目的探讨Smad3、Smad4蛋白在正常前列腺组织和前列腺癌中的表达,以及与临床分期、病理分级、预后的关系。方法采用免疫组织化学ABC法对正常前列腺组织和前列腺癌组织中Smad3和Smad4蛋白进行检测。结果Smad4在正常前列腺中阳性表达率为83.3%(10/12),在Gleasons评分≤5者,6~8者及≥9者肿瘤中的阳性表达率,分别为56.5%(13/23),44.4%(8/18)和25%(2/8),在T1-T2和T3-T4肿瘤中的表达为52.4%(11/21)和42.8%(12/28)。Smad4表达在病理分级间有显著性差异,在临床分期间无显著性差异,Smad3在前列腺组织和前列腺癌的表达间无显著性差异。T1-T2期与正常前列腺组织相比P<0.05;T3-T4期与正常前列腺组织相比P<0.05;高分化前列腺癌与正常前列腺组织相比P>0.05;中分化前列腺癌与正常前列腺组织相比P<0.05;低分化前列腺癌与正常前列腺组织相比P<0.01;低分化腺癌与高分化腺癌相比P<0.05。结论前列腺癌中Smad4蛋白表达减低,与肿瘤分级、分期有关,其异常表达与预后不良有关,Smad3与正常组织相比无显著性差异。 Objective To investigate the expression of Smad3 and Smad4 in normal prostatic tissue and prostate cancer, as well as their relationship with clinical stage, pathological grade and prognosis. Methods Immunohistochemical ABC method was used to detect Smad3 and Smad4 protein in normal prostate and prostate cancer tissues. Results The positive expression rate of Smad4 in normal prostate was 83.3% (10/12), and the positive rates of Smad4 in tumors with Gleason score ≤5, 6 ~ 8 and ≥9 were 56.5% (13/23) 44.4% (8/18) and 25% (2/8) expressed 52.4% (11/21) and 42.8% (12/28) in T1-T2 and T3-T4 tumors. Smad4 expression in the pathological grade were significantly different, no significant difference in the clinical stage, Smad3 in prostate tissue and prostate cancer expression was no significant difference. P <0.05 in T1-T2 stage compared with normal prostate tissue; P <0.05 in T3-T4 stage compared with normal prostate tissue; P> 0.05 in well-differentiated prostate cancer compared with normal prostate tissue; moderately differentiated prostate cancer and normal prostate tissue Compared with P <0.05; poorly differentiated prostate cancer compared with normal prostate tissue P <0.01; poorly differentiated adenocarcinoma compared with well-differentiated adenocarcinoma P <0.05. Conclusions The expression of Smad4 in prostate cancer is decreased, which is related to tumor grade and stage. The abnormal expression of Smad4 is related to the poor prognosis. There is no significant difference between Smad3 and normal tissues.