Patient-derived Organoid Cultures Research Articles

Epidermal Growth Factor Receptor Targeting in Colorectal Carcinoma: Antibodies and Patient-Derived Organoids as a Smart Model to Study Therapy Resistance.

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Therefore, the need for new therapeutic strategies is still a challenge. Surgery and chemotherapy represent the first-line interventions; nevertheless, the prognosis for metastatic CRC (mCRC) patients remains unacceptable. An important step towards targeted therapy came from the inhibition of the epidermal growth factor receptor (EGFR) pathway, by the anti-EGFR antibody, Cetuximab, or by specific tyrosine kinase inhibitors (TKI). Cetuximab, a mouse-human chimeric monoclonal antibody (mAb), binds to the extracellular domain of EGFR thus impairing EGFR-mediated signaling and reducing cell proliferation. TKI can affect the EGFR biochemical pathway at different steps along the signaling cascade. Apart from Cetuximab, other anti-EGFR mAbs have been developed, such as Panitumumab. Both antibodies have been approved for the treatment of KRAS-NRAS wild type mCRC, alone or in combination with chemotherapy. These antibodies display strong differences in activating the host immune system against CRC, due to their different immunoglobulin isotypes. Although anti-EGFR antibodies are efficient, drug resistance occurs with high frequency. Resistant tumor cell populations can either already be present before therapy or develop later by biochemical adaptations or new genomic mutations in the EGFR pathway. Numerous efforts have been made to improve the efficacy of the anti-EGFR mAbs or to find new agents that are able to block downstream EGFR signaling cascade molecules. Indeed, we examined the importance of analyzing the anti-EGFR antibody-drug conjugates (ADC) developed to overcome resistance and/or stimulate the tumor host's immunity against CRC growth. Also, patient-derived CRC organoid cultures represent a useful and feasible in vitro model to study tumor behavior and therapy response. Organoids can reflect tumor genetic heterogeneity found in the tissue of origin, representing a unique tool for personalized medicine. Thus, CRC-derived organoid cultures are a smart model for studying the tumor microenvironment and for the preclinical assay of anti-EGFR drugs.

ΔNp63-restricted viral mimicry response impedes cancer cell viability and remodels tumor microenvironment in esophageal squamous cell carcinoma

Tumor protein p63 isoform ΔNp63 plays roles in the squamous epithelium and squamous cell carcinomas (SCCs), including esophageal SCC (ESCC). By integrating data from cell lines and our latest patient-derived organoid cultures, derived xenograft models, and clinical sample transcriptomic analyses, we identified a novel and robust oncogenic role of ΔNp63 in ESCC. We showed that ΔNp63 maintains the repression of cancer cell endogenous retrotransposon expression and cellular double-stranded RNA sensing. These subsequently lead to a restricted cancer cell viral mimicry response and suppressed induction of tumor-suppressive type I interferon (IFN–I) signaling through the regulations of Signal transducer and activator of transcription 1, Interferon regulatory factor 1, and cGAS-STING pathway. The cancer cell ΔNp63/IFN-I signaling axis affects both the cancer cell and tumor-infiltrating immune cell (TIIC) compartments. In cancer cells, depletion of ΔNp63 resulted in reduced cell viability. ΔNp63 expression is negatively associated with the anticancer responses to viral mimicry booster treatments targeting cancer cells. In the tumor microenvironment, cancer cell TP63 expression negatively correlates with multiple TIIC signatures in ESCC clinical samples. ΔNp63 depletion leads to increased cancer cell antigen presentation molecule expression and enhanced recruitment and reprogramming of tumor-infiltrating myeloid cells. Similar IFN-I signaling and TIIC signature association with ΔNp63 were also observed in lung SCC. These results support the potential application of ΔNp63 as a therapeutic target and a biomarker to guide candidate anticancer treatments exploring viral mimicry responses.

Wnt/β-catenin signaling is a therapeutic target in anaplastic thyroid carcinoma.

