The Molecular Mechanism Of RNF146 In Regulating Proliferation And Migration Of Non-small Cell Lung Cancer

Objective:At present,malignant tumors have become a major category of diseases that seriously threaten human health.Lung cancer is one of the highest morbidity and mortality rates in the world.In terms of the number of cases,lung cancer still ranks first in the incidence of malignant tumors in China.Non-small cell lung cancer（NSCLC）accounts for about 75-80%of the total lung cancer.Therefore,the study of the mechanism of lung cancer occurrence and development,metastasis and action targets has important guiding significance for the further treatment and prevention of lung cancer.RNF146 is an E3 ubiquitin ligase whose gene is located on human chromosomes6q22,33^[1].The protein encoded by the RNF146 gene is a widely expressed cytoplasmic polypeptide and is an evolutionarily conserved protein.It contains WWE and N-terminal RING finger domains^[1].Studies have shown that RNF146,as an E3 ubiquitin ligase under the control of PARsylation（poly ADP ribosylation）,regulates the degradation of tankyrase（PARP5）-dependent Axin,thereby positively regulating the Wnt signaling pathway^[1].Previous research results showed that the expression of RNF146 was significantly up-regulated in clinical non-small cell lung cancer specimens and cell lines,and its expression level was related to the clinicopathological factors of patients.The expression of RNF146 protein was negatively correlated with the expression of Axin and positively with cell proliferation,invasion,and migration^[2].The molecular mechanism of RNF146 regulating Wnt signaling pathway is not clear.Our research aims to explore whether RNF146 regulates the expression ofβ-catenin through WWE or RING finger domain and regulates Wnt signaling pathway,thereby promoting the proliferation and migration of lung cancer cells.Methods:1.A549 cells were transiently transfected with plasmids（pCDNA4-TO,RNF146△RING,RNF146△WWE,siRNA-resistant full-length RNF146）.2.Western Blot was used to detect the plasmid transfection and the expression ofβ-catenin.3.Cell scratch test,transwell migration test and MTT test were used to detect the effects of plasmid transfection on the proliferation and migration ability of A549 cells.Results:1.The expression ofβ-catenin after plasmid transfection in A549 cell line was lower in pCDNA4-TO group than in RNF146△RING group,RNF146△WWE group,and siRNA-resistant full-length RNF146 group,and the expression of RNF146△WWE group was slightly higher than RNF146△RING group,the difference between the groups was statistically significant（P﹤0.05）.2.The plasmid-transfected RNF146△RING group,RNF146△WWE group,and siRNA-resistant full-length RNF146 group all promoted cell proliferation and migration ability.The siRNA-resistant full-length RNF146 group had the most significant promotion effect,and there were differences between groups.It has statistical significance（P﹤0.05）,but the effect of RNF146△WWE group is more obvious than that of RNF146△RING group.Conclusion:1.The WWE and RING finger domains contained in RNF146 both play a role in regulatingβ-catenin expression,thereby further regulating the Wnt signaling pathway and promoting the proliferation and migration ability of lung cancer cells.2.The combination of WWE and RING finger domain of RNF146 promotes the proliferation and migration of lung cancer cells;RING finger domain may play a more important role in regulating the proliferation and migration of lung cancer cell lines.