Localisation of somatostatin and somatostatin receptors in benign and malignant ovarian tumours

Abstract

Somatostatin has been identified as having anti-proliferative, anti-angiogenic and pro-apoptotic actions in many tumour systems, and these effects are mediated through a family of five transmembrane G-protein coupled SRIF receptors. Ovarian cancer is the commonest gynaecological malignancy in the UK and maintenance therapy is urgently required. Native somatostatin expression and its receptors sst 1,2,3 and 5 were studied with immunohistochemistry in 63 malignant and 35 benign ovarian tumours of various histological types. Fifty-seven out of 63 (90%) of malignant and 26/35 (74%) benign tumours expressed somatostatin. Receptors sst 1,2,3 and 5 were expressed variably in epithelial, vascular and stromal compartments for both benign and malignant tumours. Somatostatin was found to correlate significantly with stromal sst 1 (P=0.008), epithelial sst 1 (P50.001), stromal sst 2 (P=0.019), vascular sst 2 (P=0.026), epithelial sst 3 (P=0.026), stromal sst 5 (P=0.013) and vascular sst 5 (P=0.038). Increased expression of native somatostatin correlating with somatostatin receptors in malignant ovarian tumours raises the possibility that either synthetic somatostatin antagonists or receptor agonists may have therapeutic potential.

Somatostatin receptors 2 and 5 are preferentially expressed in proliferating endothelium

“…Sst 1 has previously been detected in HUVECs (Curtis et al, 2000), and in the endothelium of neuroblastomas (Albers et al, 2000) and benign and malignant ovarian tumours (Hall et al, 2002). Sst 3 expression has also been demonstrated in HUVECs (Jia et al, 2003), and in the endothelial cell line Eahy926 (Florio et al, 2003).…”

Neuropeptide Y receptor expression in human primary ovarian neoplasms

“…Vasoactive intestinal peptide receptors were found in high density and homogeneity in 83%, 14 cholecystokinin-B in 14%, 15 and different somatostatin receptor subtypes in 19-54% 13 of ovarian adenocarcinomas. Most interestingly, however, cholecystokinin-B receptors are present in 100% of sex cord-stromal tumors.…”

“…Moreover, only few other peptide hormone receptors were reported to be expressed in a high percentage of ovarian tumors. [13][14][15] Ovarian malignancies are a major problem in oncology. Adenocarcinomas are frequently diagnosed at an advanced stage with dissemination in the peritoneal cavity and beyond.…”

Somatostatin Receptors 3, 4 and 5 Play Important Roles in Gallbladder Cancer

“…A plenty of researches show the regulatory action of SST counts on specific receptors expression presenting on target cells (Hall et al, 2002;Pisarek et al, 2009). Somatostatin receptor (SSTR), as a G protein coupled receptor, formed by seven specific transmembrane segments and expressed in multiple human primary tumors (Hall, et al, 2002).…”