scholarly journals Overexpression of Insulin-Like Growth Factor Binding Protein-5 Helps Accelerate Progression to Androgen-Independence in the Human Prostate LNCaP Tumor Model through Activation of Phosphatidylinositol 3′-Kinase Pathway*

Endocrinology ◽  
2000 ◽  
Vol 141 (6) ◽  
pp. 2257-2265 ◽  
Author(s):  
Hideaki Miyake ◽  
Colleen Nelson ◽  
Paul S. Rennie ◽  
Martin E. Gleave
Keyword(s):  
Growth Factor ◽  
Binding Protein ◽  
Tumor Model ◽  
Human Prostate ◽  
Insulin Like Growth Factor ◽  
Phosphatidylinositol 3 Kinase ◽  
Androgen Independence ◽  
Factor Binding ◽  
Kinase Pathway ◽  
Phosphatidylinositol 3

Insulin-like growth factor-binding protein-3 expression and secretion by cultures of human prostate epithelial cells and stromal fibroblasts

1994 ◽  
Vol 141 (3) ◽  
pp. 535-540 ◽  
Author(s):  
R S Birnbaum ◽  
J L Ware ◽  
S R Plymate
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Conditioned Medium ◽  
Binding Protein ◽  
Human Prostate ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Cell Extracts ◽  
Prostate Epithelial Cells ◽  
Igfbp 3

Abstract Prostate-specific antigen (PSA) was recently shown to be an insulin-like growth factor-binding protein (IGFBP)-3 protease. However, only IGFBPs-2 and -4 have been identified in conditioned medium of prostate epithelial cells. Using cultures of human prostate epithelial and stromal fibroblastic cells, we examined conditioned medium and cell extracts for evidence of IGFBP-3 expression and secretion. Western ligand blotting of conditioned medium from epithelial or stromal cultures revealed the presence of IGFBPs in the molecular weight range 36–48 kDa, suggestive of IGFBP-3. Western immunoblots of these media confirmed the presence of IGFBP-3. Northern analyses of extracts of both stromal and epithelial cells showed a 2·5 kb band, the size of IGFBP-3 mRNA. We conclude that prostate cells express IGFBP-3 and that local proteolysis by PSA could modify this binding protein's actions in the prostate. Journal of Endocrinology (1994) 141, 535–540

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