miR-223-5p Suppresses Tumor Growth and Metastasis in Non-Small Cell Lung Cancer by Targeting E2F8.

miR-223-5p has been demonstrated to regulate the development and progression of various cancers, such as hepatocellular carcinoma, breast cancer, and gastric carcinoma. However, the role of miR-223-5p in non-small cell lung cancer (NSCLC) requires further investigation. In this study, we found that the expression of miR-223-5p was significantly downregulated in NSCLC tissues and cell lines. Moreover, the expression level of miR-223-5p is negatively correlated with the malignance of NSCLC. We found that overexpression of miR-223-5p remarkably suppressed the proliferation of NSCLC cells in vitro and in vivo. miR-223-5p overexpression also led to reduced migration and invasion in NSCLC cells. Mechanistically, we found that E2F8, a key transcription factor involved in many kinds of biological processes, was a direct target gene of miR-223-5p. Overexpression of miR-223-5p significantly decreased the mRNA and protein levels of E2F8 in NSCLC cells. We also showed that restoration of E2F8 rescued the proliferation, migration, and invasion of miR-223-5p-overexpressing NSCLC cells. Taken together, our findings demonstrated that miR-223-5p suppressed NSCLC progression through targeting E2F8.