title: Expression and mutations of KCNJ5 mRNA in Japanese patients with aldosterone-producing adenomas.
abstract: BACKGROUND
  Mutations of the KCNJ5 gene have recently been identified in patients with aldosterone-producing adenomas (APA).
  
  
  OBJECTIVE
  Our objective was to investigate the expression and mutations of the KCNJ5 gene in Japanese patients with APA.
  
  
  METHODS
  We sequenced KCNJ5 cDNA and measured KCNJ5 mRNA levels in 23 patients with APA operated on at Gunma University Hospital.
  
  
  METHODS
  Mutations and mRNA levels of the KCNJ5 gene were examined and compared to those in cortisol-producing adenomas (Cushing's syndrome) and pheochromocytomas.
  
  
  RESULTS
  Of the 23 patients with APA, 15 (65.2%) had two somatic mutations of the KCNJ5 gene: 12 cases of p.G151R (eight with c.451G>A, and four with c.451G>C) and three cases of p.L168R (c.503T>G). Levels of KCNJ5 mRNA were significantly higher in the APA with mutations than those without. Immunohistochemistry also showed a stronger staining of KCNJ5 on the cell membrane in the tumor with a mutation. Furthermore, a PCR-restriction fragment length polymorphism assay with c.503T>G revealed the mutant mRNA to be expressed at a similar level to the wild type. The level of KCNJ5 mRNA in cortisol-producing adenomas was approximately 30% of that in APA, and almost no expression was observed in pheochromocytomas.
  
  
  CONCLUSIONS
  We found that: 1) a significant number of patients with APA had somatic mutations of the KCNJ5 gene; 2) KCNJ5 mRNA levels were higher in the APA with KCNJ5 mutations; and 3) the expression of KCNJ5 mRNA was significantly higher in APA than cortisol-producing adenomas and pheochromocytomas.
authors.affiliation: Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi, Gunma 371-8511, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Taguchi
authors.forename: Masanobu
authors.initials: M
authors.lastname: Yamada
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Tetsurou
authors.initials: T
authors.lastname: Satoh
authors.forename: Koshi
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shibusawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ozawa
authors.forename: Shuichi
authors.initials: S
authors.lastname: Okada
authors.forename: Nana
authors.initials: N
authors.lastname: Rokutanda
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takata
authors.forename: Yukio
authors.initials: Y
authors.lastname: Koibuchi
authors.forename: Jun
authors.initials: J
authors.lastname: Horiguchi
authors.forename: Tetsunari
authors.initials: T
authors.lastname: Oyama
authors.forename: Izumi
authors.initials: I
authors.lastname: Takeyoshi
authors.forename: Masatomo
authors.initials: M
authors.lastname: Mori
mesh_terms: D000306:Adrenal Cortex Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D000310:Adrenal Gland Neoplasms / Q000235:genetics / Q000378:metabolism; D018246:Adrenocortical Adenoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D000328:Adult; D000368:Aged; D001483:Base Sequence; D003430:Cross-Sectional Studies; D003480:Cushing Syndrome / Q000235:genetics / Q000378:metabolism; D005260:Female; D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D056726:Genetic Association Studies; D006801:Humans; D006929:Hyperaldosteronism / Q000209:etiology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010673:Pheochromocytoma / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D051676:G Protein-Coupled Inwardly-Rectifying Potassium Channels; C484274:KCNJ5 protein, human; D009363:Neoplasm Proteins; D012333:RNA, Messenger