Esophageal squamous cell carcinoma (ESCC), a predominant form of esophageal cancer in East Asia and Japan, continues to pose a formidable challenge in oncology due to its high lethality and frequent recurrence following treatment. Ranking seventh in incidence and sixth in cancer-related mortality worldwide, esophageal cancer’s aggressive nature is compounded by the persistent issue of chemotherapy resistance, which limits effective management and worsens patient outcomes. In an innovative leap forward, researchers at the newly established Institute of Science Tokyo have harnessed the cutting-edge organoid technology to develop a comprehensive library of patient-derived ESCC organoids. These three-dimensional cellular structures faithfully recapitulate the complex biology of individual tumors, providing unprecedented insight into the mechanisms underlying chemotherapy resistance.
Traditional models of chemotherapy resistance often rely on prolonged drug exposure to cancer cell lines, ultimately resulting in artificial adaptations that only partially mirror patient tumors. In contrast, the organoids generated by Professor Toshiaki Ohteki’s team represent chemo-resistant ESCCs directly sourced from diverse patient specimens, maintaining essential oncogenic mutations and tumor microenvironmental characteristics. This patient-specific fidelity allows for more accurate evaluation of drug responses and molecular pathways driving resistance. The resulting organoid library encapsulates a spectrum of genetic backgrounds and clinical histories, reflecting the heterogeneity inherent in ESCC and offering a robust platform for personalized medicine approaches.
The study, published in Communications Biology, is the product of an extensive collaboration among researchers from the Institute of Science Tokyo’s Medical Research Laboratory, along with notable contributions from Keio University and Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital. By cultivating organoids from 24 patients, the researchers confirmed that these miniaturized tumors retained hallmark ESCC features, including nuclear accumulation of the p53 protein, a common consequence of TP53 mutations which play a pivotal role in tumorigenesis. Genomic and transcriptomic analyses revealed that each organoid preserved patient-specific mutational landscapes and gene expression profiles linked to heightened proliferative capacity and DNA replication—key hallmarks of malignancy.
To evaluate the organoids’ physiological relevance, the team transplanted them into immunodeficient murine models, where the organoids recapitulated the histopathological architecture of the original tumors. The xenografts exhibited both morphological characteristics and molecular markers consistent with human ESCC, underscoring the organoids’ utility as faithful in vivo models. This dual validation—both in vitro and in vivo—offers a powerful tool for dissecting tumor biology, enabling researchers to interrogate resistance mechanisms and potential therapeutic interventions across multiple levels.
A central focus of the investigation was the response of the organoid lines to the standard chemotherapy regimen of cisplatin combined with 5-fluorouracil (CF), commonly employed in treating ESCC. While the majority of organoids displayed sensitivity to this treatment, a significant subset, approximately 29%, demonstrated inherent resistance. Intriguingly, these resistant organoids exhibited robust activation of the nuclear factor erythroid 2-related factor 2 (NRF2) pathway. This pathway orchestrates cellular defenses against oxidative stress by regulating antioxidant gene expression, but when aberrantly activated in cancer cells, NRF2 confers a survival advantage that blunts the efficacy of chemotherapy. Elevated expression of NRF2 downstream target genes such as ALDH3A1, SPP1, and TXNRD1 highlighted their potential role as biomarkers predictive of therapeutic resistance.
The identification of NRF2 pathway hyperactivity in chemo-resistant ESCC organoids aligns with emerging evidence implicating this signaling axis as a key modulator of tumor resilience. NRF2’s control over antioxidant response elements enables malignant cells to offset the oxidative damage inflicted by chemotherapeutic agents, contributing to treatment failure. Recognizing this, the research not only advances understanding of resistance biology but also underscores the necessity for precision medicine strategies that incorporate biomarker-guided patient stratification, enabling clinicians to tailor therapeutic regimens consonant with tumor-specific molecular profiles.
Despite the protective shield provided by NRF2 activation, the researchers serendipitously discovered that the drug fedratinib, originally developed as a Janus kinase 2 (JAK2) inhibitor for myeloproliferative disorders, exerted superior antitumor effects against resistant ESCC organoids compared to standard CF therapy. Remarkably, this efficacy appeared independent of the NRF2 pathway, suggesting alternative mechanisms at play. Subsequent investigations revealed that fedratinib’s anti-proliferative properties are linked to the inhibition of bromodomain-containing protein 4 (BRD4), a chromatin reader implicated in regulating transcriptional programs essential for cancer cell growth and survival. By repressing BRD4 function, fedratinib disrupts oncogenic transcriptional networks, representing a promising therapeutic avenue capable of bypassing NRF2-mediated resistance.
The deployment of patient-derived organoids as a preclinical testing platform exemplifies the translational power of this technology. Beyond modeling cancer heterogeneity, organoids permit high-throughput drug screening and mechanistic studies within a physiologically relevant context, accelerating the identification of novel treatments and combination strategies. This paradigm shift from traditional cell line models towards patient-specific organoids heralds a new era in oncology research, where therapeutic decisions can be informed by direct functional assessment of tumor responses, enhancing treatment precision and efficacy.
Professor Ohteki emphasizes that the ESCC organoid library’s breadth—encompassing multiple chemo-resistant clones with diverse oncogenic mutations—provides an invaluable resource for probing differential drug susceptibilities and resistance pathways. As approximately 28% of ESCC patients exhibit suboptimal responses to neoadjuvant chemotherapy, the availability of such predictive biomarkers and organoid models is critical for early identification of patients unlikely to benefit from standard protocols. This will facilitate timely transition to alternative therapies, potentially improving survival outcomes and quality of life.
The research heralds significant clinical implications, notably the prospect of personalizing ESCC treatment regimens based on organoid-based sensitivity profiling and biomarker expression, such as NRF2 targets and BRD4 activity. Moreover, the successful repurposing of fedratinib underscores how existing drugs can be redirected to combat chemotherapy-resistant malignancies, potentially shortening the timeline to clinical application. Future investigations are poised to extend these findings, exploring combination therapies that may overcome multifaceted resistance mechanisms and investigating the role of tumor microenvironmental factors within organoid systems.
The Institute of Science Tokyo, newly formed through the merger of the Tokyo Medical and Dental University and Tokyo Institute of Technology, reinforces its mission to advance scientific discovery and translate research into societal value through this pioneering study. By integrating multidisciplinary expertise and leveraging innovative technologies, the institute contributes to combating one of the most challenging cancers, offering renewed hope for patients afflicted with ESCC.
In conclusion, the development of a patient-derived ESCC organoid library has illuminated critical pathways underpinning chemotherapy resistance while providing a versatile platform for preclinical drug evaluation. This work exemplifies the potential for organoid technology to transform cancer research, enabling precision oncology to move from concept to clinical reality. As these findings propagate through the medical community, they promise to stimulate further research and accelerate the development of effective, personalized therapies that address the urgent unmet needs in esophageal cancer treatment.
Subject of Research: Cells
Article Title: An organoid library of human esophageal squamous cell carcinomas (ESCCs) uncovers the chemotherapy-resistant ESCC features
News Publication Date: 1-Apr-2025
Web References:
DOI: 10.1038/s42003-025-07869-4
Image Credits: Institute of Science Tokyo
Keywords: Esophageal cancer, Diseases and disorders, Cancer, Carcinoma, Medical treatments
