Publications

<p>Table S2 and S4</p>

Abstract Background. Colorectal cancer (CRC) is the third most common cancer and remains a large unmet need. Dysregulation of Wnt and receptor tyrosine kinase (RTK) signalling pathways are important oncogenic driving events in CRC. Due to this dysregulation, Wnt target genes are expressed at higher levels in CRC particularly in tumor initiating cells. We previously performed an unbiased screen of bispecific antibodies (bAbs) targeting Wnt and RTK targets that resulted in the selection of MCLA-158. Methods. A cohort of 32 genetically and transcriptionally annotated patient-derived colorectal cancer and normal colon organoids were used to functionally characterize responses to antibodies based on morphological changes with high content 3D imaging. Binding affinity was measured by surface plasma resonance and cell based assays. The antibody binding epitopes were mapped by shotgun mutagenesis and FACS based screening. Ligand (R-spondin or EGF) blocking activity was measured in vitro by competition for ligand binding or functional inhibition of ligand dependent growth. In vivo activity was evaluated in xenograft models generated from organoids subcutaneously implanted into immunocompromised mice. Safety was evaluated via once weekly intravenous administration of MCLA-158 to cynomolgus monkeys for 4 weeks and monitoring for pathological changes. Results. MCLA-158, an ADCC enhanced common light chain IgG1 bispecific antibody, binds in domain III of EGFR and in the N-Cap/1st LRR of LGR5, both ligand binding regions, however, only EGF binding was blocked by MCLA-158. MCLA-158 demonstrated inhibitory activity in 74% of tumor organoids independent of KRAS mutational status but was not active on organoids of the cohort harboring both KRAS and PIK3CA mutations. MCLA-158 was significantly more active on organoids derived from tumors than from normal tissue in contrast to cetuximab, which demonstrated equivalent activity on both (range 20-100 fold, n=4). In vivo activity was evaluated against tumor organoids with different KRAS mutation status shown to be sensitive to MCLA-158 in vitro. In all cases, MCLA-158 significantly inhibited the growth of the tumor compared to both control and cetuximab treatment. Inhibitors of both the Wnt and EGFR pathways have shown significant toxicity in humans. An initial evaluation of MCLA-158 toxicity in cynomolgus monkeys did not demonstrate any pathological finding after repeated dosing at 25mg/kg. Conclusions. MCLA-158 demonstrates superior activity compared to reference antibodies in both in vitro and in vivo tumor organoid based assays regardless of KRAS status and was well tolerated in non-human primates. These preclinical data suggest MCLA-158 could benefit patients with metastatic CRC and warrant clinical evaluation. Citation Format: Rob Roovers, Bram Herpers, Mark James, Berina Eppink, Carme Cortina, David Maussang-Detaille, Ingrid Kolfschoten, Sylvia Boy, Marc van de Wetering, Wim De Lau, Robert Doornbos, Kuan Yan, Lucia Salinaro, Lex Bakker, john de Kruif, Hans Clevers, Robert Vries, Eduard Batlle, Leo Price, Mark Throsby. Preclinical evaluation of MCLA-158: A bispecific antibody targeting LGR5 and EGFR using patient-derived colon carcinoma organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 32. doi:10.1158/1538-7445.AM2017-32

Abstract Loss of the cell–cell adhesion protein E‐cadherin underlies the development of diffuse‐type gastric cancer (DGC), which is characterized by the gradual accumulation of tumor cells originating from the gastric epithelium in the surrounding stroma. How E‐cadherin deficiency drives DGC formation remains elusive. Therefore, we investigated the consequences of E‐cadherin loss on gastric epithelial organization utilizing a human gastric organoid model and histological analyses of early‐stage DGC lesions. E‐cadherin depletion from gastric organoids recapitulates DGC initiation, with progressive loss of a single‐layered architecture and detachment of individual cells. We found that E‐cadherin deficiency in gastric epithelia does not lead to a general loss of epithelial cohesion but disrupts the spindle orientation machinery. This leads to a loss of planar cell division orientation and, consequently, daughter cells are positioned outside of the gastric epithelial layer. Although basally delaminated cells fail to detach and instead reintegrate into the epithelium, apically mispositioned daughter cells can trigger the gradual loss of the single‐layered epithelial architecture. This impaired architecture hampers reintegration of mispositioned daughter cells and enables basally delaminated cells to disseminate into the surrounding matrix. Taken together, our findings describe how E‐cadherin deficiency disrupts gastric epithelial architecture through displacement of dividing cells and provide new insights in the onset of DGC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

No abstract is provided for this article.

Introduction Introduction: Lung neuroendocrine tumours (LNETs) arise from a rare lung cell population, called pulmonary neuroendocrine cells (PNECs), and account for 20%–25% of all lung cancers. Despite the involvement of PNECs in LNETs and a number of other respiratory diseases, relatively little is known about their normal function or contribution to cancer development and progression. To date, the study of PNECs has been limited by difficulties in isolating and culturing this cell population. Material and methods Building on methods developed in our lab for the isolation and long-term expansion of healthy and diseased human airway cells, we have generated lung organoids derived from embryonic lung tissue. We have identified cultures conditions that allow for the enrichment of PNECs in embryonic lung organoids. In parallel, we have begun to generate a biobank of both low- and high-grade LNET organoids. Results PNEC-enriched embryonic lung organoids can be expanded indefinitely over multiple passages. Preliminary analysis by qPCR and whole mount immunofluorescence shows that PNEC-enriched organoids express a number of PNEC lineage markers including ASCL1, NEUROD1, and UCHL1. PNEC-enriched lung organoids also express PNEC-associated bioactive compounds such as SST and CGRP. Conclusions We have generated human embryonic lung organoids that contain significant numbers of PNECs. Applying the same principles, we have established organoid cultures of human LNETs. PNEC-enriched organoids and LNET organoids are currently being used for further molecular and genetic analyses.

<p>Figure S7. Molecular and phenotypic characterisation of conditional deletion of Myc in Apc-mutant gastric adenomas.</p>

Abstract SARS-CoV-2 is more infectious and transmissible in humans than SARS-CoV, despite the genetic relatedness and sharing the same cellular receptor. We sought to assess whether human airway organoids can model SARS-CoV-2 infection in the human airway and elucidate the cellular basis underlying its higher transmissibility. We demonstrate that SARS-CoV-2 can establish a productive infection in human airway organoids, in which ciliated cell and basal cell are infected. Wildtype SARS-CoV-2 carrying a furin cleavage motif exhibits comparable replication kinetics to a mutant virus without the motif. Human airway organoids sustain higher replication of SARS-CoV-2 than SARS-CoV, whereas interferon response is more potently induced in the latter than the former. Overall, human airway organoids can model SARS-CoV-2 infection and recapitulate the disposable role of furin cleavage motif for virus transmission in humans. SARS-CoV-2 stealth growth and evasion of interferon response may underlie pre-symptomatic virus shedding in COVID-19 patients, leading to its high infectiousness and transmissibility.