Dietary isothiocyanate sulforaphene induces reactive oxygen species, caspase -9, -8, -3-dependent apoptosis and modulates PTEN/PI3Kinase in human cervical cancer cells

Abstract

Purpose: To investigate the apoptotic activity, cell proliferation inhibition and different signaling protein expressions after treatment with a new isothiocyanate, sulforaphene, in human cervical cancer (HeLa) cells. Methods: Cytotoxicity was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after sulforaphene treatment for 3, 6, 12 and 24 h. Apoptosis assay, cell cycle analysis, intracellular oxygen species (ROS) measurement, mitochondrial membrane depolarization and western blot analysis were performed in four time-intervals to explore sulforaphene activity. Results: HeLa cell viability was reduced by sulforaphene dose and time dependently. ROS plays a causative role in sulforaphene induced cytotoxicity and apoptosis during which stimulation of Bax and blocking of Bcl2 were involved. Mitochondrial membrane potential depletion and cytochrome C, AIF modulation suggest mitochondrial pathway for the apoptosis. Activation of caspase -9, -8 and -3 in treated HeLa cells demonstrated caspase-dependent apoptosis by sulforaphene. Again, sulforaphene induced HeLa cell proliferation inhibition was evidenced by cell cycle arrest and PTEN/PI3Kinase modulation. Conclusion: Dietary sulforaphene induces HeLa cell apoptosis by enhancing intracellular ROS levels, thereby activating multiple apoptotic signal cascades. Therefore, sulforaphene is a potential candidate for anticancer therapy.