RESUMO
Purpose To clarify the effect of adenosine on brain metastasis of lung cancer and the possible mechanism of adenosine promoting brain metastasis of lung cancer. Methods Western blot was used to dynamically detect the expression level of hypoxia inducible factor-1 (HIF-1) in lung cancer cells and tight junction protein ZO-1 in brain microvascular endothelial cells on blood-brain barrier. The content of adenosine in lung cancer cell culture was determined by ELISA. Fluorescence analysis was used to detect the changes of permeability of the blood-brain barrier model in vitro. Hemocytometer counts the number of A549 lung cancer cells in Transwell's lower chamber. Results The expression level of HIF-1 in lung cancer cells and the content of adenosine in lung cancer cell culture reached the highest level when lung cancer cells were deprived of oxygen for 12 hours. At the same time, the expression level of ZO-1 protein in the blood-brain barrier was the lowest, the blood-brain barrier permeability was the highest (7.11), and the number of lung cancer cells passing through the blood-brain barrier model was the highest (84.6). The permeability of the blood-brain barrier model increased after the action of adenosine, and its change trend was consistent with the effect of hypoxic lung cancer cell culture solution. Conclusion Hypoxia can induce the lung cancer cell to release adenosine, the increased adenosine can reduce the expression of tight junction protein ZO-1 in blood brain barrier, which leads to the increase of permeability of blood-brain barrier and eventually lead to brain metastasis of lung cancer.