Stromelysin/transin and tumor progression.

Transin is an oncogene-inducible protein which has been shown to be the rat homologue of an extracellular matrix-degrading metalloproteinase known as stromelysin. The activity of transin/stromelysin is regulated at several levels: (1) at the transcriptional level, it is positively regulated by oncogenes, tumor promoters, and certain growth factors, and is negatively regulated by several agents including glucocorticoids and transforming growth factor-beta; (2) the protease activity is produced by processing of an inactive precursor form to an active enzyme; and (3) total protease activity is modulated by activity of tissue inhibitors of metalloproteinases (TIMPs). The association of transin/stromelysin expression with tumor progression suggests that it plays an important role in cancer.