Abstract: Objective To explore the relationship between long non-coding RNA (lncRNA) non-coding repressor of nuclear factor of activated T cells (NRON),long non-coding RNA small NF90-associated RNA (snaR) and the prognosis of triple negative breast cancer (TNBC).Methods From February 2018 to February 2020,100 TNBC patients accepted by our hospital were collected,and their tumor and adjacent tissues were taken during surgery.Based on the 3-year follow-up prognosis,they were separated into a good prognosis group（72 cases） and a poor prognosis group(28 cases).Real-time quantitative fluorescent PCR (RT-qPCR) method was applied to detect the expression levels of lncRNA NRON and lncRNA snaR in tumor tissue and adjacent tissues.Pearson method was applied to analyze the correlation between lncRNA NRON and lncRNA snaR in tumor tissue of TNBC patients.Multivariate Cox regression was applied to analyze the prognostic factors of TNBC patients.Receiver operating characteristic (ROC) curve was applied to analyze the prognostic value of lncRNA NRON and lncRNA snaR expression levels in tumor tissue of TNBC patients.Results Compared with adjacent tissues,the level of lncRNA NRON in tumor tissues of TNBC patients obviously decreased (1.01±0.10 vs 0.65±0.08，P<0.001),while the level of lncRNA snaR obviously increased (1.03±0.13 vs 2.42±0.30，P<0.001).The expression levels of lncRNA NRON and lncRNA snaR were related to TNM staging and tumor differentiation (P<0.05).Compared with the good prognosis group,the level of lncRNA NRON in tumor tissue of TNBC patients in poor prognosis group obviously decreased (0.69±0.09 vs 0.55±0.05，P<0.001),while the level of lncRNA snaR obviously increased (2.28±0.26比2.78±0.40，P＜0.001).Pearson method analysis showed that there was a negative correlation between lncRNA NRON and lncRNA snaR expression levels in tumor tissue of TNBC patients (r=-0.617,P<0.001).Multivariate Cox regression analysis showed that lncRNA NRON was a protective factor for the prognosis of TNBC patients (P<0.05),LncRNA snaR was a risk factor for the prognosis of TNBC patients (P<0.05).The combination of lncRNA NRON and lncRNA snaR expression levels in predicting better prognosis in TNBC patients than lncRNA snaR alone (Z_combination-lncRNA snaR=3.200,P=0.001).Conclusion The level of lncRNA NRON is down-regulated and lncRNA snaR level is obviously up-regulated in tumor tissues of TNBC patients,they are related to the prognosis of TNBC patients and may be biomarkers for evaluating TNBC prognosis.

Key words: long non-coding RNA non-coding repressor of nuclear factor of activated T cells; long non-coding RNA small NF90-associated RNA; triple negative breast cancer; prognosis