Abstract:

Objective To investigate the differences in the expression levels of miR-196a-5p and miR-105-5p in serum of patients with benign and malignant pulmonary nodules and their diagnostic value of malignant pulmonary nodules. Methods The expression levels of miRNAs in cancer tissues of lung adenocarcinoma and lung squamous cell carcinoma and paracancerous tissues in The Cancer Genome Atlas (TCGA) database were analyzed, and the miRNAs with significantly different expression levels in cancer tissues and paracancerous tissues were selected as target miRNAs. A total of 72 patients with pulmonary nodules admitted to Weifang People's Hospital of Shandong Province from June 2019 to July 2020 were selected. The expression levels of target miRNAs in serum of patients with pulmonary nodules were detected by qRT-PCR. Receiver operating characteristic (ROC) curve was used to compare the diagnostic value of target miRNAs with tumor markers Cyfra21-1, NSE and CEA in malignant pulmonary nodules. Results After screening, the target miRNAs were identified as miR-196a-5p and miR-105-5p. Twenty-six patients in the benign pulmonary nodules group and 46 patients in the malignant pulmonary nodules group were included. The levels of serum miR-196a-5p [M (P₂₅, P₇₅)] in the benign and malignant nodules group were 0.63 (0.09, 2.15) and 1.93(0.93, 4.97) respectively, and the levels of miR-105-5p in the two groups were 2.03 (0.54, 7.95) and 10.65 (5.94, 18.39) respectively. Compared with the benign pulmonary nodules group, the levels of serum miR-196a-5p and miR-105-5p in the malignant pulmonary nodules group were increased, and there were statistically significant differences (Z=-3.083, P=0.002; Z=-4.092, P<0.001). The levels of serum Cyfra21-1 in the benign and malignant pulmonary nodules group were 2.48 (1.84, 3.78) and 2.20 (1.47, 3.32) μg/L respectively, the levels of serum NSE in the two groups were 15.58 (12.45, 18.95) and 14.43 (12.07, 17.87) μg/L respectively, and the levels of serum CEA in the two groups were 1.16 (0.55, 2.11) and 1.17 (0.61, 1.68) μg/L respectively. There were no significant differences in serum Cyfra21-1, NSE and CEA between the benign and malignant pulmonary nodules group (Z=-1.161, P=0.246; Z=-0.305, P=0.761; Z=-0.271, P=0.786). The area under the curve (AUC) of the combination of miR-196a-5p and miR-105-5p for the diagnosis of malignant pulmonary nodules was 0.762 (sensitivity 89.1%, specificity 61.5%), which was higher than the value of the combination of Cyfra21-1, NSE and CEA for the diagnosis of malignant pulmonary nodules (AUC=0.591, sensitivity 58.7%, specificity 64.5%). Conclusion The combination of serum miR-196a-5p and miR-105-5p can assist in the diagnosis of malignant pulmonary nodules and has higher diagnostic value.

Key words: Solitary pulmonary nodule, Lung neoplasms, microRNAs, Diagnosis