But now researchers at The University of Texas M. D. Anderson Cancer Center have begun to understand how breast cancer cells suddenly stop responding to treatment and become more aggressive. The finding, which appears in the Aug. 8 issue of the journal Nature, points to a potential target that in principle, may reverse the process and restore hormone responsiveness to breast cancer cells.
A research team led by Dr. Rakesh Kumar, professor of cellular and molecular oncology, reports discovering a new form of a protein that is associated with aggressive forms of cancer, including breast cancer. The new protein, termed MTA1s (metastatic tumor antigen 1, short version), appears to intercept the key protein receptor that is responsible for communicating with the female hormone estrogen inside cells.
An estimated 192,200 women will be diagnosed with invasive breast cancer and 40,200 women will die this year, according to the American Cancer Society. About 60 percent of breast cancers are classified as estrogen-receptor positive by conventional evaluation methods, meaning that they respond to signals from the female hormone estrogen through its receptor. These patients typically respond well to hormonal treatment with tamoxifen and other anti-estrogenic compounds, which block estrogen signals that tell the cancer cells to multiply.
But after a period of time, some breast cancer cells suddenly become hormone independent, growing and multiplying more rapidly, even in the presence of anti-estrogen treatment. Physicians typically determine hormone responsiveness by looking for the estrogen re
Contact: Julie Penne or Laura Sussman
University of Texas M. D. Anderson Cancer Center