Abstract
Tumor progression due to loss of autocrine negative transforming growth factor-beta (TGF-beta) activity was reported in various cancers of epithelial origin. Estrogen receptor expressing (ER(+)) breast cancer cells are refractory to TGF-beta effects and exhibit malignant behavior due to loss or inadequate expression of TGF-beta receptor type II (RII). The exogenous TGF-beta effects on the modulation of cell cycle machinery were analyzed previously. However, very little is known regarding the endogenous control of cell cycle progression by autocrine TGF-beta. In this study, we have used a tetracycline regulatable RII cDNA expression vector to demonstrate that RII replacement reconstitutes autocrine negative TGF-beta activity in ER(+) breast cancer cells as evidenced by the delayed entry into S phase by the RII transfectants. Reversal of the delayed entry into S phase by the RII transfectants in the presence of tetracycline in addition to the decreased steady state transcription from a promoter containing the TGF-beta responsive element (p3TP-Lux) by TGF-beta neutralizing antibody treatment of the RII transfected cells confirmed that autocrine-negative TGF-beta activity was induced in the transfectants. Histone H1 kinase assays indicated that the delayed entry of RII transfectants into phase was associated with markedly reduced cyclin-dependent kinase (CDK)2 kinase activity. This reduction in kinase activity was due to the induction of CDK inhibitors p21/waf1/cip1 and p27/kip, and their association with CDK2. Tetracycline treatment of RII transfectants led to the suppression of p21/waf1/cip1and p27/kip expression, thus, directly demonstrating induction of CDK inhibitors by autocrine TGF-beta leading to growth control of ER(+) breast cancer cells.
Publication types
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Research Support, U.S. Gov't, P.H.S.
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Retracted Publication
MeSH terms
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Breast Neoplasms / genetics
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Breast Neoplasms / metabolism
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Breast Neoplasms / pathology*
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CDC2-CDC28 Kinases / metabolism
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Cell Adhesion / physiology
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Cell Cycle / physiology
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Cell Cycle Proteins / antagonists & inhibitors
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Cell Cycle Proteins / biosynthesis
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Cell Cycle Proteins / genetics
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Cell Cycle Proteins / physiology
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Cell Division / physiology
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Cell Line, Tumor
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Cyclin-Dependent Kinase 2
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Cyclin-Dependent Kinase 4
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Cyclin-Dependent Kinase Inhibitor p21
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Cyclin-Dependent Kinase Inhibitor p27
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Cyclin-Dependent Kinases / metabolism
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Cyclins / antagonists & inhibitors
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Cyclins / biosynthesis
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Cyclins / genetics
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Cyclins / physiology
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Disease Progression
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Flow Cytometry
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Humans
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Protein Serine-Threonine Kinases
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Proto-Oncogene Proteins*
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RNA, Small Interfering / genetics
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Receptor, Transforming Growth Factor-beta Type II
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Receptors, Transforming Growth Factor beta / biosynthesis
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Receptors, Transforming Growth Factor beta / genetics
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Receptors, Transforming Growth Factor beta / physiology
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Tetracycline / pharmacology
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Transfection
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Transforming Growth Factor beta / physiology*
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Tumor Suppressor Proteins / antagonists & inhibitors
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Tumor Suppressor Proteins / biosynthesis
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Tumor Suppressor Proteins / genetics
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Tumor Suppressor Proteins / physiology
Substances
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CDKN1A protein, human
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Cell Cycle Proteins
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Cyclin-Dependent Kinase Inhibitor p21
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Cyclins
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Proto-Oncogene Proteins
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RNA, Small Interfering
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Receptors, Transforming Growth Factor beta
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Transforming Growth Factor beta
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Tumor Suppressor Proteins
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Cyclin-Dependent Kinase Inhibitor p27
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Protein Serine-Threonine Kinases
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CDC2-CDC28 Kinases
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CDK2 protein, human
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CDK4 protein, human
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Cyclin-Dependent Kinase 2
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Cyclin-Dependent Kinase 4
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Cyclin-Dependent Kinases
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Receptor, Transforming Growth Factor-beta Type II
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Tetracycline