Presence of corticotropin-releasing factor-like immunoreactivity in human tumors

Corticotropin-releasing factor (CRF)-like immunoreactivity was measured by radioimmunoassay in human organs and tumors associated with and without ectopic adrenocorticotropic hormone (ACTH) syndrome. It was found to be distributed widely in the stomach, pancreas, adrenal gland, and various tumors (e.g., medullary thyroid carcinoma, small cell carcinoma of the lung, pheochromocytoma, and adenocarcinoma of the gastrointestinal tract and pancreas) in a concentration less than one tenth of that of the hypothalamus. Dilution curves of CRF-like immunoreactivity in tissue extracts paralleled that of synthetic rat (human) CRF. Sephadex G-50 gel filtration showed that a major CRF-like immunoreactivity in tissue extracts coeluted with synthetic rat (human) CRF. Results suggest that a material(s) closely related immunologically to CRF is present widely in normal and tumor tissues outside of the central nervous system.