Apoptotic induction of lung adenocarcinoma A549 cells infected by recombinant RVG Newcastle disease virus (rL-RVG) in vitro

Mol Med Rep. 2015 Jan;11(1):317-26. doi: 10.3892/mmr.2014.2657. Epub 2014 Oct 15.

Abstract

Newcastle disease virus (NDV) is a member of the genus Avulavirus in the Paramyxoviridae family and its antitumor properties depend on its ability to kill malignant cells while not affecting normal cells. The present study investigated a recombinant avirulent NDV LaSota strain (wild-type NDV strain) expressing the rabies virus glycoprotein (rL-RVG), examined its oncolytic effect on the lung adenocarcinoma A549 cell line and evaluated its potential to serve as a vaccine against lung cancer. A549 cells were infected with the rL-RVG virus and analyzed by MTT, western blot, polymerase chain reaction (PCR), immunofluorescence, terminal deoxynucleotidyl transferase dUTP nick end labeling and flow-cytometric analyses. PCR, western blot and immunofluorescence showed that the RVG gene and protein were stably expressed in A549 cells following infection with rL-RVG. The growth of A549 cells in the rL-RVG group was inhibited more effectively compared to those infected with the wild-type NDV strain. MTT results showed that cell growth inhibition rates in the rL-RVG group were significantly higher than those in the NDV group (P<0.05). Early apoptosis in the rL-RVG group was also more evident, with the apoptotic index being increased in rL-RVG group. The expression of the pro-apoptotic proteins caspase-3, -8 and -9 increased. The expression of caspase-3 decreased following application of the broad-specificity caspase inhibitor Z-VAD-FMK. However, the expression of the inhibitory apoptosis protein B-cell lymphoma 2 (bcl-2) did not change, but bcl-2-associated X/bcl-2 ratio was higher in the rL-RVG group than that in the NDV group. The rL-RVG strain was able to suppress lung cancer cell growth and promote lung cancer cell apoptosis to a greater extent than the wild-type NDV strain. Therefore, the rL-RVG strain is a potent antitumor agent.

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / virology
  • Adenocarcinoma of Lung
  • Apoptosis*
  • Caspases / genetics
  • Caspases / metabolism
  • Cell Line, Tumor
  • Gene Expression Regulation, Viral
  • Genes, Viral
  • Humans
  • In Vitro Techniques
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / virology
  • Newcastle disease virus* / genetics
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Recombination, Genetic
  • bcl-2-Associated X Protein / genetics
  • bcl-2-Associated X Protein / metabolism

Substances

  • Proto-Oncogene Proteins c-bcl-2
  • bcl-2-Associated X Protein
  • Caspases