Publications by authors named "Maximilian Reichert"

Droplet-based organoid culture offers several advantages over conventional bulk organoid culture, such as improved yield, reproducibility, and throughput. However, organoids grown in droplets typically display only a spherical geometry and lack the intricate structural complexity found in native tissue. By incorporating singularised pancreatic ductal adenocarcinoma cells into collagen droplets, we achieve the growth of branched structures, indicating a more complex interaction with the surrounding hydrogel.

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Background: Evidence on patient pathways, care coordination, and patient needs in rare cancers (RC) is limited but essential for optimising healthcare systems and resource allocation. Addressing these gaps requires country-specific data reflecting national healthcare structures and cultural differences. This is the first study in Germany to explore these dimensions.

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Pancreatic ductal adenocarcinoma (PDAC) is a highly invasive and heterogeneous malignancy, posing challenges for reproducible modeling and functional phenotypic analysis. To address these limitations, we developed a standardized 3D patternoid platform using collagen-based microcavity arrays to enhance organoid formation consistency and quantify subtype-specific invasion mechanisms. We utilized murine primary PDAC cells stratified by epithelial-mesenchymal transition (EMT) into three subtypes: epithelial (), hybrid EMT (), and mesenchymal ().

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Resistance to chemotherapy of pancreatic ductal adenocarcinoma (PDAC) is largely driven by intratumoral heterogeneity (ITH) due to tumor cell plasticity and clonal diversity. To develop alternative strategies to overcome this defined mechanism of resistance, tools to monitor and quantify ITH in a rapid and scalable fashion are needed urgently. Here, we employed label-free digital holographic microscopy (DHM) to characterize ITH in PDAC.

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Background: mutations are frequently observed in human cholangiocarcinoma (CCA), while they are relatively rare in hepatocellular carcinoma (HCC). The role of RAS-dependent signalling pathways in CCA development is currently not well understood.

Objective: The objective of this study was to investigate RAS-dependent signalling pathways in CCA and their role in tumour development and differentiation.

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Intestinal organoids reflect the 3D structure and function of their original tissues. Organoid are typically cultured in Matrigel, an extracellular matrix (ECM) mimicking the basement membrane, which is suitable for epithelial cells but does not accurately mimic the tumour microenvironment of colorectal cancer (CRC). The ECM and particularly collagen type I is crucial for CRC progression and invasiveness.

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Metastatic cancer remains a leading cause of cancer-related mortality, with a 5-year survival rate of just 8% for pancreatic ductal adenocarcinoma (PDAC). Among patients with metastatic PDAC, those with liver metastases experience significantly worse outcomes compared with the rare cases of isolated lung metastases. Recent findings by Link and colleagues reveal that these distinct metastatic patterns reflect underlying biological differences beyond established molecular subtypes.

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KRAS-dependent acinar-to-ductal metaplasia (ADM) is a fundamental step in the development of pancreatic ductal adenocarcinoma (PDAC), but the involvement of cell death pathways remains unclear. Here, we show that key regulators of programmed cell death (PCD) become upregulated during KRAS-driven ADM, thereby priming transdifferentiated cells to death. Using transgenic mice and primary cell and organoid cultures, we show that transforming growth factor (TGF)-β-activated kinase 1 (TAK1), a kinase regulating cell survival and inflammatory pathways, prevents the elimination of transdifferentiated cells through receptor-interacting protein kinase 1 (RIPK1)-mediated apoptosis and necroptosis, enabling PDAC development.

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Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive and characterized by pronounced desmoplasia. PDAC cells communicate with cancer-associated fibroblasts (CAFs) in a paracrine/reciprocal manner, substantially promoting tumor growth and desmoplastic responses. This study highlights the critical role of anterior gradient 2 (AGR2), an endoplasmic reticulum protein disulfide isomerase, secreted by PDAC cells to activate CAFs via the Wnt signaling pathway.

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The DNA-damaging agent Gemcitabine (GEM) is a first-line treatment for pancreatic cancer, but chemoresistance is frequently observed. Several clinical trials investigate the efficacy of GEM in combination with targeted drugs, including kinase inhibitors, but the experimental evidence for such rationale is often unclear. Here, we phenotypically screened 13 human pancreatic adenocarcinoma (PDAC) cell lines against GEM in combination with 146 clinical inhibitors and observed strong synergy for the ATR kinase inhibitor Elimusertib in most cell lines.

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In patients with pancreatic ductal adenocarcinoma (PDAC), intratumoural and intertumoural heterogeneity increases chemoresistance and mortality rates. However, such morphological and phenotypic diversities are not typically captured by organoid models of PDAC. Here we show that branched organoids embedded in collagen gels can recapitulate the phenotypic landscape seen in murine and human PDAC, that the pronounced molecular and morphological intratumoural and intertumoural heterogeneity of organoids is governed by defined transcriptional programmes (notably, epithelial-to-mesenchymal plasticity), and that different organoid phenotypes represent distinct tumour-cell states with unique biological features in vivo.

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We propose a quantum lidar protocol to jointly estimate the range and velocity of a target by illuminating it with a single beam of pulsed displaced squeezed light. In the lossless scenario, we show that the mean-squared errors of both range and velocity estimations are inversely proportional to the squared number of signal photons, simultaneously attaining the Heisenberg limit. This is achieved by engineering the multiphoton squeezed state of the temporal modes and adopting standard homodyne detection.

