title: GI24 enhances tumor invasiveness by regulating cell surface membrane-type 1 matrix metalloproteinase.
abstract: GI24, an immunoglobulin superfamily member, has been cloned from a placenta cDNA library as a gene product that promoted activation of matrix metalloproteinase (MMP)-2 mediated by membrane type (MT) 1-MMP. Co-expression of GI24 with MT1-MMP in HEK293T cells increased the cell-surface level of MT1-MMP concomitant with the cleavage of the GI24 at the juxtamembrane site to shed the extracellular domain. HT1080 fibrosarcoma cells stably transfected with the GI24 gene expressed a higher level of MT1-MMP and showed more invasive ability in collagen gel than the control cells. GI24 was cleaved in HT1080 cells, which was blocked by the administration of MMP inhibitor BB94 or transfection of small interfering RNA (siRNA) targeting MT1-MMP. GI24 expression is relatively high in some squamous carcinoma and hepatocarcinoma cell lines. Transfection of siRNA for GI24 into oral squamous carcinoma-derived HSC-4 cells, which express GI24 and MT1-MMP genes reduced the expression of not only GI24 but also MT1-MMP, and attenuated invasive growth in the collagen matrix. These results suggest that GI24 contributes to tumor-invasive growth in the collagen matrix by augmenting cell surface MT1-MMP.
authors.affiliation: Department of Molecular Virology and Oncology, Cancer Research Institute, Kanazawa University, Kanazawa, Japan.
authors.forename: Moustafa A
authors.initials: MA
authors.lastname: Sakr
authors.forename: Takahisa
authors.initials: T
authors.lastname: Takino
authors.forename: Takahiro
authors.initials: T
authors.lastname: Domoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakano
authors.forename: Richard W
authors.initials: RW
authors.lastname: Wong
authors.forename: Motoko
authors.initials: M
authors.lastname: Sasaki
authors.forename: Yasuni
authors.initials: Y
authors.lastname: Nakanuma
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
mesh_terms: D060887:B7 Antigens; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism; D004789:Enzyme Activation; D005260:Female; D015723:Gene Library; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000494:pharmacology; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011480:Protease Inhibitors / Q000494:pharmacology; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013876:Thiophenes / Q000494:pharmacology; D014162:Transfection
chemical_list: D060887:B7 Antigens; D061965:Matrix Metalloproteinase Inhibitors; D008565:Membrane Proteins; D011480:Protease Inhibitors; D013876:Thiophenes; C000588758:VSIR protein, human; D010649:Phenylalanine; D003094:Collagen; C080985:batimastat; D020778:Matrix Metalloproteinase 2; D053511:Matrix Metalloproteinase 14