Expression of the insulin-like growth factor I receptor and urokinase plasminogen activator in breast cancer is associated with poor survival: potential for intervention with 17-allylamino geldanamycin.
Cancer Res
; 64(1): 286-91, 2004 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-14729636
ABSTRACT
Urokinase plasminogen activator (uPA) expression in breast cancer is associated with relapse and a reduction in disease-specific survival. Thus, efforts are under way to identify uPA inhibitors. By screening a chemical library of >1000 compounds, 17-allyaminogeldanamycin (17AAG) was identified as a potent inhibitor of uPA by the National Cancer Institute and is now in Phase I clinical trials. At this time, it remains unclear how 17AAG blocks uPA; one possibility is through disruption of the insulin-like growth factor I receptor (IGF-IR) pathway. This would be consistent with studies from our laboratory showing that activation of IGF-IR results in the induction of uPA protein. In the study described herein, we observed that IGF-IR and uPA were highly expressed in 87 and 55% of breast cancer by screening tumor tissue microarrays representing 930 cases. A significant proportion (52.1% = 354 of 680 cases, P < 0.0001) of the patients had tumors expressing both proteins. uPA alone (P = 0.033) or in combination with IGF-IR (P = 0.0104) was indicative of decreased disease-specific survival. Next, we demonstrated that treating MDA-MB-231 cells with increasing concentrations of 17AAG resulted in IGF-IR degradation (IC(50) = 1.0 micro M) and blocked signal transduction through the Akt and mitogen-activated protein kinase pathways. Finally, we found that 17AAG had a robust inhibitory effect on the production of uPA mRNAand protein in the presence of IGF-I. Thus, our study raises the possibility that 17AAG could prove to be an effective therapeutic agent for a large number of breast cancer patients by inhibiting the IGF-IR and ultimately uPA.
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Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
/
Ativador de Plasminogênio Tipo Uroquinase
/
Regulação Neoplásica da Expressão Gênica
/
Receptor IGF Tipo 1
/
Rifabutina
Tipo de estudo:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article