c-Myb regulates matrix metalloproteinases 1/9, and cathepsin D: implications for matrix-dependent breast cancer cell invasion and metastasis
1 Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
2 International Clinical Research Center, CBCE, St. Anne's University Hospital, Brno, Czech Republic
3 First Department of Pathological Anatomy, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Brno, Czech Republic
4 Department of Pathological Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
5 Department of Cytokinetics, Academy of Sciences of the Czech Republic, Institute of Biophysics, Brno, Czech Republic
Molecular Cancer 2012, 11:15 doi:10.1186/1476-4598-11-15Published: 23 March 2012
The c-Myb transcription factor is essential for the maintenance of stem-progenitor cells in bone marrow, colon epithelia, and neurogenic niches. c-Myb malfunction contributes to several types of malignancies including breast cancer. However, the function of c-Myb in the metastatic spread of breast tumors remains unexplored. In this study, we report a novel role of c-Myb in the control of specific proteases that regulate the matrix-dependent invasion of breast cancer cells.
Ectopically expressed c-Myb enhanced migration and ability of human MDA-MB-231 and mouse 4T1 mammary cancer cells to invade Matrigel but not the collagen I matrix in vitro. c-Myb strongly increased the expression/activity of cathepsin D and matrix metalloproteinase (MMP) 9 and significantly downregulated MMP1. The gene coding for cathepsin D was suggested as the c-Myb-responsive gene and downstream effector of the migration-promoting function of c-Myb. Finally, we demonstrated that c-Myb delayed the growth of mammary tumors in BALB/c mice and affected the metastatic potential of breast cancer cells in an organ-specific manner.
This study identified c-Myb as a matrix-dependent regulator of invasive behavior of breast cancer cells.