The immunohistochemical localisation of somatostatin receptors 1, 2, 3, and 5 in acoustic neuromas.
OBJECTIVE
Acoustic neuroma is a benign tumour, which develops through an overproliferation of Schwann cells along the vestibular nerve. Somatostatin is a naturally occurring peptide, which exerts antiproliferative and antiangiogenic effects via five membrane bound receptor subtypes. The aim of this study was to determine whether somatostatin receptor subtypes (SSTRs) 1, 2, 3, and 5 are present in acoustic neuromas.


METHODS
The expression of SSTRs 1, 2, 3, and 5 was studied in both the Schwann cells and blood vessels of eight acoustic neuroma specimens, by means of immunohistochemistry using novel rabbit polyclonal antibodies raised against human SSTR 1, 2, and 5 subtype specific peptides, and a commercial anti-SSTR3 antibody.


RESULTS
SSTR2 was the most prevalent subtype in Schwann cells (seven of eight), with intermediate expression of SSTR3 (six of eight), and lower expression of SSTRs 1 and 5 (four of eight and five of eight, respectively). There was ubiquitous vascular expression of SSTR2, with no evidence of SSTR 1, 3, or 5 expression in blood vessels.


CONCLUSIONS
SSTRs 1, 2, 3, and 5 are differentially expressed in acoustic neuromas. Somatostatin analogues may have a therapeutic role in the management of this rare and challenging condition.
Stafford
N D
ND
Department of Otolaryngology-Head and Neck Surgery, Hull Royal Infirmary, Anlaby Road, Hull HU3 2JZ, UK. N.D.Stafford@hull.ac.uk
Condon
L T
LT
Rogers
M J C
MJ
Helboe
L
L
Crooks
D A
DA
Atkin
S L
SL
D000328:Adult; D000368:Aged; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009464:Neuroma, Acoustic / Q000098:blood supply / Q000378:metabolism*; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012583:Schwann Cells / Q000378:metabolism
D009363:Neoplasm Proteins; D017481:Receptors, Somatostatin; C103631:somatostatin receptor 3; C101130:somatostatin receptor type 1; C094573:somatostatin receptor 5; C093733:somatostatin receptor 2