Oncolytic Effect of Newcastle Disease Virus AF2240 Strain on the MCF-7 Breast Cancer Cell Line

Objective: This study was carried out to investigate the oncolytic effect of the Newcastle disease virus (NDV) strain AF2240 on the MCF-7 breast cancer cell line. Materials and Methods: The NDV-AF2240 was propagated in 11 days old embryonated chicken eggs for 72 hours. The virus in the allantoic fluid was harvested and purified. The haemagglutination (HA) test was conducted on the purified virus to determine the virus titre which was 16384 haemagglutination units (HAUs). The microculture tetrazolium assay (MTA) was carried out via two methods-the monolayer and co-culture techniques-to determine the inhibitory concentration (IC50) of NDV-AF2240 against the MCF-7 breast cancer cell line. Confocal laser scanning microscopy was carried out on polyclonal chicken antibody and fluorescein isothiocynate (FITC) conjugated goat anti-chicken antibody to observe virus localization in the cells. The terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay was conducted to quantify the percentage of apoptotic cells. Results: IC50 value of NDV-AF2240 was two HAUs in both the monolayer and co-cultures. Virus particles were detected in the cytoplasm of MCF-7 breast cancer cell line after 24 and 48 hours post treatment. Virus budding was detected 72 hours post treatment. The number of apoptotic cells was significantly increased (p<0.05) 72 hours post NDV-AF2240 treatment. Conclusion: The findings of this study show that NDV-AF2240 has an oncolytic effect against the MCF-7 breast cancer cell line. Further studies are needed to understand the anti cancer mechanism of this virus.