Why do estrogen-dependent breast-cancer cells grow and spread rapidly?
Researchers at the University of Illinois at Urbana-Champaign say it may be because estrogen virtually eliminates levels of a vitally important regulatory protein. In a paper that will appear in the Sept. 13 issue of the Proceedings of the National Academy of Sciences, the scientists report that human breast-cancer cells exposed to estrogen in their laboratory showed a dramatic reduction in numbers of a crucial nuclear receptor corepressor, a protein known as N-CoR (pronounced “en CORE”). They also found that the anti-estrogen drug tamoxifen, often used in breast-cancer treatments, encouraged N-CoR recovery, a beneficial activity. The paper was published online last week.