Valerie Weaver and collaborators have identified the first
positive regulator of BRCA1, establishing that the loss of the
homeobox gene HoxA9 promotes tumor growth in breasts. The
scientists found that restoring HoxA9 in breast cancer cells
inhibited their malignant behavior in culture and in vivo.
Intriguingly, the researchers learned that while HoxA9 has been
shown to promote leukemia, it actually functions as a tumor
suppressor in the breast. This eight-year project was led by
Valerie M. Weaver, PhD, a faculty member in the Department of
Surgery, "The finding demonstrates what we've seen before - that a
gene that drives tumors in one disease can reduce tumors in another
disease," she says.