Dual regulation of proliferation and growth arrest in prostatic stromal cells by transforming growth factor-beta1.
In a preliminary study, we observed that TGF-beta1 induced both proliferation and growth arrest in prostatic stromal cells, depending on the concentration of TGF-beta1 used in the culture medium. In this study, we explored possible mechanisms of this dual effect of TGF-beta. Primary cultures of prostatic stromal cells, established from clinical surgical specimens and treated with low doses of TGF-beta1 (0.001-0.01 ng/ml), resulted in an increase in cell proliferation. The addition of neutralizing antibody against platelet-derived growth factor (PDGF)-BB, but not anti-PDGF-AA, abrogated this stimulatory effect of TGF-beta1. TGF-beta1 treatment resulted in a dose-related increase in PDGF-BB production as measured by ELISA. Cells underwent growth arrest at high concentrations of TGF-beta1 (1.0 and 10 ng/ml). An inhibitor of cyclin-dependent kinase (cdk), p15INK4b, was up-regulated at both transcript and protein levels in these cultures by TGF-beta1 in a dose-related manner as determined by RT-PCR and Western blot analysis. The transcript, but not the protein, for another cdk inhibitor, p21Cip1, was up-regulated with treatment of TGF-beta1 to these cells. Levels of other cdk inhibitors, such as p16INK4a and p27Kip1, were constitutively expressed in prostatic stromal cells and were not significantly affected by TGF-beta1 treatment. Finally, the growth arrest effect of TGF-beta1 was abrogated when antisense oligonucleotides to p15INH4b, but not p21Cip1, were added to the culture medium. These data indicate that the dual effect of TGF-beta1 is mediated, at least, by up-regulation of PDGF-BB and p15INK4b, respectively.
Zhou
Wei
W
Department of Urology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA.
Park
Irwin
I
Pins
Michael
M
Kozlowski
James M
JM
Jovanovic
Borko
B
Zhang
Ju
J
Lee
Chung
C
Ilio
Kenneth
K
D000906:Antibodies / Q000494:pharmacology; D000077214:Becaplermin; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors; D016213:Cyclins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008297:Male; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis / Q000276:immunology; D011467:Prostate / Q000166:cytology* / Q000378:metabolism; D020574:Proto-Oncogene Proteins c-sis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017154:Stromal Cells / Q000166:cytology* / Q000378:metabolism; D013936:Thymidine / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D025521:Tumor Suppressor Proteins; D015854:Up-Regulation
D000906:Antibodies; C493956:CDKN1A protein, human; C493966:CDKN2B protein, human; D018797:Cell Cycle Proteins; D003470:Culture Media; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D016376:Oligonucleotides, Antisense; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D025521:Tumor Suppressor Proteins; D000077214:Becaplermin; D018844:Cyclin-Dependent Kinases; D013936:Thymidine