miR-325 Supresses Cell Proliferation and Migration in Non-Small Cell Lung Cancer via Targeting DNA Ligase 1 (LIG1).

Abstract

DNA ligase 1 (LIG1) plays a key role in DNA synthesis and DNA damage repair pathways. LIG1 has been shown to be up-regulated in human non-small cell lung cancer (NSCLC); however, its role and molecular regulatory mechanism in NSCLC cell proliferation are still not fully understand. In this study, we aimed to explore the role of LIG1 and post-transcripional regulators in NSCLC. Utilizing bioinformatic tools and qRT-PCR, our investigation substantiated the up-regulation of LIG1 within NSCLC cell lines and tumour tissues. Remarkably, individuals exhibiting elevated levels of LIG1 had diminished survival rates. Functionally, the depletion of LIG1 inhibited cell proliferation and migration, contrasting with the increased proliferation and migration upon LIG1 over-expression. Prediction from the TargetScanHuman database and results of dual luciferase reporter assays indicated that miR-325 could directly bind to and negatively regulate LIG1. Moreover, our findings demonstrated that the mimicry of miR-325 decreased cell viability, whereas its inhibition correspondingly increased viability, indicative of the tumour-suppressive role of miR-325 through the down-regulation of LIG1. Collectively, our findings show that LIG1 could promote tumour progression and knockdown of LIG1 could exert suppressive effects on NSCLC. As the post-transcriptional factor of LIG1, miR-325 could negatively regulate the expression of LIG1 to inhibit tumour progression in vitro. These findings suggest that LIG1 and miR-325 might be potential therapeutic targets for NSCLC treatment.