Figure 2.

Enhancer alterations deregulating MYC transcription. (a) In B-cells, the immunoglobulin (Ig) gene locus (left) is controlled by an upstream enhancer that ensures constitutive high expression levels of antibodies. In Burkitt Lymphoma, the Ig and MYC loci translocate rendering MYC under the influence of a highly active enhancer (right). Translocation can be visualized on a chromosomal level when comparing the length of sister chromatids in anaphase spread assays. (b) Deregulation of MYC by regulatory elements at the MYC locus. Lineage-specific super-enhancers have been mapped to the gene desert area surround MYC at the 8q24.21 locus, as indicated by colored cartoon peaks representing H3K27 acetylation. Two single nucleotide polymorphisms (SNPs) have been linked to altered MYC transcription: rs6983267, located 335 kb upstream of the MYC locus, and rs55705857, located within an enhancer 1.7 Mb downstream of MYC.