CCK receptors in human neuroendocrine tumors: clinical implications.
Receptors for gastrin and cholecystokinin have been shown to be expressed in several types of human cancers. CCK-B receptors for instance have been identified in several types of neuroendocrine tumors. One of the highest incidences of CCK-B receptors has been reported in medullary thyroid cancers at the protein and at the mRNA level using in vitro receptor autoradiography and RT-PCR. It is likely that these receptors mediate the stimulation of calcitonin secretion from neoplastic C-cells by pentagastrin, a well established clinical test to detect occult medullary thyroid cancers. In order to target these tumors in vivo in patients, several peptide radiopharmaceuticals such as DTPA-linked minigastrins or non-sulfated CCK-8 analogs radiolabeled with 111Indium or 90Yttrium have recently been developed. As a proof of concept, it could be demonstrated that a majority of medullary thyroid cancer primary tumors and metastases are visualized in vivo with CCK-B receptor scintigraphy using these radioligands. More recently, radiotherapy of CCK-B receptor expressing medullary thyroid cancers with radiolabeled minigastrin has been successfully reported in a small number of patients, giving support to the proposal that CCK-B receptors overexpressed in tumors represent a useful target for clinical application.
Reubi
J C
JC
Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Switzerland. reubi@patho.unibe.ch
D018276:Carcinoma, Medullary / Q000235:genetics / Q000378:metabolism / Q000532:radiotherapy; D006801:Humans; D018358:Neuroendocrine Tumors / Q000235:genetics / Q000378:metabolism* / Q000532:radiotherapy; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin / Q000235:genetics / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000235:genetics / Q000378:metabolism / Q000532:radiotherapy
D019275:Radiopharmaceuticals; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; D011949:Receptors, Cholecystokinin