The contribution of epithelia-mesenchyme interaction to normal development (eg., tissue formation) and to neoplasia has become a subject of increasing interest to scientists because of recent progress in deciphering the molecular signals that mediate this interaction. Clearly, some of the same types of molecules (eg., growth factors and their receptors, proteolytic enzymes, cell adhesion molecules, and structural proteins of the extracellular matrix) mediate exchange of information between epithelia and mesenchyme during normal development and malignant growth. However, defects in the regulation of this exchange appear to contribute to malignancy by allowing growth promoting, invasogenic, and angiogenic factors to accumulate within the microenvironment of the tumor. For example, recent studies suggest that abnormal interactions between tumor epithelial cells and stromal mesenchymal cells contribute to the overproduction and accumulation of scatter factor (hepatocyte growth factor), an invasogenic and angiogenic cytokine, in certain types of tumor. The production and and activation of type IV collagenase, a matrix-degrading enzyme required for tumor cell invasion, appears to require intimate cooperation between tumor and stromal cells. The material contained in this volume highlights the state-of-the-art of knowledge of the molecular mechanisms by which epithelia and mesenchyme collaborate, and the abnormalities in these mechanisms that may lead to the development of cancer.

Inhalt
Epithelial-mesenchymal transitions in development and tumor progression.- Regulation of scatter factor (hepatocyte growth factor) production by tumor-stroma interaction.- Regulation of HGF and HGFR gene expression.- The role of scatter factor and the c-met proto-oncogene in angiogenic responses.- Modulation of intercellular junctions of epithelia by scatter factor (hepatocyte growth factor).- The Met-HGF/SF autocrine signaling mechanism is involved in sarcomagenesis.- Tumor cell interactions with the vascular endothelium and their role in cancer metastasis.- Stimulation and regulation of tumor cell motility in invasion and metastasis.- Tumor-stromal cytokine interactions in ovarian neoplasms.- Keratinocyte growth factor as a cytokine that mediates mesenchymal-epithelial interaction.- Stromal-epithelial interaction in type IV collagenase expression and activation: The role in cancer metastasis.- Angiogenesis as a component of epithelial-mesenchymal interactions.- Mammary tumor fibroblasts are phenotypically distinct from non-tumor fibroblasts.- Fibroblast subpopulations as accelerators of tumor progression: The role of migration stimulating factor.