Inhibition of inflammation and infiltration of M2 macrophages in NSCLC through the ATF3/CSF1 axis: Role of miR-27a-3p

Non-small cell lung cancer (NSCLC) imposes a significant economic burden on patients and society due to its low overall cure and survival rates. Tumour-associated macrophages (TAM) affect tumour development and may be a novel therapeutic target for cancer. We collected NSCLC and tumour-adjacent tissue samples. Compared with the tumour-adjacent tissues, the Activation Transcription Factor 3 (ATF3) and Colony Stimulating Factor 1 (CSF-1) were increased in NSCLC tissues. Levels of ATF3 and CSF-1 were identified in different cell lines (HBE, A549, SPC-A-1, NCI-H1299 and NCI-H1795). Overexpression of ATF3 in A549 cells increased the expression of CD68, CD206 and CSF-1. Moreover, levels of CD206, CD163, IL-10 and TGF-beta increased when A549 cells were co-cultured with M0 macrophages under the stimulation of CSF-1. Using the starbase online software prediction and dual-luciferase assays, we identified the targeting between miR-27a-3p and ATF3. Levels of ATF3, CSF-1, CD206, CD163, IL-10 and TGF-beta decreased in the miR-27a mimics, and the tumour growth was slowed in the miR-27a mimics compared with the mimics NC group. Overall, the study suggested that miR-27a-3p might inhibit the ATF3/CFS1 axis, regulate the M2 polarization of macrophages and ultimately hinder the progress of NSCLC. This research might provide a new therapeutic strategy for NSCLC.