Abstract
Several lines of evidence suggest that aberrant Notch signaling contributes to the development of several types of cancer. Activation of Notch receptor is executed through intramembrane proteolysis by γ-secretase, which is a multimeric membrane-embedded protease comprised of presenilin, nicastrin (NCT), anterior pharynx defective 1 and PEN-2. In this study, we report the neutralization of the γ-secretase activity by a novel monoclonal antibody A5226A against the extracellular domain of NCT, generated by using a recombinant budded baculovirus as an immunogen. This antibody recognized fully glycosylated mature NCT in the active γ-secretase complex on the cell surface, and inhibited the γ-secretase activity by competing with the substrate binding in vitro. Moreover, A5226A abolished the γ-secretase activity-dependent growth of cancer cells in a xenograft model. Our data provide compelling evidence that NCT is a molecular target for the mechanism-based inhibition of γ-secretase, and that targeting NCT might be a novel therapeutic strategy against cancer caused by aberrant γ-secretase activity and Notch signaling.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amyloid Precursor Protein Secretases / genetics
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Amyloid Precursor Protein Secretases / immunology*
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Amyloid Precursor Protein Secretases / metabolism
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Animals
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Antibodies, Monoclonal / immunology*
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Antibodies, Monoclonal / metabolism
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Antibodies, Monoclonal / pharmacology
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Antibodies, Neutralizing / immunology*
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Antibodies, Neutralizing / metabolism
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Antibodies, Neutralizing / pharmacology
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Antibody Specificity / immunology
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Biocatalysis / drug effects
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Cell Line, Tumor
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Cell Proliferation / drug effects
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Dose-Response Relationship, Drug
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HEK293 Cells
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HeLa Cells
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Humans
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Immunoblotting
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Male
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Membrane Glycoproteins / genetics
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Membrane Glycoproteins / immunology*
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Membrane Glycoproteins / metabolism
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Mice
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Mice, Inbred BALB C
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Mice, Knockout
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Mice, SCID
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Neoplasms / metabolism
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Neoplasms / pathology
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Neoplasms / prevention & control
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Neutralization Tests
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Protein Binding / drug effects
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Tumor Burden / drug effects
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Xenograft Model Antitumor Assays
Substances
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Antibodies, Monoclonal
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Antibodies, Neutralizing
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Membrane Glycoproteins
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nicastrin protein
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Amyloid Precursor Protein Secretases