Absence of mutations in exon 3 of the GnRH receptor in human gonadotroph adenomas.
OBJECTIVE
The mechanisms of tumourogenesis for the majority of pituitary tumours are unknown. Mutations of G-protein coupled receptors (GPCRs) have recently been described as important in diverse human diseases, including thyroid adenomas. To test this hypothesis in pituitary gonadotroph adenomas, we amplified and sequenced the GnRH receptor gene in 12 human tumours. We restricted our analysis to the third exon, since this represents the hotspot for activating mutations in other GPCRs.


METHODS
Pituitary adenoma tissue was identified from patients who had tumours resected and where a diagnosis of gonadotroph adenoma had been made on the basis of immunohistochemical demonstration of LH and/or FSH.


METHODS
Genomic DNA was extracted from paraffin-embedded tissue of 18 gonadotroph adenomas. The third exon was successfully amplified by PCR in 12 cases and directly sequenced.


RESULTS
We found no missense point mutations or even silent polymorphisms in any tumour studied.


CONCLUSIONS
We conclude that activating mutations of the GnRH receptor gene do not represent an important mechanism of pituitary gonadotroph tumourogenesis.
Kaye
P V
PV
MRC Regulatory Peptide Research Unit, Department of Anatomical Pathology, UCT Medical School, Cape Town, South Africa.
Hapgood
J
J
Millar
R P
RP
D000236:Adenoma / Q000235:genetics* / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D004587:Electrophoresis, Agar Gel; D005091:Exons; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D006801:Humans; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000235:genetics* / Q000378:metabolism; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011966:Receptors, LHRH / Q000235:genetics*
D011966:Receptors, LHRH; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone