THROMBOSPONDIN, A POTENTIATOR OF TUMOR-CELL METASTASIS

  • 1 August 1987
    • journal article
    • research article
    • Vol. 47  (15) , 4130-4133
Abstract
The platelet-secreted protein thrombospondin (TSP) potentiates tumor cell metastasis. Human TSP injected i.v. into mice 5 min prior to i.v. injection of T241 sarcoma cells potentiates lung tumor colony formation. Several lines of evidence suggest that the TSP-enhancing effect involves both TSP-mediated tumor cell adhesion and the host''s hemostatic system: (a) TSP potentiates the initial, rapid sequestering of tumor cells in the lung; (b) TSP promotes the adhesion of tumor cells in vitro; (c) the effect of TSP on tumor cell metastasis is dependent on the presence of platelets and a normal plasma clotting system, since TSP does not potentiating lung tumor colony formation in either thrombocytopenic mice or mice anticoagulated with Coumadin. Our results suggest a central role for TSP in the metastasis process.