ObjectiveTo explore the mechanism by which the tumor suppressor gene Testin affects the proliferation, migration, and invasive biological activity of lung adenocarcinoma cell lines by regulating the RhoA pathway. MethodThe cbioportal tumor gene expression was used to screen for genes with high correlation with TES gene expression in lung adenocarcinoma, and the 200 genes with the highest correlation were selected for pathway enrichment analysis. Upload these 200 genes to the David gene annotation tool for GO_Biological Process pathway analysis, GO Molecular Function pathway analysis, KEGG pathway analysis, and Reactome pathway analysis. The lung adenocarcinoma cell line H1299 was cultured, and an overexpression Testin plasmid was constructed and transfected into H1299 cells. The mRNA and protein expression of RhoA, Rac1, and Cdc42 were detected using qRT PCR and western blot. On the basis of downregulating RhoA expression through overexpression of Testin, the overexpression plasmid of RhoA (TES+RhoA) was transfected simultaneously to induce a downregulation of RhoA expression, and the changes in malignant phenotype of lung adenocarcinoma cells were detected. The biological activity changes of adenocarcinoma cell lines after the above intervention were verified through CCK-8 experiment, Transwell experiment, and Matrigel experiment. Results The results of pathway analysis prediction showed that Testin may be involved in regulating the Rho GTPase signaling pathway. Overexpression of Testin did not affect the mRNA levels of RhoA, Rac1, and Cdc42 (all P>0.05), nor did it affect the protein expression levels of Rac1 and Cdc42 (all P>0.05), but it significantly reduced the protein level of RhoA (P<0.05). Knocking down RhoA in lung adenocarcinoma cell H1299 can significantly inhibit cell proliferation, migration, and invasion ability (all P<0.05). Simultaneously transfecting RhoA overexpression plasmid on the basis of overexpression of Testin can downregulate RhoA expression, but does not affect Testin expression. ConclusionsRhoA plays a pro-cancer role in lung adenocarcinoma, and Testin can inhibit RhoA expression. Overexpression of RhoA can rescue Testin's effect on lung adenocarcinoma cell proliferation, migration, and invasion. Testin exerts its anti-cancer biological activity by regulating RhoA.
ObjectiveTo investigate the effect of ambroxol hydrochloride on c-Jun N-terminal kinase (JNK) signal pathway in gastric aspiration lung injury. MethodsForty healthy male Sprague Dawley rats were randomly divided into a control group, an injury group, a SP600125 (JNK specific inhibitor) group and an ambroxol group. The model of gastric aspiration lung injury was established by aspiration of gastric contents. The rats in the SP600125 group preoperatively received intravenous injection of JNK specific inhibitor SP600125 (3 mg/100 g). The rats in the ambroxol group received intravenous injection of ambroxol hydrochloride (50 mg/kg) 2 hours after the damage occurred. The neutrophil count and malondialdehyde (MDA) activity in bronchoalveolar lavage fluid (BALF), the lung wet weight/dry weight ratio (W/D), and myeloperoxidase (MPO) activity were measured. The protein expressions of JNK and phosphorylated JNK (p-JNK) and inducible nitric oxide synthase (iNOS) in lung tissue were detected by Western blot method. The changes of lung tissue structure were observed under light microscope. ResultsIn the injury group, the neutrophil counts and MDA activity in BALF, W/D, MPO activity, p-JNK and iNOS protein expression increased significantly, lung tissue appeared obvious histopathological injury compared with the control group. In the SP600125 group and the ambroxol group, neutrophil count and MDA activity in BALF, lung W/D, MPO activity, p-JNK and iNOS protein expression were significantly decreased compared with the injury group (P < 0.05), and the damage of the lung tissue pathology was reduced. The expression of JNK protein in lung tissue was not different in all groups (P > 0.05). ConclusionsJNK is involved in inflammatory reaction of gastric aspiration lung injury. The protective effect of ambroxol may be related to the inhibition of JNK signaling pathway and the inhibition of iNOS expression.