Expression of cholecystokinin-B/gastrin receptors in medullary thyroid cancer.

OBJECTIVE

To characterise the cholecystokinin (CCK) receptor subtypes in medullary thyroid cancer by measuring the expression of CCK-A and CCK-B/gastrin receptor mRNA.

DESIGN

Open study.

SETTING

Teaching hospital, Sweden.

SUBJECTS: 6 patients with medullary thyroid cancer.

INTERVENTION: Pentagastrin stimulation test and measurement of calcitonin concentration. Biopsy specimens were analysed using reverse transcription polymerase chain reaction (RT-PCR).

MAIN OUTCOME MEASURE: Presence of CCK-A and CCK-B/gastrin receptors.

RESULTS

All 6 patients with medullary thyroid cancer had positive pentagastrin tests preoperatively. CCK-B/gastrin receptors but not CCK-A receptors were detected by RT-PCR in all six biopsy specimens. By contrast, no CCK receptors were found in normal thyroid tissues or in other thyroid tumours (follicular adenoma, papillary carcinoma, or anaplastic carcinoma).

CONCLUSION

The presence of CCK-B/gastrin receptors in medullary thyroid tumours may have important clinical implications.