In Vivo and In Vitro Analysis of the Regulation of C-myc Proto-oncogene Expression in Human Breast Cancer.

The purpose of this research was to characterize the factors controlling the expression of c-myc and other genes that are commonly mis-regulated in transformed cells. Genomic DNA exists in the form of chromatin, which generally renders the DNA inaccessible to factors that promote gene expression. Here we report characterization of a cellular protein complex, hSWISNF, that can alter chromatin structure in an energy dependent manner and can facilitate the interaction of transcription factors with chromatin. The results indicate that the change in chromatin structure induced by hSWISNF is stable in the absence of continued ATP hydrolysis. The increased ability of transcription factors to bind to chromatin is not dependent on concurrent hSWISNF activity.