Abstract: Objective To detect and analyze the expression levels of serum microRNA(miR)-455 and miR-383 in patients with non-small cell lung cancer (NSCLC),and to explore their clinical diagnostic value.Methods A total of 98 NSCLC patients in our hospital from March 2020 to January 2023 were regarded as the NSCLC group,98 patients with benign lung diseases admitted during the same period were regarded as the benign lung disease group,and another 98 healthy volunteers who underwent physical examination in our hospital during the same period were collected as the health group.Real-time fluorescence quantitative PCR (RT-qPCR) method was applied to detect the expression levels of miR-455 and miR-383 in serum.Pearson was applied to analyze the correlation between serum miR-455 expression level and miR-383 level in NSCLC patients;multivariate Logistic regression and ROC curve was applied to analyze the influencing factors and diagnostic value of NSCLC occurrence.Results The expression levels of miR-455 and miR-383 in the serum of the healthy group,benign lung disease group,and NSCLC group decreased sequentially.Pearson analysis showed there was a positive correlation between serum miR-455 expression level and miR-383 level in NSCLC patients (r=0.582,P＜0.05).Logistic analysis found that low expression levels of miR-455 and miR-383 were risk factors for the occurrence of NSCLC (P＜0.05).ROC curve analysis showed that the AUC of NSCLC diagnosed by the combination of miR-455 and miR-383 was obviously higher than that diagnosed by miR-455 alone (Z=3.604,P=0.000) and miR-383 alone (Z=2.594,P=0.010).Conclusion The relative expression levels of miR-455 and miR-383 in serum of NSCLC patients are obviously down-regulated.The combined detection of the two has high diagnostic value for NSCLC.

Key words: non-small cell lung cancer；micro RNA-455；micro RNA-383；diagnosis