Elevation of growth hormone secretagogue receptor type 1a mRNA expression in human growth hormone-secreting pituitary adenoma harboring G protein alpha subunit mutation.

Abstract

OBJECTIVE:

The purpose of this study was to investigate the relationship between the ghrelin or GHSR-1a mRNA levels and clinical characteristics and to confirm the effect of gsp mutations on ghrelin/GHSR-1a system in human GH-secreting pituitary adenomas.

METHODS:

The expression levels of ghrelin, GHSR-1a mRNA were determined by SYBR green real-time fluorescent quantitative PCR. The gsp mutations in 43 cases of human GH-secreting pituitary adenomas were detected using PCR-DNA direct sequencing analysis. Clinical data were obtained from the medical records of 43 acromegalic patients who had GH and IGF-1 assays in the same laboratory.

RESULTS:

The expression of GHSR-1a correlated positvely with tumor size (R=0.411, p=0.006) and invasiveness (p<0.05). In contrast, ghrelin mRNA levels correlated positively only with tumor size (R=0.331, p=0.030) but not with tumor invasiveness (p>0.05). The expression level of GHSR-1a mRNA was significantly higher in gsp positive adenomas than in negative adenomas (p<0.05). Whereas, there was no significant difference in the expression of ghrelin mRNA between gsp mutation-positive and -negative adenomas (p>0.05). Additionally there was a significant positve correlation between the ghrelin and GHSR-1a mRNA expression levels in gsp-positive (R=0.553, p=0.040) or -negative adenomas (R=0.489, p=0.007).

CONCLUSIONS:

GHSR-1a correlated positively with tumor size and invasiveness, while ghrelin correlated positively only with tumor size. Gsp mutations may upregulate the expression of GHSR-1a mRNA and have no effect on ghrelin mRNA levels in human GH-secreting pituitary adenomas.

• Authors: Tongjiang Xu, Fei Ye, Baofeng Wang, Chunlei Tian, Sheng Wang, Kai Shu, Dongsheng Guo, Ting Lei
• Journal: Neuro endocrinology letters (Neuro Endocrinol Lett) Vol. 31 Issue 1 Pg. 147-54 ( 2010) ISSN: 0172-780X [Print] Sweden
• PMID: 20150876 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• GTP-Binding Protein alpha Subunits
• Ghrelin
• RNA, Messenger
• Receptors, Ghrelin

Topics

• Acromegaly (etiology, genetics)
• Adenoma (complications, genetics, metabolism, pathology)
• Adult
• Female
• GTP-Binding Protein alpha Subunits (genetics)
• Ghrelin (genetics, metabolism)
• Growth Hormone-Secreting Pituitary Adenoma (complications, genetics, metabolism, pathology)
• Humans
• Male
• Middle Aged
• Mutation
• RNA, Messenger (metabolism)
• Receptors, Ghrelin (genetics, metabolism)
• Retrospective Studies
• Tumor Burden
• Up-Regulation
• Young Adult