Induction of reactive oxygen species-stimulated distinctive autophagy by chelerythrine in non-small cell lung cancer cells

Chelerythrine (CHE), a natural benzo[c]phenanthridine alkaloid, shows anti-cancer effect through a number of mechanisms. Herein, the effect and mechanism of the CHE-induced Autophagy, a type II programmed cell death, in non-small cell lung Cancer (NSCLC) cells were studied for the first time. CHE induced cell viability decrease, colony formation inhibition, and Apoptosis in a concentration-dependent manner in NSCLC A549 and NCI-H1299 cells. In addition, CHE triggered the expression of phosphatidylethanolamine-modified microtubule-associated protein light-chain 3 (LC3-II). The CHE-induced expression of LC3-II was further increased in the combination treatment with chloroquine (CQ), an Autophagy Inhibitor, and large amounts of red-puncta were observed in the CHE-treated A549 cells with stable expression of mRFP-EGFP-LC3, indicating that CHE induces Autophagy flux. Silence of beclin 1 reversed the CHE-induced expression of LC3-II. Inhibition of Autophagy remarkably reversed the CHE-induced cell viability decrease and Apoptosis in NCI-H1299 cells but not in A549 cells. Furthermore, CHE triggered Reactive Oxygen Species (ROS) generation in both cell lines. A decreased level of ROS through pretreatment with N-acetyl-L-cysteine reversed the CHE-induced cell viability decrease, Apoptosis, and Autophagy. Taken together, CHE induced distinctive Autophagy in A549 (accompanied Autophagy) and NCI-H1299 (pro-death Autophagy) cells and a decreased level of ROS reversed the effect of CHE in NSCLC cells in terms of cell viability, Apoptosis, and Autophagy.