MicroRNA-520a-3p suppresses non-small-cell lung carcinoma by inhibition of High Mobility Group Box 1 (HMGB1).

Objective: Currently, pathogenesis of non-small cell lung carcinoma (NSCLC) is still unknown and the treatment is far from ideal. Therefore, we investigated the effect of inhibiting microRNA-520a-3p in NSCLC cells. Materials and

Methods: NCI-H157 cells were treated with microRNA-520a-3p analogs for 48 h, or microRNA-520a-3p analogs and its inhibitor, for a total of 48 h. Many tests were performed, including MTT, flow cytometry, wound healing assay and transwell assay. The tumor model was established, and HMGB1 mRNA was detected by RT-PCR. Protein levels of HMGB1, MMP-2, MMP-9, Bcl-2, Bax, and Caspase-3 were assessed by Western Blot.

Results: microRNA-520a-3p could significantly inhibit the proliferation, migration and invasion of NCI-H157 cells, inducing their apoptosis. microRNA-520a-3p inhibited tumor growth and decreased the mRNA and protein levels of HMGB1. Additionally, it decreased the Bcl-2/Bax ratio, MMP-2 and MMP-9 expression, and increased caspase-3 expression.

Conclusions: microRNA-520a-3p exhibited an effective inhibition on NCI-H157 tumor growth likely by inhibiting HMGB1 expression.