Role of Runx2 in breast cancer-mediated bone metastasis.

Breast cancer is one of the most prevalent forms of cancer in women. The currently available treatment for breast cancer is mostly curative except when it becomes metastatic. One of the major sites for metastasis of breast cancer is the bone.

Transforming growth factor-β1 regulation of ATF-3, c-Jun and JunB proteins for activation of matrix metalloproteinase-13 gene in human breast cancer cells.

Transforming growth factor-beta1 (TGF-β1) plays a significant role in breast cancer mediated bone metastasis, and it stimulated expression of matrix metalloproteinase-13 (MMP-13; an invasive and metastasis gene) via activating transcription factor-3 (ATF-3) in human breast cancer cells (MDA-MB231). We further dissected the role of ATF-3 and its interacting proteins (activator protein-1; AP-1) for TGF-β1-stimulation of MMP-13 expression in these cells. Chromatin immunoprecipitation (ChIP) experiment identified the TGF-β1-stimulation of ATF-3 interaction at the AP-1 site of the MMP-13 promoter in a sustained and prolonged manner in MDA-MB231 cells.