Abstract |
Increased tyrosine phosphorylation has been correlated with human cancer, including breast cancer. In general, the activation of tyrosine kinases (TKs) can be antagonized by the action of protein-tyrosine phosphatases ( PTPs). However, in some cases PTPs can potentiate the activation of TKs. In this study, we have investigated the functional role of PTPε in human breast cancer cell lines. We found the up-regulation and activation of receptor PTPε (RPTPε) in MCF-7 cells and MDA-MB-231 upon PMA, FGF, and serum stimulation, which depended on EGFR and ERK1/2 activity. Diminishing the expression of PTPε in human breast cancer cells abolished ERK1/2 and AKT activation, and decreased the viability and anchorage-independent growth of the cells. Conversely, stable MCF-7 cell lines expressing inducible high levels of ectopic PTPε displayed higher activation of ERK1/2 and anchorage-independent growth. Our results demonstrate that expression of PTPε is up-regulated and activated in breast cancer cell lines, through EGFR, by sustained activation of the ERK1/2 pathway, generating a positive feedback regulatory loop required for survival of human breast cancer cells.
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Authors | Caroline E Nunes-Xavier, Ari Elson, Rafael Pulido |
Journal | The Journal of biological chemistry
(J Biol Chem)
Vol. 287
Issue 5
Pg. 3433-44
(Jan 27 2012)
ISSN: 1083-351X [Electronic] United States |
PMID | 22117074
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Carcinogens
- Fibroblast Growth Factors
- EGFR protein, human
- ErbB Receptors
- Proto-Oncogene Proteins c-akt
- MAPK1 protein, human
- Mitogen-Activated Protein Kinase 1
- Mitogen-Activated Protein Kinase 3
- PTPRE protein, human
- Receptor-Like Protein Tyrosine Phosphatases, Class 4
- Tetradecanoylphorbol Acetate
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Topics |
- Breast Neoplasms
(enzymology, genetics, pathology)
- Carcinogens
(pharmacology)
- Cell Line, Tumor
- Cell Survival
(drug effects, genetics)
- Enzyme Activation
(drug effects, genetics)
- ErbB Receptors
(agonists, genetics, metabolism)
- Female
- Fibroblast Growth Factors
(pharmacology)
- Humans
- MAP Kinase Signaling System
- Mitogen-Activated Protein Kinase 1
(genetics, metabolism)
- Mitogen-Activated Protein Kinase 3
(genetics, metabolism)
- Proto-Oncogene Proteins c-akt
(genetics, metabolism)
- Receptor-Like Protein Tyrosine Phosphatases, Class 4
(genetics, metabolism)
- Tetradecanoylphorbol Acetate
(pharmacology)
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