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Article Synopsis
  • Preclinical studies suggest that combining MEK inhibition with autophagy or CDK4/6 targeting may be beneficial for pancreatic cancer (PDAC) patients.
  • A retrospective analysis of 34 patients treated with trametinib combined with hydroxychloroquine (THCQ) or palbociclib (TP) was conducted to evaluate the effectiveness of these regimens.
  • Results showed that both combinations were ineffective, with most patients experiencing disease progression within a short time frame, highlighting the need for better treatment strategies for advanced PDAC with specific genetic mutations.
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Article Synopsis
  • * Direct KRAS inhibitors are showing promise in clinical trials, but resistance to treatment is a concern, prompting the search for combination therapies.
  • * Unbiased drug screening identified effective combinations involving SOS1 inhibitors, PTPN11/SHP2 inhibitors, and multi-kinase inhibitors, validated using a unique KRAS-mutated patient-derived organoid model.
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Background: A standardised dose-reduction strategy has not been established for the widely used gemcitabine plus nab-paclitaxel regimen in patients with metastatic pancreatic ductal adenocarcinoma. We aimed to investigate the efficacy and tolerability of alternating treatment cycles of nab-paclitaxel-gemcitabine combination therapy and gemcitabine alone versus continuous treatment with the nab-paclitaxel-gemcitabine combination.

Methods: ALPACA was a randomised, open-label, phase 2 trial conducted at 29 study centres across Germany.

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Article Synopsis
  • Lumens play a vital role in the architecture of both healthy pancreas tissues and precancerous pancreatic ductal adenocarcinoma (PDAC) lesions, facilitating enzyme transport and cyst-like structures.
  • Pancreatic-cancer organoids replicate critical features of both healthy and diseased pancreas, but the transition to hollowness in these structures is not well understood.
  • The study identifies two key mechanisms for lumen formation in these organoids: one involves fluid intake leading to multiple microlumen merging, and the other is through the death of central cells, creating hollow spaces.
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Article Synopsis
  • Cancer cells adapt to various stresses, including those from treatments, through metabolic adaptability, focusing on the energy sensor AMP-activated protein kinase (AMPK).
  • In pancreatic ductal adenocarcinoma (PDAC), high levels of AMPK expression and activity were observed, leading to the identification of PF-3758309 as a potential AMPK inhibitor through drug repurposing.
  • PF-3758309 not only demonstrates pre-clinical effectiveness in PDAC models but also helps sensitizes cancer cells to ferroptosis inducers, paving the way for AMPK-targeted therapies in combination treatments for this type of cancer.
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The prognosis for pancreatic cancer remains poor. Molecular diagnostics and customized therapies are becoming increasingly important in clinical routine. Patient-derived, predictive model systems such as organoids have the potential to substantially increase the depth of information from biopsy material by functional and molecular characterization.

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Background & Aims: The highly heterogeneous cellular and molecular makeup of pancreatic ductal adenocarcinoma (PDAC) not only fosters exceptionally aggressive tumor biology, but contradicts the current concept of one-size-fits-all therapeutic strategies to combat PDAC. Therefore, we aimed to exploit the tumor biological implication and therapeutic vulnerabilities of a clinically relevant molecular PDAC subgroup characterized by SMAD4 deficiency and high expression of the nuclear factor of activated T cells (SMAD4/NFATc1).

Methods: Transcriptomic and clinical data were analyzed to determine the prognostic relevance of SMAD4/NFATc1 cancers.

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Solid cancers like pancreatic ductal adenocarcinoma (PDAC), a type of pancreatic cancer, frequently exploit nerves for rapid dissemination. This neural invasion (NI) is an independent prognostic factor in PDAC, but insufficiently modeled in genetically engineered mouse models (GEMM) of PDAC. Here, we systematically screened for human-like NI in Europe's largest repository of GEMM of PDAC, comprising 295 different genotypes.

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Nivolumab is a promising monoclonal antibody inhibitor of programmed death-1, a protein on the surface of T-cells. As such, it is approved for use in patients with multiple advanced malignancies and can significantly elongate progression-free survival. However, monoclonal antibody inhibitors can lead to adverse hepatic reactions, which in rare cases result in further hepatic damage.

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The acquisition of mesenchymal traits is considered a hallmark of breast cancer progression. However, the functional relevance of epithelial-to-mesenchymal transition (EMT) remains controversial and context dependent. Here, we isolate epithelial and mesenchymal populations from human breast cancer metastatic biopsies and assess their functional potential in vivo.

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Targeting KRAS downstream signaling remains an important therapeutic approach in pancreatic cancer. We used primary pancreatic ductal epithelial cells and mouse models allowing the conditional expression of oncogenic Kras, to investigate KRAS signaling integrators. We observed that the AP1 family member FRA1 is tightly linked to the KRAS signal and expressed in pre-malignant lesions and the basal-like subtype of pancreatic cancer.

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Background: Risk stratification and recommendation for surgery for intraductal papillary mucinous neoplasm (IPMN) are currently based on consensus guidelines. Risk stratification from presurgery histology is only potentially decisive owing to the low sensitivity of fine-needle aspiration. In this study, we developed and validated a deep learning-based method to distinguish between IPMN with low grade dysplasia and IPMN with high grade dysplasia/invasive carcinoma using endoscopic ultrasound (EUS) images.

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