scholarly journals TMOD-26. MODELING GLIOBLASTOMA BY IMPLANTATION OF INTACT PATIENT-DERIVED ORGANOIDS INTO RODENT BRAINS

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi268-vi268
Author(s):  
Phuong Nguyen ◽  
Fadi Jacob ◽  
Ryan Salinas ◽  
Daniel Zhang ◽  
Hongjun Song ◽  
...  
Keyword(s):  
Treatment Options ◽  
Tumor Biology ◽  
Tumor Resection ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
In Vitro Models ◽  
Distinct Cell ◽  
Xenograft Models

Abstract Glioblastoma multiforme (GBM) is the most common primary and aggressive brain tumors in adults with extremely poor prognosis and limited treatment options. A major hallmark of GBM is the rapid and diffused infiltration of tumor cells into the surrounding healthy tissue that contribute to tumor recurrence and therapeutic resistance. However, existing in vitro cell culture or in vivo xenograft models inadequately recapitulate the inter-tumoral and intra-tumoral heterogeneity which are key features of GBM. For example, common oncogenic drivers of GBM such as epidermal growth factor receptor (EGFR) amplification and EGFRvIII mutation do not persist in traditional in vitro models due to selection pressures, thus requires exogenous overexpression. Alternatively, EGFR statuses can be maintained in xenografted mice, but implantation of the primary GBM cells into the flank is required to first establish the tumor prior to secondary injection into the brains. Recently, we have established a novel protocol for culturing GBM tissue as organoids (GBOs) directly from patient tumor resection that retain many distinct cell populations in vitro with high fidelity evidenced by histological, whole-exome, bulk and single cell RNA analyses. Compared to prolonged generation time of previously established in vitro and xenograft models, our methodology is robust for generating GBOs within 1–2 weeks from initial resection. In addition, these GBOs can be readily xenografted into the adult mouse brains as an intact organoid, exhibit rapid and aggressive infiltration phenotypes, and maintains driver mutation EGFRviii within as little as one month. Consequently, they can be used to test in vivo treatment efficacies in a timely fashion. The presence of diverse cell types in this GBO model offers a promising platform for not only understanding of tumor biology, but also more strategic development of new therapies.

scholarly journals Modelling the Human Placental Interface In Vitro—A Review

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 884
Author(s):  
Marta Cherubini ◽  
Scott Erickson ◽  
Kristina Haase
Keyword(s):  
Drug Testing ◽  
Cell Types ◽  
In Vitro Models ◽  
Placental Development ◽  
Scientific Challenge ◽  
Induced Pluripotent ◽  
And Function ◽  
And Control

Acting as the primary link between mother and fetus, the placenta is involved in regulating nutrient, oxygen, and waste exchange; thus, healthy placental development is crucial for a successful pregnancy. In line with the increasing demands of the fetus, the placenta evolves throughout pregnancy, making it a particularly difficult organ to study. Research into placental development and dysfunction poses a unique scientific challenge due to ethical constraints and the differences in morphology and function that exist between species. Recently, there have been increased efforts towards generating in vitro models of the human placenta. Advancements in the differentiation of human induced pluripotent stem cells (hiPSCs), microfluidics, and bioprinting have each contributed to the development of new models, which can be designed to closely match physiological in vivo conditions. By including relevant placental cell types and control over the microenvironment, these new in vitro models promise to reveal clues to the pathogenesis of placental dysfunction and facilitate drug testing across the maternal–fetal interface. In this minireview, we aim to highlight current in vitro placental models and their applications in the study of disease and discuss future avenues for these in vitro models.

scholarly journals Production of Human Pluripotent Stem Cell-Derived Hepatic Cell Lineages and Liver Organoids: Current Status and Potential Applications

2020 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
João P. Cotovio ◽  
Tiago G. Fernandes
Keyword(s):  
Cell Types ◽  
In Vitro Models ◽  
Hepatic Cell ◽  
Current Status ◽  
Organ Shortage ◽  
Cell Lineages ◽  
Potential Applications ◽  
Liver Organoids

Liver disease is one of the leading causes of death worldwide, leading to the death of approximately 2 million people per year. Current therapies include orthotopic liver transplantation, however, donor organ shortage remains a great challenge. In addition, the development of novel therapeutics has been limited due to the lack of in vitro models that mimic in vivo liver physiology. Accordingly, hepatic cell lineages derived from human pluripotent stem cells (hPSCs) represent a promising cell source for liver cell therapy, disease modelling, and drug discovery. Moreover, the development of new culture systems bringing together the multiple liver-specific hepatic cell types triggered the development of hPSC-derived liver organoids. Therefore, these human liver-based platforms hold great potential for clinical applications. In this review, the production of the different hepatic cell lineages from hPSCs, including hepatocytes, as well as the emerging strategies to generate hPSC-derived liver organoids will be assessed, while current biomedical applications will be highlighted.

