In Silico Discovery of a Small Molecule Suppressing Lung Carcinoma A549 Cells Proliferation and Inducing Autophagy via mTOR Pathway Inhibition

Mammalian target of rapamycin (mTOR) kinase is vital to the regulation of cell growth and proliferation, and it has been taken as a promising target to develop cancer therapies. By reference to the crystal structure of mTOR-PP242, we explored to discover potential ATP-competitive inhibitors of mTOR. Through the integrated use of multiple in silico screenings, the tremendous amount of compounds from the SPECS database were finally reduced to 30. After several rounds of convincing biological tests in A549 cells, the newfound C-4 was identified as a potential ATP-competitive inhibitor of mTOR. Besides A549 cell proliferation suppression caused by C-4, autophagy was also determined through autophagosome observation and autophagy flux detection in C-4 treated A549 cells. We demonstrated that C-4 could inhibit cell growth and proliferation, and this inhibition may be associated with autophagy.