Expression Of FPR2 In NSCLC

Studies have shown that formyl peptide receptor（FPR2）plays a tumor suppressor role in various cancers such as liver cancer and gastric cancer,but the mechanism of its role in lung cancer is still unclear.Through the previous sequencing analysis on lung cancer tissues,adjacent normal tissues of the carcinoma and normal lung tissuues,we found that FPR2 expression in lung cancer tissues was lower than that in adjacent normal tissues and normal lung tissues,and the expression of SNHG16 was elevated when FPR2 expression was low,accompanied by related changes of mi R-660-5P,which plays a role in tumor suppression in various cancer,andβ-catenin,a candidate therapeutic target for lung cancer.This study focused on the role of FPR2 and its downstream molecule SNHG16/mi R-660-5P/β-catenin in non-small cell lung cancer（NSCLC）.OBJECTIVE:To investigate the role of FPR2 in non-small cell lung cancer and its associated downstream signaling pathways.Methods:1.In this study,we collected specimens of lung cancer tissues and adjacent normal tissues from patients for gene sequencing,and used TCGA and oncomine database for data analysis and data mining.2.We constructed A549 cell lines with low expression and overexpression of FPR2 by stable transfection,and further verified the proliferation and migration ability of lung cancer cells by Transwell assay and CCK-8 assay.3.Western Blot and Quantitative real-time PCR were used to determine n-cadherin and e-cadherin,so as to verify the ability of epithelial mesenchymal transition in the FPR2 knockdown group and the FPR2 overexpression group.4.Quantitative real-time PCR was used to verify the relationship between FPR2,SNHG16 and mir-660-5p.After mi R-660-5p was treated with the mimetic and inhibitor,the expression ofβ-catenin was verified by Quantitative Real-Time PCR and Western Blot.5.After SNHG16 was further knocked out on the basis of silencing FPR2,the expression of mir-660-5p and the epithelial-mesenchymal transition of lung cancer cells A549 were verified by Quantitative Real-Time PCR,Western Blot and Transwell assay.6.We transplanted FPR2 knockdown A549 cells to nude mice in order to determine their development and epithelial-mesenchymal transition.Results:1.Through gene sequencing of lung cancer tissue and adjacent normal tissue specimens of patients,data analysis and mining with TCGA and oncomine database,it was found that the expression of SNHG16 increased when FPR2 expression was low in lung cancer tissue.2.Successfully constructed A549 cell lines with low expression and overexpression of FPR2 by stable transfection.Through Transwell cell migration assay,it was found that up-regulation of FPR2 expression reduced the migration ability of A549 cells(p=1.43*10^-5,P≤0.001),and the expression of silencing FPR2enhanced the the migration ability of A549 cells(p=2.48*10^-5,P≤0.001);Cck-8assay showed that the proliferation of A549 lung cancer cells increased after FPR2silencing(p=2*10^-4,P≤0.001),and decreased after FPR2 overexpression(p=1.27*10^-4,P≤0.001).3.Western blot and real-time PCR showed FPR2 scilencing up-regulated n-cadherin and down-regulated e-cadherin in A549 lung cancer cells,while overexpression of FPR2 decreased n-cadherin and increased e-cadherin in A549 lung cancer cells.（P≤0.001）.4.Through Quantitative real-time PCR,it was found that FPR2 silencing up-regulated the expression of SNHG16 and down-regulated the expression of mir-660-5p.Overexpression of FPR2 down-regulated the expression of SNHG16 and up-regulated the expression of mir-660-5p.Silencing mi R-660-5P up-regulated the expression ofβ-catenin,overexpression of mi R-660-5p down-regulated the expression ofβ-catenin（P≤0.001）.5.Knockout of SNHG16 under FPR2 silencing up-regulated the expression of mir-660-5p and inhibited the migration ability of lung cancer cells,（P≤0.001）.6.The tumor formation model of nude mice was successfully constructed.The tumor growth volume of the FPR2 silencing group was significantly higher than that of the control group.Western Blot of the removed tumor showed that the expression of E-cadherin was decreased(p=3*10^-5,P≤0.001),while the expression of N-cadherin(p=1.69*10^-4,P≤0.001)and Vimentin(p=1.73*10^-4,P≤0.001),ZEB1(p=1.44*10^-4,P≤0.001)were increased.Conclusion:FPR2 inhibits the proliferation,migration and epithelial-mesenchymal transition of lung cancer cells by down-regulating SNHG16.SNHG16 further inhibits the development of lung cancer by regulating mi R-660-5p.