One of the most frequently mutated epigenetic factors in cancer is a large protein complex called SWI/SNF, which regulates gene transcription and is crucial for proper cell differentiation. An important question has been how SWI/SNF is recruited to cell-type-specific regions of DNA, called enhancers.
Researchers led by Blaine Bartholomew, Ph.D., found a special class of non-coding enhancer RNA (eRNA) that recruits SWI/SNF to cell-type specific enhancers involved in the switch from undifferentiated to differentiated cells. By initially recruiting SWI/SNF, the eRNA promotes the assembly of transcription factors and co-activators onto these enhancers. The study shows that super-enhancers, which are known to be important in determining cell identity and are often targeted in cancer, also are activated by eRNA and SWI/SNF.