MicroRNA-99b inhibits NSCLC cell invasion and migration by directly targeting NIPBL

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. microRNAs (miRNAs) have been confirmed as vital regulators of multiple tumors, including NSCLC. The aim of the current study was to explore the biological mechanisms of miR-99b in NSCLC progression.

NSCLC tissues and adjacent matched human non-neoplastic lung tissues used in this study were collected from 50 cases of NSCLC patients. The expression of miR-99b and NIPBL in NSCLC tissues and cell lines (A549, NCI-H460, NCI-H1299 and SPC-A1) were determined by real-time-polymerase chain reaction (qRT-PCR). The NIPBL protein level was measured by Western blot. Dual-Luciferase reporter, Western blotting and qRT-PCR were carried out to verify the potential target of miR-99b. Transwell assay was used for investigating miR-99b effect on cell migration and invasion in NSCLC cells.

The results of qRT-PCR indicated that the expression of miR-99b was downregulated in the NSCLC tissues and cell lines. Overexpression of miR-99b could significantly inhibit the invasion and migration capacities in NSCLC cells. Furthermore, we also determined that NIPBL was a direct target of miR-99b. Additionally, we found NIPBL was implicated in the suppressive effects on NSCLC cell invasion and migration mediated by miR-99b.

In summary, miR-99b exerted anti-tumor functions in NSCLC via regulation of NIPBL, suggesting that miR-99b/NIPBL axis may be novel biomarkers for NSCLC treatments.