTS: 2,6-DMBQ significantly reduced cell growth and induced G1 phase cell cycle arrest and apoptosis in gastric cancer cells. 2,6-DMBQ reduced the activity of mTOR in vitro. The inhibition of cell growth by 2,6-DMBQ is dependent upon the expression of the mTOR protein. Remarkably, 2,6-DMBQ strongly reduced patient-derived xenograft gastric tumor growth in an in vivo mouse model. CONCLUSIONS: 2,6-DMBQ is an mTOR inhibitor that can be useful for treating gastric cancer. It has therapeutic implications for gastric cancer patients.