Cholecystokinin Expression in Tumors: Biogenetic and Diagnostic Implications

ABSTRACT

Cholecystokinin (CCK) is a classic gut hormone. CCK is also a complex system of peptides expressed in several molecular forms in enteroendocrine I cells, in cerebral and peripheral neurons, in cardiac myocytes and spermatozoa. CCK gene expression has now been found at protein or peptide level in different neuroendocrine tumors; cerebral gliomas and astrocytomas and specific pediatric tumors. Tumor hypersecretion of CCK was recently reported in a patient with a metastatic islet cell tumor and hypercholecystokininemia resulting in a novel tumor syndrome, the cholecystokininoma syndrome. This review presents an overview of the cell-specific biogenesis of CCK peptides, and a description of the CCK expression in tumors and of the cholecystokininoma syndrome. Finally, assays for the diagnosis of CCK-producing tumors are reviewed.

KEYWORDS:

• carcinogenesis
• CCK
• CCK receptors
• cholecystokinin
• cholecystokininoma syndrome
• diagnostic assays
• growth promotion
• neuroendocrine tumors
• neuropeptides
• peptide biosynthesis
• proCCK

Acknowledgements

The skilful and patient secretarial assistance of C Bundgaard is gratefully acknowledged. The review is to a significant extent based on studies of cholecystokinin and cancer in the Department of Clinical Biochemistry, Rigshospitalet.

Financial & competing interests disclosure

These studies have been supported by grants from the Danish Medical Research Council, the Danish Cancer Union and the Danish Biotechnology Program for Cellular Communication. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.