bims-tuchim Biomed News
on Tumor-on-chip models
Issue of 2021–11–21
eight papers selected by
Philipp Albrecht, Friedrich Schiller University



  1. Front Cell Dev Biol. 2021 ;9 748631
      Pancreatic ductal adenocarcinoma (PDAC) is a hostile solid malignancy coupled with an extremely high mortality rate. Metastatic disease is already found in most patients at the time of diagnosis, resulting in a 5-year survival rate below 5%. Improved comprehension of the mechanisms leading to metastasis is pivotal for the development of new targeted therapies. A key field to be improved are modeling strategies applied in assessing cancer progression, since traditional platforms fail in recapitulating the complexity of PDAC. Consequently, there is a compelling demand for new preclinical models that mirror tumor progression incorporating the pressure of the immune system, tumor microenvironment, as well as molecular aspects of PDAC. We suggest the incorporation of 3D organoids derived from genetically engineered mouse models or patients as promising new tools capable to transform PDAC pre-clinical modeling and access new frontiers in personalized medicine.
    Keywords:  GEMMs; PDAC – pancreatic ductal adenocarcinoma; metastasis; metastasis models; organoids; pancreatic cancer
    DOI:  https://doi.org/10.3389/fcell.2021.748631
  2. Nat Rev Cancer. 2021 Nov 17.
      Pancreatic ductal adenocarcinoma (PDAC), already among the deadliest epithelial malignancies, is rising in both incidence and contribution to overall cancer deaths. Decades of research have improved our understanding of PDAC carcinogenesis, including characterizing germline predisposition, the cell of origin, precursor lesions, the sequence of genetic alterations, including simple and structural alterations, transcriptional changes and subtypes, tumour heterogeneity, metastatic progression and the tumour microenvironment. These fundamental advances inform contemporary translational efforts in primary prevention, screening and early detection, multidisciplinary management and survivorship, as prospective clinical trials begin to adopt molecular-based selection criteria to guide targeted therapies. Genomic and transcriptomic data on PDAC were also included in the international pan-cancer analysis of approximately 2,600 cancers, a milestone in cancer research that allows further insight through comparison with other tumour types. Thus, this is an ideal time to review our current knowledge of PDAC evolution and heterogeneity, gained from the study of preclinical models and patient biospecimens, and to propose a model of PDAC evolution that takes into consideration findings from varied sources, with a particular focus on the genomics of human PDAC.
    DOI:  https://doi.org/10.1038/s41568-021-00418-1
  3. Nat Commun. 2021 Nov 18. 12(1): 6738
      FOLFIRINOX, a combination of chemotherapy drugs (Fluorouracil, Oxaliplatin, Irinotecan -FOI), provides the best clinical benefit in pancreatic ductal adenocarcinoma (PDAC) patients. In this study we explore the role of miRNAs (MIR) as modulators of chemosensitivity to identify potential biomarkers of response. We find that 41 and 84 microRNA inhibitors enhance the sensitivity of Capan1 and MiaPaCa2 PDAC cells respectively. These include a MIR1307-inhibitor that we validate in further PDAC cell lines. Chemotherapy-induced apoptosis and DNA damage accumulation are higher in MIR1307 knock-out (MIR1307KO) versus control PDAC cells, while re-expression of MIR1307 in MIR1307KO cells rescues these effects. We identify binding of MIR1307 to CLIC5 mRNA through covalent ligation of endogenous Argonaute-bound RNAs cross-linking immunoprecipitation assay. We validate these findings in an in vivo model with MIR1307 disruption. In a pilot cohort of PDAC patients undergoing FOLFIRONX chemotherapy, circulating MIR1307 correlates with clinical outcome.
    DOI:  https://doi.org/10.1038/s41467-021-27099-6
  4. J Immunother Cancer. 2021 Nov;pii: e003213. [Epub ahead of print]9(11):
       BACKGROUND: Tumor-specific cytotoxic T cells and T cell receptors are effective tools for cancer immunotherapy. Most efforts to identify them rely on known antigens or lymphocytes that have infiltrated into the tumor bed. Approaches to empirically identify tumor-targeting T cells and T cell receptors by exploiting all antigens expressed on tumor cell surfaces are not well developed for most carcinomas, including pancreatic cancer.
