Research Of Hypoxia Inducible Factor-1α In Benign Prostatic Hyperplasia

Objective To determine the expression of hypoxia inducible factor-lalpha(HIF-1α) in benign prostatic hyperplasia (BPH) tissues, and to research the function of HIF-1α in the pathogenesy and progress of BPH.Methods (1) The expression of HIF-1α was assayed by means of immunohisto--chemical technique in the tissues of 12 fetal prostates(FP),10 normal prostates(NP), 95 inner hyperplasia zones of BPH, 12 outer zones of BPH, 7cancers and 2 sarcomas of prostate. According to the different staining levels, expressions were scored strongly, moderately, weakly positive and negative.(2) All the weights(Wt) of inner hyperplasia zones of BPH were recorded and divided into 3 Wt groups: A(25g~50g), B(50g~75g) and C( > 75g). Statistical method was performed to analyze the dependablity between Wt and the levels of HIF-1α.(3) The BPH cases with acute urine retention (AUR) were recorded, and the dependablity between AUR's occurrence and the levels of HIF-1α was analyzed by Statistical method.Results (1) In all the prostatic tissues above, positive expression of HIF-1α wasobserved as follows: 69.5% in inner hyperplasia tissues of BPH, out of which moderately and weakly positive were 33.7%(32/95) and 35.8%(34/95) respectively; 85.7%(6/7) in carcer of prostate , with 5 strongly positive and 1 moderately positive, 2 cases of prostatic sarcoma were both strongly positive; all FP were stained positive, 3 strongly positive, 7 moderately positive and 2 weakly positive; NP and outer zones of BPH tissues were all stained negative. HIF-1α levels in the tissues of FP and prostate malignant tumors were higher than those in hyperplasia tissues of BPH significantly (P < 0.05), and the expression of HIF-1α in inner hyperplasia tissues of BPH was much higher than those in the tissues of NP and outer zones of BPH (P < 0.05). In addition, HIF-1α was also detected in mesenchymal cells of 7 cases of inner hyperplasia tissues of BPH and 8 cases of FP tissues.(2) In Wt groups A,B and C, the rates of weakly positive expression were 38.9%, 34.2% and 35.9% respectively, with moderately positive expression were 11.1%, 23.7% and 53.8% respectively. The levels of HIF-1α significantly increased with the increase of Wt(P < 0.05).(3) 42 cases of BPH once suffered AUR, incidence of AUR in HIF-1α-moderately positive, weakly positive and negative groups were 84.4%(27/32), 32.4%(11/34) and 13.8% (4/28) respectively. Compared with HIF-1α- negative cases, HIF-1α-positive cases had significantly increase in the incidence of AUR(P < 0.05), and the incidence of AUR significantly increased with the increase of HIF-1α's levels detected in inner hyperplasia tissues of BPH (P < 0.05).Conclusion As a key factor in facilitating the growth of prostatic tissues, HIF-1αexpresses in actively growing prostatic tissues, such as FP, inner hyperplasia tissues of BPH and prostate malignant tissues, meanwhile, HIF-1α fails to be detected in the tissues of NP and outer zones of BPH. The levels of HIF-1α show a positive correlation with weights of inner hyperplasia tissues of BPH and the incidence of AUR, moreover, HIF-1α-moderately positive cases seem to suffer a high risk of severe BPH and AUR. Accordingly, HIF-1α might play an important role in the pathogenesy of BPH and might be used to predict the clinical progress of BPH.