MMP1, MMP9, and COX2 Expressions in Promonocytes Are Induced by Breast Cancer Cells and Correlate with Collagen Degradation, Transformation-Like Morphological Changes in MCF-10A Acini, and Tumor Aggressiveness

Figure 6

Model of the establishment of an inflammatory protumoral microenvironment. Our data supports that in solid tumors, the expression of genes important for establishing an inflammatory protumoral microenvironment is importantly promoted through cell communication mechanisms between epithelial tumor and other stromal cells, such as promonocytes. The information flows substantially from the BRC cells to the promonocytes, likely in an important extent mediated by soluble factors secreted to the medium. Among the activities promoted is the proteolysis of ECM components. The soluble factors found in supernatant from BRC and promonocyte cocultures were able to trigger morphological changes in MCF-10A acini, similar to changes often seen after oncogene expression (see text for more details). COX2: Cyclooxygenase 2; MMP1,9: metalloproteases 1 and 9; PGE2: prostaglandin E2; ECM: extracellular matrix.