Research On Relevant Secretion Function Of Sub-clinical Adrenocortical Neoplasm

Background:Adrenocortical neoplasm (AN) is a common endocrine adenoma. With the popularization of routine examination of ultrasonic B and CT, its incidence rate increases significantly, and there are many non-functional and sub-clinical AN. At present, its occurrence and progress have yet unclear genetic and histopathological characteristic, especially some issues significant for guiding clinical treatment (such as the relation among clinical, non-functional and functional state of AN).At present, sub-clinical Cushing's syndrome is a syndrome with the auto-secretion of glycocorticosteroid but without the clinical manifestation of typical Cushing's syndrome. Domestic and foreign institutions are still at starting stage for recognizing and researching sub-clinical AN.ACTH-R is an ultra family of melatonin receptor. Different from other families of melatonin receptor, ACTH-R binds with only ACTH specifically, and distributes in highly tissue-specific way (i.e. mainly in adrenal cortex). ACTH-R is highly homologous in species and highly specific in expression site, indicating that it plays an important role in occurrence and progress of AN. At present, there is yet insufficient recognition of relation between ACTH-R and AN.As verified by some past experimental researches, ACTH-R was expressed at significantly different level in different ANs, indicating that abnormal ACTH-R might participate in the proliferation and differentiation of cells in AN. This research will mainly study the distribution characteristic of ACTH-R (i.e. melanocortin receptor-2(MCR-2)) in n sub-clinical Cushing's syndrome and adrenal nonfunctional adenoma (NFA) by combining molecular biological, immunohistochemical and electronic microscopic examination. This research aims to provide the evidence for the research on the relation between ACTH-R and AN. At present, there are temporarily yet no relevant researches both at home and abroad.Objectives:1,To research and analyze different expression levels of ACTH-R in different ANs.2,To deeply research the similarity, difference and relation between sub-clinical Cushing's syndrome and Cushing's syndrome.3,To study whether abnormal ACTH-R participates in the proliferation and differentiation of cells in AN.4,To explore the feasibility of immunohistochemical examination for AN differentiation.5,To observe ultra-structural difference in different ANs.Method:1. Detect the expression of ACTH-R and internal-reference β-actin mRNA in different AN tissues through fluorescent real-time quantitative RT-PCR method, compare the different expression of ACTH-R mRNA in different tissues, and make correlation analysis on ACTH-R expression in AN. 2. Research ACTH-R expression in different AN tissues through Polymer immunohistochemical staining.3. Observe the ultra-structural difference in different adrenocortical/adrenomedullary adenoma through microscopy.Results:1,ACTH-R mRNA ratio was0.961±0.164,0.845±0.386,0.636±0.104,1.242±0.372, and1.297±0.228in normal adrenal cortex, aldosterone-producing adenoma (APA), cortisol-producing adenoma (CPA), sub-CPA, and NFA respectively.2,ACTH-R mRNA expression was significantly higher in NFA and sub-CPA than in normal adrenal cortex, APA and CPA (P<0.01), was not significantly different between NFA and sub-CPA (P=0.539), was significantly lower in CPA than in other groups (P<0.05), and was not significantly different between APA and normal adrenal cortex (P=0.214).3,ACTH-R was not expressed in pheochromocytoma (PHEO).4,ACTH-R expression was different in different AN tissues as shown by immunohistochemical examination.5,AN had some same microscopic characteristics.6,Different ANs were significantly different in microscopy. And microscopy was an important technology to judge the sub-type of AN.7,Adrenocortical and adrenomedullary adenoma were significantly different in microscopy. Conclusions:1,sub-Clinical Cushing's syndrome is an independent disease, and its progress into Cushing's syndrome depends on many factors (possibly different expression of ACTH-R).2,sub-CPA and NFA, the inactive secretion function of tumor cells may cause by the high expression of ACTH-R mRNA, and thus coordinate/inhibit the transcription of steroid synase.3, ACTH-R mRNA may not participate in the occurrence and progress of PHEO.4, ACTH-R mRNA expression is significantly higher in sub-clinical cortisol-producing adenoma (sub-CPA) than in CPA (p<0.01), but significantly different in each group, indicating that some tumors may progress into CPA of active secretion function.5,Immunohistochemical examination can be used to auxiliarily judge the secretion function of AN.6,Different ANs are significantly different in microscopy. And microscopy can auxiliarily judge the sub-type of AN.