Phenethyl isothiocyanate induces apoptotic cell death through the mitochondria-dependent pathway in gefitinib-resistant NCI-H460 human lung cancer cells in vitro

Abstract

Background/Aim: Some lung cancer patients treated with gefitinib develop resistance to this drug resulting in unsatisfactory treatment outcomes. Phenethyl isothiocyanate (PEITC), present in our common cruciferous vegetables, exhibits anticancer activities in many human cancer cell lines. Currently, there is no available information on the possible modification of gefitinib resistance of lung cancer in vitro by PEITC. Thus, the effects of PEITC on gefitinib resistant lung cancer NCI-H460 cells were investigated in vitro. Materials and Methods: The total cell viability, apoptotic cell death, production of reactive oxygen species (ROS) and Ca2+, levels of mitochondria membrane potential (m) and caspase-3, -8and -9 activities were measured by flow cytometry assay. PEITCinduced chromatin condensation was examined by DAPIstaining. Results: PEITC-induced cell morphological changes,decreased total viable cell number and induced apoptotic celldeath in NCI-H460 and NCI-H460/G cells. PEITC decreasedROS production in NCI-H460 cells, but increased production inNCI-H460/G cells. PEITC increased Ca2+ production,decreased the levels of m and increased caspase-3, -8 and -9 activities in both NCI-H460 and NCI-H460/G cells. Westernblotting was used to examine the effect of apoptotic cell deathassociated protein expression in NCI-H460 NCI-H460/G cellsafter exposure to PEITC. Results showed that PEITC increasedexpression of cleaved caspase-3, PARP, GADD153, Endo G andpro-apoptotic protein Bax in NCI-H460/G cells. Conclusion:Based on these results, we suggest that PEITC inducesapoptotic cell death via the caspase- and mitochondriadependentpathway in NCI-H460/G cells.