Stromal resistance of fibroblasts against oxidative damage: involvement of tumor cell-secreted platelet-derived growth factor (PDGF) and phosphoinositide 3-kinase (PI3K) activation.

A critical step in tumor progression is the interaction of malignant and stromal cells via paracrine mechanisms. Stromal cells, particularly fibroblasts, support cancer cells in invasion of the surrounding tissue for access to the vascular system. Here, the question is addressed of whether tumor cells induce 'stromal resistance', i.