Fig. 3: Transcriptional activation of proto-oncogenes from distal promoter-enhancer interaction.

In some cases of HCC, aberrant chromatin loop formation brings de novo distal enhancers in close proximity to the promoter of several proto-oncogenes. The chromatin loop is stabilized by the CCCTC-binding factor (CTCF) and the cohesin complex to facilitate gene transcription. These interactions are associated with increased neovascularization, tumor growth, invasion, and metastasis in HCC.