Creating in vitro models of diseases of the pancreatic ductal compartment requires a comprehensive understanding of the developmental trajectories of pancreas-specific cell types. Here, we report the single-cell characterization of the differentiation of pancreatic duct-like organoids (PDLOs) from human induced pluripotent stem cells (hiPSCs) on a microwell chip that facilitates the uniform aggregation and chemical induction of hiPSC-derived pancreatic progenitors. Via time-resolved single-cell transcriptional profiling and immunofluorescence imaging of the forming PDLOs, we identified differentiation routes from pancreas progenitors through ductal intermediates to two types of mature duct-like cell and a few non-ductal cell types. PDLO subpopulations expressed either mucins or the cystic fibrosis transmembrane conductance regulator, and resembled human adult duct cells. We also used the chip to uncover ductal markers relevant to pancreatic carcinogenesis, and to establish PDLO co-cultures with stellate cells, which allowed for the study of epithelial–mesenchymal signalling. The PDLO microsystem could be used to establish patient-specific pancreatic-duct models.

Background Organotypic cultures derived from pancreatic ductal adenocarcinoma (PDAC) termed pancreatic ductal cancer organoids (PDOs) recapitulate the primary cancer and can be derived from primary or metastatic biopsies. Although isolation and culture of patient-derived pancreatic organoids were established several years ago, pros and cons for individualized medicine have not been comprehensively investigated to date. Methods We conducted a feasibility study, systematically comparing head-to-head patient-derived xenograft tumor (PDX) and PDX-derived organoids by rigorous immunohistochemical and molecular characterization. Subsequently, a drug testing platform was set up and validated in vivo. Patient-derived organoids were investigated as well. Results First, PDOs faithfully recapitulated the morphology and marker protein expression patterns of the PDXs. Second, quantitative proteomes from the PDX as well as from corresponding organoid cultures showed high concordance. Third, genomic alterations, as assessed by array-based comparative genomic hybridization, revealed similar results in both groups. Fourth, we established a small-scale pharmacotyping platform adjusted to operate in parallel considering potential obstacles such as culture conditions, timing, drug dosing, and interpretation of the results. In vitro predictions were successfully validated in an in vivo xenograft trial. Translational proof-of-concept is exemplified in a patient with PDAC receiving palliative chemotherapy. Conclusion Small-scale drug screening in organoids appears to be a feasible, robust and easy-to-handle disease modeling method to allow response predictions in parallel to daily clinical routine. Therefore, our fast and cost-efficient assay is a reasonable approach in a predictive clinical setting.

The most frequent malignancy of the pancreas is the pancreatic ductal adenocarcinoma (PDAC). Despite many efforts PDAC has still a dismal prognosis. Biomarkers for early disease stage diagnosis as a prerequisite for a potentially curative treatment are still missing. Novel blood-based markers may help to overcome this limitation. Methods: Prior to surgery plasma levels of thrombospondin-2 (THBS2), which was recently published as a novel biomarker, and CA19-9 from 52 patients with histologically proven PDAC were determined, circulating cell-free (cfDNA) was quantified. 15 patients with side-branch IPMNs without worrisome features and 32 patients with chronic pancreatitis served for comparison. Logit (logistic regression) models were used to test the performance of single biomarkers and biomarker combinations. Results: CA19-9 and THBS2 alone showed comparable c-statistics of 0.80 and 0.73, respectively, improving to 0.87 when combining these two markers. The c-statistic was further increased to 0.94 when combining CA19-9 and THBS2 with cfDNA quantification. This marker combination performed best for all PDAC stages but also for PDACs grouped by stage. The greatest improvement over CA19-9 was seen in the group of stage I PDAC, from 0.69 to 0.90 for the three marker combination. Conclusion: These data establish the combination of CA19-9, THBS2 and cfDNA as a composite liquid biomarker for non-invasive diagnosis of early-stage PDAC.

The recognition of intra-tumoral cellular heterogeneity has given way to the concept of the cancer stem cell (CSC). According to this concept, CSCs are able to self-renew and differentiate into all of the cancer cell lineages present within the tumor, placing the CSC at the top of a hierarchical tree. The observation that these cells—in contrast to bulk tumor cells—are able to exclusively initiate new tumors, initiate metastatic spread and resist chemotherapy implies that CSCs are solely responsible for tumor recurrence and should be therapeutically targeted. Toward this end, dissecting and understanding the biology of CSCs should translate into new clinical therapeutic approaches. In this article, we review the CSC concept in cancer, with a special focus on hepatocellular carcinoma.

Objectives: IgG4-related disease (IgG4-RD) is a chronic fibro-inflammatory disorder affecting virtually any organ. Type 1 autoimmune (type 1 AIP) is its pancreatic manifestation. To date, steroids are considered the first-line pancreatitis treatment. The CD20-binding antibody rituximab (RTX) appears a promising steroid-sparing therapy, although long-term data are lacking. We aimed to bridge this gap with a cohort of IgG4-RD patients treated with RTX and to assess the potential value of the Responder Index (RI) as a discriminatory score for disease activity. Methods: We retrospectively evaluated 46 patients from a tertiary referral centre who were diagnosed with IgG4-RD and/or type 1 AIP according to the International Consensus Diagnostic Criteria or Unifying-AIP criteria between June 2006 and August 2019. Results: Patients resembled previous cohorts in terms of characteristics, diagnosis, and therapeutic response. Thirteen of the 46 patients with IgG4-RD/type 1 AIP were treated with RTX pulse therapy due to relapse, adverse reactions to steroids, or high-risk constellations predicting a severe course of disease with multi-organ involvement. Median follow-up after diagnosis was 52 months for all subjects, and 71 months in IgG4-RD patients treated with RTX. While patients in the RTX group showed no significant response to an initial steroid pulse, clinical activity as measured by the RI significantly decreased in the short-term after RTX induction. Within 16 months, 61% of patients relapsed in the RTX group but responded well to re-induction. Clinical and laboratory parameters improved equally in response to RTX. Conclusion: RTX therapy in patients with IgG4-RD is an effective and safe treatment to induce treatment response and possible long-term remission. Repeated RTX administration after 6–9 months may be of value in reducing the risk of relapse. The RI appears to be a reasonable index to assess disease activity and to identify patients with IgG4-related disease who may benefit from B-cell-depleting therapy.