Accession Number : ADA331277

Title :   In Vivo Footprinting of the PS2 Gene in Human Breast Cancer Cells.

Descriptive Note : Final rept. 29 Sep 94-28 Jun 97,

Corporate Author : ILLINOIS UNIV CHAMPAIGN

Personal Author(s) : Nardulli, Ann M.

PDF Url : ADA331277

Report Date : AUG 1997

Pagination or Media Count : 31

Abstract : In vivo footprinting was utilized to examine the estrogen-responsive pS2 gene in MCF-7 human breast cancer cells. Estrogen treatment resulted in an extensive region of protection within and adjacent to the pS2 estrogen response element (ERE). The ERE was also strongly protected after addition of either 4-hydroxytamoxifen and ICI 182,780, but the pattern of protection was distinct with each of these antiestrogens. Protein-DNA interactions in several other regions of the pS2 promoter were also differentially affected by estrogen and antiestrogen treatment. The TATA and CAAT sequences in the proximal promoter were protected in MCF-7 cells in the presence and in the absence of hormone, but were flanked by hypersensitive sites, which were unaffected by hormone treatment. Hypersensitive sites, which were observed in the region of the pS2 ERE in MCF-7 cells, were not observed in estrogen receptor (ER)-negative MDA MB 231 cells and the overall organization of the gene was distinctly different. Taken together, these findings imply that the ER is involved not only in mediating the cellular response to hormone, but may also be involved in organization of the proximal promoter in the absence of hormone.

Descriptors :   *IN VITRO ANALYSIS, *GENES, *CELLS(BIOLOGY), *ESTROGENS, *BREAST CANCER, HORMONES, ORGANIZATIONS, HUMANS, REGIONS, PROTECTION, PATTERNS, RESPONSE(BIOLOGY), SENSE ORGANS.

Subject Categories : Anatomy and Physiology
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE