Expression Data from Normal or Tumor Fibroblasts With or Without Ets2

The mechanisms involved in epithelium-stroma interactions remain poorly understood, despite the importance of the microenvironment during tumorigenesis. Here, we studied the role of the Ets2 transcription factor in tumor-associated fibroblasts in the MMTV-PyMT mammary tumor model. Inactivation of Ets2 specifically in fibroblasts using Fsp-cre significantly reduced tumor growth, in contrast to Ets2 inactivation in epithelium, in which no differences in tumor growth were observed. Microarray analysis on isolated fibroblasts demonstrated the important role of Ets2 in remodeling of the extracellular matrix and angiogenesis in these cells. At the molecular level, Ets2 regulated Mmp9 expression through direct binding to the promoter region. Tumors lacking Ets2 in fibroblasts had diminished blood vessels. We also found a significant correlation between phosphorylation of ETS2 and MMP9 levels in stroma of human breast cancer samples. Collectively, our results suggest Ets2 uniquely contributes to angiogenesis from fibroblasts in the tumor microenvironment. Primary mammary fibroblasts were isolated from mice without the PyMT oncogene with or without Ets2, and from mice with the PyMT oncogene with or without Ets2. RNA was extracted and samples were submitted for Affymetrix gene expression arrays.