scholarly journals Microphysiological Systems: A Pathologist’s Perspective

2020 ◽  
Vol 57 (3) ◽  
pp. 358-368
Author(s):  
Radhakrishna Sura ◽  
Terry Van Vleet ◽  
Brian R. Berridge
Keyword(s):  
Drug Discovery ◽  
Biomedical Research ◽  
Interdisciplinary Collaboration ◽  
Cell Types ◽  
In Vitro Models ◽  
In Vitro Methods ◽  
Microphysiological Systems ◽  
Regulatory Acceptance

High-throughput in vitro models lack human-relevant complexity, which undermines their ability to accurately mimic in vivo biologic and pathologic responses. The emergence of microphysiological systems (MPS) presents an opportunity to revolutionize in vitro modeling for both basic biomedical research and applied drug discovery. The MPS platform has been an area of interdisciplinary collaboration to develop new, predictive, and reliable in vitro methods for regulatory acceptance. The current MPS models have been developed to recapitulate an organ or tissue on a smaller scale. However, the complexity of these models (ie, including all cell types present in the in vivo tissue) with appropriate structural, functional, and biochemical attributes are often not fully characterized. Here, we provide an overview of the capabilities and limitations of the microfluidic MPS model (aka organs-on-chips) within the scope of drug development. We recommend the engagement of pathologists early in the MPS design, characterization, and validation phases, because this will enable development of more robust and comprehensive MPS models that can accurately replicate normal biology and pathophysiology and hence be more predictive of human responses.

scholarly journals Mesenchymal Stem Cells as a Promising Cell Source for Integration in Novel In Vitro Models

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1306
Author(s):  
Ann-Kristin Afflerbach ◽  
Mark D. Kiri ◽  
Tahir Detinis ◽  
Ben M. Maoz
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Cell Types ◽  
In Vitro Models ◽  
Cell Source ◽  
Fundamental Research ◽  
Multiple Cell ◽  
Vitro Model

The human-relevance of an in vitro model is dependent on two main factors—(i) an appropriate human cell source and (ii) a modeling platform that recapitulates human in vivo conditions. Recent years have brought substantial advancements in both these aspects. In particular, mesenchymal stem cells (MSCs) have emerged as a promising cell source, as these cells can differentiate into multiple cell types, yet do not raise the ethical and practical concerns associated with other types of stem cells. In turn, advanced bioengineered in vitro models such as microfluidics, Organs-on-a-Chip, scaffolds, bioprinting and organoids are bringing researchers ever closer to mimicking complex in vivo environments, thereby overcoming some of the limitations of traditional 2D cell cultures. This review covers each of these advancements separately and discusses how the integration of MSCs into novel in vitro platforms may contribute enormously to clinical and fundamental research.

Simultaneous protection against anti-EGFR antibody-dependent cellular cytotoxicity and EGFR-signaling blockade by oncogenic RAS.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 440-440
Author(s):  
M. H. Schuler ◽  
F. Breitenbuecher ◽  
T. Trarbach ◽  
S. Brandau ◽  
K. W. Schmid ◽  
...  
Keyword(s):  
Treatment Options ◽  
Growth Factor Receptor ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Egfr Signaling ◽  
Oncogenic Ras ◽  
Total Body ◽  
Egfr Antibody

440 Background: Monoclonal antibodies against the epidermal growth factor receptor (EGFR) have improved treatment options for colorectal cancer (CRC), but tumors harboring RAS mutations are resistant. Full molecular understanding of RAS-mediated protection is key to the development of sensitization strategies. Methods: We have used cell culture and murine CRC transplant models to study whether RAS solely imposes resistance by compensating EGFR signaling blockade, or additionally interferes with antibody-dependent cellular cytotoxicity (ADCC). Results: Both clinically approved anti-EGFR antibodies, cetuximab and panitumumab, were equally cytotoxic in CRC cells in vitro. Interestingly, cetuximab, a chimeric IgG1 antibody capable of triggering ADCC, was more effective than panitumumab (human IgG2) in murine CRC transplant models in vivo. The advantage of cetuximab in vivo was completely abolished by leukocyte depletion following total body irradiation. Moreover, oncogenic RAS neutralized the in vivo therapeutic activity of cetuximab and panitumumab to the same extent. Mechanistically, RAS conferred antibody resistance by upregulation of BCL-XL, which was overcome by cotreatment with a BH3 mimetic. In support, RAS-mutant primary human CRCs exhibited increased BCL-XL expression as detected by immunohistochemistry. Conclusions: RAS-mutant CRCs escape anti-EGFR antibody-mediated receptor blockade as well as ADCC in vivo. Pharmacologic modulation of RAS downstream effectors, such as BCL-XL, can restore sensitivity to antibody effector mechanisms. [Table: see text]

scholarly journals Shared Nucleotide Flanks Confer Transcriptional Competency to bZip Core Motifs

