ASCL1 and NEUROD1 Reveal Heterogeneity in Pulmonary Neuroendocrine Tumors and Regulate Distinct Genetic Programs

• DOI: 10.1016/j.celrep.2016.06.081
• Publication Date: 2016-07-21T22:18:32Z
• Authors: Mark D. Borromeo; Trisha K. Savage; Rahul K. Kollipara; Min He; Alexander Augustyn; Jihan K. Osborne; Luc Girard; John D. Minna; Adi F. Gazdar; Melanie H. Cobb; Jane E. Johnson
• Keywords: Male; 0301 basic medicine; Lung Neoplasms; QH301-705.5; Gene Expression; Oncogenes; Small Cell Lung Carcinoma; Gene Expression Regulation, Neoplastic; Proto-Oncogene Proteins c-myc; Mice; Neuroendocrine Tumors; 03 medical and health sciences; Neuroendocrine Cells; Cell Line, Tumor; Basic Helix-Loop-Helix Transcription Factors; Animals; Humans; Female; Biology (General); Transcription Factors

Small cell lung carcinoma (SCLC) is a high-grade pulmonary neuroendocrine tumor. The transcription factors ASCL1 and NEUROD1 play crucial roles in promoting malignant behavior and survival of human SCLC cell lines. Here, we find that ASCL1 and NEUROD1 identify heterogeneity in SCLC, bind distinct genomic loci, and regulate mostly distinct genes. ASCL1, but not NEUROD1, is present in mouse pulmonary neuroendocrine cells, and only ASCL1 is required in vivo for tumor formation in mouse models of SCLC. ASCL1 targets oncogenic genes including MYCL1, RET, SOX2, and NFIB while NEUROD1 targets MYC. ASCL1 and NEUROD1 regulate different genes that commonly contribute to neuronal function. ASCL1 also regulates multiple genes in the NOTCH pathway including DLL3. Together, ASCL1 and NEUROD1 distinguish heterogeneity in SCLC with distinct genomic landscapes and distinct gene expression programs.