Protective Role of Transforming Growth Factorβ(TGFβ) in Tumor-Induced Degradation of Basement Membranes

Abstract
Human fibrosarcoma cells derived from a patient with multiple metastases extensively degrade artificial basement membranes (BM) and secrete interstitial type of collagenase, a proteolytic enzyme responsible for degradation of type I collagen. Exposure of invasive cell line to TGF .beta. abrogates destruction of BM. TGF .beta. reduces collagenase activity and stimulates specific metalloproteinase inhibitor (TIMP) in invasive tumor cells. We preassume that TGF .beta. could play a protective role in tumor invasion.