Fibroblast-dependent regulation of the stem cell properties of cancer cells.

There is emerging evidence that cancer stem cells (CSCs), like normal tissue stem cells, are regulated by a niche formed of mesenchymal cells. In this review we summarize the current knowledge of the role of cancer associated fibroblasts (CAFs) in a tentative CSC niche. We also discuss findings from our own studies showing that CAF derived factors have a strong stimulatory effect on the stem cell properties of breast cancer cells. Based on recent literature we conclude that CAFs are strong modulators of the stem cell properties of cancer cells. This effect is likely to be particularly relevant under circumstances of early stages of tumor cell dissemination and metastasis.