Use of Animal Venom Peptides/Toxins in Cancer Therapeutics

Abstract

Animal venoms possess variety of toxins/proteins/peptides which act as ionic channel inhibitors and target vital physiological processes. Toxin peptides isolated from honey bee, wasp and scorpion show membrane binding, growth inhibition and strong cytolytic properties. These also inhibit angiogenesis and induce caspase-dependent apoptosis in melanoma cells through the intrinsic mitochondrial pathway protecting the experimental animals against tumor development. These toxin peptides exert cytotoxic effects on human oral cancer cells by inducting apoptosis via a p53-dependent intrinsic apoptotic pathway. These can be used as cancer therapeutic agents by loading them in liposomes. This lead to increase in their target specificity against cancer cells, shorten cell survival, and produce higher reactive oxygen species (ROS), and does enhancement in the number of apoptotic cells. In addition, toxins enhance G0/G1 enrichment upon treatment of cancer cells. Further, encapsulated honey bee, wasp and scorpion venoms exert much potent anti-cancer effect on many cancer cells lines. Upon slight chemical modifications animal toxins could gear up higher selectivity, show much improved target specificity and lesser toxic effects because of charge optimization. After their improvement they show superiority over the conventional chemical drugs as an increase in net charge of the peptide, its hydrophobicity and anionicity and fluidity of the target cell membranes. It primarily imparts effect through biophysical interaction with the target cell membrane. Toxin peptides are best candidate as they selectively target malignant gliomas and play significant role in GBM immunotherapy. Venom toxins/peptides are good natural sources of compounds/molecules which could act as prototype or template which can be used for development of new therapeutic agents and best tools for diagnosis of not only for cancer but also for other diseases.