Combinatorial transcriptional regulation of HEB/ZEB1/ASCL1 and MYBL2 on Ras/ErbB signaling.

ABSTRACT

Gene expression is tightly regulated by transcription factors (TFs) which play an important role in development and tumorigenesis. Abnormal transcriptional regulation leads to oncogene activation or tumor suppressor inhibition, thus promoting the occurrence and progression of tumors. MYBL2 (alias B-Myb), a ubiquitously expressed transcription factor of the MYB family, is a nuclear protein involved in cell cycle progression and overexpressed and associated with poor patient outcomes in numerous cancer entities. However, the further effectors of the MYBL2 downstream transcriptional network mediating its cancer-promoting properties remain not well elaborated. Here, we systemic investigated the global MYBL2 targets base on ChIP-seq data from melanoma, breast cancer, lung carcinoma, and liver cancer. Functional enrichment and further validation of MYBL2 downstream binding targets on melanoma cells demonstrated that genes in the Ras and ErbB signaling pathways were regulated by MYBL2. Moreover, when integrating breast cancer, lung carcinoma and liver cancer data, we identified HEB, ZEB1 and ASCL1 colocalized on Ras/ErbB signaling gene locus with MYBL2, indicating the regulatory complex on activating oncogenic expression. Taken together, this study provides a reference for a better understanding of the MYBL2 regulatory mechanism in tumorigenesis.