Analysis of the polymorphism in the androgen receptor gene of BPH patients

雄激素受体(AR)基因含有一个多态的CAG微卫星。以往的研究表明，CAG重复序列的长度与AR的转录活性呈负相关，CAG重复序列长度较短可能与前列腺癌的风险增加有关。为探讨AR基因CAG重复长度与增生性腺瘤生长的关系，对252例前列腺摘除术后病理诊断为BPH的患者进行了检测。此外，我们检查了41名对照组(65岁)，他们的前列腺小于20ml，且血清PSA水平正常。前列腺癌患者CAG重复长度与腺瘤重量呈负相关。较大(*g：平均值+0.8SD)、较小(24g：平均值-0.8SD)腺瘤亚组和对照组的平均重复长度分别为21.7*2.9和2.8*2.2和23.12.4。较大的腺瘤亚组的CAG重复长度往往比较小的腺瘤亚组或对照组短(P&lt；0.05和P&lt；0.02)，对于CAG重复数为23的患者，发生较大的腺瘤的相对风险有统计学意义(相对危险度；2.83.95%可信区间；1.21-6.61)。CAG重复数为17的所有病例的腺瘤均较大。综上所述，我们的结果提示雄激素受体基因的短CAG重复序列可能作为遗传因素之一对前列腺增生症的生长具有促进作用。

The androgen receptor (AR) gene contains a polymorphic CAG microsatellite. Previous studies showed that the length of the CAG repeat correlates inversely with transcriptional activity of the AR and the short CAG repeat length might be associated with the increased risk of the prostate cancer. The purpose of the present study was to evaluate an association between the growth of hyperplastic adenoma and the CAG repeat lengths in AR gene.We examined 252 patients who underwent prostatectomy and had the pathological diagnosis of BPH by the step section. Furthermore, we examined 41 controls (>65 year old) with the prostate smaller than 20ml and with normal serum PSA level. CAG repeat length was inversely related to the weight of adenomas in the prostatectomized patients. The mean repeats length for the larger (*64 g : mean+0.8SD), smaller (24 g : mean-0.8SD) adenoma subgroup and the control group were 21.7*2.9 and 2.8*2.2 and 23.12.4, respectively. The larger adenoma subgroup tended to have shorter CAG repeat length than either smaller adenoma subgroup or control group (p<0.05 and p<0.02, respectively), For the patient with <23 CAG repeats, the relative risk developing the larger adenoma was statistically significant (Relative risk ; 2.83.95% confidence interval ; 1.21-6.61). All cases with *17 CAG repeats had the larger adenomas. In summary, our results suggested that short CAG repeats of the androgen receptor gene might have the promoting influence on the growth of the prostatic hyperplasia as one of the genetic factors.