학술논문
Expression of protein tyrosine phosphatase alpha (RPTPα) in human breast cancer correlates with low tumor grade, and inhibits tumor cell growth in vitro and in vivo.
Document Type
Article
Author
Source
Subject
*PROTEIN-tyrosine phosphatase
*BREAST cancer
*TUMOR markers
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Language
ISSN
0950-9232
Abstract
Tyrosine phosphorylation is controlled by a balance of tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Whereas the contribution of PTKs to breast tumorigenesis is the subject of intense scrutiny, the potential role of PTPs is poorly known. RPTPα is implicated in the activation of Src family kinases, and regulation of integrin signaling, cell adhesion, and growth factor responsiveness. To explore its potential contribution to human neoplasia, we surveyed RPTPα protein levels in primary human breast cancer. We found RPTPα levels to vary widely among tumors, with 29% of cases manifesting significant overexpression. High RPTPα protein levels correlated significantly with low tumor grade and positive estrogen receptor status. Expression of RPTPα in breast carcinoma cells led to growth inhibition, associated with increased accumulation in G0 and G1, and delayed tumor growth and metastasis. To our knowledge, this is the first example of a study correlating expression level of a specific bona fide PTP with neoplastic disease status in humans. Oncogene (2000) 19, 4979–4987 [ABSTRACT FROM AUTHOR]