Newcastle disease virus as an anticancer agent - A preliminary study

Cancer remains one of the top causes of death in humans. It can affect any organ (s) of the body regardless of the age, gender, race/ethnic background, diet and the environment. Progress has been made in the overall survival of cancer patients after the advent of better imaging and diagnostic techniques, improved understanding of the molecular processes that cause cancer, and the additional knowledge of treatment using combined chemo and radiotherapy. However the current chemo and radiotherapy regimens have not improved the survival of the patients diagnosed with metastatic diseases. The goal of cancer therapy is to promote the death (apoptosis) of cancer cells without causing too much damage to normal cells. The use of viruses that specifically kill tumor cells while sparing normal cells; known as oncolytic virotherapy has reemerged over the past decade. Wild types of viruses have been discovered that have tumor specific cytolysis such as vesicularstomatitis, vaccinia, reo and parvoviruses etc. Newcastle disease virus is one such virus with inherent ability to cause oncolysis. NDV cause highly infectious disease (ND) in poultry worldwide. Although NDV is being extensively studied in India, there are still no studies on its potential as an anticancer agent. Keeping this long-term objective, a preliminary study was carried out to evaluate its ability to induce apoptosis in chicken embryo fibroblasts (CEF). CEF were infected with NDV (Bareilly strain) for 24 and 48 h. CEF were harvested and processed for apoptotic study using DNA fragmentation assay, flowcytometry and fluorescent microscopy. DNA fragmentation assay detected the ladder pattern of DNA at 48 h of post infection indicating the fragmentation of cellular DNA. Flow cytometric analysis of infected cells showed increase in the side scatter on dot plots suggesting the population of smaller cells, which also showed decreased DNA fluorescence (DNA fragmentation) up on histogram analysis. Fluorescent microscopy detected cells with condensed chromatin. Further upon initial screening for NDV-induced haemagglutination neuraminidase (HN) at 96 h of post transfection, oligonucleosomal sized DNA ladder was observed on 1% agarose gel. These data suggest NDV induces apoptosis in CEF cells. This apoptotic inducing potential can be exploited further to develop NDV as an anticancer agent.