A Novel Peptide from Vespa ducalis Induces Apoptosis in Osteosarcoma Cells by Activating the p38 MAPK and JNK Signaling Pathways.

Osteosarcoma (OS) is a typical bone cancer, and most frequently used cancer treatments for OS are limited due to severe drug-related toxicities. Wasp venoms contain functional components that may offer pharmaceutical components for the treatment of cancers. This study aimed to isolate and characterize a novel peptide (venom anti-cancer peptide 1, VACP1) derived from the wasp venom of Vespa ducalis SMITH. Toxins from Vespa ducalis crude venom were separated by gel filtration and purified by C18 reverse-phase HPLC. As examined by Edman degradation, the amino acid sequence of VACP1 is AQKWLKYWKADKVKGFGRKIKKIWFG. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays revealed that VACP1 inhibited the cell proliferation of MG-63, U-2 OS and Saos-2 cells. Furthermore, annexin V and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining revealed that VACP1 could induce the apoptosis of OS cell lines. In addition, VACP1 increased the protein levels of cleaved poly ADP-ribose polymerase (PARP), caspase 3, but decreased B-cell lymphoma 2 (Bcl-2). Apoptotic signaling pathway screening in MG-63 cells via an antibody array revealed that VACP1 activated the p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) pathways. The present study demonstrates that VACP1 potently suppressed cell proliferation and induced the cell apoptosis of OS cells by inducing the activation of the p38 MAPK and JNK signaling pathways, suggesting that VACP1 is a promising agent for OS therapy.