Selective anti-tumor activities of venom peptides from the lesser paper wasp Parapolybia varia

Abstract

We identified vespid chemotactic peptide (VCP) and vespakinin (Vespk) from the lesser paper wasp, Parapolybia varia. The cDNA, genomic DNA, and mature peptide sequences of P. varia VCP (PvVCP) and Vespk (PvVespk) were determined. To investigate the pharmacological and toxicological properties of PvVCP and PvVespk, their hemolytic, anti-microbial, anti-fungal, and anti-tumor activities were evaluated and compared with those of Vespa mandarina VCP (VmVCP) and Vespk (VmVespk). PvVCP, PvVespk, and VmVespk showed little to low hemolytic activities. Only VmVCP showed hemolytic activity at a high concentration. Among the four peptides tested, VmVCP showed both anti-microbial and anti-fungal activities, whereas PvVCP showed only anti-fungal activity to Candida albicans. Interestingly, PvVCP showed significantly stronger anti-tumor activities to two ovarian cancer cell lines compared with VmVCP. Vespks only showed anti-tumor activity to SK-OV-3 cells but not to NIH-OVCAR-3 cells. These differences in anti-tumor activity might have been caused by the differences in secondary structure among peptides. A circular dichroism spectrometry analysis revealed that VCPs have more amphiphilic α-helix structures than Vespks. Taken together, the low hemolytic but strong anti-tumor activities of PvVCP suggest that this peptide could be a candidate for developing a new anti-tumor peptide drug or drug carrier in the future.