Increase of free insulin-like growth factor-1 in normal human breast in vivo late in the menstrual cycle
2003 (English)In: Breast Cancer Research and Treatment, ISSN 0167-6806, Vol. 80, no 2, 193-198 p.Article in journal (Refereed) Published
Prolonged exposure to endogenous and exogenous sex steroids increases the risk of breast cancer but the mechanisms are poorly understood. Increased levels of circulating insulin-like growth factor-1 (IGF-1) and low levels of IGF binding protein are associated with increased risk of breast cancer suggesting that IGF-1 has to be in its free form to be biologically active. Little is known about sex steroid regulation of IGF-1 locally in the breast. In this study microdialysis was used to determine the local levels of free IGF-1 in normal human breast tissue in healthy female volunteers during the menstrual cycle. The results showed that the extracellular levels of free IGF-1 locally in the breast were doubled in the luteal phase, when estradiol and progesterone levels were elevated, compared with the follicular phase. In plasma, free IGF-1 levels also exhibited a cyclic variation but to a less extent. The increased local levels of the tree form of IGF-1 may promote proliferation in the breast epithelium. This could be important in sex steroid dependent breast cancer development.
Place, publisher, year, edition, pages
2003. Vol. 80, no 2, 193-198 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-24980DOI: 10.1023/A:1024575103524Local ID: 9392OAI: oai:DiVA.org:liu-24980DiVA: diva2:245304