Abstract: Objective To analyze the expression levels of long non-coding RNA(lncRNA) XIST and microRNA(miR)-186-5p in non-small cell lung cancer(NSCLC) tissues and their relationship with pathological features and prognosis.Methods From September 2020 to March 2022,92 NSCLC patients who underwent diagnosis and surgical treatment in our hospital were collected.Cancer tissues(study group) and adjacent tissues(control group) of NSCLC patients were collected during surgery,and real-time quantitative reverse transcription polymerase chain reaction(qRT-PCR) was employed to detect the expression levels of lncRNA XIST and miR-186-5p in both cancerous and adjacent non-cancerous tissues.A 2-year follow-up was conducted after surgery.NSCLC patients were separated into survival group and death group.Pearson method was applied to analyze the correlation between lncRNA XIST and miR-186-5p in cancer tissue.Cox regression was applied to analyze the factors affecting the prognosis of patients.Kaplan-Meier was applied to analyze the relationship between lncRNA XIST,miR-186-5p expression and prognosis in patients.Results The expression level of lncRNA XIST in cancer tissues of NSCLC patients was obviously higher than that in adjacent tissues(1.44±0.43 vs 1.03±0.16),and the expression level of miR-186-5p was obviously lower than that in adjacent tissues(0.76±0.18 vs 0.97±0.21)(P<0.05).There was a targeted binding site between lncRNA XIST and miR-186-5p in cancer tissue of NSCLC patients,and their expression levels were negatively correlated(r=0.416,P<0.05).TNM staging,lymph node metastasis,and degree of differentiation had a obvious impact on the expression of lncRNA XIST and miR-186-5p in NSCLC patients(P<0.05).TNM staging,lymph node metastasis,degree of differentiation,and lncRNA XIST were risk factors for the prognosis of NSCLC patients.miR-186-5p was a protective factor for the prognosis of NSCLC patients(P<0.05).The 2-year survival rate of NSCLC patients with low expression of lncRNA XIST(92.16%) was higher than that of high expression of lncRNA XIST(73.17%).The 2-year survival rate of NSCLC patients with high expression of miR-186-5p(91.23%) was higher than that of low expression of miR-186-5p(71.43%).Conclusion In cancer tissues of NSCLC patients,the expression level of lncRNA XIST is increased,while the expression level of miR-186-5p is reduced.lncRNA XIST and miR-186-5p are related to the prognosis of NSCLC patients.

Key words: long non-coding RNA XIST;microRNA-186-5p;non small cell lung cancer;pathological features;prognosis