Collagen and Elastin Synthesis in Human Stroma and Breast Carcinoma Cell Lines: Modulation by the Extracellular Matrix

Abstract

The desmoplastic response to breast carcinoma is being studied. The stimulation of stromal cell proliferation by a preformed breast tumor matrix was shown. An additional mechanism for stimulating scleroprotein deposition is described here. On a per-cell basis, the synthesis of collagen and elastin was increased by 50% and 70%, respectively, in fibroblasts grown on the preformed breast tumor matrix compared to the same cells grown on plastic or on their own preformed matrix. Breast tumor cells themselves synthesized small amounts of collagen and elastin compared to fibroblasts. These levels were unchanged when breast tumor cells were grown on the preformed matrix of fibroblasts. Addition of steroid hormones to cultured cells grown on plastic or on preformed matrices in various combinations, did not change the levels of either collagen or elastin synthesis. The matrix of human breast tumor cells exerts a dual effect; it is mitogenic for fibroblasts, and also stimulates the level of collagen and elastin synthesis, events that could contribute to the formation of the desmoplastic response to human breast cancer in situ.