Anaplastic thyroid carcinoma (ATC) is a highly aggressive malignancy that has consistently shown Wnt/β-catenin (canonical) signaling activation in various study populations. There are currently no targetable treatments for BRAF-wildtype ATC and a lack of effective treatment for BRAFV600EATC. Our aim is to identify whether Wnt inhibitors could be potential therapeutic agents for ATC patients with limited treatment options. In this Institutional Review Board-approved study, we utilize a cohort of 32 ATCs and 20 non-neoplastic multinodular goiters (MNG). We also use 4 ATC spheroid cell lines (THJ-16T, THJ-21T, THJ-29T, and THJ-11T) and two primary patient-derived ATC organoid cultures (VWL-T5 and VWL-T60). Finally, we use a murine xenograft mouse model of ATC for in vivo treatment studies. Using a large patient cohort, we demonstrate that this near-universal Wnt signaling activation is associated with ligand expression- rather than being mutationally-driven. We show that pyrvinium pamoate, a potent Wnt inhibitor, exhibits in vitro efficacy against both ATC cell lines and primary patient-derived ATC organoids VWL-T5 (p < 0.05) and VWL-T60 (p < 0.01) Finally, using a murine xenograft model of ATC, we show that pyrvinium significantly delays the growth of ATC tumors in THJ-16T (p < 0.005) and THJ-21T (p < 0.001). We tested Wnt inhibitor treatment, both in vitro and in vivo, as a potential novel therapy for this highly lethal disease. Future large-scale studies utilizing multiple Wnt inhibitors will lay the foundation for the development of these novel therapies for patients with ATC.

Mesothelioma-Associated Fibroblasts Modulate the Response of Mesothelioma Patient-Derived Organoids to Chemotherapy via Interleukin-6.

Malignant pleural mesothelioma (MPM) remains an incurable disease. This is partly due to the lack of experimental models that fully recapitulate the complexity and heterogeneity of MPM, a major challenge for therapeutic management of the disease. In addition, the contribution of the MPM microenvironment is relevant for the adaptive response to therapy. We established mesothelioma patient-derived organoid (mPDO) cultures from MPM pleural effusions and tested their response to pemetrexed and cisplatin. We aimed to evaluate the contribution of mesothelioma-associated fibroblasts (MAFs) to the response to pemetrexed and cisplatin (P+C). Organoid cultures were obtained from eight MPM patients using specific growth media and conditions to expand pleural effusion-derived cells. Flow cytometry was used to verify the similarity of the organoid cultures to the original samples. MAFs were isolated and co-cultured with mPDOs, and the addition of MAFs reduced the sensitivity of mPDOs to P+C. Organoid formation and expression of cancer stem cell markers such as ABCG2, NANOG, and CD44 were altered by conditioned media from treated MAFs. We identified IL-6 as the major contributor to the attenuated response to chemotherapy. IL-6 secretion by MAFs is correlated with increased resistance of mPDOs to pemetrexed and cisplatin.

Establishing mesothelioma patient-derived organoid models from malignant pleural effusions

ObjectivesPleural mesothelioma is a cancer arising in the cells that line the lungs and chest wall with poor survival and poor response to first-line therapy. Organoid models of cancer can faithfully recapitulate the genetic and histopathological characteristics of individualized tumors and have potential to be used for precision medicine, however methods of establishing patient-derived mesothelioma organoids have not been well established in the published literature. Materials and methodsLong-term mesothelioma patient-derived organoids were established from ten malignant pleural effusion fluids. Mesothelioma patient-derived organoids were compared to the corresponding biopsy tissue specimens using immunohistochemistry labelling for select diagnostic markers and the TruSight Oncology-500 sequencing assay. Cell viability in response to the chemotherapeutic drug cisplatin was assessed. ResultsWe established five mesothelioma patient-derived organoid cultures from ten malignant pleural effusion fluids collected from nine individuals with pleural mesothelioma. Mesothelioma patient-derived organoids typically reflected the histopathological and genomic features of patients’ matched biopsy specimens and displayed cytotoxic sensitivity to cisplatin in vitro. ConclusionThis is the first study of its kind to establish long-term mesothelioma organoid cultures from malignant pleural effusions and report on their utility to test individuals’ chemotherapeutic sensitivities ex vivo.

Abstract 6573: Targeting DLK1, a Notch ligand, with an antibody-drug conjugate in adrenocortical carcinoma

