Figure 4

Immunoprecipitation and western blot analysis of IGF-IR pathway protein expression in leiomyoma and myometrial tissues.

(A) Immunoprecipitation and immunoblots for phospho-Shc or IRS-I, and Grb2 were done to look for an association of phospho-Shc or IRS-I to the IGF-IRβ, and an association of Grb2 to phospho-Shc. (B) Concentrations of phosphorylated Shc associated with IGF-IRβ were significantly higher (P < 0.02) in leiomyoma (L) tissue samples compared with myometrial (M) tissue samples. Levels of Grb2 associated with Shc were also significantly higher (P < 0.001) in leiomyomas compared with myometrial samples. However, there was no difference in levels of phosphorylated IRS-I associated with IGF-IRβ in myometrial and leiomyoma samples. The procedure was performed at least three times in three independent leiomyoma and matched myometrial tissue preparations from eight patients with comparable results. The band intensity of the blots was expressed as means ± SE in eight patient samples.