Insulin-like growth factor (IGF)-system mRNA quantities in normal and tumor breast tissue of women with sporadic and familial breast cancer risk.
Breast Cancer Res Treat
; 84(3): 225-33, 2004 Apr.
Article
em En
| MEDLINE
| ID: mdl-15026620
ABSTRACT
The insulin-like growth factor (IGF)-system plays a role in breast cancer susceptibility as well as in growth and progression of breast carcinomas. So far, findings have been based on serum IGF-I levels and semi-quantitative assessment of IGF-system expression levels in model systems and human tissue. Quantitative data on mRNA expression in different types of human breast tissue are lacking. Breast tissue samples ( n = 83) were available from 72 women. Messenger RNA expression of IGF-I, IGF-II, and their receptors (IGF-1R and IGF-2R) was assessed by real-time RT-PCR. We found a large variation in mRNA levels. Expression of each gene was significantly higher in normal tissue than in tumor tissue (median for normal and tumor tissue, respectively (arbitrary units); IGF-I 25.2 and 1.4; IGF-II 5.9 and 0.6; IGF-1R 0.18 and 0.07; IGF-2R 1.8 and 0.9; p < 0.0001, Mann-Whitney test). Interestingly, in tumor tissue from patients with a strong family history of breast cancer, expression of both receptors was higher than in sporadic patients (IGF-1R 0.13 and 0.05, p = 0.04; IGF-2R 1.1 and 0.8, p = 0.04). For cancer-free controls, expression of IGF-II and IGF-2R in normal breast tissue was also higher in women with a family history of breast cancer than in women without such a family history (IGF-II 7.2 and 1.5, p = 0.02; IGF-2R 2.6 and 1.5, p = 0.09). Our study quantitatively shows that mRNA expression levels of IGF-system components in the breast are generally higher in normal tissue compared with tumor tissue, and higher in tissue from women with a family history of breast cancer. A basis has therefore been created for studies aimed at understanding IGF as a breast cancer risk factor, the relationship between IGF-systems in serum and tissues, and effects of lifestyle factors on the IGF-system.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Mama
/
RNA Mensageiro
/
Fator de Crescimento Insulin-Like I
/
Fator de Crescimento Insulin-Like II
/
Predisposição Genética para Doença
/
Perfilação da Expressão Gênica
Tipo de estudo:
Etiology_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
/
Female
/
Humans
/
Middle aged
Idioma:
En
Ano de publicação:
2004
Tipo de documento:
Article