Elevated expression of angiomodulin (AGM/IGFBP-rP1) in tumor stroma and its roles in fibroblast activation.

Abstract

Angiomodulin (AGM/IGFBP-rP1), a glycoprotein of about 30 kDa, is overexpressed in tumor vasculature as well as some human cancer cell lines, but it has been suggested to be a tumor suppressor. To elucidate roles of angiomodulin (AGM) in tumor progression, we here examined distribution of AGM in three types of human cancer tissues by immunohistochemistry. The results showed that AGM was overexpressed in the stroma as well as the vasculature surrounding tumor cells in the human cancer tissues. AGM and α-smooth muscle actin (α-SMA) as an activated fibroblast marker were often colocalized in cancer-associated fibroblasts (CAFs). In vitro analysis indicated that transforming growth factor (TGF)-β1 might be an important inducer of AGM in normal human fibroblasts. AGM strongly stimulated the expression of fibronectin and weakly that of α-SMA in normal fibroblasts. AGM significantly stimulated the proliferation and migration of fibroblasts. The AGM-induced expression of fibronectin and α-SMA was blocked by a TGF-β signal inhibitor but neither the stimulation of cell growth nor migration. These results imply that AGM activates normal fibroblasts by TGF-β-dependent and independent mechanisms. These findings also suggest that AGM and TGF-β1 cooperatively or complementarily contribute to the stromal activation and connective tissue formation in human cancer tissues, contributing to tumor progression.

• Authors: Eriko Komiya, Momoko Furuya, Naoko Watanabe, Yohei Miyagi, Shouichi Higashi, Kaoru Miyazaki
• Journal: Cancer science (Cancer Sci) Vol. 103 Issue 4 Pg. 691-9 (Apr 2012) ISSN: 1349-7006 [Electronic] England
• PMID: 22321149 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 Japanese Cancer Association.

Chemical References

• Insulin-Like Growth Factor Binding Proteins
• Transforming Growth Factor beta
• insulin-like growth factor binding protein-related protein 1

Topics

• Cell Line
• Cell Movement (drug effects)
• Cell Proliferation (drug effects)
• Disease Progression
• Fibroblasts (physiology)
• Humans
• Insulin-Like Growth Factor Binding Proteins (metabolism)
• Neoplasms (blood supply, metabolism)
• Stromal Cells (metabolism)
• Transforming Growth Factor beta (pharmacology)