title: Expression of thrombospondin-1 in human pancreatic adenocarcinomas: role in matrix metalloproteinase-9 production.
abstract: Human pancreatic adenocarcinoma, an aggressive malignant disease, shows a strong desmoplastic reaction characterized by a remarkable proliferation of interstitial connective tissues. Thrombospondin-1 (TSP-1), a 450 kDa platelet and matrix glycoprotein, has been implicated in tumor invasion, angiogenesis and metastasis. TSP-1 and MMP-9 expression in pancreatic adenocarcinoma and control pancreas tissues was measured by immunohistochemistry. TSP-1 expression in pancreatic carcinoma cell lines, fibroblasts, and endothelial cells was measured by a competitive TSP-1 enzyme linked immunosorbent assay (ELISA). The effect of TSP-1 on MMP-9 production in pancreatic carcinoma cell lines was measured by zymography and Western blot analysis. Eighty five per cent (23/27) of cases of pancreatic adenocarcinoma showed increased TSP-1 staining in the desmoplastic stroma adjacent to tumor cells. No specific positive staining for TSP-1 was observed in the normal pancreatic tissues and the inflammatory areas. TSP-1 localized in tumor stroma surrounding the tumor cells expressing MMP-9. Using TSP-1 competitive ELISA, the secretion of TSP-1 by different pancreatic cancer cell lines into culture medium varied from 11.45 plus minus 14.08 to 275.82 plus minus 45.56 ng/10 6 cells/24 hours. The amounts of TSP-1 detected in both culture media and cell extracts from fibroblasts or endothelial cells were at least 2-3 fold higher than those from pancreatic cancer cells. TSP-1 augmented the production of matrix metalloproteinase-9, a matrix degrading enzyme, in pancreatic cancer cells in vitro. Stromally-derived TSP-1 up-regulates the production of MMP-9 by pancreatic adenocarcinoma. These data are consistent with the conclusion that TSP-1-rich stroma is involved in regulating matrix remodeling in tumor invasion.
authors.affiliation: MCP Hahnemann University, Department of Pathology, Philadelphia, PA 19102-1192, USA.
authors.forename: X
authors.initials: X
authors.lastname: Qian
authors.forename: V L
authors.initials: VL
authors.lastname: Rothman
authors.forename: R F
authors.initials: RF
authors.lastname: Nicosia
authors.forename: G P
authors.initials: GP
authors.lastname: Tuszynski
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D015153:Blotting, Western; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007124:Immunoenzyme Techniques; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D017154:Stromal Cells / Q000378:metabolism; D019700:Thrombospondin 1 / Q000378:metabolism* / Q000494:pharmacology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000187:drug effects; D015854:Up-Regulation
chemical_list: D019700:Thrombospondin 1; D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9