A Novel, Potent, Small Molecule AKT Inhibitor Exhibits Efficacy against Lung Cancer Cells In Vitro

PURPOSE: Anomalies of Akt regulation, including overexpression in lung cancer, impart resistance to conventional chemotherapy and radiation, thereby implicating this kinase as a therapeutic intervention point. A novel scaffold of Akt inhibitors was developed through virtual screening of chemical databases available at Birla Institute of Technology and Science, Pilani, Hyderabad, based on docking studies using Maestro. A benzothienopyrimidine derivative (BIA-6) was identified as a potential lead molecule that inhibited Akt1 enzyme activity with an IC(50) of 256 nM. MATERIALS AND METHODS: BIA-6 was tested for in vitro Akt1 inhibition using a fluorescence resonance energy transfer kit. Anti-proliferative activity was tested in NCI-H460, A549, NCI-H1975, and NCI-H2170 cell lines. The effect of the compound on p-Akt (S(473)) was estimated. RESULTS: BIA-6 allosterically caused a dose dependent reduction of growth of cell lines with a half maximal growth inhibition (GI(50)) range of 0.49 μM to 6.6 μM. Cell cycle analysis indicated that BIA-6 caused a G1 phase arrest at < 100 nM but led to apoptosis at higher doses. BIA-6 also exhibited synergism with standard chemotherapeutic agents. CONCLUSION: BIA-6 is a novel, allosteric Akt inhibitor with potent anti-cancer activity in lung cancer cell lines, that effectively blocks the phosphoinositide-3 kinase/Akt pathway with a high margin selectivity towards normal cells.