title: Shedding of syndecan-1 by stromal fibroblasts stimulates human breast cancer cell proliferation via FGF2 activation.
abstract: The cell surface heparan sulfate proteoglycan syndecan-1 is induced in stromal fibroblasts of breast carcinomas and participates in a reciprocal feedback loop, which stimulates carcinoma cell growth in vitro and in vivo. To define the molecular mechanism of carcinoma growth stimulation, a three-dimensional co-culture model was developed that combines T47D breast carcinoma cells with immortalized human mammary fibroblasts in collagen gels. By silencing endogenous syndecan-1 induction with short interfering RNA and expressing mutant murine syndecan-1 constructs, it was determined that carcinoma cell mitogenesis required proteolytic shedding of syndecan-1 from the fibroblast surface. The paracrine growth signal was mediated by the syndecan-1 heparan lfate chains rather than the ectodomain of the core protein and required fibroblast growth factor 2 and stroma-derived factor 1. This paracrine pathway may provide an opportunity for the therapeutic disruption of stromaepithelial signaling.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA.
authors.forename: Gui
authors.initials: G
authors.lastname: Su
authors.forename: Stacy A
authors.initials: SA
authors.lastname: Blaine
authors.forename: Dianhua
authors.initials: D
authors.lastname: Qiao
authors.forename: Andreas
authors.initials: A
authors.lastname: Friedl
mesh_terms: D000818:Animals; D001940:Breast / Q000378:metabolism / Q000473:pathology; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002461:Cell Line, Transformed; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D020868:Gene Silencing; D006801:Humans; D051379:Mice; D009154:Mutation; D019899:Paracrine Communication / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology; D053668:Syndecan-1 / Q000235:genetics / Q000378:metabolism*
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D034741:RNA, Small Interfering; C508241:SDC1 protein, human; C508242:Sdc1 protein, mouse; D053668:Syndecan-1; D016222:Fibroblast Growth Factor 2