Abstract Adrenocortical carcinoma (ACC) is an aggressive and rare endocrine malignancy with poor prognosis. First-line therapy (adrenolytic agent mitotane in combination with chemotherapy) for recurrent and metastatic ACC has limited efficacy and there are no approved second-line therapies. Antibody-drug conjugates (ADCs) are an emerging immunotherapeutic class in which a cytotoxic payload is directed to tumor cells via antibodies to cell surface proteins. As Notch ligands, such as DLL3, are ADC targets in neuroendocrine cancers, we screened for expression of Notch ligands in ACC. Among Notch ligands (DLL1, DLL3, DLK1, JAG1, JAG2), DLK1 (delta-like non-canonical Notch ligand 1) was the most highly expressed. Moreover, ACC had the near highest expression of DLK1 across all TCGA tumors likely because this ligand is of adrenal origin (with limited expression in other normal tissues apart from the pituitary gland and ovaries). By immunohistochemistry, we verified DLK1 to be expressed, at variable levels, in 97% of ACC tumors (n=30/31). We then tested a DLK1-directed antibody-drug conjugate (ADCT-701; DLK1-PBD), consisting of a humanized anti-DLK1 monoclonal antibody coupled to DNA damaging pyrrolobenzodiazepine (PBD) dimers (SG3199; drug-to-antibody ratio~1.8) via a cleavable linker in ACC pre-clinical models. ADCT-701 exhibited potent, nanomolar cytotoxicity in DLK1-expressing ACC cell lines and ACC patient-derived short-term organoid cultures. ADCT-701 cytotoxicity was dependent on DLK1 expression as DLK1 knockout and DLK1 overexpression abrogated and facilitated cytotoxicity, respectively. Mechanistically, ADCT-701 induced cytotoxicity through DLK1 dependent receptor-mediated internalization and DNA damage (γH2AX) as well as apoptosis (annexin V/PI positive cells, cleaved PARP, and cleaved caspase-3). In vivo studies showed that ADCT-701 was highly effective against DLK1-positive ACC xenografts and PDX models with durable anti-tumor activity. Our pre-clinical data demonstrate DLK1 as an important therapeutic target in ACC and support an upcoming phase I clinical trial of ADCT-701 in patients with neuroendocrine tumors including ACC (NCT06041516). Citation Format: Nai-Yun Sun, Suresh Kumar, Amber Weiner, Yoo Sun Kim, Arnulfo Mendoza, Rosa Nguyen, Reona Okada, Yves Pommier, Dan Martinez, Jennifer Pogoriler, Sharon Diskin, John Maris, Jaydira Del Rivero, Nitin Roper. Targeting DLK1, a Notch ligand, with an antibody-drug conjugate in adrenocortical carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6573.

Abstract 5853: Regulatory network inference of lung adenocarcinoma drug-tolerant persister cells

Abstract Despite the effectiveness of the latest generation of cancer drugs, partial tumor response and subsequent disease relapse is commonly observed in patients. Recent evidence suggests that treatment resistance emerges from drug-tolerant persister cells (DTPC) that survive through non-genetic tumor cell adaptation. Although DTPC are mostly slow-cycling, a rare subset can re-enter the cell cycle under constitutive presence of treatment. Understanding how DTPC dynamically remodel their molecular portraits at the single-cell level may provide high-resolution insights into the molecular circuits associated with adaptive survival to therapy.Here, we use single-cell RNA sequencing (scRNA-seq) to identify potential mechanisms that promote survival of DTPC and decipher their underlying gene regulatory networks (GRNs), in a model of EGFR-mutant lung adenocarcinoma treated with osimertinib (EGFR inhibitor). Gene expression analysis revealed fewer cell states in DTP compared to treatment-naïve cells (TN). We confirmed the acquisition of DTPC hallmarks (e.g., high epithelial-mesenchymal transition, slow-cycling phenotype, deficient DNA repair). We also identified subpopulations of cells that display intermediate transcriptional states: a pre-existing DTP-like state in a bulk of TN cells, and DTPC with enriched cell cycle signatures, evoking a phenotype of cycling DTPC. To characterize the GRN that govern TN cells, DTPC and the intermediate cell states, we applied the network inference tool PYSCENIC, which associates transcription factors (TFs) to their candidate target genes (TGs) on the basis of the scRNA-seq data and enrichment of TF binding motifs in the genomic regions around TGs. The resulting (GRN) consisted of 5 TF modules clustered on the basis of correlated TF activity.This analysis revealed that, compared to TN cells, DTPC and the intermediate cell states display a marked decreased expression of TFs and TGs involved in mRNA splicing, and more specifically in the initiation of spliceosome assembly through E-complex and A-complex formation. Interestingly, the splicing-related TFs all appear to have affinity for binding to a GCCxC consensus motif or close variant in genes (i.e., SNRPB and SNRPE) that code for key effectors of these initiation complexes. This pilot study highlights that scRNA-seq analyses coupled with inference of regulatory networks might enable the identification of molecular mechanisms that potentially trigger cell state transitions during drug-tolerance. The role of altered mRNA splicing in persistence to EGFR-targeted therapies will be explored experimentally in patient-derived cell lines and 3D organoid cultures. Citation Format: Lisa Chabrier, Camille Leonce, Raphael Schneider, Cyril Degletagne, Pierre Saintigny, Anton Crombach, Sandra Ortiz-Cuaran. Regulatory network inference of lung adenocarcinoma drug-tolerant persister cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5853.

