Endocrine Abstracts

Introduction: Somatostatin (SST) is a widely distributed polypeptide that modulates the endocrine and exocrine secretion, cellular proliferation and differentiation, and apoptosis via G protein-linked receptors. Our previous studies showed high SSTR expression in adrenocortical carcinoma (ACC), aldosterone producing adenoma (APA) and in cortisol producing adenoma (CPA). Only very few information are available about the effectiveness of SST analogs in adrenal tumors.

Objective: The aim of this study was to evaluate the effect of SOM230 on hormonal secretion and apoptosis in human adrenal carcinoma cell line, H295R, and in primary cell cultures from adrenal tumors.

Material and methods: For our studies we collected three APA and two ACC primary cell cultures (one obtained from a cortisol secreting adrenocortical carcinoma and the other from a non secreting adrenocortical carcinoma). Cortisol and aldosterone concentrations in the medium were measured by RIA. The apoptosis evaluation was performed by immunofluorescence using MitoPT kit both in H295R cells and in the two ACC primary cell cultures.

Results: Our data showed an inhibition of hormonal secretion after the treatment with SOM230 both in H295R cells and particularly in adrenal primary cell cultures. Nanomolar concentrations of SOM230 reduced the cortisol secretion in ACC primary cell culture and also reduced the aldosterone secretion in APA primary cell cultures. Furthermore, SOM230 at nanomolar concentrations showed a positive effect on apoptosis induction in H295R cells and in two ACC primary cell cultures.

Conclusion: SOM230 inhibitory effect on hormonal secretion in H295R and especially in adrenal primary cell cultures, the positive effect on apoptosis induction in adrenal cells suggests a possible therapeutic role of SSTR agonists in adrenal tumors. Supported by AIRC.