Superenhancer–transcription factor regulatory network in malignant tumors

OBJECTIVE: This study aims to identify superenhancer (SE)–transcriptional factor (TF) regulatory network related to eight common malignant tumors based on ChIP-seq data modified by histone H3K27ac in the enhancer region of the SRA database. METHODS: H3K27ac ChIP-seq data of eight common malignant tumor samples were downloaded from the SRA database and subjected to comparison with the human reference genome hg19. TFs regulated by SEs were screened with HOMER software. Core regulatory circuitry (CRC) in malignant tumor samples was defined through CRCmapper software and validated by RNA-seq data in TCGA. The findings were substantiated in bladder cancer cell experiments. RESULTS: Different malignant tumors could be distinguished through the H3K27ac signal. After SE identification in eight common malignant tumor samples, 35 SE-regulated genes were defined as malignant tumor-specific. SE-regulated specific TFs effectively distinguished the types of malignant tumors. Finally, we obtained 60 CRC TFs, and SMAD3 exhibited a strong H3K27ac signal in eight common malignant tumor samples. In vitro experimental data verified the presence of a SE–TF regulatory network in bladder cancer, and SE–TF regulatory network enhanced the malignant phenotype of bladder cancer cells. CONCLUSION: The SE–TF regulatory network with SMAD3 as the core TF may participate in the carcinogenesis of malignant tumors.