1. Interplay and cooperation between SREBF1 and master transcription factors regulate lipid metabolism and tumor-promoting pathways in squamous cancer.
- Author
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Li LY, Yang Q, Jiang YY, Yang W, Jiang Y, Li X, Hazawa M, Zhou B, Huang GW, Xu XE, Gery S, Zhang Y, Ding LW, Ho AS, Zumsteg ZS, Wang MR, Fullwood MJ, Freedland SJ, Meltzer SJ, Xu LY, Li EM, Koeffler HP, and Lin DC
- Subjects
- Acetylation, Carcinoma, Squamous Cell genetics, Cell Line, Tumor, Cell Movement genetics, Cell Proliferation genetics, Chromatin Immunoprecipitation Sequencing, Chromatography, Liquid, Epigenomics, ErbB Receptors genetics, ErbB Receptors metabolism, Esophageal Neoplasms genetics, Fatty Acids biosynthesis, Fatty Acids metabolism, Gene Expression Regulation, Neoplastic, Head and Neck Neoplasms genetics, Histones metabolism, Humans, Kruppel-Like Transcription Factors genetics, Lung Neoplasms genetics, Regulatory Elements, Transcriptional, Signal Transduction genetics, Sphingolipids biosynthesis, Sphingolipids metabolism, Sterol Regulatory Element Binding Protein 1 genetics, TOR Serine-Threonine Kinases genetics, TOR Serine-Threonine Kinases metabolism, Tandem Mass Spectrometry, Transcription Factors genetics, Transcriptome genetics, Tumor Suppressor Proteins genetics, Carcinoma, Squamous Cell metabolism, Esophageal Neoplasms metabolism, Head and Neck Neoplasms metabolism, Kruppel-Like Transcription Factors metabolism, Lipid Metabolism genetics, Lung Neoplasms metabolism, Sterol Regulatory Element Binding Protein 1 metabolism, Transcription Factors metabolism, Tumor Suppressor Proteins metabolism
- Abstract
Squamous cell carcinomas (SCCs) comprise one of the most common histologic types of human cancer. Transcriptional dysregulation of SCC cells is orchestrated by tumor protein p63 (TP63), a master transcription factor (TF) and a well-researched SCC-specific oncogene. In the present study, both Gene Set Enrichment Analysis (GSEA) of SCC patient samples and in vitro loss-of-function assays establish fatty-acid metabolism as a key pathway downstream of TP63. Further studies identify sterol regulatory element binding transcription factor 1 (SREBF1) as a central mediator linking TP63 with fatty-acid metabolism, which regulates the biosynthesis of fatty-acids, sphingolipids (SL), and glycerophospholipids (GPL), as revealed by liquid chromatography tandem mass spectrometry (LC-MS/MS)-based lipidomics. Moreover, a feedback co-regulatory loop consisting of SREBF1/TP63/Kruppel like factor 5 (KLF5) is identified, which promotes overexpression of all three TFs in SCCs. Downstream of SREBF1, a non-canonical, SCC-specific function is elucidated: SREBF1 cooperates with TP63/KLF5 to regulate hundreds of cis-regulatory elements across the SCC epigenome, which converge on activating cancer-promoting pathways. Indeed, SREBF1 is essential for SCC viability and migration, and its overexpression is associated with poor survival in SCC patients. Taken together, these data shed light on mechanisms of transcriptional dysregulation in cancer, identify specific epigenetic regulators of lipid metabolism, and uncover SREBF1 as a potential therapeutic target and prognostic marker in SCC., (© 2021. The Author(s).)
- Published
- 2021
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