MicroRNA-891a-5p is a novel biomarker for non-small cell lung cancer and targets HOXA5 to regulate tumor cell biological function.

Numerous studies have shown that the dysregulation of microRNA (miRNA/miR) is an important factor in the pathogenesis of lung cancer. However, the role of miR-891a-5p in non-small cell lung cancer (NSCLC) remains unclear. Therefore, the present study aimed to examine the clinical value and biological function of miR-891a-5p in NSCLC. The mRNA expression level of miR-891a-5p in NSCLC was determined using reverse transcription-quantitative PCR and was used to determine the diagnostic value of miR-891a-5p, by creating a receiver operating characteristic curve. Kaplan-Meier and Cox regression analyses were used to evaluate its prognostic value in patients with NSCLC. Furthermore, cell experiments were performed to investigate the underlying mechanisms and functional role of miR-891a-5p in NSCLC progression. The results indicated that miR-891a-5p expression level was significantly higher in serum and tissues from patients with NSCLC and NSCLC cell lines. In addition, serum miR-891a-5p was found to have a diagnostic value in patients with NSCLC, and the increase in the expression level of miR-891a-5p in tumor tissues was associated with differentiation, and the tumor, node and metastases stages of cancer, which could be used for NSCLC prognosis. In addition, the experiments revealed that NSCLC cell proliferation, invasion and migration were significantly increased by the overexpression of miR-891a-5p and were significantly reduced by its downregulation. Furthermore, a luciferase reporter assay and the protein expression levels of HOXA5 showed that HOXA5 might be a miR-891a-5p target gene. In summary, the results indicated that high miR-891a-5p expression level could be a novel biomarker in patients with NSCLC and that it promoted tumor cell proliferation, invasion and migration. HOXA5 may be a target of miR-891a-5p, which may mediate miR-891a-5p function in NSCLC.