Adaptive cell fate decisions in response to changing microenvironmental conditions, including therapy-imposed selective pressure, are fundamental to tumor evolution. Cellular plasticity enables tumor initiation, detachment from the primary lesion, dissemination, and metastatic outgrowth. At the same time, plasticity fuels intratumoral heterogeneity, promotes immune evasion, and underlies resistance to therapy, making it a central mechanistic principle of cancer progression.

Transcription factor isoforms execute distinct functions in PDAC progression and metastasis

We identified the transcription factor Paired-related homeobox 1 (Prrx1) as a central regulator of cellular plasticity in pancreatic ductal adenocarcinoma (PDAC) (Reichert et al., Genes & Development, 2013). Using complementary in vitro and in vivo models, we uncovered opposing roles of Prrx1 isoforms in metastasis: Prrx1b promotes invasion, dedifferentiation, and epithelial-to-mesenchymal transition, whereas Prrx1a drives metastatic outgrowth, tumor differentiation, and mesenchymal-to-epithelial transition (Takano, Reichert et al., Genes & Development, 2016). Isoform switching between Prrx1b and Prrx1a governs EMT plasticity in both mouse models and human PDAC. Mechanistically, we identified hepatocyte growth factor (HGF) as a direct transcriptional target of Prrx1b, and combined targeting of HGF with gemcitabine suppressed primary tumor growth and eliminated metastases in preclinical PDAC models. These findings directly informed a phase 1b clinical trial (NCT03316599).

Regulation of epithelial plasticity determines metastatic organotropism in pancreatic cancer

Epithelial plasticity critically depends on the ability of cancer cells to establish and release cell–cell contacts, a process stabilized by membranous E-cadherin through its interaction with p120-catenin (p120ctn). Using complementary genetically engineered mouse models, we demonstrated that metastatic organotropism in pancreatic ductal adenocarcinoma (PDAC) is governed by p120ctn-mediated epithelial identity (Reichert et al., Developmental Cell, 2018). Mono-allelic loss of p120ctn accelerates KrasG12D-driven PDAC formation and promotes liver metastasis while preserving E-cadherin–dependent adhesion, whereas bi-allelic loss shifts metastatic tropism toward the lung. Rescue of p120ctn restores liver metastasis, and in p120ctn-independent models, mosaic E-cadherin loss reveals selective pressure for E-cadherin–positive liver and E-cadherin–negative lung metastases. Together, these findings establish epithelial plasticity as a key determinant of metastatic organotropism and provide a mechanistic explanation for the more favorable prognosis of PDAC patients with isolated lung metastases.

Cancer-associated fibroblast plasticity drives aggressive pancreatic cancer biology

Dynamic cell fate decisions in pancreatic ductal adenocarcinoma (PDAC) extend beyond tumor cells to the tumor microenvironment, particularly cancer-associated fibroblasts (CAFs), whose differentiation states determine tumor-promoting or tumor-restraining functions. We identified PRRX1 expression in the stromal compartment of murine and human PDAC, where high stromal PRRX1 levels associate with the aggressive squamous subtype, while low expression characterizes classical PDAC, suggesting a functional role for PRRX1 in CAFs (Feldmann et al., Gastroenterology, 2021). Using a fibroblast-specific conditional Prrx1 knockout, we demonstrated that loss of Prrx1 induces CAF activation, increases extracellular matrix deposition, improves tumor differentiation, reduces circulating tumor cells, and suppresses metastasis. Mechanistically, PRRX1-expressing CAFs promote epithelial-to-mesenchymal transition and chemoresistance in tumor cells via paracrine HGF signaling. Notably, Prrx1-deficient CAFs remodel the tumor microenvironment toward an immune-infiltrated state, revealing fibroblast plasticity as a tractable therapeutic vulnerability to convert tumor-promoting into tumor-restraining stroma.

Generation of patient-derived organoids

In the past, we have generated three-dimensional (3D) organoid cell cultures of mouse PDAC cells (Reichert et al., Nature Protocols 2013). With our expertise in 3D culture, we applied this technology to generate disease models directly from the patient. Over the past decade, organoid technology has reshaped biomedical and translational research in oncology and beyond. Importantly, tumor organoids maintain the genetic heterogeneity of the parenteral tumor, therefore these 3D structures represent a promising preclinical model system, particularly, for a heterogeneous cancer such as pancreatic cancer. Using this model system, we are able to make contributions to different areas in the field of cancer research including studies published in Cancer Cell, Nature Medicine, Gastroenterology, Cell Stem Cell, Nature Communications, Molecular Systems Biology, and Nature Biomedical Engineering.

Studying tumor morphogenesis and metastasis using patient-derived organoids in in vivo systems

To interrogate complex biological processes such as invasion and metastasis, we integrated patient-derived organoid (PDO) technology with in vivo models. Orthotopic transplantation of PDOs into the pancreas of immunocompromised mice generates PDOX tumors that closely recapitulate patient tumor histology and metastatic behavior (Dantes et al., JCI Insight, 2020). More recently, we established a PDO-on-chick chorioallantoic membrane (CAM) model, a scalable and naturally immunodeficient in vivo system that enables efficient analysis of tumor invasion and dissemination. PDO-derived tumors on the CAM faithfully reproduce the morphology of their parental tumors and metastasize to distant tissues, which can be quantitatively assessed using human-specific Alu sequence detection. This in ovo platform allows genetic and pharmacologic manipulation of patient-derived and murine PDAC organoids and supports medium-scale functional screening of metastatic capacity.

