| Modification Notes |
The Testican family, also designated BM-40/SPARC/osteonectin, is composed of highly conserved, extracellular, calcium-binding, sulfate proteoglycans. Expression of Testicans is detected in a variety of tissues, but is most abundant in brain. Family members include Testican-1, Testican-2, Testican-3, and an amino-terminal splice variant of Testican-3, designated N-Tes. Most Testicans inhibit MT-MMPs and thereby inhibit the activity of pro-MMP-2. Testican-3 is a 436-amino acid protein that contains a follistatin-like domain, a calcium-binding domain, a COOH-terminal thyroglobulin domain, and two glycosaminoglycan attachment sites. Both Testican-3 and N-Tes are expressed in normal brain but down-regulated in glioma tissues. Transfection of either the N-Tes or Testican 3 gene into transformed glioma or kidney cells suppresses their invasive growth in collagen gel, suggesting that both N-Tes and Testican 3 interfere with tumor invasion. |