SOX2 and p63 colocalize at genetic loci in squamous cell carcinomas

• Published in: The Journal of clinical investigation Vol. 124; no. 4; pp. 1636 - 1645
• Main Authors: Watanabe, Hideo, Ma, Qiuping, Peng, Shouyong, Adelmant, Guillaume, Swain, Danielle, Song, Wenyu, Fox, Cameron, Francis, Joshua M, Pedamallu, Chandra Sekhar, DeLuca, David S, Brooks, Angela N, Wang, Su, Que, Jianwen, Rustgi, Anil K, Wong, Kwok-kin, Ligon, Keith L, Liu, X Shirley, Marto, Jarrod A, Meyerson, Matthew, Bass, Adam J
• Format: Journal Article
• Language: English
• Published: United States American Society for Clinical Investigation 01-04-2014
• Subjects: Adenovirus E1A Proteins - genetics; Binding sites; Binding Sites - genetics; Biomedical research; Carcinoma, Squamous Cell - genetics; Carcinoma, Squamous Cell - metabolism; Cell Line; Cell Line, Tumor; Charitable foundations; Chromatiaceae - genetics; Chromatiaceae - metabolism; Deoxyribonucleic acid; Development and progression; DNA; Embryonic Stem Cells - metabolism; Embryos; Gene Amplification; Gene expression; Gene Expression Regulation, Neoplastic; Genetic aspects; Genomes; Humans; Octamer Transcription Factor-3 - metabolism; Oncogenes; Physiological aspects; Pluripotent Stem Cells - metabolism; Protein Binding; Proteins; Proto-Oncogene Proteins - genetics; SOXB1 Transcription Factors - genetics; SOXB1 Transcription Factors - metabolism; Squamous cell carcinoma; Studies; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transcriptome; Tumor proteins; Tumor Suppressor Proteins - genetics; Tumor Suppressor Proteins - metabolism; Tumors
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI71545

The transcription factor SOX2 is an essential regulator of pluripotent stem cells and promotes development and maintenance of squamous epithelia. We previously reported that SOX2 is an oncogene and subject to highly recurrent genomic amplification in squamous cell carcinomas (SCCs). Here, we have further characterized the function of SOX2 in SCC. Using ChIP-seq analysis, we compared SOX2-regulated gene profiles in multiple SCC cell lines to ES cell profiles and determined that SOX2 binds to distinct genomic loci in SCCs. In SCCs, SOX2 preferentially interacts with the transcription factor p63, as opposed to the transcription factor OCT4, which is the preferred SOX2 binding partner in ES cells. SOX2 and p63 exhibited overlapping genomic occupancy at a large number of loci in SCCs; however, coordinate binding of SOX2 and p63 was absent in ES cells. We further demonstrated that SOX2 and p63 jointly regulate gene expression, including the oncogene ETV4, which was essential for SOX2-amplified SCC cell survival. Together, these findings demonstrate that the action of SOX2 in SCC differs substantially from its role in pluripotency. The identification of the SCC-associated interaction between SOX2 and p63 will enable deeper characterization the downstream targets of this interaction in SCC and normal squamous epithelial physiology.