Melittin exerts antitumorigenic effects in human MM1.S multiple myeloma cells through the suppression of AKT/mTOR/S6K1/4E-BP1 signaling cascades

[摘要] Although melittin, a water-soluble 26-amino acid peptide derived from bee venom of Apis mellifera, is known to exert anti-proliferative effects on various tumor cell lines, very little is known about its potential molecular mechanism(s) of action. In the present study, we investigated the effects of melittin on the AKT/mTOR/S6K1/4E-BP1 activation, associated gene products, cellular proliferation, and apoptosis in several tumor cells. We found that melittin inhibited both constitutive phosphorylation of AKT and mTOR and exerted a significant time-dependent anti-proliferative effect on MM1.S cells as compared to other types of tumor cells. Indeed, melittin clearly suppressed the constitutive activation of AKT/mTOR/S6K1/4E-BP1 signaling cascades, which correlated with the induction of apoptosis. Melittin can cause broad-spectrum inhibition of AKT/mTOR/S6K1/4E-BP1 axes in multiple myeloma cells when compared with various pharmacological AKT/mTOR inhibitors. Aberrant AKT activation by pcDNA3-myr-HA-AKT1 plasmid could not prevent the observed suppressive effect of melittin on constitutive mTOR, S6K1, and 4E-BP1 activation and overexpression of Bcl-2 also attenuated melittin-mediated apoptosis in the cells. Our results clearly indicate that melittin can interfere with multiple signaling cascades involved in carcinogenesis and thereby used as a potential drug candidate for both the prevention and treatment of cancer.

[学科分类] 药学

[关键词] Multiple myeloma