The Effects And Mechanisms Of CX3CL1/CX3CR1 On Human Lung Adenocarcinoma A549 Cells In Bone Microenvironment

Objective: To investigate the effects and underlying mechanisms of CX3CL1/CX3CR1 on non-small cell lung cancer in bone microenvironment,and it may offer a new clue and theoretical foundation for migration and therapy of lung cancer.Methods: The mRNA and protein level of CX3CR1 in human lung adenocarcinoma cells A549,lung squamous carcinoma cells H520 and bronchial epithelial cells HBE were detected by RT-qPCR and western blot.Immunohistochemical staining was used to detect the expression of CX3CR1 in human lung cancer tissues and the adjacent tissues.The A549 cell was treated with different concentrations of human CX3CL1 recombinant protein,then the biological characteristics of cell proliferation and migration were detected by MTT and Wound-healing methods.The expression of CX3CL1 specific receptor CX3CR1 was detected by RTqPCR and western blot,which were also used to determine the change of the factor associated with proliferation and migration at the level of mRNA and protein.The expressions of MAPK/ERK,PI3K/AKT signaling pathway were detected using the method of western blot.Then the CX3CR1 was knockdown in A549 cells and the interference effect of CX3CR1 was detected by RT-qPCR and western blot.The effect of CX3CL1 on the migration ability of A549 was detected by Wound-healing method after being interfered with CX3CR1.Human lung adenocarcinoma A549 cell was treated with bone marrow stromal cell HS-5 conditioned medium(HS-5-CM).MTT and Wound-healing were used to detect the effect of HS-5-CM on proliferation and migration of A549.At the same time,the expression of CX3CR1 in the cells of each group was detected by RT-qPCR.The CX3CR1 was knockdown in human A549 cells to detect the effect of HS-5-CM on the migration ability of A549 cells after being interferred with CX3CR1.A549 was pretreated with MAPK/ERK pathway inhibitor U0126,and then western blot was used to detect the activation of MAPK/ERK in A549 cells treated by HS-5-CM.The migration of cells in each group was examined by Wound-healing assay.Results: The expression of CX3CR1 in HBE cells was higher than that in A549 and H520,and the expression of CX3CR1 in cancer tissue was higher than that in paracancerous tissue.The effect of CX3CL1 on the proliferation ability of A549 was not obvious,but it could promote the migration of A549.During this process,MAPK / ERK and PI3K/AKT were activated,and the expression of CX3CR1 was up-regulated.Inhibition of CX3CR1 partially reversed the role of CX3CL1 in promoting the migration of A549.HS-5 conditioned medium could promote the proliferation and migration of A549 and up-regulate the expression of p-ERK and CX3CR1.Interfering with CX3CR1 could inhibit the effect of HS-5 on A549.MAPK/ERK pathway inhibitor U0126 can effectively inhibit the activation of ERK pathway,the expression of CX3CR1,as well as the migration of A549 cells.Conclusion: CX3CL1 could promote the migration of A549 in the manner of receptor CX3CR1 dependence.Bone marrow stromal cells(HS-5)could promote the proliferation and migration of A549 cells.The interference of CX3CR1 could inhibit the effect of HS-5 on A549 cells.The mechanism may be related to the MAPK/ERK signaling pathway.