2018 ◽  
Author(s):  
Daniel M. Cohen ◽  
Hee-Woong Lim ◽  
Kyoung-Jae Won ◽  
David J. Steger
Keyword(s):  
Binding Sites ◽  
Cell Types ◽  
In Vitro Models ◽  
Strongly Correlated ◽  
Core Motif ◽  
Resolution Mapping ◽  
Dna Specificity ◽  
Dna Shape

ABSTRACTSequence-specific DNA binding recruits transcription factors (TFs) to the genome to regulate gene expression. Here, we perform high resolution mapping of CEBP proteins to determine how sequence dictates genomic occupancy. We demonstrate a fundamental difference between the sequence repertoire utilized by CEBPs in vivo versus the palindromic sequence preference reported by classical in vitro models, by identifying a palindromic motif at less than 1% of the genomic binding sites. On the native genome, CEBPs bind a diversity of related 10 bp sequences resulting from the fusion of degenerate and canonical half-sites. Altered DNA specificity of CEBPs in cells occurs through heterodimerization with other bZip TFs, and approximately 40% of CEBP-binding sites in primary human cells harbor motifs characteristic of CEBP heterodimers. In addition, we uncover an important role for sequence bias at core-motif-flanking bases for CEBPs and demonstrate that flanking bases regulate motif function across mammalian bZip TFs. Favorable flanking bases confer efficient TF occupancy and transcriptional activity, and DNA shape may explain how the flanks alter TF binding. Importantly, motif optimization within the 10-mer is strongly correlated with cell-type-independent recruitment of CEBPβ, providing key insight into how sequence sub-optimization affects genomic occupancy of widely expressed CEBPs across cell types.

scholarly journals Encapsulated multicellular tumor spheroids as a novel in vitro model to study small size tumors

2003 ◽  
Vol 57 (12) ◽  
pp. 585-588 ◽  
Author(s):  
Elena Markvicheva ◽  
Lina Bezdetnaya ◽  
Artur Bartkowiak ◽  
Annie Marc ◽  
Jean-Louis Gorgen ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Tumor Biology ◽  
Cell Encapsulation ◽  
Large Cell ◽  
In Vitro Models ◽  
Multicellular Tumor Spheroids ◽  
Tumor Spheroids ◽  
Vitro Model

Presently multicellular tumor spheroids (MTS) are being widely used in various aspects of tumor biology, including studies in biology and photodynamic therapy. The cellular organization of spheroids allows the recreation of in vivo small tumors much better than all common two-dimensional in vitro models. The cell encapsulation method could be proposed as a novel technique to quickly and easily prepare a large number of spheroids with narrow size distribution within a desirable diameter range. Moreover, the proposed technique for spheroid generation using encapsulated growing tumor cells could provide entirely new avenues to develop a novel spheroid co-culture model (for instance, the in vitro co-cultvation of tumor cells and monocytes, or epithelial cells, or fibroblasts etc). The current research was aimed at developing a simple and reliable method to encapsulate tumor cells and to cultivate them in vitro. In order to generate spheroids, MCF-7 cells were encapsulated and cultivated in 200 ml T-flasks in a 5% CO2 atmosphere at 37?C for 4-5 weeks. The cell proliferation was easily observed using a light microscope. The cells grew in aggregates increasing in size with time. The cell growth resulted in the formation of large cell clusters (spheroids) which filled the whole microcapsule volume in 4-5 weeks.

Therapeutics and Research Related to Glioblastoma: Advancements and Future Targets

2020 ◽  
Vol 21 (3) ◽  
pp. 186-198 ◽  
Author(s):  
Vishal Chavda ◽  
Vimal Patel ◽  
Dhananjay Yadav ◽  
Jigar Shah ◽  
Snehal Patel ◽  
...  
Keyword(s):  
Treatment Options ◽  
Graphene Quantum Dots ◽  
Primary Brain Tumor ◽  
In Vitro Models ◽  
Molecular Pathways ◽  
Dismal Prognosis ◽  
Novel Drugs

Glioblastoma, the most common primary brain tumor, has been recognized as one of the most lethal and fatal human tumors. It has a dismal prognosis, and survival after diagnosis is less than 15 months. Surgery and radiotherapy are the only available treatment options at present. However, numerous approaches have been made to upgrade in vivo and in vitro models with the primary goal of assessing abnormal molecular pathways that would be suitable targets for novel therapeutic approaches. Novel drugs, delivery systems, and immunotherapy strategies to establish new multimodal therapies that target the molecular pathways involved in tumor initiation and progression in glioblastoma are being studied. The goal of this review was to describe the pathophysiology, neurodegeneration mechanisms, signaling pathways, and future therapeutic targets associated with glioblastomas. The key features have been detailed to provide an up-to-date summary of the advancement required in current diagnosis and therapeutics for glioblastoma. The role of nanoparticulate system graphene quantum dots as suitable therapy for glioblastoma has also been discussed.

