Abstract Library

#4588 Spatial transcriptomics identifies Wnt signalling in multifocal ileal neuroendocrine tumours

Introduction: Ileal neuroendocrine tumours (i-NETs) often present with multiple primary tumours (>30-40%). Recent studies showed no shared somatic mutations in multiple primary tumours, highlighting the need to examine the tumour microenvironment in tumorigenesis. The Wnt signalling pathway is crucial for organ stem cell regulation. While the Wnt/β-catenin pathway influences prostate and pancreatic NET/Cs, its role in i-NETs remains unclear.

Conference:

Presenting Author:

Authors: Yogo A, Akanuma N, Kim G, Thirlwell C, Mäkinen N,

Keywords: Wnt Signalling, Spatial Transcriptomics,

#4539 Single-nucleus profiling of the tumour microenvironment in SI-NET patients

Introduction: Small intestinal neuroendocrine tumours (SI-NETs) are frequently present as multiple synchronous primary tumours in the small bowel. They are thought to arise from enterochromaffin (EC) cells in the gut, which account for less than 1% of the intestinal epithelium. Previously reported lack of shared somatic driver alterations in SI-NETs suggests that other, non-genetic mechanisms are likely involved in their tumorigenesis.

Conference:

Presenting Author: Mäkinen N

Authors: Mäkinen N, Kasai Y, Kim G, Thirlwell C, Nakakura E,

Keywords: small intestinal NET, tumour microenvironment, single-nucleus sequencing,

#3651 Mesenteric fibrosis in small intestinal neuroendocrine tumors (SI-NETs) – Steps towards understanding its pathogenesis

Introduction: Mesenteric fibrosis (MF) occurs in 50% of patients with SI-NETs, causing significant morbidity and mortality. The pathogenesis of MF in SI-NETs is incompletely understood with no biomarkers or radiological criteria to predict long-term complications of SI-NET associated MF.

Conference:

Presenting Author:

Authors: Hodgetts H, Martins M, Luong T, Hall A, Thirlwell C,

Keywords: small, intestine, neuroendocrine tumor, fibrosis, mesenteric, rna-sequencing, biomarker,

#3392 The chromosome 18 loss of heterozygosity axis of small intestinal neuroendocrine tumors

Introduction: Small intestinal neuroendocrine tumors (siNETs) are rare neoplasms which have low mutational burdens: With subtypes characterised in terms of copy number variation (CNV). Subtypes are defined as: Chromosome 18 loss of heterozygosity (18LOH), multiple copy number variation (MultiCNV), or no copy number variations (NoCNV). 18LOH tumors are associated with improved outcomes, the reasons for which are poorly understood.

Conference:

Presenting Author: Waterfield S

Authors: Waterfield S, Yousefi P, Amaulu A, Relton C, Thirlwell C,

Keywords: neuroendocrine, small intestinal, methylation, epigenetics, omics,

#3388 Epigenetic progression steps in alpha-lineage MEN1-DAXX/ATRX mutated Pancreatic Neuroendocrine Tumors (PanNET)

Introduction: Recently, based on DNA methylation profiles, we have hypothesized that PanNETs with mutations in ATRX, DAXX and MEN1 originate from α-cells. Alpha-like PanNETs, small and indolent, were enriched for mutations in MEN1 only, while epigenetically intermediate PanNETs, larger and with high relapse risk, showed mutations in both MEN1 and DAXX/ATRX (Int-ADM). Int-ADM PanNETs show progressive loss of alpha cell differentiation.

Conference:

Presenting Author: Marinoni I

Authors: Di Domenico A, Kirchner P, Maire R, Thirlwell C, Perren A,

Keywords: Epigenetics, DAXX/ATRX, PanNET, PanNET progression,