The biological characteristics of a highly brain metastatic lung cancer sub-clone and the significance of expression of VEGF and MMP-9 / 肿瘤

ABSTRACT

Objective: To investigate the biological characteristics and cytokine expression of a highly brain metastatic lung cancer sub-clone to partly reveal the mechanism of brain metastasis of lung cancer. Methods: Through repeated injection of PC14 cells into nude mice, we have established a highly brain metastatic sub-clone of a human lung cancer cell line named PC14/B. The in vitro metastasis-related behaviors of PC14/B cells, such as adhesion to extracellular matrix (ECM), migration, and invasion were determined and compared with primary PC14 cells and A549 cells without brain metastasis. Vascular epithelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP-9) expressions in the three cell lines were measured by immunohistochemical staining. Results: The screened PC14/B cells had enhanced activities of adhesion, migration, and invasion and increased expression of VEGF and MMP-9 compared with PC14 and A549 cells (P <0.05), whereas the difference was not significant between PC14 and A549 cells. Conclusion: The expressions of VEGF and MMP-9 increase the invasion activity of lung cancer cells and promote brain metastasis, which partly explained the mechanism of brain metastasis of lung cancer.