[RL-RVG inhibits proliferation and promotes apoptosis of lung cancer cells in vitro].

OBJECTIVE: To infect lung adenocarcinoma A549 cells with recombinant LaSota strain Newcastle disease virus (NDV) vaccine expressing the rabies virus glycoprotein (rL-RVG), and explore the effect of rL-RVG on proliferation and apoptosis of lung cancer cells.

METHODS: A549 cells were infected with the rL-RVG and then detected for the expressions of RVG and NDV proteins by Western blotting. The cell proliferation was examined by MTT assay and apoptosis index and cell early apoptosis were respectively detected by TUNEL and annexin V-FITC/PI staining combined with flow cytometry. The expression of pro-apoptotic protein caspase-3 was observed by Western blotting. The LaSota strain of NDV was used as control group and PBS was the blank control.

RESULTS: Both RVG and NDV proteins were stably expressed in A549 cells infected with rL-RVG. MTT assay results showed that cell proliferation was significantly inhibited, and the inhibition rate of the rL-RVG group was higher than that of LaSota group. The apoptosis of A549 cells were promoted by rL-RVG infection. Flow cytometry revealed that the early apoptotic cells of the rL-RVG group increased as compared with the other two groups (P<0.05). Consistently, TUNEL assay showed the apoptotic index increased in the rL-RVG group as compared with the other two groups (P<0.05). Western blotting demonstrated that the expression of the pro-apoptotic protein caspase-3 was up-regulated. However, when we added specific broad-spectrum caspase inhibitor Z-VAD-FMK, the expression of the caspase-3 protein was obviously reduced.

CONCLUSION: The rL-RVG is stably expressed in the infected A549 cells. The rL-RVG inhibits lung cancer cell growth and promote cell apoptosis, and the effect of rL-RVG is better than the wild LaSota strain.