Abstract 4242: Preserving lung cancer patient mutations in 3D organoid models: Advancing cancer research through innovative culture systems

Abstract Lung cancer is one of the most prevalent cancers worldwide. There are currently many anticancer drugs available, but they have numerous issues in terms of treatment, such as drug resistance and recurrence. Culturing systems that can replace a patient's cancer tissue are crucial, and the existing 2D culturing systems have many limitations. Patient-derived cancer organoid culture is the most advanced culture system for understanding mechanism of cancers. Using a 3D organoid culture system, we have successfully established a culture system for lung cancer using biopsy/surgical specimens and malignant effusions, including a long-term culture system. There are two critical indicators to determine the success of 3D organoid culture. One is whether the organoids retain their cancer-specific mutations from patient’s lung cancer tissue, and the second is whether the organoids grow well and can be maintained in long-term culture for more than 20-30 passages. We typically assess gene mutations in EGFR, ALK, ROS, and P53 when evaluating lung cancer organoids. We confirm these mutations when we establish organoids. and currently we have established a total of 127 patient-derived lung cancer organoids. Among the 127 organoids, we completed NGS analysis on 108 of them and validated that 86.5% exhibit similarity when compared to lung cancer tissues. Additionally, we achieved a 100% retention of mutations in the long-term culturing of these organoids. Our studies indicate that patient-derived lung cancer organoids represent a meaningful organoid system for cancer tissue replacement and treatment response in the context of precision cancer medicine. Citation Format: Ji-yeon Park, Seo Rin Gu, Jiyeon Lee, Na-Gyeong Lee, Dojin Choi, Sang Eun Park, Ji Min Kim, Jinguen Rheey. Preserving lung cancer patient mutations in 3D organoid models: Advancing cancer research through innovative culture systems [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4242.

Abstract 4268: Engineered hydrogel elucidates contributions of matrix mechanics to pathobiology of adenocarcinoma and identify matrix-activated therapeutic targets

Abstract Dysregulation of the extracellular matrix (ECM) properties disturbs tissue homeostasis and contributes to pathological conditions, such as cancer. Recent studies have demonstrated that ECM stiffening is associated with metaplasia-dysplasia-adenocarcinoma sequence in the esophagus. This underscores a compelling need to develop a physiologically-relevant 3D culture model to enable the study of the independent contribution of matrix stiffness to the initiation and progression of esophageal adenocarcinoma (EAC). Such a model will then serve as a platform for pre-clinical drug screening in the context of matrix properties. In this context, we have engineered a hyaluronic acid-based 3D hydrogel platform that supports the growth and differentiation of patient-derived Barrett’s esophagus (BE) organoids, a precursor to EAC, as well as patient-derived EAC organoids. The engineered biomaterial 3D platform allows control over matrix stiffness to better recapitulate the mechanically dynamic esophageal cancer microenvironment and help identify therapeutic targets in EAC.Our data demonstrates that BE and EAC organoid density, growth and proliferation can be controlled by matrix stiffness. RNA sequencing data show that increased matrix stiffness promotes changes in the transcriptional profiles of BE and EAC organoids, revealing enrichment of pathways associated with tumorigenesis and disease progression. Furthermore, we demonstrate through molecular and functional assays that increased matrix stiffness endows stem-like properties to the EAC organoids via Yap-Sox9 mechano-activation. Finally, targeted therapy studies in our in vitro and in vivo engineered environments revealed that Yap inhibition regressed the effects of increased matrix stiffness in EAC organoids. In summary, our data suggest that matrix mechanics have a significant role in activation of EAC-associated signaling pathways in patient-derived BE and EAC organoids. We also demonstrate that the engineered hydrogel serves as a platform to identify potential therapeutic targets to disrupt the contribution of pro-tumorigenic matrix mechanics in EAC. Together, these studies establish an engineered patient-derived organoid culture platform that can be used to elucidate underlying matrix-mediated mechanisms of the metaplasia-dysplasia-adenocarcinoma sequence and inform the development of novel therapeutics that target ECM stiffness in EAC. FUNDING SOURCES: NCI P01CA098101, U54 CA163004 and NIDDK K01 DK133620. Citation Format: Ricardo Cruz-Acuna, Secunda W. Kariuki, Kensuke Sugiura, Spyros Karaiskos, Eleanor M. Plaster, Claudia Loebel, Gizem Efe, Tatiana Karakasheva, Joel T. Gabre, Jianhua Hu, Jason A. Burdick, Anil K. Rustgi. Engineered hydrogel elucidates contributions of matrix mechanics to pathobiology of adenocarcinoma and identify matrix-activated therapeutic targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4268.

