JLE

European Cytokine Network

MENU

An accumulation of insulin-like growth factor I (IGF-I) in human myometrium and uterine leiomyomas in various stages of tumour growth Volume 15, numéro 4, December 2004

Auteurs
Department of Medical Biochemistry, Medical Academy of Białystok, Białystok, Poland

It is commonly thought that uterine leiomyomas result from hyperstimulation of myometrium by ovarian hormones. Some observations suggest that cytokines and growth factors are intermediate elements through which the ovarian hormones may exert their growth-stimulatory effects on leiomyomas. Human myometrium and uterine leiomyomas of various weights were homogenised and extracted with 1M acetic acid or with 0.05M Tris/HCl, pH 7.6. The extracts were assayed for IGF-I using the ELISA technique. It was found that 0.05 M Tris/HCl extracts contained several times more IGF-I than the 1M acetic acid extracts. Nanogram amounts of IGF-I were found in both control myometrium and in leiomyomas. It was found that the amounts of IGF-I extracted from leiomyomas were distinctly higher in comparison to control myometrium and they increased as a function of tumour growth. Polyacrylamide gel electrophoresis, followed by Western immunoblotting, demonstrated that IGF-I in acidic and alkaline extracts exists as stable complexes, probably with extracellular matrix components. No free IGF-I was detected. Furthermore, it was found that some components of both the acidic and alkaline extracts were able to bind exogenous 125I-labeled IGF-I. It is suggested that IGF-I plays an important role both in myometrium biology and in the growth of uterine leiomyomas.