Overexpression of lung developmental transcription factors TTF-1, NKX2-8 and PAX9

We investigated the clinical implications of lung developmental transcription factors (TTF-1, NKX2-8, and PAX9) which we recently discovered as cooperating oncogenes activated by way of gene amplification at chromosome 14q13 in lung cancer. Using stable transfectants of human bronchial epithelial cells, RNA expression profiles (signatures) representing activation of the biological pathways defined by each of the three genes were determined and used to risk stratify a non-small cell lung cancer (NSCLC) clinical dataset consisting of ninety-one early stage tumors. Co-activation of the TTF-1 and NKX2-8 pathways identified a cluster of patients with poor survival, representing approximately 20% of patients with early stage NSCLC, whereas activation of individual pathways did not reveal significant prognostic power. Importantly, the poor prognosis associated with co-activation of TTF-1 and NKX2-8 was validated in two other independent clinical datasets. Further, lung cancer cell lines showing co-activation of the TTF-1 and NKX2-8 pathways were shown to exhibit resistance to cisplatin, the standard of care for the treatment of NSCLC. Since TTF-1 and NKX2-8 lack specific inhibitors at the current time, we explored an alternative therapeutic strategy. Using signatures of signaling pathway activation, we identified deregulation of specific oncogenic pathways (Ras and Myc) in the TTF-1/NKX2-8 co-activated cohort.

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Hsu DS, Acharya CR, Balakumaran BS, Riedel RF, Kim MK, Stevenson M, Tuchman S, Mukherjee S, Barry W, Dressman HK, Nevins JR, Powers S, Mu D, Potti A