Oncolytic viruses & their specific targeting to tumour cells.

Cancer is one of the major causes of death worldwide. In spite of achieving significant successes in medical sciences in the past few decades, the number of deaths due to cancer remains unchecked. The conventional chemotherapy and radiotherapy have limited therapeutic index and a plethora of treatment related side effects. This situation has provided an impetus for search of novel therapeutic strategies that can selectively destroy the tumour cells, leaving the normal cells unharmed. Viral oncotherapy is such a promising treatment modality that offers unique opportunity for tumour targeting. Numerous viruses with inherent anti-cancer activity have been identified and are in different phases of clinical trials. In the era of modern biotechnology and with better understanding of cancer biology and virology, it has become feasible to engineer the oncolytic viruses (OVs) to increase their tumour selectivity and enhance their oncolytic activity. In this review, the mechanisms by which oncolytic viruses kill the tumour cells have been discussed as also the development made in virotherapy for cancer treatment with emphasis on their tumour specific targeting.

Newcastle disease virus as an oncolytic agent.

Cancer is a major cause of deaths in humans. Though there has been significant progress in cancer therapy, the limited efficacy and toxicities of current chemo- and radiotherapies have provided an impetus for the search of new therapeutics. A therapeutic approach, which uses viruses for the treatment of cancer termed, oncolytic virotherapy has recently emerged. Newcastle disease virus (NDV) is one such virus with an inherent oncolytic property. NDV causes a highly infectious disease in poultry worldwide. In humans it is reported to have oncolytic and immuno-stimulatory effects. It specifically replicates in tumour cells while sparing normal cells and cause oncolysis. For many years different strains of the NDV have been investigated for treatment of various human cancers. Recent advances in reverse genetics provided investigators the tools to produce recombinant NDV with improved oncolytic property.