The m6A modification mediated-lncRNA POU6F2-AS1 reprograms fatty acid metabolism and facilitates the growth of colorectal cancer via upregulation of FASN.

Long noncoding RNAs (lncRNAs) have emerged as key players in tumorigenesis and tumour progression. However, the biological functions and potential mechanisms of lncRNAs in colorectal cancer (CRC) are unclear. The novel lncRNA POU6F2-AS1 was identified through bioinformatics analysis, and its expression in CRC patients was verified via qRT-PCR and FISH. In vitro and in vivo experiments, such as BODIPY staining, Oil Red O staining, triglyceride (TAG) assays, and liquid chromatography mass spectrometry (LC-MS) were subsequently performed with CRC specimens and cells to determine the clinical significance, and functional roles of POU6F2-AS1. Biotinylated RNA pull-down, RIP, Me-RIP, ChIP, and patient-derived organoid (PDO) culture assays were performed to confirm the underlying mechanism of POU6F2-AS1. The lncRNA POU6F2-AS1 is markedly upregulated in CRC and associated with adverse clinicopathological features and poor overall survival in CRC patients. Functionally, POU6F2-AS1 promotes the growth and lipogenesis of CRC cells both in vitro and in vivo. Mechanistically, METTL3-induced m6A modification is involved in the upregulation of POU6F2-AS1. Furthermore, upregulated POU6F2-AS1 could tether YBX1 to the FASN promoter to induce transcriptional activation, thus facilitating the growth and lipogenesis of CRC cells. Our data revealed that the upregulation of POU6F2-AS1 plays a critical role in CRC fatty acid metabolism and might provide a novel promising biomarker and therapeutic target for CRC.

Abstract A059: Heterogeneous cell populations in organoid models derived from breast preinvasive and invasive carcinomas after endocrine therapy

Abstract Approximately 80% of ductal carcinoma in situ (DCIS) and invasive breast cancers express hormone receptors (HR), and are typically treated with selective estrogen receptor modulators (SERMs) or aromatase inhibitors, or with additional HR-targeting agents in the research setting. However, the development of resistance poses a significant challenge. To better understand the mechanisms behind endocrine resistance and explore new treatment strategies, it is essential to have a reliable model system that accurately reflects the heterogeneous nature of breast lesions. In this study, we developed a protocol to generate patient-derived organoid cultures of pre-invasive and malignant breast lesions from patients with persistent or residual disease in the active surveillance or neoadjuvant setting after treatment with endocrine therapy. We generated n = 11 HR+ DCIS and n = 18 HR+ breast cancer organoids and used single-cell RNA-sequencing to characterize cell heterogeneity within individual organoid cultures. We observed mixed non-cancerous and malignant cells present within some cultures, and optimized protocols to minimize non-cancerous cell types. To better define endocrine sensitivity versus resistance, we also assessed responsiveness to estrogen and anti-estrogen therapy in individual cultures by monitoring organoid growth through live cell imaging and evaluating estrogen-response markers at the protein and RNA levels in response to treatment in vitro. Next, we applied our model system to evaluate endocrine resistance in heterogeneous tumor populations. We compared changes in cellular composition and signaling pathways in endocrine-resistant and endocrine-sensitive breast organoids based on in vitro metrics and/or correlation with clinical variables. In addition, within single cultures heterogeneous cell populations were identified with differential expression of ESR1 and HR target genes, generally falling into three cluster groups that could be defined based on different patterns of FOXA1, GATA3, TFF1, and XBP1 expression, among others. These populations also differed with evidence of co-expressed genes and signaling pathways related to breast tumorigenesis and differentiation (estrogen response, androgen response, mTOR signaling, metabolism) in putative HR-active cell populations in both pre-invasive and invasive breast cases. In summary, our study demonstrates that patient-derived breast and breast cancer organoids can be used to model estrogen responsiveness and endocrine resistance. We have established a platform that enables us to investigate the mechanisms underlying endocrine resistance at different premalignant and tumor stages to evaluate new treatment approaches. The ultimate goal of this work is to contribute to the development of new targeted therapies for endocrine-resistant breast lesions. Citation Format: Nadine Goldhammer, Shruti Warhadpande, Liana Beld, Cristian K. Maldonado Rodas, Allison Lam, Tam Binh Bui, Shoko Emily Abe, Michael Alvarado, Cheryl Ewing, Karen Goodwin, Rita Mukhtar, Jasmine Wong, Lamorna Brown Swigart, Gillian Hirst, Christopher Schwartz, Laura van't Veer, Laura Esserman, Jo Chien, Jennifer M. Rosenbluth. Heterogeneous cell populations in organoid models derived from breast preinvasive and invasive carcinomas after endocrine therapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A059.

