A POLYMERIC FORM OF FIBRONECTIN HAS ANTIMETASTATIC EFFECTS AGAINST MULTIPLE TUMOR TYPES

Metastasis accounts for most deaths in cancer patients. Tumor cell adh esion to the extracellular matrix through integrins is thought to be a critical step in metastasis and a potential target for therapeutic in tervention. We show here that treatment of human osteosarcoma, melanom a and carcinoma cells with a polymeric form of fibronectin (sFN), befo re inoculation into nude mice, prevented tumor formation. Intraperiton eally administered sFN significantly reduced lung colonization from in travenously injected tumor cells (experimental metastasis) and from su bcutaneous tumors in nude mice (spontaneous metastasis). Treatment wit h sFN blocked cell spreading and migration in vitro suggesting a possi ble mechanism for the antimetastatic effect.