MiR-126 Acts as a Tumor Suppressor in Pancreatic Cancer Cells via the Regulation of ADAM9
MOLECULAR CANCER RESEARCH
Authors: Hamada, Shin; Satoh, Kennichi; Fujibuchi, Wataru; Hirota, Morihisa; Kanno, Atsushi; Unno, Jun; Masamune, Atsushi; Kikuta, Kazuhiro; Kume, Kiyoshi; Shimosegawa, Tooru
Abstract
The epithelial-mesenchymal transition (EMT) is a critical step for pancreatic cancer cells as an entry of metastatic disease. Wide variety of cytokines and signaling pathways are involved in this complex process while the entire picture is still cryptic. Recently, miRNA was found to regulate cellular function including EMT by targeting multiple mRNAs. We conducted comprehensive analysis of miRNA expression profiles in invasive ductal adenocarcinoma (IDA), intraductal papillary mucinous adenoma, intraductal papillary mucinous carcinoma, and human pancreatic cancer cell line to elucidate essential miRNAs which regulate invasive growth of pancreatic cancer cells. Along with higher expression of miR-21 which has been shown to be highly expressed in IDA, reduced expression of miR-126 in IDA and pancreatic cancer cell line was detected. The miR-126 was found to target ADAM9 (disintegrin and metalloproteinase domain-containing protein 9) which is highly expressed in pancreatic cancer. The direct interaction between miR-126 and ADAM9 mRNA was confirmed by 30 untranslated region assay. Reexpression of miR-126 and siRNA-based knockdown of ADAM9 in pancreatic cancer cells resulted in reduced cellular migration, invasion, and induction of epithelial marker E-cadherin. We showed for the first time that the miR-126/ADAM9 axis plays essential role in the inhibition of invasive growth of pancreatic cancer cells. Mol Cancer Res; 10(1); 3-10. (C) 2011 AACR.
MT1-MMP Inactivates ADAM9 to Regulate FGFR2 Signaling and Calvarial Osteogenesis
DEVELOPMENTAL CELL
Authors: Chan, Kui Ming; Wong, Hoi Leong Xavier; Jin, Guoxiang; Liu, Baohua; Cao, Renhai; Cao, Yihai; Lehti, Kaisa; Tryggvason, Karl; Zhou, Zhongjun
Abstract
MMP14 encodes a membrane-tethered metalloproteinase MT1-MMP, capable of remodeling the extracellular matrix and modulating receptors on the cell surface. Loss of MT1-MMP results in craniofacial abnormalities. Here we show that MT1-MMP forms a complex with FGFR2 and ADAM9 in osteoblasts and proteolytically inactivates ADAM9, hence protecting FGFR2 from ADAM9-mediated ectodomain shedding on the cell surface. In Mmp14(-/-) osteoblasts, FGF-induced proliferation and downstream signaling are specifically compromised, in conjunction with ADAM9 upregulation and FGFR2 shedding. The retarded parietal growth in Mmp14(-/-) embryos starts at 15.5 dpc, attributable to the impaired FGFR2 signaling due to increased shedding mediated by ADAM9. Adam9 depletion completely rescues the defective FGFR2 signaling and largely restores calvarial bone growth in Mmp14(-/-) embryos. These data reveal a regulatory paradigm for FGRF2 signaling and identify MT1-MMP as a critical negative modulator of ADAM9 activity to maintain FGFR2 signaling in calvarial osteogenesis.