NKX2-1 impacts prognosis in early stage NSCLC not harboring TP53 mutations

NKX2-1, a key molecule in lung development, is strongly expressed in lung cancer, especially in adenocarcinoma patients. Recently, two microRNAs interacting with NKX2-1 have been described: miR-365 that down-regulate NKX2-1; and miR-33a that is directly upregulated. To date, in non-small cell lung cancer (NSCLC) contradictory prognostic information about NKX2-1 and its microRNAs has been described. Aim: Elucidate the prognostic role of NKX2-1 and its microRNAs in resected NSCLC patients. Methods: mRNA and microRNA expression was determined using TaqMan assay in 142 NSCLC patients. The cohort was molecularly characterized including mutational status of TP53, EGFR and KRAS. Results: Locally advanced stages (III) had higher NKX2-1 expression than early stages (I-II) (p=0.002). High NKX2-1 expression was associated with longer disease-free survival (DFS) only in early stages (p=0.0389). Regarding to TP53 status, NKX2-1 was significantly downregulated in TP53-mutated patients (p=0.0087). Interestingly, TP53-WT patients with high expression of NKX2-1 had longer overall survival (OS) (p=0.0274) and longer DFS (p=0.00276). A negative correlation between NKX2-1 and miR-365 was found (r=-0.342, p Conclusions: In our cohort NKX2-1 impacts prognostic in early stage NSCLC particularly in patients without TP53 mutation, but no prognostic value was confirmed for its associated microRNAs. Supported by PFR Hospital Clinic de Barcelona, Becario SEPAR 2015, Mutual Medica 2015.