Abstract:
Objective To explore the effect of osteoclast-derived exosome miR-183-5p on the invasion and proliferation of lung adenocarcinoma cells and its possible mechanisms.
Methods Osteoclasts were induced by RAW264.7 cells and the exosomes were extracted and identified by transmission electron microscope and dynamic light scattering. The exosomes were co-cultured with lung adenocarcinoma cell line A549 cells, and the expression of miR-183-5p in A549 cells was detected by qRT-PCR. Scratch test and Transwell invasion test were used to observe the effect of miR-183-5p on the migration and invasion of A549 cells. CCK-8 was used to detect the proliferation activity of co-cultured A549 cells, and Annexin Ⅴ/PI staining was used to detect the apoptosis of A549 cells. Western blotting was used to detect the relative expression of programmed cell death 4 (PDCD4), cyclin D1 (CCND1) and cyclin-dependent kinase 4 (CDK4) in co-cultured A549 cells.
Results The exosome showed a clear oval vesicle-like structure with a clear edge, and the particle size was 30-200 nm. Fluorescence probe showed that the exosome was quickly absorbed by A549 cells, and the expression level of miR-183-5p in A549 cells increased significantly after co-culture (P < 0.01). The results of scratch test and Transwell assay showed that the migration and invasion ability of co-cultured A549 cells at 72 h was significantly higher than that at 24 h (P < 0.01). The CCK-8 and Annexin Ⅴ/PI tests showed that the activity of co-cultured A549 cells was significantly higher than that in the control group (P < 0.01), and the apoptosis rate of co-cultured A549 cells was significantly lower than that in the control group (P < 0.05). Western blotting showed that after overexpression of miR-183-5p, the expression of PDCD4 decreased, and the expression of CCND1 and CDK4 increased in A549 cells (P < 0.05).
Conclusions Osteoclast-derived exosomes co-cultured with A549 cells can increase the expression of miR-183-5p, and miR-183-5p can promote the invasion, proliferation and migration of lung adenocarcinoma cells by targeting inhibition of PDCD4 expression, etc..