Single-cell phenotyping of PDAC to study intratumoral heterogeneity and EMT plasticity

We established digital holographic microscopy (DHM) as a label-free, high-throughput technology for functional characterization of pancreatic cancer cells (Wittenzellner et al., JCI Insight, 2025). DHM captures quantitative phase information derived from intracellular refractive index differences, providing rich single-cell–resolved phenotypic information. Coupling DHM with microfluidic systems enables high-throughput analysis of non-adherent single-cell suspensions. Using pixel-based machine learning approaches, we classify cells by identity, epithelial–mesenchymal transition status, or malignancy, and stratify pancreatic cancer patient-derived organoids into classical and quasi-mesenchymal subtypes, mirroring transcriptomic classifications. The technology is patented (Patent No.: EP20206259.2) and offers broad potential for scalable clinical translation.

Next-generation organoids to interrogate intratumoral heterogeneity in PDAC

In Papargyriou et al. (Nature Biomedical Engineering, 2025), we introduce a next-generation organoid platform designed to systematically capture and interrogate intratumoral heterogeneity in PDAC. By integrating advanced organoid engineering with high-content imaging and multi-modal molecular profiling, this approach enables parallel analysis of distinct tumor cell states in distinct PDAC subtypes. The platform preserves spatial, phenotypic, and functional diversity and allows quantitative linkage of cellular heterogeneity to therapeutic response. This work establishes next-generation organoids as a scalable and clinically relevant framework to dissect tumor complexity and to inform precision oncology strategies in PDAC. 

Employing patient-derived organoids as a translational validation platform

Patient-derived organoids (PDOs) faithfully recapitulate key biological features of their parental tumors and serve as a powerful engine for forward and reverse translation in oncology. By bridging conventional in vitro assays, animal models, and clinical studies, PDOs provide a versatile platform for functional validation of therapeutic concepts. Using PDOs, we demonstrated the relevance of a β2-adrenergic–neurotrophin feed-forward loop in PDAC and showed that propranolol significantly reduces PDO viability and enhances the efficacy of gemcitabine (Renz et al., Cancer Cell, 2018). We also supported targeting the KRAS dependency on PTPN11/SHP2, contributing to the initiation of an international phase I/Ib clinical trial (SHERPA trial; Ruess et al., Nature Medicine, 2018). Beyond tumor cell–intrinsic vulnerabilities, we applied PDOs to evaluate CAR-T cell therapies and complex tumor–microenvironment interactions, highlighting their modular integration with immune cells and cancer-associated fibroblasts (Lesch et al., Nature Biomedical Engineering, 2021; Feldmann et al., Gastroenterology, 2021).

Cell-free DNA in PDO supernatant recapitulates patient tumor genomics

A major limitation of patient-derived organoids (PDOs) in precision oncology is the time required from biopsy to molecular and functional characterization, particularly when tumor material from EUS-guided fine-needle aspirations is scarce. To accelerate this process, we analyzed cell-free tumor DNA (cfDNA) released into PDO-conditioned media during early culture. Genetic alterations detected in PDO supernatants as early as 72 hours after biopsy accurately recapitulate the mutational landscape of the parental tumor, even in cases where conventional tissue profiling was not feasible. This approach enables rapid molecular profiling and downstream drug testing from minimal biopsy material, supporting timely clinical implementation of PDO-based precision oncology (Dantes et al., JCI Insight, 2020).

Implementation of a functional precision oncology platform

Despite major advances in precision oncology, the rate of molecularly informed treatment decisions in pancreatic ductal adenocarcinoma (PDAC) remains low. Primary tumor models such as patient-derived organoids (PDOs) enable the addition of a functional and mechanistic layer to precision oncology by allowing systematic genetic and pharmacological interrogation. We established a longitudinal functional precision oncology platform to identify therapy-induced vulnerabilities and demonstrated that chemotherapy-driven tumor cell plasticity dynamically reshapes sensitivity to targeted therapies—even in the absence of selectable genetic biomarkers (Peschke et al., EMBO Molecular Medicine, 2022). These findings highlight tumor plasticity as a tractable and exploitable feature in highly adaptive cancers such as PDAC.

Building on this work, we initiated a Germany-wide patient-derived organoid platform for pancreatic and colorectal cancer within the German Cancer Consortium (DKTK). This platform aims to implement organoid technologies at scale to functionally link tumor biology with clinical outcomes. The DKTK organoid platform is led and coordinated by Max Reichert together with Daniel Stange (Dresden) and Henner Farin (Frankfurt), providing a national infrastructure for functional precision oncology and prospective clinical translation.

A central pillar of our research is the direct implementation of organoid-based and immune-engineering technologies into prospective clinical trials. By embedding functional model systems into trial design, we aim to translate biological insights into clinically actionable strategies and advance precision oncology beyond purely molecular stratification.

The UNITEPANC trial (lead center: Ulm) is the first study in Germany to implement patient-derived organoid technology to guide therapy decisions in the adjuvant setting for resectable pancreatic cancer. This trial provides a unique opportunity to prospectively evaluate organoid-informed treatment strategies and to translate functional precision oncology into routine clinical care.

In the ESPAC-6 trial, Max Reichert serves as both clinical investigator and Chair of the Translational Committee. This dual role enables active shaping of the clinical study protocol alongside a tightly integrated translational research program, aligning clinical endpoints with organoid-based functional analyses and biomarker development.

Our clinical platform was further expanded through ResCPa, a nationwide, BMBF-funded “Grand Challenge” project that launched in December 2024. ResCPa aims to develop a novel CD318-directed CAR-T cell therapy for pancreatic cancer, addressing a major unmet need in solid tumor immunotherapy. The consortium includes the University Hospitals of Freiburg, Tübingen, Heidelberg, TUM University Hospital, and the BIH at Charité, in collaboration with Miltenyi Biotec. The project spans preclinical development through early clinical testing, with a first-in-human study planned for 2026 and exemplifies our strategy to rapidly translate experimental innovations into clinical application.