Figures & data
Figure 1. MYC-regulated miRNAs and the hallmarks of B-cell lymphomas. MYC and miRNAs form forward-feedback (double-negative) regulatory loops contributing to sustained MYC activation, miRNA downregulation, and subsequent dramatic deregulation of the hallmarks of lymphoma. “↑”, upregulation; “↓”, repression by MYC. MYC utilizes one or more of the above mechanisms in combination to exert its oncogenic functions.
Figure 2. Potential mechanisms of miRNA repression by MYC. (A) MYC recruits HDAC complex to miRNA promoter (of miR-15a/16-1) to induce histone tail deactylation, compact chromatin, and lead to miRNA transcription suppression. (B) PRC2 is tethered to miRNA promoter (of miR-26a, miR-29 and miR-548 min) with HDAC3 by MYC to methylate and deacetylate histone tail and subsequently inhibits miRNA transcription. (C) DNMT3 is recruited to miRNA promoter (of miR-34a and miR-146a) by MYC to methylate DNA and lead to repression of miRNA transcription. (D) MYC induces Lin-28B expression through direct association with the Lin-28 promoter, and Lin-28 proteins act as negative regulators of miRNAs (let-7 and miRNA-150) maturation and biogenesis.
