Open AccessCollagen regulation of let-7 in pancreatic cancer involves TGF-β1-mediated membrane type 1-matrix metalloproteinase expression
Author(s) -
Surabhi Dangi-Garimella,
Matthew J. Strouch,
Paul J. Grippo,
David J. Bentrem,
Hidayatullah G. Munshi
Publication year - 2010
Publication title -
oncogene
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.395
H-Index - 342
eISSN - 1476-5594
pISSN - 0950-9232
DOI - 10.1038/onc.2010.485
Subject(s) - matrix metalloproteinase , pancreatic cancer , biology , cancer research , type i collagen , microrna , fibrosis , transforming growth factor , carcinogenesis , extracellular matrix , signal transduction , microbiology and biotechnology , cancer , endocrinology , medicine , biochemistry , gene , genetics
Pancreatic ductal adenocarcinoma (PDAC) is associated with a pronounced collagen-rich fibrosis known as desmoplastic reaction; however, the role of fibrosis in PDAC is poorly understood. In this report we show that collagen can regulate the tumor suppressive let-7 family of microRNAs in pancreatic cancer cells. PDAC cells growing in 3D collagen gels repress mature let-7 without affecting the precursor form of let-7 in part through increased expression of membrane type 1-matrix metalloproteinase (MT1-MMP, MMP-14) and ERK1/2 activation. PDAC cells in collagen also demonstrate increased TGF-β1 signaling, and blocking TGF-β1 signaling attenuated collagen-induced MT1-MMP expression, ERK1/2 activation and repression of let-7 levels. Although MT1-MMP overexpression was not sufficient to inhibit let-7 on 2D tissue culture plastic, overexpression of MT1-MMP in PDAC cells embedded in 3D collagen gels or grown in vivo repressed let-7 levels. Importantly, MT1-MMP expression significantly correlated with decreased levels of let-7 in human PDAC tumor specimens. Overall, our study emphasizes the interplay between the key proteinase MT1-MMP and its substrate type I collagen in modulating microRNA expression, and identifies an additional mechanism by which fibrosis may contribute to PDAC progression.