title: Dopamine receptor subtype 2 expression profile in nonfunctioning pituitary adenomas and in vivo response to cabergoline therapy.
abstract: OBJECTIVE
  To determine the dopamine receptor subtype 2 (DR2) mRNA levels and protein expression and to evaluate the effect of adjuvant cabergoline therapy on tumour volume (TV) in patients with postoperative residual nonfunctioning pituitary adenoma (NFPA).
  
  
  METHODS
  The mRNA expression was quantified by real-time RT-PCR (TaqMan(®)), and protein expression was evaluated by immunohistochemistry. Tumours were classified according to the percentage of immunostained cells for DR2 as scores 1 (<50% of stained cells) or 2 (≥50%). Cabergoline was started at least 6 months after surgery in nine patients with residual tumours (3 mg/week). The cabergoline effect was prospectively evaluated by magnetic resonance imaging using three-dimensional volume calculation. TV reduction >25% was considered significant.
  
  
  RESULTS
  The DR2 mRNA expression was variable but was observed in 100% of the samples (N = 20). DR2 protein expression was also observed in all the tumours (N = 34). Twenty-nine tumours (85%) were classified as score 2. The median DR2 mRNA expression was higher in the tumours classified as score 2 compared with score 1 (P = 0·007). TV reduction with cabergoline therapy was observed in 67% of the patients (6/9). The median TV before and after 6 months of treatment was 1·90 cm(3) (0·61-8·74) and 1·69 cm(3) (0·36-4·20) [P = 0·02], respectively.
  
  
  CONCLUSIONS
  In conclusion, DR2 is expressed in all adenomas and the majority of the patients in this study displayed tumour shrinkage on cabergoline (CAB) therapy. Thus, CAB might be useful in adjuvant therapy in NFPA patients with residual tumours after surgery.
authors.affiliation: Neuroendocrinology Research Center/Endocrinology Section, Medical School and Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Endocrinology Unit, Hospital Federal da Lagoa, Rio de Janeiro, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Vieira Neto
authors.forename: Luiz Eduardo
authors.initials: LE
authors.lastname: Wildemberg
authors.forename: Aline B
authors.initials: AB
authors.lastname: Moraes
authors.forename: Leandro M
authors.initials: LM
authors.lastname: Colli
authors.forename: Leandro
authors.initials: L
authors.lastname: Kasuki
authors.forename: Nelma Verônica
authors.initials: NV
authors.lastname: Marques
authors.forename: Emerson L
authors.initials: EL
authors.lastname: Gasparetto
authors.forename: Margaret
authors.initials: M
authors.lastname: de Castro
authors.forename: Christina Maeda
authors.initials: CM
authors.lastname: Takiya
authors.forename: Mônica R
authors.initials: MR
authors.lastname: Gadelha
mesh_terms: D000236:Adenoma / Q000188:drug therapy* / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D000077465:Cabergoline; D004873:Ergolines / Q000627:therapeutic use*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000188:drug therapy* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; C581293:DRD2 protein, human; D004873:Ergolines; D019394:Ki-67 Antigen; D012333:RNA, Messenger; D017448:Receptors, Dopamine D2; D000077465:Cabergoline