[Utilization of the stable ectopic expression cell line as a model for the investigation of RIG-G gene].

Objective To investigate the biological function of RIG-G gene by establishing a cell line stably expressing RIG-G protein.Methods Ectopic RIG-G gene was transfected into U937 cells by using Tet-off expression system.Changes before and after RIG-G expression were detected for cell growth,cell mor- phology,cell surface antigen and cell cycle regulating proteins.Results RIG-G protein arrested the cells at G_0/G_1 phase and inhibited cell growth by increasing the cell cycle inhibitors P21 and P27.As compared to that in control group,the proportion of cells at G_0/G_1 phase in RIG-G-expressing cell group increased from (43.9±5.6)% to(63.9±2.3)%(P0.01).The rate of growth inhibition was(68.7±0.2)%.In ad- dition,an increase in CD11C expression [(61.3±1.1)% vs(18.0±0.4)%(P0.01)] and in cells with morphologic features of partial differentiation(smaller cell size,reduced nucleus-cytoplasm ratio,not- ched nucleus and coarse chromatin)was also observed in RIG-G-expressing cells.Conclusions RIG-G has potential abilities to inhibit cell proliferation and promote cell differentiation.