title: Synaptophysin immunoreactivity in adrenocortical adenomas: a correlation between synaptophysin and CYP17A1 expression.
abstract: METHODS
  The adrenal cortex is not considered to be an intrinsic part of the diffuse neuroendocrine system, but adrenocortical neoplasms possess neuroendocrine properties. In this study, we examined synaptophysin (SYP) and neural cell adhesion molecule (NCAM) expression in adrenocortical adenomas in relation to adrenal function.
  
  
  RESULTS
  Immunohistochemical analysis showed that 50.7 and 98.6% of the cortical adenomas showed SYP and NCAM immunoreactivities respectively. There was no apparent difference in NCAM immunoreactivity among the adenomas. However, the immunostaining for SYP was significantly stronger in cortisol-producing adenomas (CPA) than in aldosterone-producing adenomas (APA), nonfunctioning adenomas (NFA), showing no clinical or endocrinological abnormality, or adenomas associated with preclinical Cushing's syndrome (preCS). Western blotting and real-time PCR demonstrated that the expression level of SYP protein and mRNA was significantly higher in CPA than in APA or NFA. Additionally, the SYP mRNA level showed a positive correlation with CYP17A1 mRNA. In addition to the plasma membrane, mitochondria, and smooth endoplasmic reticulum, SYP immunoreactivity was detected in the Golgi area, which is known to be involved in the regulation of mitochondrial cholesterol and the transport of steroid intermediates. It was unexpected that the ratio of positive cells for SYP in preCS was less than that in APA and NFA. However, further examination is required, because the number of preCS cases we investigated was very small.
  
  
  CONCLUSIONS
  We propose that SYP expression in adrenocortical cells may be involved in some aspect of adrenal function such as transport or secretion of glucocorticoids.
authors.affiliation: Department of Pathology, Japanese Red-Cross Nagasaki Atomic Bomb Hospital, Nagasaki 852-8511, Japan. shigek@nagasaki-med.jrc.or.jp
authors.forename: Kazuto
authors.initials: K
authors.lastname: Shigematsu
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Nishida
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Igawa
authors.forename: Kan
authors.initials: K
authors.lastname: Toriyama
authors.forename: Akira
authors.initials: A
authors.lastname: Nakatani
authors.forename: Osamu
authors.initials: O
authors.lastname: Takahara
authors.forename: Kioko
authors.initials: K
authors.lastname: Kawai
mesh_terms: D000302:Adrenal Cortex / Q000737:chemistry*; D000310:Adrenal Gland Neoplasms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D019006:Neural Cell Adhesion Molecules / Q000096:biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D013254:Steroid 17-alpha-Hydroxylase / Q000096:biosynthesis*; D016708:Synaptophysin / Q000032:analysis* / Q000096:biosynthesis
chemical_list: D019006:Neural Cell Adhesion Molecules; D012333:RNA, Messenger; D016708:Synaptophysin; C501892:CYP17A1 protein, human; D013254:Steroid 17-alpha-Hydroxylase