[ACTH-secreting tumors. Deregulation of the proopiomelanocortin gene and alterations in processing].

Abstract

ACTH is produced by proteolysis of a polypeptide precursor, proopiomelanocortin (or POMC). Various POMC-derived peptides are cosecreted with ACTH. Analysis of the ACTH--and its "satellite" peptides--molecular forms establishes the POMC "maturation profile" in different tissues. This profile is identical in normal and tumoral pituitaries (Cushing's disease and/or Nelson's syndrome). It is often altered in non-pituitary tumors responsible for the ectopic ACTH syndrome: abnormal peptides may be generated (CLIP h beta MSH5-22) which can be detected in blood. Analysis of POMC gene transcription in pituitary tumors shows no abnormality. In some non-pituitary tumors the activation of upstream promoters up to 369 nucleotides from the normal (pituitary) transcription initiation site can be shown. In normal non-pituitary tissues a third type of transcription is observed generating a short and probably non-functional messenger RNA limited to a portion of the gene non-coding region.

• Authors: X Bertagna, Y De Keyzer, A Kahn, F Girard, J P Luton
• Journal: Annales d'endocrinologie (Ann Endocrinol (Paris)) Vol. 49 Issue 4-5 Pg. 374-6 ( 1988) ISSN: 0003-4266 [Print] France
• Vernacular Title: Les tumeurs ACTH sécrétantes. Dérégulation du gène de la proopiomélanocortine et pathologie de la maturation.
• PMID: 2849366 (Publication Type: Journal Article, Review)

Chemical References

• Hormones, Ectopic
• Peptide Fragments
• RNA, Messenger
• Pro-Opiomelanocortin
• Adrenocorticotropic Hormone

Topics

• Adrenal Gland Neoplasms (genetics)
• Adrenocorticotropic Hormone (metabolism)
• Gene Expression Regulation
• Hormones, Ectopic (metabolism)
• Humans
• Immunologic Techniques
• Peptide Fragments (immunology)
• Pheochromocytoma (genetics)
• Pro-Opiomelanocortin (genetics)
• RNA, Messenger (genetics)