TOWARDS FUNCTIONAL PATIENT-DERIVED ORGANOIDS AS MODELS FOR SOFT-TISSUE JOINT DISEASE

In-vitro models of disease are valuable tools for studying disease and analysing response to therapeutics. Recently, advances in patient-derived organoid (PDO) models have been shown to faithfully recapitulate structure, function, and therapeutic response for a wide range of tissues. Frozen shoulder is a rare example of a chronic inflammatory fibrotic disease which is self-limiting, unlike many other soft tissue fibrotic disorders. As no in-vitro 3D models or in-vivo animal models exist for frozen shoulder, establishing an organoid model which recapitulates core diseases features may give insight into fibrosis resolution. Consequently, using biocompatible hydrogels, primary capsular fibroblasts, monocyte-derived macrophages and HUVEC cells, we generated stable PDO cultures which exhibited key disease phenotypes, including vascularization, increased stiffness, and an expanded lining layer over 21 days of culture. Through further investigation of cell-matrix and cell-cell interactions in the organoid model, we intend to unpack the differences between resolving and non-resolving fibrotic disease and uncover clinically relevant therapeutic targets for fibrosis.

Prostate Cancer Organoids for Tumor Modeling and Drug Screening.

Prostate cancer (PCa) is the second most common malignancy and the fifth leading cause of cancer death in men worldwide. Despite its prevalence, the highly heterogenic PCa has shown difficulty to establish representative cell lines that reflect the diverse phenotypes and different stages of the disease in vitro and hence hard to model in preclinical research. The patient-derived organoid (PDO) technique has emerged as a groundbreaking three-dimensional (3D) tumor modeling platform in cancer research. This versatile assay relies on the unique ability of cancer stem cells (CSCs) to self-organize and differentiate into organ-like mini structures. The PDO culture system allows for the long-term maintenance of cancer cells derived from patient tumor tissues. Moreover, it recapitulates the parental tumor features and serves as a superior preclinical model for in vitro tumor representation and personalized drug screening. Henceforth, PDOs hold great promise in precision medicine for cancer. Herein, we describe the detailed protocol to establish and propagate organoids derived from isolated cell suspensions of PCa patient tissues or cell lines using the 3D semisolid Matrigel™-based hanging-drop method. In addition, we highlight the relevance of PDOs as a tool for evaluating drug efficacy and predicting tumor response in PCa patients.

Patient-derived organoid culture in epithelial ovarian cancers-Techniques, applications, and future perspectives.

Epithelial ovarian cancer (EOC) is a heterogeneous disease composed of different cell types with different molecular aberrations. Traditional cell lines and mice models cannot recapitulate the human tumor biology and tumor microenvironment (TME). Patient-derived organoids (PDOs) are freshly derived from patients' tissues and are then cultured with extracellular matrix and conditioned medium. The high concordance of epigenetic, genomic, and proteomic landscapes between the parental tumors and PDOs suggests that PDOs can provide more reliable results in studying cancer biology, allowing high throughput drug screening, and identifying their associated signaling pathways and resistance mechanisms. However, despite having a heterogeneity of cells in PDOs, some cells in TME will be lost during the culture process. Next-generation organoids have been developed to circumvent some of the limitations. Genetically engineered organoids involving targeted gene editing can facilitate the understanding of tumorigenesis and drug response. Co-culture systems where PDOs are cultured with different cell components like immune cells can allow research using immunotherapy which is otherwise impossible in conventional cell lines. In this review, the limitations of the traditional in vitro and in vivo assays, the use of PDOs, the challenges including some tips and tricks of PDO generation in EOC, and the future perspectives, will be discussed.

