Moreover, clinical manifestations of CD may vary depending on hormonal activity; however, factors involved in the hormonal aggressiveness of adrenocorticotropic hormone (ACTH)-secreting pituitary tumors have not been fully clarified.
OBJECTIVESuccessful transsphenoidal surgery for adrenocorticotropin hormone (ACTH)-producing pituitary tumors is associated with subnormal postoperative serum cortisol levels, which may guide decisions regarding immediate reoperation.
Expression of Matrix Metalloproteinase-9, Pituitary Tumor Transforming Gene, High Mobility Group A 2, and Ki-67 in Adrenocorticotropic Hormone-Secreting Pituitary Tumors and Their Association with Tumor Recurrence.
However, there has been no report showing the effects of RXR agonists on Cushing's disease, which is caused by excessive ACTH secretion in a corticotroph tumor of the pituitary gland.
Results showed that the endocrinologically active adrenocorticotropic hormone (ACTH)-producing pituitary tumors and the silent subtypes were immunopositve for hK10.
ACTH is frequently produced in non-pituitary tumours, leading to the ectopic-ACTH syndrome, but the molecular mechanisms of its expression remain obscure.
Non-pituitary tumors that produce adrenocorticotropic hormone (ACTH) exhibit resistance to the normal feedback effects of glucocorticoids on proopiomelanocortin (POMC) gene expression.
In Cushing's syndrome, ACTH-secreting pituitary tumours show a degree of glucocorticoid resistance, whilst ACTH-secreting extra-pituitary tumours have an even greater resistance to glucocorticoid excess.
It is still not clear why glucocorticoids fail to inhibit the POMC gene in these extra-pituitary tumours despite the presence of glucocorticoid receptors.
Tumor POMC peptides including ACTH and its phosphorylated form usually show no peculiar or unexpected molecular forms in contrast with what is often found when POMC expression occurs in a non-pituitary tumor.
Tissue concentration of 7B2, pro-opiomelanocortin products (joining peptide and beta-endorphin) were measured in 13 pituitary corticotrophic adenomas and 13 non-pituitary tumours associated with the ectopic ACTH syndrome (five out of 20 bronchial carcinoid tumours, two out of 19 phaeochromocytomas, one out of 11 medullary thyroid carcinomas, three pancreatic and two thymic carcinoid tumours).