MODULATIONS OF BREAST FIBROBLAST AND CARCINOMA CELL-INTERACTIONS BY ADEXTRAN DERIVATIVE (CMDB7)

Modulation of interactions between human breast carcinoma cells (MCF-7 ras) and fibroblasts from normal breast tissue (MG3) and from a post-r adiation fibrosis with recurrent breast carcinoma (FPR7) by a dextran derivative (CMDB7) was investigated. In a coculture system, MCF-7ras p roliferation was increased (50%) by fibroblasts, and fibroblasts showe d a 84% growth increase with MCF-7ras. This co-stimulation did not dep end on fibroblast origin. CMDB7 can inhibit the growth of MCF-7ras but not the growth of fibroblasts. The addition of CMDB7 blocks the MCF-7 ras stimulation by fibroblasts but not the fibroblast stimulation by M CF-7ras. Fibroblast-Conditioned Medium stimulated over 2-3 fold MCF-7r as's DNA synthesis but CMDB7 did not influence this paracrine stimulat ion. IGFI, IGFII stimulated MCF-7ras's DNA synthesis whereas bFGF inhi bited it. CMDB7 did not block IGFI and IGFII's stimulatory effects but increased bFGF's inhibitory effects. These results indicate that CMDB 7 can inhibit fibroblast-breast cancer cell interactions possibly by i nterfering with paracrine growth factor loops.