YY1-mediated DNA looping promotes the generation of ecDNA (HiCUT)

YY1 is a widely expressed transcriptional regulatory factor that is overexpressed in various cancer types, promoting the expression of numerous oncogenes and contributing to cancer progression. It has been identified as a significant biomarker of cancer, correlating with poor prognosis in cancer patients. Moreover, YY1 is an essential regulator of DNA looping, preferentially occupying enhancers and promoters. YY1-mediated enhancer-promoter loops participate in various cancer-related biological functions by regulating gene expression. The circular nature of ecDNA suggests that its formation involves a DNA looping process. Notably, in tumor cells, YY1-mediated DNA looping is closely associated with the activation of multiple oncogenes and immunosuppressive genes, resembling the types of genes carried by ecDNA. Therefore, we investigated the link between DNA looping mediated by YY1 and ecDNA generation. We conducted YY1 HiCUT in COLO320-DM/HSR cells. We found that in COLO320-DM cells, a large number of YY1-mediated loops were located in the MYC amplification region, while only 1% of these loops were observed in the same region in COLO320-HSR cells. The result indicates YY1 mediates DNA looping through dimerization in cells has potential correlation with ecDNA biogenesis. Overall design: other