Demonstration of subpopulations with differing cancer stem cell phenotypes in xenograft and in vitro models of colorectal liver metastases.

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 394-394
Author(s):  
Dominic E. Sanford ◽  
Andrew Giorgi ◽  
Brian D. Goetz ◽  
Roheena Z. Panni ◽  
William G. Hawkins ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Liver Metastases ◽  
In Vitro Models ◽  
Model Systems ◽  
Cell Populations ◽  
Tumor Initiating Cells ◽  
Distinct Cell

394 Background: Tumors are composed of heterogeneous cell populations, some of which demonstrate enhanced tumor-forming capabilities (so-called tumor initiating cells [TIC] or cancer stem cells). In colorectal cancer (CRC), CD133, 44, and 24 are cell surface markers that identify TIC. Therefore, we sought to determine if CRC liver metastases (CRC-LM) form xenografts (in vivo) and cell cultures (in vitro) with TIC markers. Methods: CRC-LM were grafted in NOD/SCID mice and passaged serially. Xenografts were mechanically dissociated and cultured under sphere forming conditions. Flow cytometry was performed for TIC phenotype. Results: 16 of 18 (89%) CRC-LM specimens formed tumors in mice. Xenografts formed EpCAM+ tumors and spheres. The frequency of CD133+, CD44+, and CD133+/CD44+ tumor cells were 55%, 33%, and 23%, respectively. There was a subpopulation of CD133+/CD44+ cells with elevated CD44 expression(CD44hi). This CD133+/CD44hi population was also CD24+; representing 5% of cells. Eight of eleven (73%) xenografts formed spheres in vitro. The frequency of CD133+, CD44+, and CD133+/CD44+ cells were 63%, 47%, and 26%, respectively. CD133+/CD44+/CD24+ cells made up 8% of sphere-forming cells. There was a non-significant trend towards increased frequency of CD133+, CD44+, and CD133/CD44 positive cells in the spheres compared to the xenografts. However, the percentage of CD133+/CD44+/CD24+ cells was significantly increased in spheres relative to xenografts (8% vs. 5%, respectively; p<0.05) (see Table). Conclusions: CRC-LM derived xenografts and spheres are composed of distinct cell populations with differing levels of TIC/cancer stem cells. Sphere cultures may enhance for the most enriched TIC population. Thus, xenografts and sphere cultures are important model systems to further study the importance of cancer stem cells in CRC progression and metastases. [Table: see text]

Prepupal differentiation in Drosophila: distinct cell types elaborate a shared structure, the pupal cuticle, but accumulate transcripts in unique patterns

Development ◽  
1989 ◽  
Vol 106 (4) ◽  
pp. 649-656 ◽  
Author(s):  
K. Fechtel ◽  
D.K. Fristrom ◽  
J.W. Fristrom
Keyword(s):  
Cell Types ◽  
Imaginal Discs ◽  
Specific Expression ◽  
Distinct Cell ◽  
Cuticle Proteins ◽  
Shared Structure ◽  
Pupal Cuticle

The components of the pupal cuticle are the main differentiation products synthesized by both the larval and adult epidermis during the prepupal period of Drosophila development. The pupal cuticle is formed in vitro by imaginal discs in response to a 6 h pulse of 20-hydroxyecdysone (20-HE). We previously described the isolation and initial characterization of four ecdysone-dependent genes (EDGs) whose expression in imaginal discs occurs only in response to a pulse of 20-HE. In this report, we demonstrate that the pattern of temporal and tissue-specific expression of these EDGs in vivo is like that expected for genes that encode pupal cuticle proteins. Transcripts of these genes are detected in prepupae only in the epidermis and only when cuticle components are synthesized and secreted. Nonetheless, their temporal and spatial patterns of accumulation differ. EDG-84A-1 transcripts accumulate only in prepupae and only in imaginal cells. EDG-78E and EDG-64CD transcripts accumulate at the same time in both larval and imaginal cells. EDG42-A transcripts appear first in prepupae in imaginal cells and then, after a 2–4 h lag, in larval cells. It is evident that some genes are not restricted in their expression to only larval or imaginal epidermis.

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