类固醇合成酶在亚临床库欣综合征患者中的表达及意义

目的 通过检测类固醇合成酶CYP11B1和CYP17在亚临床库欣综合征腺瘤(SCS)、正常肾上腺皮质(NA)、肾上腺无功能瘤(NFA)及皮质醇分泌瘤(CPA)中的表达，探讨SCS的分泌状态是否与类固醇合成酶的表达相关。方法 提取20例CPA、6例SCS、15例NFA、8例NA的组织RNA，采用实时荧光定量PCR、Western印迹及免疫组织化学方法检测CYP17、CYP11B1mRNA及蛋白在不同肾上腺组织中的表达，比较不同组织中二者表达的差异，并与患者的临床资料行相关性分析。结果 CYP17、CYP11B1mRNA及蛋白在不同组织中均有表达。二者在CPA中高表达，在SCS中表达稍高于NA和NFA (P<0.05)。二者在CPA中的表达与血清皮质醇水平呈正相关，与ACTH水平呈负相关(P<0.05)。结论 亚临床库欣综合征腺瘤中高表达的CYP11B1和CYP17可能与患者皮质醇分泌异常相关。

Expression of steroidogenic enzyme in subclinical Cushing’s syndrome due to adrenal adenomas

Objective To determine whether steroidogenic enzyme expression is associated with the steroid secretory pattern of subclinical Cushing’s syndrome (SCS) by investigating the expression of CYP17 and CYP11B1 in SCS adenomas, normal adrenal cortices (NA), non-functional adrenal adenomas (NFA) and cortisol-producing adenomas (CPA). Methods Total RNA and protein were extracted from 20 CPA, 6 SCS, 15 NFA, and 8 NA. Real-time quantitative polymerase chain reaction (PCR), western blotting and immunohistochemistry analysis were performed to determine the mRNA and protein expression of CYP17 and CYP11B1 in different tissues. Expressions of CYP17 and CYP11B1 in the adrenocortical tumors were compared in NA. Results Expressions of both CYP11B1 and CYP17 mRNA and protein were detected in all samples tested. Expressions of CYP11B1 mRNA and protein were significantly higher in CPA group than the others, and were slightly higher in SCS samples than that in NA and NFA samples (P<0.05). Expressions of CYP17 mRNA and protein in different tissues were similar to that of CYP11B1. They showed positive correlations with plasma cortisol and negative correlations with adrenocorticotrophin levels (P<0.05). Conclusion CYP11B1 and CYP17 were over-expressed in subclinical CPA,and their over-expressions were caused by the increased production of cortisol in CPA.