384. ROBUST CULTURE OF PATIENT-DERIVED ESOPHAGEAL ADENOCARCINOMA ORGANOIDS OF SINGLE CELL LINEAGE

Abstract Background Esophageal adenocarcinoma (EAC) has a high mutational rate leading to significant intratumoral heterogeneity. We have previously generated patient-specific organoid models of EAC from endoscopic biopsies and resection specimens. It is unclear whether intratumoral heterogeneity is retained in these organoid models, but we did observe morphologic heterogeneity in these organoid cultures. In this study, we sought to generate methods to isolate clonal organoids from patient-derived EAC organoid cultures. Methods Patient derived EAC organoids were resuspended into single cell solution and dead cells were stained with DAPI. Automatic cell sorter was used to pipette a single live cell into Matrigel coated 96 well plate. Single cell per well was pipetted and checked within 24 hours using light microscope. Cells were coated with a second coat of Matrigel and media and allowed to grow into full size organoids. Organoids of single morphology were expanded and collected for further analysis. Results We have established a high-throughput method to culture patient-derived organoids deriving from a single cell, allowing for lineage analysis. Organoids grown from a single cell take up to 21 days to grow to a full-sized organoid of distinct morphology. We identified 4 distinct EAC organoid morphologies which we have designated: solid, cystic, budding, and grape. Conclusion Isolating EAC organoid morphology is the first step in studying inter- and intra- tumour heterogeneity in EAC organoids. This method allows for studying morphology-transcriptome and morphology-drug response correlations.

198. MODELING CANCER CACHEXIA USING PATIENT TUMOR ORGANOID-DERIVED XENOGRAFTS IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Cancer cachexia is a metabolic and functional multifactorial body wasting syndrome and is one of the major causes of death in late-stage patients. Esophageal squamous cell carcinoma (ESCC) presents one of the highest morbidity and mortality rates due to cancer cachexia. However, there is limited effective and approved targeted treatment. Cancer cachexia animal models are highly limited, with few cancer types available as a pre-clinical drug testing platform and with none related to esophageal carcinoma. Methods We have developed a panel of ESCC patient-derived organoid xenograft (PDOX) mouse models based on our latest patient-derived organoid cultures from Hong Kong patients. Results Our PDOX mouse model displays cachexic phenotypes that traditional cell line-derived xenografts lack, including body wasting and functional signs. The slow-proliferating characteristic of the ESCC PDOX on mice allows development of cachexic conditions before the humane endpoint. Our comprehensive panel of PDOX lines allowed us to identify full spectrum and differential cachexia severities across mice bearing different PDOXs, indicating a heterogenous nature and allowing faithful mimicking of various patient conditions. Molecular analysis showed that several classic cachexia-related gene expressions were up-regulated in the isolated liver and inguinal adipose tissues of cachexic mice, along with elevated circulating Il-6 levels. Conclusion Our ESCC PDOX model potentially serves as a useful pre-clinical cachexia-targeted drug testing platform, providing more treatment options for ESCC patients for better disease management. Acknowledgments We acknowledge the Research Grants Council (Theme-based Research Scheme T12–701/17-R to MLL) and the Food and Health Bureau (Health and Medical Research Fund 06171566 to VZY) of the Hong Kong Special Administrative Region for funding support. We acknowledge DSMZ (German Collection of Microorganisms and Cell Culture) for the KYSE cell lines. We acknowledge the University of Hong Kong LKS Faculty of Medicine Centre for PanorOmic Sciences for providing imaging facilities.

Simultaneous establishment of pancreatic cancer organoid and cancer-associated fibroblast using a single-pass endoscopic ultrasound-guided fine-needle biopsy specimen.

Considering the critical roles of cancer-associated fibroblasts (CAFs) in pancreatic cancer, recent studies have attempted to incorporate stromal elements into organoid models to recapitulate the tumor microenvironment. This study aimed to evaluate the feasibility of patient-derived organoid (PDO) and CAF cultures by using single-pass endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) samples from prospectively enrolled pancreatic cancer patients. The obtained samples were split into two portions for PDO and CAF cultures. PDOs and CAFs were cultured successfully in 54.4% (31/57) and 47.4% (27/57) of the cases, respectively. Both components were established in 21 cases (36.8%). Various clinicopathologic factors, including the tumor size, tumor location, clinical stage, histologic subtype, and tumor differentiation, did not influence the PDO establishment. Instead, the presence of necrosis in tumor samples was associated with initial PDO generation but no further propagation beyond passage 5 (P = 0.024). The "poorly cohesive cell carcinoma pattern" also negatively influenced the PDO establishment (P = 0.018). Higher stromal proportion in tumor samples was a decisive factor for successful CAF culture (P = 0.005). Our study demonstrated that the coestablishment of PDOs and CAFs is feasible even with a single-pass EUS-FNB sample, implying an expanding role of endoscopists in future precision medicine.

