ABSTRACT
Objective To investigate the role of chemokine ligand 19 (CCL19) and protein kinase-B (AKT) signaling pathway in lung cancer development. Methods The human lung adenocarcinoma cell line, A549 cells, in logarithmic growth phase were randomly divided into five groups： blank control group, solvent control group, CCL19 treatment group, AKT inhibition group, and antibody neutralization group. The blank control group received no treatment. The other four groups were treated with dimethyl sulfoxide, CCL19, MK-2206 (AKT inhibitor), and a combination of CCL19 and MK-2206, respectively. Cell viability was assessed using the CCK-8 assay, while cell migration and invasion capabilities were evaluated using the cell scratch and transwell assays. The relative expression levels of Pan-AKT, p-AKT (Ser473), p-AKT (Thr308), E-cadherin (E-cad), N-cadherin (N-cad), and Snail proteins in A549 cells were detected using Western blotting. Lung cancer tissue samples from 60 patients with non-small cell lung cancer (NSCLC) were collected, and the expression of CCL19 and matrix metalloproteinase 9 (MMP9) proteins in the specimens was examined using immunohistochemistry. Results The survival rate of A549 cells in the AKT inhibition group and antibody neutralization group was lower than that in blank control group, solvent control group, and CCL19 treatment group (all P<0.05). The cell scratch assay result showed that the cell migration rate of the CCL19 treatment group was higher at 36.0 and 48.0 hours than those of the blank control group, solvent control group, AKT inhibition group, and neutralizing antibody group (all P<0.05). The Transwell assay result showed that the invasion amount of A549 cells in the AKT inhibition group was less than that in the CCL19 treatment group (P<0.05). Compared with the blank control group, the relative expression of E-cad protein in the CCL19 treatment group decreased, while the relative expression of p-AKT (Ser473), p-AKT (Thr308), N-cad and Snail proteins increased (all P<0.05). The relative expression of p-AKT (Ser473), p-AKT (Thr308), N-cad, and Snail proteins in A549 cells decreased (all P<0.05), and relative expression of E-cad protein increased (all P<0.05) in the AKT inhibition group and antibody neutralization group compared with the blank control group, solvent control group, and CCL19 treatment group. There was no significant difference in the expression of CCL19 and MMP9 in lung cancer tissues of NSCLC patients in Xuanwei City, Gejiu City, and other regions (all P>0.05). The expression of CCL19 and MMP9 in NSCLC patients with lymph node metastasis was higher than in patients without lymph node metastasis (all P<0.01). Conclusion CCL19 can promote the invasion and metastasis of lung cancer cells and induce epithelial-mesenchymal transition. Its expression level is related to lymph node metastasis in NSCLC patients. The AKT signaling pathway may be an important mechanism underlying lung cancer development.