Human endocrine
tumors often express the
somatostatin receptors SSTR 1-5 with different intensity. It has been widely investigated their distribution in
pituitary adenomas,
brain tumors, adrenal
tumors and
neuroendocrine tumors in gastrointestinal tract (NET). Some of studies also concern the expression of SSTRs in thyroid
tumors but they are mainly limited to parafollicular C cells - derived medullary
thyroid carcinomas (MTC). Results of
SSTR 1-5 detection in other thyroid pathologies like
follicular adenomas and papillary
cancers are still scarce and often controversial, depending of investigation method used. The aim of this study was to report the presence of all the 5 subtypes of SSTR (including 2A and 2B SSTR
isoforms) in some surgically treated human thyroid
tumors by means of immunohistochemistry and real-time PCR method and to correlate the results obtained with both techniques.
SSTR 1 protein was expressed in 88.8% of investigated cases, SSTR 2A and 2B both in 44.4%, SSTR 3 in 55.5%, SSTR 4 in 11.2% and SSTR 5 in 33.3%.
SSTR 1 is the dominant form in the thyroid gland
tumor and
hyperplasia. We found positive confirmation of both methods in 88.8% for
SSTR 1, 2A, 3 subtypes, in 22.2% for SSTR 4 and in 100% for SSTR 5. It suggests that
somatostatin multiligand analogs or selective
SSTR 1 agonists may be used in thyroid
tumors treatment.