The oncolytic properties of two newcastle disease virus strains

English: Since the 1950's, several virus strains have been found to specifically infect and lyse human carcinoma cells, while not causing serious side effects in the patient. However, the available technology did not allow either sufficient characterization of, or research on these viruses until the development of molecular biology technology. We are now able to further explore this subject with renewed hope of "curing" cancer. Newcastle Disease Virus (NOV) is a commonly occurring avian virus that is known not to infect normal human cells or cause side effects other than mild conjunctivitis and laryngitis in humans upon exposure to even the most virulent strains. Some NOV strains have been shown to be oncolytic in recent studies. Much research remains to be done on the molecular mechanisms, selectivity and biochemical apoptotic pathways involved in this oncolytic mechanism. Two of the most commonly occurring cancers in South Africa are cervical and esophageal cancer. The aim of this study was to assess the oncolytic properties of the two NOV strains La Sota and Texas GB in vitro (in cell culture) and in vivo (in an immune compromized mouse model). In vitro results were promising: both strains were shown to be oncolytic, Texas GB more aggressively than La Sota. Both strains were shown to induce apoptosis and polycaryocyte formation, which leads to necrosis, in both cervical and esophageal cancer cell lines'. In vivo, it was shown that intratumoural administration of either virus strain had either a carcinostatic effect, or caused reduction in tumour volume in cervical cancer tumours in immune compromized mice. In some cases the results were temporary and in other cases the treatment had a prolonged effect. This is probably due to leakage of the inoculation from the treatment site. The results were not statistically significant due to the small number of mice used in the study. These results warrant further evaluation of the oncolytic efficiency of the La Sota strain of NDV in immune competent mice, other cancer types and in clinical trials.