A free fatty acid receptor agonist inducing autophagy in HT-29 cells by downregulating the AKT/mTOR signaling pathway.

Aims: GW9508, a free fatty acid receptor agonist acts in a G-coupled protein receptor 40 (GPR40)-dependent pathway. Here, we investigated the induction of stress oxidative and autophagy by GW9508 in the human colorectal cancer cell line (HT-29) and the crosstalk between autophagy and apoptotic in HT-29 cells.

Methods: HT-29 was treated with GW9508 at a concentrations range of 50-500 μM in fibrin gel. Cell viability was investigated using an MTT assay. Induction of autophagy and apoptosis was assessed through Western blotting for associated proteins, acridine orange staining, MDC staining, qRT-PCR, and electron microscopy. Also, we estimated the molecular interactions between GW9805 and some markers through molecular docking.

Results: GW9508 inhibited HT-29 cell proliferation, induced apoptosis, and resulted in autophagy. The induced autophagy in cells was confirmed by the observation of autophagosomes, the presence of autophagy markers, including beclin-1, LC3, AMPK, and lack expression of mTOR and AKT. Moreover, GW9508 treatment significantly increased the expression of catalase and superoxide dismutase in cells.

Discussion: Our results indicated that GW9508 could induce autophagy by inhibiting the Akt/mTOR in HT-29. Hence, GW9508 is suggested as a novel anticancer reagent.