Abstract Library

#2988 Epigenetic Treatment with Histone Deacetylase Inhibitor Enhances Uptake of [111In]In-DOTA-TATE by Increased SST2 Expression on Neuroendocrine Tumor Cells

Introduction: The somatostatin-2 receptor (SST2) is a target for peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumors (NETs). By using epigenetic drugs, which can regulate gene transcription, PRRT efficacy may be further improved due to enhanced SST2 expression.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author: Klomp I

Authors: Klomp I, Dalm S, van Koetsveld P, Dogan-Oruç F, de Jong M,

Keywords: neuroendocrine tumors, bon-1, epigenetic, histone, histone deacetylase inhibitor, HDACi, upregulation, reversibility, somatostatin receptor-2, somatostatin,

#2905 DNA Methyltransferase Inhibitor Hydralazine Induces Upregulation of Somatostatin Type 2 Receptors in Human Neuroendocrine Tumor Cells

Introduction: Epidrugs like DNA methyltransferase inhibitors (DNMTi) can increase somatostatin receptor type 2 (SST2) expression in neuroendocrine tumor (NET) cells in vitro and in vivo. This effect could be used for NET patients with low SST2 expression who are currently ineligible for somatostatin analogue (SSA) treatment. However, the DNMTi known to stimulate SST2 have either a high toxicity profile or are not yet approved.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author: Refardt J

Authors: Refardt J, Klomp I, van Koetsveld P, Dogan-Oruç F, de Herder W,

Keywords: somatostatin type 2 receptor, BON-1, GOT-1, upregulation, DNA methyltransferase inhibitor, histone deacetylase inhibitor, epigenetic,

#2902 DNA Methylation Analysis of the PDX1 Gene Can Be Used for PNET Subtyping and Has a Possible Prognostic Value

Introduction: Estimating prognosis of pancreatic neuroendocrine tumor (PNET) patients remains challenging. Mutation status of DAXX/ATRX/MEN1, histone modification patterns and immunohistochemistry for relevant transcription factors, including PDX1, were recently used to perform subtyping and distinguished two main types, A and B. These subtypes are linked to cell-of-origin and associated with clinical outcome.

Conference: 17th Annual ENETSConcerence (2020)

Presenting Author:

Authors: Boons G, Vandamme T, Ibrahim J, Schepers A, Roeyen G,

Keywords: Pancreatic Neuroendocrine Tumor, DNA Methylation, Prognostic Biomarker,

#2279 Expression of FOXM1 in G3 Neuroendocrine Tumors (NET G3) and G3 Neuroendocrine Carcinomas (NEC G3) of the Pancreas and the Intestine

Introduction: G3 gastroenteropancreatic neuroendocrine tumors (G3 NET) and carcinomas (G3 NEC) differ considerably concerning their biological behavior and patients outcome. Whereas the WHO2017 classification for pancreatic NETs proposes a distinction of both groups using the Ki-67 proliferation marker (Klöppel et al. Reviews and Reports 2017), a useful marker for the subclassification of G3 intestinal NETs have not been recommended until now.

Conference: 15th Annual ENETSConcerence (2018)

Presenting Author: Briest F

Authors: Briest F, Konukiewitz B, Anlauf M, Klöppel G, Grabowski P,

Keywords: gastroenteropancreatic neuroendocrine tumors, GEP-NET, NET G3, NEC G3, Tumor marker, FOXM1, Ki-67, differentiation,

#2129 Phosphohistone H3 (PHH3) Immunohistochemical Staining Outperforms Conventional H&E Mitotic Count in Classifying Pulmonary Carcinoids

Introduction: Pulmonary carcinoids (PC) are well-differentiated NETs and are classified as typical carcinoid (TC) and atypical carcinoid (AC). Despite the fact that TC and AC exhibit significant differences in patient survival, their classification depends on relatively subtle differences in mitotic count (MC). Although careful counting of mitotic figures (MF) is essential, it is a very subjective task, time-consuming and lacks of sensitivity and interobserver reproducibility, due to selection bias of the hot spots, heterogeneous distribution of MF, difficulty in distinguishing MF from similar chromatin changes (i.e. in apoptotic cells or due to crush, karyorrhectic debris, pyknosis or apoptosis).

Conference: 15th Annual ENETSConcerence (2018)

Presenting Author: Luong T

Authors: Luong T, McCaughran W, Caplin M, Toumpanakis C, Thirlwell C,

Keywords: Phosphohistone H3, Pulmonary Carcinoids, Typical Carcinoid, Atypical Carcinoid, Mitotic Count, H&E,