    METHODS: Autologous tumor organoids were stimulated with T cells from the patients' peripheral blood for 2 weeks to generate the organoid-primed T (opT) cells. opT cell phenotype was analyzed by monitoring changes in the expression levels of 28 cell surface and checkpoint proteins. Expression of ligands of the immune checkpoints was investigated by immunohistochemistry staining. T cells were labeled with carboxyfluorescein succinimidyl ester (CFSE) and assayed by flow cytometry to monitor tumor-induced T cell proliferation changes. opT cell-mediated killing of three-dimensional organoids was measured using an M30 ELISA kit. T cell receptors (TCRs) were identified by deep sequencing of gDNA isolated from T cells, and the TCR specificity was confirmed by transferring TCRs to the T cell line SKW-3 or donor T cells.
    RESULTS: The co-culture was effective in the generation of CD8 + or CD4+opT cells. The opT cells killed autologous tumors in a granzyme B or Fas-Fas ligand-dependent manner and expressed markers of tissue-resident memory phenotype. Each patient-derived opT cell culture displayed a unique complement of checkpoint proteins. Interestingly, only NKG2A blockade showed a potent increase in the interferon-γ production compared with blocking programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) or TIM3 or TIGIT or LAG3. Importantly, TCR sequencing demonstrated a dramatic clonal expansion of T cells with a restricted subset of TCRs. Cloning and transferring the TCRs to heterologous T cells was sufficient to confer tumor cell recognition and cytotoxic properties in a patient-specific manner.
    CONCLUSION: We report a platform for expanding tumor-targeting T cells from the peripheral blood of patients with pancreatic cancer. We identify the NKG2A-HLA-E axis as a potentially important checkpoint for CD8 +T cells for pancreatic cancer. Lastly, we demonstrate empirical identification of tumor-targeting TCRs that can be used for TCR-therapeutics.
    Keywords:  antigen-mediated; clonal selection; gastrointestinal neoplasms; immunologic techniques
    DOI:  https://doi.org/10.1136/jitc-2021-003213
  5. Front Immunol. 2021 ;12 769047
      Pancreatic ductal adenocarcinoma (PDAC) is a malignant tumor characterized by rapid progression, early metastasis, high recurrence, and limited responsiveness to conventional therapies. The 5-year survival rate of PDAC is extremely low (<8%), which lacks effective prognostic evaluation indicators. In this study, we used xCell to analyze infiltrating immune cells in a tumor and through the univariate and multivariate Cox analyses screened out two prognosis-related immune cells, CD4+TN and common lymphoid progenitor (CLP), which were used to construct a Cox model and figure out the risk-score. It was found that the constructed model could greatly improve the sensitivity of prognostic evaluation, that the higher the risk-score, the worse the prognosis. In addition, the risk-score could also identify molecular subtypes with poor prognosis and immunotherapy sensitivity. Through transcriptome and whole-exome sequencing analysis of PDAC dataset from The Cancer Genome Atlas (TCGA), it was found that copy number deletion and low expression of CCL19 might be crucial factors to affect the risk-score. Lastly, validation of the above findings was confirmed not only in Gene Expression Omnibus (GEO) datasets but also in our PDAC patient samples, Peking2020 cohort.
