The Effects And Mechanisms Of BMP9 On Non-Small Cell Lung Cancer A549 Cells In Bone Microenviroment

Objective:To investigate the effects and underlying mechanisms of BMP9 on non-small cell lung cancer A549 cells in bone microenviroment, and it may offer a new maker and theoretical foundation for clinical diagnosis and therapy of lung cancer.Methods: The mRNA and protein level of BMP9 in human lung adenocarcinoma cells A549 and bronchial epithelial cells HBE were detected by qRT-PCR and western blot. A549 cells were transfected with recombinant adenovirus AdBMP9, the expression of BMP9 was verified by qRT-PCR and western blot. The biological characteristics of cell proliferation, apoptosis, migration and invasion abilities of A549 cells were measured by MTT, FCM, wound-healing and Transwell assay. The proliferation, apoptosis or migration related protein were tested by western blot.When co-culture system of A549 cells and bone marrow stroma cells HS-5 was established in Transwell chamber, A549 cells were transfected with AdBMP9. Cell biological characteristics were measured by MTT, wound-healing and Transwell assay. Metastases & osteoclast-related factors IL-6 and IL-8 were detected by qRT-PCR and western blot. The activation of MAPK, PI3K/AKT and NF-κB signaling pathway was examined by western blot. In vivo, the growth and metastasis of A549 cells were determined by building subcutaneous tumor and tibial transfer model in nude mice.Results: The level of BMP9 was lower in A549 cells than HBE cells. Overexpression of BMP9 inhibited the proliferation, migration and invasion abilities of A549 cells significantly, and the apoptosis rate increased.When A549 cells co-cultured with HS-5, the proliferation, migration and invasion abilities of A549 cells were increased, as also enhanced the level of IL-6 and IL-8, p-ERK and p-P65 in A549 cells. However, BMP9 inhibited the promoting effect of HS-5 cells on A549 cells. In vivo, HS-5 cells accelerated the tumor growth of A549 cells, and BMP9 slowed the growth rate or osteolytic metastasis of A549 cells.Conclusions: BMP9 inhibited the proliferation, migration and invasion abilities, and promoted apoptosis of A549 cells. Bone marrow stroma cells HS-5 increased the proliferation, migration and invasion of A549 cells, but BMP9 inhibited the the promoting effect of HS-5. MAPK/ERK and NF-κB signaling pathway may be involved in those effects.