Abstract: Background and purpose: Retinoic acid-induced gene G (RIG-G) is a tumor suppressor gene which is cloned by NB4 cell line from a acute promyelocytic leukemia cell. This study aimed to investigate the effect of RIG-G in lung cancer cells A549 by constructing a lentiviral vector expressing RIG-G under doxycycline (DOX) regulation. Methods: RIG-G gene amplification was performed by quantitative real-time PCR (qRT-PCR). pLenti6/ TO/V5-GIM-RIG-G lentiviral vector with GFP was built by LR recombination system. The concentration of pLenti6/ TO/V5-GIM-RIG-G lentiviral vector and Tet-on lentiviral vector were measured by virus titer method. After infecting A549 cells, stably transfected lines were selected via limiting dilution analysis. RIG-G gene expression was examined by immunofluorescence staining and Western blot assay. Cellular proliferation was determined by CCK-8 assay. Results: The concentrations of pLenti6/TO/V5-GIM-RIG-G lentiviral vector and Tet-on lentiviral vector were 1.0×10⁸ TU/mL and 4×10⁹ VP/mL, respectively. RIG-G was expressed in lentivirus infected A549 cells after adding DOX, and the amount of cells with GFP could be observed by fluorescence microscopy. After the expression of RIG-G protein, the proliferation activity of A594 cell was significantly inhibited compared to the control group (1.168±0.107 vs 2.099±0.162, P<0.05). Conclusion: The regulated expression of RIG-G gene was established in A549 lung cancer cell line. The RIGG protein has potential abilities to inhibit the proliferation of lung cancer cell A549.

Key words: Retinoic acid-induced gene G, Lentiviral, Expression regulation, Cell proliferation