Abstract: Objective To investigate the mechanism underlying the inhibitory effects of Demethylzeylasteral (T-96) on non-small cell lung cancer (NSCLC) cells. Methods We first examined the effects of different concentrations (1, 3, 10, and 30 μmol/L) of demethylzeylasteral on morphology and cell number of A549 and H1299 cells. The changes in proliferation, cell viability, migration, invasion, and apoptosis of A549 and H1299 cells following demethylzeylasteral treatment were detected using clone formation, CCK-8, cell scratch, Transwell, and flow cytometric assays, and the effect of SC79 treatment against demethylzeylasteral-induced cell apoptosis was assessed. Western blotting was performed to detect the changes in expressions of E-cadherin, N-cadherin, vimentin, Bax, Bcl-2 and cleaved caspase-3 and phosphorylation of AKT/CREB in demethylzeylasteral-treated A549 and H1299 cells and the cellular expressions of apoptotic proteins following treatment with both demethylzeylasteral and SC79. Results T-96 treatment caused elongation of the cell body and widening of the intercellular space and significantly inhibited cell viability, proliferation, migration and invasion of A549 and H1299 cells (P<0.05). Flow cytometry showed that demethylzeylasteral induced apoptosis in both A549 and H1299 cells, whereas SC79 treatment obviously attenuated its pro-apoptotic effect (P<0.05). Western blotting revealed up-regulated expressions of Bax and cleaved caspase-3 proteins and lowered Bcl-2 expression level in demethylzeylasteral-treated A549 and H1299 cells, but co-treatment with SC79 obviously attenuated the expressions of the apoptotic proteins. T-96 significantly up-regulated the expression level of E-cadherin, down- regulated the expressions of N-cadherin and vimentin, and inhibited the phosphorylation of AKT and CREB in the two cell lines (P<0.05). Conclusion T-96 inhibits the proliferation, migration and invasion and induces apoptosis of NSCLC cells possibly by inhibiting the AKT/CREB signaling pathway.

Key words: non-small cell lung cancer; demethylzeylasteral; AKT; CREB