Scientists studying the protein RANKL and its role in the production of bone cells have discovered a connection with breast cancer. RANKL is a protein that activates bone cells to replace lost bone, e.g. through osteoporosis. Normal RANKL activity includes stimulation of bone cells to die and replacement cells to grow. When something disrupts the RANKL system, the protein overproduces, causing bone cell production but interrupting cellular death.
The connection to breast cancer is that scientists have found the same protein in the tissue of breast cancer. Further, synthetic hormones (progestin) found in HRT and contraceptives cause RANKL production, which in turn causes breast cancer cells to multiply and to fail to die.
A proposal is pending for research that would study denosumab, a monoclonal antibody that blocks RANKL for treating bone metastasis in advanced breast cancer. Another study of denosumab treatment for osteoporosis has already received approval in the US and the EU.
Daniel Schramek, Andreas Leibbrandt, Verena Sigl, Lukas Kenner, John A. Pospisilik, Heather J. Lee, Reiko Hanada, Purna A. Joshi, Antonios Aliprantis, Laurie Glimcher, Manolis Pasparakis, Rama Khokha, Christopher J. Ormandy, Martin Widschwendter, Georg Schett, Josef M. Penninger. “Osteoclast differentiation factor RANKL controls development of progestin-driven mammary cancer.” Nature, 2010; DOI: 10.1038/nature09387.5 6 7 8 © 2004-2010 Donna Peach. All rights reserved.