Study On The Expression Of Insulin-Like Growth Factors And Receptor In Transitional Zone Of Prostate

Objective: Benign prostatic hyperplasia(BPH) is a common disease in aged male. Up to nowadays, the pathogenesis of the disease is not very clear. We only know that is an androgen-dependent disease. Stromal-epithelial interaction has a pivotal role in the regulation of the development and growth of the prostate, and locally produced peptide growth factors are considered important mediators of this interaction. Insulin-like growth factor I (IGF-I) and II(IGF-II), which are mitoses,acting through type 1 IGF receptor (IGF-IR), have mitogenic and anti-apoptotic effects on many kind of cells, also on epithelial and stromal prostatic cells. Prostate is divided into three parts: peripheral zone, central zone and transitional zone. Transitional zone is the only place where BPH take place. Through the study on the expression of insulin-like growth factor I, II and receptor I in transitional zone of BPH and normal prostate, we may know the role they play in BPH.Methods: Specimens were removed from human prostate and divided into two groups: (1) hyperplastic group: the specimens were removed by suprapubic prostatectomyfrom 30 BPH patients (aged from 58-74 years old, mean 67.2 years old). Macroscopically, the specimens were BPH tissues. (2) Control group: the normal specimens were removed from corpses(aged from 22-35 years old, mean 28.3years old). Macroscopically, the specimens were normal tissues. The tissues of transitional zone were cut from the specimens by McNeal's methods, put into 70% alcohol, and then stored in the refrigerator of 4°C. The specimens were quantitatively analyzed with flow cytometry (FCM). The data were expressed with labeled rate(percentage,%) and expression level(presented by fluorescence channel numbers collects as linear data).Results: The labeled rate and expression level of IGF-I in BPH group(38.63%,6.85)were significantly higher than those in Control group(27.83%,4.79)(P<0.01). The labeled rate and expression level of IGF-II in BPH group(42.56%,8.01)were significantly higher than those in Control group(25.20%,4.97)(P<0.01). The labeled rate and expression level of IGF-IR in BPH group(39.58%,5.75)were significantly higher than those in Control group(17.75%,4.61)(P<0.05).Conclusion: Transitional zone of prostate is the only place where BPH take place. This study shows that the expression of IGF-I,IGF-II,IGF-IR are higher in BPH than in normal prostate. The IGF families may play an important role in BPH....