    Keywords:  PDAC; immunotherapy sensitivity; molecular subtype; prognosis prediction; risk-score
    DOI:  https://doi.org/10.3389/fimmu.2021.769047
  6. Biomaterials. 2021 Nov 13. pii: S0142-9612(21)00605-0. [Epub ahead of print] 121248
      Hemodynamics play a central role in the health and disease of the coronary and peripheral vascular systems. Vessel-lining endothelial cells are known mechanosensors, responding to disturbances in flow - with mechanosensitivity hypothesized to change in response to metabolic demands. The health of our smallest microvessels have been lauded as a prognostic marker for cardiovascular health. Yet, despite numerous animal models, studying these small vessels has proved difficult. Microfluidic technologies have allowed a number of 3D vascular models to be developed and used to investigate human vessels. Here, two such systems are employed for examining 1) interstitial flow effects on neo-vessel formation, and 2) the effects of flow-conditioning on vascular remodeling following sustained static culture. Interstitial flow is shown to enhance early vessel formation via significant remodeling of vessels and interconnected tight junctions of the endothelium. In formed vessels, continuous flow maintains a stable vascular diameter and causes significant remodeling, contrasting the continued anti-angiogenic decline of statically cultured vessels. This study is the first to couple complex 3D computational flow distributions and microvessel remodeling from microvessels grown on-chip (exposed to flow or no-flow conditions). Flow-conditioned vessels (WSS < 1Pa for 30 μm vessels) increase endothelial barrier function, result in significant changes in gene expression and reduce reactive oxygen species and anti-angiogenic cytokines. Taken together, these results demonstrate microvessel mechanosensitivity to flow-conditioning, which limits deleterious vessel regression in vitro, and could have implications for future modeling of reperfusion/no-flow conditions.
    Keywords:  Computational fluid dynamics; Flow-conditioning; Hemodynamics; In vitro vessels; Interstitial flow; Perfusion; Shear flow; Vascular remodeling
    DOI:  https://doi.org/10.1016/j.biomaterials.2021.121248
  7. Clin Cancer Res. 2021 Nov 17. pii: clincanres.4116.2020. [Epub ahead of print]
       PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) remains a significant health issue. For most patients there are no options for targeted therapy and existing treatments are limited by toxicity. The HOPE trial (Harnessing Organoids for PErsonalized Therapy) was a pilot feasibility trial aiming to prospectively generate patient derived organoids (PDOs) from patients with PDAC and test their drug sensitivity and correlation with clinical outcomes.
    EXPERIMENTAL DESIGN: PDOs were established from a heterogeneous population of patients with PDAC including both basal and classical PDAC subtypes.
    RESULTS: A method for classifying PDOs as sensitive or resistant to chemotherapy regimens was developed to predict the clinical outcome of study subjects. Drug sensitivity testing on PDOs correlated with clinical responses to treatment in individual patients.
    CONCLUSION: These data support the investigation of PDOs to guide treatment in prospective interventional trials in PDAC.
    DOI:  https://doi.org/10.1158/1078-0432.CCR-20-4116
  8. Proc Natl Acad Sci U S A. 2021 Nov 23. pii: e2112674118. [Epub ahead of print]118(47):
      High expression of programmed death-ligand 1 (PD-L1) in cancer cells drives immune-independent, cell-intrinsic functions, leading to resistance to DNA-damaging therapies. We find that high expression of the ubiquitin E3 ligase FBXO22 sensitizes nonsmall cell lung cancer (NSCLC) cells to ionizing radiation (IR) and cisplatin, and that activation of FBXO22 by phosphorylation is necessary for this function. Importantly, FBXO22 activates PD-L1 ubiquitination and degradation, which in turn increases the sensitivity of NSCLC cells to DNA damage. Cyclin-dependent kinase 5 (CDK5), aberrantly active in cancer cells, plays a crucial role in increasing the expression of PD-L1 in medulloblastoma [R. D. Dorand et al, Science 353, 399-403 (2016)]. We show in NSCLC cells that inhibiting CDK5 or reducing its expression increases the level of FBXO22, decreases that of PD-L1, and increases the sensitivity of the cells to DNA damage. We conclude that FBXO22 is a substrate of CDK5, and that inhibiting CDK5 reduces PD-L1 indirectly by increasing FBXO22. Pairing inhibitors of CDK5 with immune checkpoint inhibitors may increase the efficacy of immune checkpoint blockade alone or in combination with DNA-damaging therapies.
    Keywords:  CDK5; FBXO22; PD-L1; lung cancer
    DOI:  https://doi.org/10.1073/pnas.2112674118