Study On The Role And Molecular Mechanism Of GPR87 In Invasion And Metastasis Of Non-small Cell Lung Cancer

Background Metastasis is one of the malignant phenotypes of lung cancer,and it is also the main cause of death in patients with lung cancer.It is very important to elucidate the molecular mechanisms regulating the invasion and metastasis of lung cancer.Objective Public databases were used to screen candidate genes,which related to invasion and metastasis of non-small cell lung cancer,and then analyze its correlation with clinical and pathologic characteristics and explore the molecular mechanism of their regulation of invasion and metastasis.GPR87 is highly expressed in non-small cell lung cancer and is closely related to clinical stage and lymph node metastasis.This study aims to explore the role and molecular mechanism of GPR87 in regulating the invasion and metastasis of non-small cell lung cancer.Methods(1)Bioinformatics and a few public databases(GEPIA、UALCAN、K-M Plotter)were used to screen the candidate genes,which are related to invasion and metastasis of the NSCLC.(2)The expression of GPR87 in clinical samples of NSCLC and its matched paracancerous were detected by immunohistochemistry,and the correlation between GPR87 and clinical and pathologic characteristics was analyzed.(3)si RNA and plasmids were transfected into cultured cells(SK-MES-1 and A549)with Turbofect reagent.(4)q RT-PCR was used to detect the gene m RNA expression of GPR87、MMP2、MMP7、MMP9、E-cadherin、N-cadherin、Vimentin、Rho A、Rho C、ROCK1,western blot was used to detect its protein expression of GPR87、MMP2、MMP9、E-cadherin、Vimentin、Rho A、ROCK1,and ELISA was used to detect the protein expression of MMP7 in the cell cultural supernatant.(5)Transwell assay was used to detect the ability of invasion and metastasis of A549 and SK-MES-1 cells.Results(1)The gene GPR87 was highly expressed in NSCLC samples of TCGA database,which was correlated with invasion and metastasis of NSCLC.High expression of GPR87 was associated with clinical stage,age,race,and p53 mutation of lung adenocarcinoma(LUAD),and with lymph node metastasis of lung squamous cell carcinoma(LUSC).(2)Immunohistochemistry results showed that in 80 cases of NSCLC samples,squamous cell carcinoma accounted for 32 cases,positive accounted for 23 cases,the positive rate was 71.9%;adenocarcinoma accounted for 48 cases,positive accounted for 28 cases,the positive rate was 58.3%.In the paired normal lung tissues,GPR87 was negative,the expression of GPR87 in squamous cell carcinoma was higher than that in adenocarcinoma.The expression of GPR87 is closely related to the clinical stage and lymph node metastasis of patients.(3)si RNA knockdown of GPR87 resulted in the decrease of m RNA and protein expression levels of MMP7,MMP9,Rho A,and ROCK1,but no significant change of EMT-related genes in A549 and SK-MES-1 cells.Overexpression of GPR87 increased of m RNA and protein expression levels of MMP7,MMP9,Rho A,and ROCK1,but no significant change of EMT-related genes.(4)si RNA knockdown of GPR87 expression can significantly reduce the invasion and migration ability of A549 and SK-MES-1 cells,while overexpression of GPR87 can enhance the invasion and migration ability of A549 and SK-MES-1 cells.Conclusion GPR87 is closely related to invasion and metastasis of NSCLC,and its high expression is related to the clinical stage and lymph node metastasis of NSCLC patients.Moreover,the overexpression of GPR87 can promote the invasion and migration of non-small cell lung cancer cells,and its mechanism may be related to the activation of the Rho/ROCK signal pathway and the promotion of MMP7 and MMP9 expression,but not related to EMT.