The evaluation of ghrelin mRNA expression in human somatotroph adenomas.
Ghrelin is one of the peptides involved into GH-release, binding to specific GHS receptors on hypothalamus and pituitary. The ghrelin peptide and ghrelin mRNA have been detected in several regions of hypothalamus, in normal pituitary, as well as in various types of pituitary adenoma, with different levels of expression in different tumour types. We decided to determine the expression of ghrelin in somatotroph adenomas. Human pituitary somatotroph adenoma tissues were obtained at the time of transsphenoidal surgery from 3 acromegalic patients and studied for ghrelin mRNA expression. Before surgery each patient received a somatostatin analogue treatment at doses 20 mg, 30 mg, 30 mg at 30 days intervals. 20 mg of each tissue sample was used for the isolation of total cellular RNA. The reverse transcription and real-time PCR were performed according to Korbonits et al. method. The reverse transcription of total RNA to cDNA was performed using Super Script TM Rnase H RT kit according to manufacturer protocol. We wished to determine the number of copies of ghrelin gene within the single cell. We used the beta-actin, and the GAPDH genes as a reference molecules for standard curve calculation. Ghrelin mRNA was not detected in any examined tissues. We postulate that the absence of the ghrelin gene transcript is mainly due to the treatment with somatostatin analogues administered preoperatively, which could have suppressed the ghrelin gene transcription.
Wasko
Ryszard
R
Department of Endocrinology, Metabolism and Internal Diseases, Karol Marcinkowski University of Medical Sciences in Poznan, Poland. rwasko@amp.edu.pl
Jaskuła
Magdalena
M
Plewa
Robert
R
Komarowska
Hanna
H
Poreba
Elzbieta
E
Goździcka-Józefiak
Anna
A
Liebert
Włodzimierz
W
Bednarek
Janusz
J
Sowiński
Jerzy
J
D000199:Actins / Q000378:metabolism; D000236:Adenoma / Q000378:metabolism* / Q000473:pathology; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D054439:Ghrelin; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D019382:Human Growth Hormone / Q000378:metabolism*; D006801:Humans; D036361:Peptide Hormones / Q000096:biosynthesis*; D010911:Pituitary Neoplasms / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000199:Actins; D018076:DNA, Complementary; D054439:Ghrelin; D036361:Peptide Hormones; D012333:RNA, Messenger; D019382:Human Growth Hormone; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases