Mauriporin, a Novel Cationic α-Helical Peptide with Selective Cytotoxic Activity Against Prostate Cancer Cell Lines from the Venom of the Scorpion Androctonus mauritanicus

Prostate cancer is the second most common cancer in men and the second leading cause of cancer-related deaths among men in the western world. Finding a cure for prostate cancer is urgently needed. Scorpion venoms are rich sources of biologically active peptides, among which the non-disulfide bridged peptides constitute an important group displaying multifunctional activities. The non-disulfide bridged scorpion venom peptides are rarely identified and poorly characterized so far. In this work, we report the molecular cloning and functional characterization of a novel non-disulfide bridged peptide from the venomous gland cDNA library of the Moroccan scorpion Androctonus mauritanicus. Named Mauriporin, the peptide was found to be composed of 48 residues and circular dichroism analysis revealed the peptide to display a well defined alpha-helical structure in membrane mimicking environments. A synthetic replicate of Mauriporin was found to exert potent selective cytotoxic and antiproliferative activity against prostate cancer cell lines (IC50 4.4-7.8 mu M) when compared with non-tumorigenic cells. In this concentration range, Mauriporin produced also negligible degrees of hemolytic activities against mammalian erythrocytes. Apoptotic studies displayed that Mauriporin is not causing cell death through an apoptotic-mediated pathway but possibly through a necrotic mode of cell death. In conclusion Mauriporin may offer a novel therapeutic strategy in the treatment of prostate cancer considering its significant cytotoxic potency against prostate cancer cells and low toxicity to non-tumorigenic cells.