P-76 Genomic and transcriptomic characterization of pancreatic neuroendocrine tumors reveals novel therapeutic candidates

Document Type

Conference Proceeding

Publication Date

10-1-2023

Publication Title

Ann Oncol

Keywords

beta catenin, CD47 antigen, chemokine receptor CXCR4, endogenous compound, nerve growth factor, neurotensin, Notch receptor, phosphatidylinositol 3 kinase, protein p53, Ran protein, Ras protein, syntaxin 1A, transcription factor, transthyretin, Wnt protein, apoptosis, cell culture, cell cycle, cell cycle regulation, cell proliferation, cohort analysis, colony formation, conference abstract, controlled study, frameshift mutation, gene set enrichment analysis, gene silencing, genetic marker, genetic transcription, histopathology, human, human cell, human tissue, immunohistochemistry, in vitro study, insulin release, missense mutation, mTOR signaling, nervous system, neuroendocrine tumor cell line, neurotransmitter release, nonsense mutation, pancreas islet cell tumor, pancreas tissue, real time reverse transcription polymerase chain reaction, RNA interference, RNA sequencing, signal transduction, sustenance, TGF beta signaling, transcription initiation, upregulation, validation process, validation study, whole exome sequencing

Abstract

Background: Pancreatic neuroendocrine tumor (pNET) incidence is on the rise and remains an unmet clinical problem in urgent need of new actionable targets. Methods: We performed whole exome sequencing (WES), and transcriptomic (RNA-seq) analysis on 81 primary pNET and 6 normal pancreas tissues. Maftools analysis was performed to identify mutated pathways. Prioritized targets were validated in a validation cohort (39 pNETs and 22 normal) using immunohistochemistry (IHC) and real-time reverse transcription polymerase chain reaction (RT-qPCR). RNAi and small molecule inhibitors were used to evaluate the impact of blocking candidate genes and resultant impact on pNET cell subsistence using different assays such as colony formation, MTT, spheroid disintegration, cell cycle and apoptosis. Results: In the primary pNETs, the most common genomic alterations include frameshift insertions, nonsense mutations, missense mutations and in frame insertions. The Maftools analysis of mutated pathways showed enrichment of RTK/Ras activation, WNT/β-catenin pathway, Notch pathway, Hippo pathway, cell cycle control, TGF-β signaling, PI3K/mTOR signaling, Myc and p53 pathways. Transcriptomic analysis showed activation of VGF nerve growth factor (VGF), Neural Proliferation Differentiation and Control 1 (NPDC1) and Neurotensin (NTS) in pNETs compared to normal tissues. GSEA analysis also showed that the genes which regulate insulin secretion, neurotransmitter secretion, nervous system process and cell cycle were significantly up-regulated in pNETs. There was statistically significant up-regulation of the neuroendocrine markers and the cell cycle and proliferation markers including FEV transcription factor, Syntaxin 1A, Transthyretin, CD47, nuclear signal transport genes XPO1, RCC1, Nup50 and RAN. There was statistically significant up-regulation of the CXCR related signaling molecules including CXCR4, JAK1 and UCHL1. RT-PCR on RNA from validation cohort confirmed the up-regulation of above identified transcripts in FFPE pNET tissues, fresh primary pNETs and established pNET cell lines. RNAi silencing of RCC1, small molecule inhibitor targeting CXCR4 and XPO1 and antibody targeting CD47 suppressed proliferation of BON-1 and QGP-1 pNET cells in multiple 2D and 3D cultures. Conclusions: Our genomic, transcriptomic and validation studies reveal previously not described novel actionable therapeutic targets that warrant further evaluation in pNETs. Legal entity responsible for the study: The authors. Funding: NIH 5R01CA240607. Disclosure: All authors have declared no conflicts of interest.

Medical Subject Headings

Hematology

PubMed ID

Not assigned.

Volume

34

First Page

S40

Last Page

S41

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