title: Timp-2 binding with cellular MT1-MMP stimulates invasion-promoting MEK/ERK signaling in cancer cells.
abstract: Both invasion-promoting MT1-MMP and its physiological inhibitor TIMP-2 play a significant role in tumorigenesis and are identified in the most aggressive cancers. Despite its antiproteolytic effects in vitro, clinical data suggest that TIMP-2 expression is positively associated with tumor recurrence, thus emphasizing the wide-ranging role of TIMP-2 in malignancies. To shed light on this role of TIMP-2, we report that low concentrations of TIMP-2, by interacting with MT1-MMP (a specific membrane receptor of TIMP-2), induce the MEK/ERK signaling cascade in fibrosarcoma HT1080 cells which express MT1-MMP naturally. TIMP-2 binding with cell surface-associated MT1-MMP stimulates phosphorylation of MEK1/2, which is upstream of ERK1/2, and the ERK1/2 substrate p90RSK. Consistent with volumes of literature, we confirmed that the activation of ERK stimulated cell migration. Both the transcriptional silencing of MT1-MMP and the inhibition of MEK1/2 reversed the signaling effects of TIMP-2/MT1-MMP while the active site-targeting MMP inhibitor GM6001 did not. Our data suggest that both the interactions of TIMP-2 with MT1-MMP, which activate the pro-migratory ERK signaling cascade,and the conventional inhibition of MT1-MMP's catalytic activity by TIMP-2, play a role in the invasion-promoting function of MT1-MMP. The TIMP-2-induced stimulation of ERK signaling in cancer cells explains the direct, as opposed to the inverse, association of TIMP-2 expression with poor prognosis in cancer.
authors: Cancer Research Center, Burnham Institute for Medical Research, La Jolla, CA 92037, USA.
authors: Nor Eddine
authors: NE
authors: Sounni
authors: Dmitri V
authors: DV
authors: Rozanov
authors: Albert G
authors: AG
authors: Remacle
authors: Vladislav S
authors: VS
authors: Golubkov
authors: Agnes
authors: A
authors: Noel
authors: Alex Y
authors: AY
authors: Strongin
mesh_terms: D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D004789:Enzyme Activation / Q000502:physiology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D010766:Phosphorylation; D034741:RNA, Small Interfering; D015398:Signal Transduction / Q000502:physiology*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism*
chemical_list: D034741:RNA, Small Interfering; D019716:Tissue Inhibitor of Metalloproteinase-2; D048049:Extracellular Signal-Regulated MAP Kinases; D020930:MAP Kinase Kinase Kinases; D053511:Matrix Metalloproteinase 14