title: Endogenous control of cell cycle progression by autocrine transforming growth factor beta in breast cancer cells.
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.
authors.affiliation: Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, New York 14263, USA.
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Ammanamanchi
authors.forename: Manoranjani P M
authors.initials: MP
authors.lastname: Tillekeratne
authors.forename: Tien C
authors.initials: TC
authors.lastname: Ko
authors.forename: Michael G
authors.initials: MG
authors.lastname: Brattain
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D042846:CDC2-CDC28 Kinases / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D045744:Cell Line, Tumor; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D018450:Disease Progression; D005434:Flow Cytometry; D006801:Humans; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering / Q000235:genetics; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D013752:Tetracycline / Q000494:pharmacology; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000502:physiology*; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology
chemical_list: C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495900:CDK4 protein, human; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D013752:Tetracycline