Role of insulin-like growth factor binding proteins in 1alpha,25-dihydroxyvitamin D(3)-induced growth inhibition of human prostate cancer cells.
Prostate
; 64(1): 9-19, 2005 Jun 15.
Article
en En
| MEDLINE
| ID: mdl-15651061
ABSTRACT
BACKGROUND:
The mechanisms underlying 1alpha,25-dihydroxyvitamin D(3) (1,25D)-induced growth inhibition of human prostate cancer cells have not been fully elucidated. To determine whether alterations in the insulin-like growth factor (IGF) signaling axis are associated with 1,25D-induced growth inhibition, we examined the ability of 1,25D to regulate expression of IGF binding proteins (IGFBPs) in human prostate cancer cell lines.METHODS:
Northern and Western blot analyses were used to detect 1,25D-induced alterations in IGFBP expression. Additional in vitro studies were performed to determine the role of IGFBP-3 in 1,25D-induced growth inhibition.RESULTS:
1,25D decreased mRNA levels of the growth stimulatory IGFBP-2 and induced IGFBP-3 mRNA in LNCaP and C4-2 cells. 1,25D treatment also increased secreted IGFBP-3 protein levels in prostate cancer cell lines sensitive to 1,25D growth inhibition but had little effect on IGFBP-3 expression in 1,25D-resistant DU145 cells. However, recombinant IGFBP-3 had only a minor effect on LNCaP cell growth in the presence of serum. Furthermore, siRNA duplexes that reduced IGFBP-3 expression did not alter 1,25D growth inhibition in either LNCaP or PC-3 cell lines grown in serum-containing media.CONCLUSIONS:
Our studies indicate 1,25D-induced up-regulation of IGFBP-3 is not required for the growth inhibitory effects of 1,25D in prostate cancer cells grown in serum-containing media.
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Banco de datos:
MEDLINE
Asunto principal:
Neoplasias de la Próstata
/
Calcitriol
/
Agonistas de los Canales de Calcio
/
Proteína 2 de Unión a Factor de Crecimiento Similar a la Insulina
/
Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina
Límite:
Humans
/
Male
Idioma:
En
Año:
2005
Tipo del documento:
Article