[Differential expression of miR-126-5p in lung adenocarcinoma and the possible mechanism]

To investigate the differential expression of miR-126-5p in patients with lung adenocarcinoma and explore the possible mechanism.

We searched STARBASE database to analyze the differential expression of miR-126-5p between lung adenocarcinoma tissues and normal lung tissues. The prognosis of patients with lung adenocarcinoma was analyzed on Kaplan-Meier Plotter online website, and the survival curves of the patients with different expression levels of miR-126-5p were generated. The target gene of mir-126-5p was predicted by STARBASE database, and the expression level of the target gene and its influence on the patients' prognosis were analyzed using online website tool. We also examined the expression levels of miR-126-5p in peripheral serum of 30 healthy control subjects and 30 patients with lung adenocarcinoma using qPCR.

Analysis of the data from STARBASE database showed a high expression of miR-126-5p in normal lung tissues but a low expression in lung adenocarcinoma tissues. Kaplan-Meier Plotter online analysis based on big data analysis showed that patients with a high expression of miR-126-5p had a better survival prognosis than those with a low expression (HR=0.68, P=0.015). MiR-126-5p was predicted to bind to the 3'UTR region of BRCC3 mRNA, and their expression levels were negatively correlated (r=0.197, P < 0.05). Compared with normal tissues, lung adenocarcinoma tissues expressed high levels of BRCC3, which was associated with a poor prognosis of the patients (HR=1.39, P < 0.05). The serum level of miR-126-5p was significantly higher in healthy control subjects than in patients with lung adenocarcinoma (1.23 ± 0.21 vs 0.63 ± 0.12, P < 0.05).

The expression level of miR-126-5p is lowered in lung adenocarcinoma tissue, and patients with lung adenocarcinoma have lower serum level of miR-126-5p than healthy subjects. A high expression of miR-126-5p is associated with a more favorable prognosis of the patients than a low expression. miR-126-5p may play a role against cancer by regulating BRCC3.