Patient-derived organoid culture of gastric cancer for disease modeling and drug sensitivity testing

BackgroundGastric cancer treatment is complicated by the molecular heterogeneity of human tumor cells, which limits the efficacy of standard therapy and necessitates the need for personalized treatment development. Patient-derived organoids (PDOs) are promising preclinical cancer models, exhibiting high clinical efficacy in predicting drug sensitivity, thus providing a new means for personalized precision medicine. MethodsPDOs were established from surgically resected gastric cancer tumor tissues. Molecular characterization of the tumor tissues and PDOs was performed using whole-exome sequencing analysis. Drug sensitivity tests were performed by treating the PDO cultures with 21 standard-of-care drugs corresponding to patient treatment. We evaluated whether the PDO drug phenotype reflects the corresponding patient's treatment response by comparing the drug sensitivity test results with clinical data. ResultsTwelve PDOs that satisfied the drug sensitivity test criteria were successfully constructed. PDOs closely recapitulated the pathophysiology and genetic changes in the corresponding tumors, and exhibited different sensitivities to the tested drugs. In one clinical case study, the PDO accurately predicted the patient's sensitivity to capecitabine and oxaliplatin, and in a second case study the PDO successfully predicted the patient's insensitivity to S-1 chemotherapy. In summary, six of the eight cases exhibited consistency between PDO drug susceptibility test results and the clinical response of the matched patient. ConclusionsPDO drug sensitivity tests can predict the clinical response of patients with gastric cancer to drugs, and PDOs can therefore be used as a preclinical platform to guide the development of personalized cancer treatment.

Abstract 363: Modelling cancer cachexia using a comprehensive panel of heterogeneous esophageal squamous cell carcinoma xenografts for therapeutic application

Abstract Background: Esophageal squamous cell carcinoma (ESCC) is one of deadliest esophageal malignancies in Asia. Cancer cachexia is a multifactorial body wasting syndrome and is one of the major causes of death in late-stage patients (1). It is characterized by skeletal muscle loss and atrophy, adipose and body wasting, and metabolic dysregulations and stress (1). ESCC is one of the cancer types with the highest morbidity and mortality rates due to cancer cachexia (2). However, there are few effective and approved treatments targeting cancer cachexia. Currently, cancer cachexia animal models are highly limited with few cancer types available as a pre-clinical drug testing platform, with none related to esophageal carcinoma (3). Results: Here we have developed a panel of ESCC patient-derived organoid xenograft (PDOX) mouse model based on our latest patient-derived organoid cultures originating from Hong Kong patients. Our immunodeficient mouse-based PDOX model resembles different cachexic phenotypes that cell line-derived xenograft lacks, including body (skeletal muscle and adipose tissue) wasting and functional signs (e.g. lack of body movement, reduced muscle strength, and loss of appetite). The slow-proliferating characteristic of the ESCC PDOX allows development of a cachexic condition before humane endpoint. Furthermore, our full panel of PDOX lines allowed us to identify the full spectrum, differential cachexia severity across mice bearing different PDOXs, indicating a heterogenous nature. We have comprehensively characterized the cachexia phenotypes and performed proof-of-concept preclinical drug tests using established anti-cachexic drugs; treated PDOX-bearing mice have improved body condition and function compared to the control, which were further verified by histological examinations of tissue samples. Molecular analysis showed that several classic cachexia related gene expressions were down-regulated in isolated liver (Il1b) and inguinal adipose tissues (adipose triglyceride lipase). Conclusions: Our ESCC PDOX model potentially serves as a great pre-clinical cachexia-targeted drug testing platform, providing more treatment options for ESCC patients for better disease management. Acknowledgement: We acknowledge the Research Grants Council (TRS T12-701/17-R to MLL) and the Food and Health Bureau (HMRF 06171566 to VZY) of Hong Kong Special Administrative Region for funding supports. We acknowledge DSMZ for the KYSE cell lines. We acknowledge the HKUMed-CPOS for providing imaging facilities.

Organoids in high-throughput and high-content screenings

Organoids are self-organized three-dimensional (3D) multicellular tissue cultures which derive from cancerous and healthy stem cells, sharing a highly similarity to the corresponding in vivo organs. Since their introduction in 2009, they have emerged as a valuable model for studying early embryogenesis, organ and tissue development, as well as tools in drug screening, disease modeling and personalized therapy. Organoids can now be established for various tissues, including brain, retina, thyroid, gastrointestinal, lung, liver, pancreas, and kidney. These micro-tissues resemble the native organ in terms of gene expression, protein expression, tissue architecture and cell-cell interactions. Despite the success of organoid-based research and the advances in patient-derived organoid culture, important challenges remain. In this review, we briefly showcase the evolution from the primary 3D systems to complex, multilayered 3D structures such as assembloids, gastruloids and ETiX embryoids. We discuss current developments in organoid research and highlight developments in organoid culturing systems and analysis tools which make organoids accessible for high-throughput and high-content screening. Finally, we summarize the potential of machine learning and computational modeling in conjunction with organoid systems.