Identification of alternatively spliced messenger ribonucleic acid encoding truncated growth hormone-releasing hormone receptor in human pituitary adenomas.

• DOI: 10.1210/jcem.80.10.7559877
• Publication Date: 2014-01-08T11:59:08Z
• Authors: K Hashimoto; M Koga; T Motomura; S Kasayama; H Kouhara; T Ohnishi; N Arita; T Hayakawa; B Sato; T Kishimoto
• Keywords: Southern blot

The expression of GHRH receptor (GHRH-R) messenger ribonucleic acid (mRNA) was studied in 22 pituitary adenomas and 2 normal anterior pituitaries. Northern blot analysis revealed that GHRH-R mRNA were expressed all 14 GH-producing adenomas, 1 3 ACTH-producing the PRL-producing adenoma, 4 nonfunctioning Their levels varied among relatively low GH-nonproducing adenomas. In addition to major transcript with a molecular mass 2.0 kilobases (kb), transcripts identified at 2.8 4.5 kb some To examine structural variations we amplified complementary DNA fragment encompassing region from third cytoplasmic loop sixth transmembrane domain GHRH-R. This selected because this G protein-coupled has been known interact protein. Two fragments masses 250 810 base pairs by reverse transcriptase-polymerase chain reaction method. nucleotide sequence smaller fragment, which expected size, no mutations found 10 examined. However, larger contained currently unidentified insertion. Compared genomic sequence, insertion be generated through alternative splicing. addition, variant form premature stop codon in-frame, indicating it encodes truncated insertion-specific probe could hybridize 2.8- 4.5-kb species on analysis, these mainly Finally, study cell transfection cAMP measurement unable transmit signals. These results suggest preferentially express as