Abstract: Objcetive To explore the possible mechanism of the recombinant avirulent NDV LaSota strain expressing the rabies virus glycoprotein (rL-RVG) inducing the apoptosis of gastric cancer cells by the acetylcholine receptor pathway.Methods The gastric cancer cell lines SGC at logarithmic proliferation stage were randomly divided into the rL-RVG, newcastle disease virus（NDV）and PBS groups.Furthermore,the acetylcholine receptor （α7-nAChR）inhibitor groups and the agonist pretreatment groups were set up, respectitively. At 24 hours after infected by viruses,CCK8 assay was used to determine the inhibitory effect of virus on the growth of gastric cancer cell lines.western blot detected the protein expression of alpha 7-nAChR, RVG, NDV and apoptosis-related proteins including cleved-caspase3 and BAX/BCL-2 as well as the expression of P-ERK and ERK. Immunofluorescence was also used to examine the expression of P–ERK. Results CCK8 showed that the concentrations of the recombinant and wild virus inhibited the growth of gastric cancer cell line SGC were greater than 10-2 /mL and 10-3 /mL, and the rL-RVG group was significantly more inhibited than NDV and PBS group(P<0.05).Western blot showed apoptosis-related proteins cleved-caspase 3, bax/bcl-2 in rL-RVG group and NDV group increased significantly compared with PBS group, the protein expression of P-ERK/ERK in the virus group was lower than the control group significantly. The apoptosis-related protein expression levels in the rL-RVG/NDV/PBS groups pretreated with choline receptor inhibitor significantly more increased than that in the groups without pretreatment.Besides,the groups pretreated with choline receptor agonist had obviously decreased apoptosis protein expression level compared with the groups without pretreating.Western blot and immunofluorescence showed the expression of P-ERK decreased in the virus group, and the recombinant virus group decreased significantly compared with the NDV and PBS group(P<0.05).Furthermore, the P-ERK protein expression in groups pretreated with acetylcholine receptor inhibitor descended.On the other hand, the level of P-ERK ascended while pretreated with choline receptor agonist(P<0.05).Conclusion One of the mechanism that rL-RVG induced apoptosis of gastric cancer cell line SGC by alpha 7-nAChR is suppressing the ERK signaling pathway.

Key words: Key words: Recombinant newcastle disease virus , rabies virus glycoprotein , gatric cancer , nAChR , ERK