10.6084/m9.figshare.5127799.v1 Kanakis G. Kanakis G. Grimelius L. Grimelius L. Spathis A. Spathis A. Tringidou R. Tringidou R. Rassidakis G.Z. Rassidakis G.Z. Öberg K. Öberg K. Kaltsas G. Kaltsas G. Tsolakis A.V. Tsolakis A.V. Supplementary Material for: Expression of Somatostatin Receptors 1-5 and Dopamine Receptor 2 in Lung Carcinoids: Implications for a Therapeutic Role Karger Publishers 2015 Somatostatin receptor subtypes Dopamine receptor 2 Immunohistochemistry Lung carcinoids 2015-02-26 00:00:00 Dataset https://karger.figshare.com/articles/dataset/Supplementary_Material_for_Expression_of_Somatostatin_Receptors_1-5_and_Dopamine_Receptor_2_in_Lung_Carcinoids_Implications_for_a_Therapeutic_Role/5127799 <b><i>Objective:</i></b> The expression of somatostatin receptors (SSTRs) and dopamine receptor 2 (DR2) in neuroendocrine tumors is of clinical importance as somatostatin analogues and dopamine agonists can be used for their localization and/or treatment. The objective of this study is to examine the expression of the five SSTR subtypes and DR2 in lung carcinoids (LCs). <b><i>Methods:</i></b> We conducted a retrospective study of 119 LCs from 106 patients [typical carcinoids (TCs): n = 100, and atypical carcinoids (ACs): n = 19]. The expression of all five SSTR subtypes and DR2 was evaluated immunohistochemically and correlated to clinicopathological data. In a subgroup of cases, receptor expression was further analyzed using semiquantitative RT-PCR. <b><i>Results:</i></b> SSTR2A was the SSTR subtype most frequently expressed immunohistochemically (72%), followed by SSTR1 (63%), SSTR5 (40%), and SSTR3 (20%), whereas SSTR4 was negative. DR2 was expressed in 74% and co-expressed with SSTR1 in 56%, with SSTR2A in 59%, with SSTR3 in 19%, and with SSTR5 in 37% of the tumors. Receptor expression was not related to the histological subtype, tumor aggressiveness (disease extent/grading) or functionality; however, DR2 was expressed more frequently in ACs than TCs (95 vs. 70%, p = 0.017). In a subset of patients, RT-PCR findings highly suggested that the expression of SSTR2A, SSTR3, DR2, and to a lesser extent that of SSTR1 and SSTR5 is the outcome of increased gene transcription. <b><i>Conclusions:</i></b> The high and variable immunohistochemical expression of the majority of SSTRs along with their co-expression with DR2 in LCs provides a rationale for their possible treatment with agents that target these receptors.