Novel imidazo[1,2-a]pyridine inhibits AKT/mTOR pathway and induces cell cycle arrest and apoptosis in melanoma and cervical cancer cells

The present study aimed to investigate the anti-cancer activity of imidazo[1,2-a]pyridine 5–7 in the A375 and WM115 melanoma and HeLa cervical cancer cell lines. The viability of cancer cells was analyzed by the MTT assay. Apoptosis was quantified by flow cytometry following staining of the cells with AnnexinV/propidium iodide (PI). The cell cycle was evaluated by flow cytometry after staining of cells with PI. The three compounds inhibited the proliferation of all cells for half maximal inhibitory concentration ranging from 9.7 to 44.6 µM following 48-h treatment. In addition, all cancer cells were more sensitive to compound 6 compared with the other compounds. Treatment with compound 6 induced G(2)/M cell cycle arrest and a significant increased level of intrinsic apoptosis in all tested cells. Furthermore, compound 6 reduced the levels of phospho (p)-protein kinase B and p-mechanistic target of rapamycin, and increased levels of the cell cycle inhibitors p53 and p21 and of the apoptosis-associated proteins BCL2 associated X protein and active caspase-9. Silencing p53 in A375 melanoma cells reduced compound 6-induced apoptosis, which suggested that compound 6 may induce p53-partially mediated apoptosis. These results demonstrated that imidazo[1,2-a]pyridines 5–7 are potential effective compounds in the treatment of melanoma and cervical cancers.