Corticotrophin-like intermediary lobe peptide as a marker of alternate pro-opiomelanocortin processing in ACTH-producing non-pituitary tumours.

Abstract

In order to evaluate which of human (h) corticotrophin-like intermediary lobe peptide (CLIP) or h beta-melanocyte stimulating hormone5-22 (h beta MSH5-22) was the better marker of alternate pro-opiomelanocortin (POMC) processing, both peptides were simultaneously sought in the same tissue extracts from a normal human pituitary, six corticotrophic adenomas, and four non-pituitary tumours responsible for an ectopic ACTH syndrome. Human CLIP was detected using a combination of gel exclusion chromatography and two different radioimmunoassays (RIAs): a mid-ACTH RIA which recognized ACTH but not CLIP, and a COOH-ACTH RIA which recognized both molecules. Human beta MSH5-22 had been measured previously. Neither hCLIP nor h beta MSH5-22 were detected in the normal or tumoural pituitaries. The four non-pituitary tumours, in contrast, contained both peptides; the hCLIP and h beta MSH5-22 ratios (CLIP/CLIP + ACTH and h beta MSH5-22/h beta MSH5-22 + h gamma LPH) ranged from 40 to 94% and from 24 to 46%, respectively. In a given tissue the hCLIP ratio was always higher than the h beta MSH5-22 ratio. hCLIP is therefore the better marker of alternate POMC processing.

• Authors: D Vieau, J F Massias, F Girard, J P Luton, X Bertagna
• Journal: Clinical endocrinology (Clin Endocrinol (Oxf)) Vol. 31 Issue 6 Pg. 691-700 (Dec 1989) ISSN: 0300-0664 [Print] England
• PMID: 2560687 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers, Tumor
• Peptide Fragments
• Corticotropin-Like Intermediate Lobe Peptide
• Pro-Opiomelanocortin
• Adrenocorticotropic Hormone
• Melanocyte-Stimulating Hormones

Topics

• ACTH Syndrome, Ectopic (metabolism)
• Adenoma (metabolism)
• Adrenocorticotropic Hormone (analysis)
• Biomarkers, Tumor (analysis)
• Bronchial Neoplasms (metabolism)
• Carcinoid Tumor (metabolism)
• Chromatography, Gel
• Corticotropin-Like Intermediate Lobe Peptide
• Humans
• Melanocyte-Stimulating Hormones (analysis)
• Paraneoplastic Endocrine Syndromes (metabolism)
• Peptide Fragments (analysis)
• Pituitary Neoplasms (metabolism)
• Pro-Opiomelanocortin (metabolism)
• Radioimmunoassay
• Thymus Neoplasms (metabolism)