Cancer-killing snake toxin
doi:10.1038/nindia.2013.55 Published online 23 April 2013
Researchers have synthesized a new, anticancer nanocomposite by fusing a protein found in snake venom with modified gold nanoparticles (GNPs)1. This nanocomposite induced controlled death of two types of cultured blood cancer cells, raising the possibility of new therapies for deadly blood cancers.
Snake venoms contain a host of proteins, peptides, free lipids and carbohydrates. Some of these snake venom proteins are toxic and show anticancer activity. However, the toxic nature of such proteins is harmful to healthy cells that usually surround cancer cells. Being inert, nanoparticles such as GNPs can reduce the toxicity of these proteins, making them benign to healthy cells but toxic to cancer cells.
No previous studies had investigated the effect of attaching a snake protein toxin to GNPs. The researchers first modified GNPs using polyethylene glycol, an organic compound. They then conjugated NKCT1, a protein toxin isolated from Indian cobra (Naja kaouthia) venom, with polyethylene-glycol-capped GNPs, producing a nanocomposite called GNP-NKCT1. The anticancer activity of GNP-NKCT1 was explored using two types of human leukaemic cells.
GNP-NKCT1 was found to cause controlled death (apoptosis) of human leukaemic cells. The cancer cells treated with GNP-NKCT1 showed nuclear and DNA fragmentation and membrane blebs, which are signs of apoptosis. GNP-NKCT1 also permeated cancer cells, evading a system in cancer cells that expels such protein toxins.
The GNP-NKCT1 retained its anticancer activity even after being stored for one month at room temperature. GNPs were found to release NKCT1 to the target cancer cells in a controlled way, increasing the anticancer effects of NKCT1. "In the future, GNP-NKCT1 may emerge as a therapy for blood cancers," says Antony Gomes, a co-author of the study.
The authors of this work are from: Laboratory of Toxicology & Experimental Pharmacodynamics, Department of Physiology and Department of Biochemistry, University of Calcutta, Kolkata, India.
- Bhowmick, T. et al. Antileukemic potential of PEGylated gold nanoparticle conjugated with protein toxin (NKCT1) isolated from Indian cobra (Naja kaouthia) venom. Cancer Nanotechnology (2013) doi: 10.1007/s12645-013-0036-5