Homeodomain containing protein HOXB9 regulates expression of growth and angiogenic factors facilitates tumor growth in vitro and is overexpressed in breast cancer tissue

摘要

HOXB9 is a homeobox containing gene and is critical for the development of mammary gland and sternum. HOXB9 is also regulated by estrogen and is critical for angiogenesis. Herein, we investigated the biochemical roles of HOXB9 and its homeodomain in cell cycle progression and tumorigenesis. Our studies demonstrated that HOXB9 is overexpressed in breast cancer tissue. HOXB9 overexpression stimulated three-dimensional colony formation in soft-agar assay. HOXB9 binds to the promoters of various tumor growth and angiogenic factors and regulates their expression. Homeodomain of HOXB9 plays crucial roles in transcriptional regulation of tumor growth factors and also in three dimensional colony formation indicating crucial roles of HOXB9 homeodomain in tumorigenesis. Overall, we demonstrated that HOXB9 is critical regulators of tumor growth factors and is associated with tumorigenesis.