Long Non-Coding RNA NANCI/NKX2-1 Duplex Impacts Prognosis in Stage I Non-Small-Cell Lung Cancer

Background: NANCI, an intergenic long non-coding RNA (lncRNA) is essential for buffering NKX2-1 expression during embryonic development and in adult tissue. We analyzed NANCI and NKX2-1 in human lung embryonic samples and adult lung tissues and evaluated their potential as prognostic markers in stage I non-small cell lung cancer (NSCLC). Methods and results: NANCI and NKX2-1 expression was assessed by TaqMan assays in 18 human embryonic samples from 8 to 13 weeks, 59 non-tumoral (NT) lung tissue samples, and 98 stage I NSCLC tumor samples. NANCI and NKX2-1 expression in embryonic and NSCLC samples were downregulated in comparison to adult NT tissue. Patients with low expression of NANCI had shorter disease-free survival (DFS) and overall survival (OS) than those with high levels (47.6 vs 69.3 months, P= 0.032 and 57.7 vs 77.6 months, P = 0.021, respectively). When the expression levels of NANCI and NKX2-1 were evaluated in combination, four groups were identified (high NANCI/high NKX2-1, low NANCI/high NKX2-1, high NANCI/low NKX2-1 and low NANCI/low NKX2-1) with differential impact on DFS (A = 0.042) and OS (A= 0.024). Interestingly, the high NANCI/high NKX2-1 duplex group had longer DFS and OS than the other three groups (71.25 vs 46.3 months, P= 0.009 and 81.3 vs 56.1 months, P= 0.004, respectively). In the multivariate analysis, the high NANCI/high NKX2-1 duplex was identified as an independent prognostic factor for longer DFS (HR 0.346, 95% CI, 0.169-0.709; P = 0.004) and OS (HR 0.309, 95% CI, 0.121-0.786; P= 0.014). Conclusions: NANCI and the NANCI-NKX2-1 duplex impacts prognosis in stage I NSCLC patients. (C) 2020 SEPAR. Published by Elsevier Espana, S.L.U. All rights reserved.