CCL21/CCR7 up-regulate vascular endothelial growth factor-D expression via ERK pathway in human non-small cell lung cancer cells.

Lymphangiogenesis has received considerable attention and become a new research hotspot of tumor metastasis. Recently, C-C chemokine receptor 7 (CCR7) is known to promote metastasis of non-small cell lung cancer (NSCLC) cells into lymph nodes. In this study, we investigated the relationship between CCL21/CCR7 and the lymphangiogenic factor vascular endothelial growth factor (VEGF)-D in human lung cancer cells and its impact on patients' prognosis. We found that CCL21/CCR7 increase the expression of VEGF-D in NSCLC Cell Lines through induced ERK1/2 and Akt phosphorylation. In addition, our study found that the expression levels of CCR7 and CCL21 were correlated with VEGF-D, lymphatic vessels density (LVD), clinical stages, lymph node metastasis, and patient Survival in 90 human non-small cell lung cancer (NSCLC) specimens. Taken together, our results provide evidence that CCL21/CCR7 induce VEGF-D up-regulation and promote lymphangiogenesis via ERK/Akt pathway in lung cancer.