Abstract | BACKGROUND: RESULTS: In this study we show that the monoclonal antibody that recognizes an epitope on the cytokeratin 8 (CK8) ectoplasmic domain (anti-CK MAb) inhibits plasminogen activation mediated by urokinase-type plasminogen activator (uPA) in MCF-7 and MCF-10A neoT cells. The ectoplasmic domain of CK8 acts as a binding site for plasminogen, however, by using confocal microscopy, we demonstrated that it is also co-localized with uPA. CK8, therefore, function also as a receptor for uPA on the cell surface, and the presence of anti-CK MAb may prevent the binding of uPA to a designated CK8 motif. The consequent inhibition of plasmin generation resulted in changed cell morphology, enhanced cell adhesion to fibronectin, reduced invasion potential, and an enhanced G1/S transition. Moreover, surface plasmon resonance analysis showed that the synthetic dodecapeptide corresponding to the epitope sequence (VKIALEVEIATY), binds uPA in the nanomolar range. CONCLUSION: These novel findings suggest a model in which CK8, together with uPA, plasminogen and fibronectin, constitutes a signaling platform capable of modulating cell adhesion/growth-dependent signal transduction in breast tumor cells. Anti-CK MAb, which competes for the binding site for uPA, could be used as an agent to reduce the invasive potential of breast tumor cells.
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Authors | Natasa Obermajer, Bojan Doljak, Janko Kos |
Journal | Molecular cancer
(Mol Cancer)
Vol. 8
Pg. 88
(Oct 21 2009)
ISSN: 1476-4598 [Electronic] England |
PMID | 19845941
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Antibodies, Monoclonal
- Fibronectins
- Keratin-8
- Peptides
- Plasminogen
- Urokinase-Type Plasminogen Activator
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Topics |
- Amino Acid Sequence
- Antibodies, Monoclonal
- Breast Neoplasms
(metabolism, pathology)
- Cell Adhesion
(drug effects)
- Cell Line, Tumor
- Cell Proliferation
(drug effects)
- Cell Shape
(drug effects)
- Female
- Fibronectins
(pharmacology)
- G1 Phase
(drug effects)
- Humans
- Keratin-8
(chemistry, metabolism)
- Molecular Sequence Data
- Neoplasm Invasiveness
- Peptides
(chemistry)
- Plasminogen
(metabolism)
- Protein Binding
(drug effects)
- Protein Structure, Tertiary
- Protein Transport
(drug effects)
- S Phase
(drug effects)
- Structure-Activity Relationship
- Urokinase-Type Plasminogen Activator
(metabolism)
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