[Clinical Application of Plasma miR-34b-3p and miR-302a-5p in the Diagnosis of Non-small Cell Lung Cancer].

Background: MicroRNA is a kind of single-stranded non-coding RNA whose length is about 22 nucleotides and its abnormal expression is related to disease closely. This study is aiming to explore the relative expression of miR-34b-3p and miR-302a-5p in the plasma of non-small cell lung cancer (NSCLC) patients and its clinical value.

Methods: The levels of miR-34b-3p and miR-302a-5p in plasma were detected by real-time polymerase chain reaction (RT-PCR) in 86 patients with NSCLC, 64 patients with pulmonary tuberculosis (PTB) and 39 healthy subjects. Analyze their value in diagnosing NSCLC by contrasting and combining carcino-embryonic antigen (CEA), neuron-specific enolase (NSE), and cytokeratin 19 fragments 21-1 (CYFRA21-1).

Results: The levels of plasma miR-34b-3p and miR-302a-5p in NSCLC group were significantly higher than those in the PTB group and the healthy group (P<0.05). In patients with NSCLC, the levels of plasma miR-34b-3p was correlated with the diameter of tumor (P<0.01). When using one plasma marker to diagnose NSCLC, miR-302a-5p had the highest sensitivity (82.6%) and CEA had the highest specificity (81.6%). While combined two plasma markers, miR-34b-3p+miR-302a-5p had the highest sensitivity (80.2%) and miR-34b-3p+CEA had the highest specificity (81.4%). As detected multiple markers, miR-302a-5p+NSE+CYFRA21-1 had the highest sensitivity (81.4%) and miR-34b-3p+CEA+NSE had the highest specificity (90.3%). The combination of miR-34b-3p, miR-302a-5p and CEA obtained the highest area under the curve (AUC), which was 0.832. Logistic regression model indicated that miR-34b-3p was independent risk factor for NSCLC compared to control groups.

Conclusions: Plasma miR-34b-3p and miR-302a-5p could be used as biological markers for the diagnosis of NSCLC.