CCR7 promote lymph node metastasis via regulating VEGF-C/D-R3 pathway in lung adenocarcinoma

Lymph node metastasis is still an important issue in metastatic process of lung adenocarcinoma. C-C chemokine receptor 7 (CCR7) has been proved to be closely associated with the metastasis of lung adenocarcinoma, and the mechanism is poorly understood. In order to investigate the relationship between CCR7 and lymph node metastasis in lung adenocarcinoma, and to explore the role of CCR7 in treating lung adenocarcinoma, 40 clinical specimens were collected to define the relationship between CCR7 and lymph node metastasis in lung adenocarcinoma by immunohistochemistry. The siRNA was used to suppress CCR7 expression in A549 cells. The scratch test, transwell test, qRT-PCR, western blot, flow cytometry and immunofluorescence were used to investigate the lymph node metastasis-related function of CCR7 in vitro. The athymic mice subcutaneous injection was used to research lung adenocarcinoma formation in vivo. Clinical case studies show that higher expression of CCR7 in lung adenocarcinoma tissues was associated with a higher lymph node metastasis. Inhibition of expression of CCR7 can reduce the migration and invasion and suppress the expression of VEGF-C, VEGF-D and VEGF-R3 in vitro and in vivo. Moreover, CCR7 silence also suppressed WNT and p-ERK pathways in vitro. All the results indicate that CCR7 can promote lymph node metastasis in lung adenocarcinoma by regulating VEGF-C/D-R3 pathway. Thus CCR7 is proposed to be a potential prediction for poor prognosis of lung adenocarcinoma, and a therapeutic target for lymph node metastasis.