scholarly journals A model-based analysis identifies differences in phenotypic resistance between in vitro and in vivo: implications for translational medicine within tuberculosis

2020 ◽  
Vol 47 (5) ◽  
pp. 421-430
Author(s):  
Oskar Clewe ◽  
Alan Faraj ◽  
Yanmin Hu ◽  
Anthony R. M. Coates ◽  
Ulrika S. H. Simonsson
Keyword(s):  
Drug Effect ◽  
Drug Effects ◽  
Bacterial Number ◽  
Natural Growth ◽  
In Vivo Models ◽  
Phenotypic Resistance ◽  
Total Bacterial Number

Abstract Proper characterization of drug effects on Mycobacterium tuberculosis relies on the characterization of phenotypically resistant bacteria to correctly establish exposure–response relationships. The aim of this work was to evaluate the potential difference in phenotypic resistance in in vitro compared to murine in vivo models using CFU data alone or CFU together with most probable number (MPN) data following resuscitation with culture supernatant. Predictions of in vitro and in vivo phenotypic resistance i.e. persisters, using the Multistate Tuberculosis Pharmacometric (MTP) model framework was evaluated based on bacterial cultures grown with and without drug exposure using CFU alone or CFU plus MPN data. Phenotypic resistance and total bacterial number in in vitro natural growth observations, i.e. without drug, was well predicted by the MTP model using only CFU data. Capturing the murine in vivo total bacterial number and persisters during natural growth did however require re-estimation of model parameter using both the CFU and MPN observations implying that the ratio of persisters to total bacterial burden is different in vitro compared to murine in vivo. The evaluation of the in vitro rifampicin drug effect revealed that higher resolution in the persister drug effect was seen using CFU and MPN compared to CFU alone although drug effects on the other bacterial populations were well predicted using only CFU data. The ratio of persistent bacteria to total bacteria was predicted to be different between in vitro and murine in vivo. This difference could have implications for subsequent translational efforts in tuberculosis drug development.

scholarly journals Two Decades of Triazine Dendrimers

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4774
Author(s):  
Eric E. Simanek
Keyword(s):  
Genetic Material ◽  
Structural Complexity ◽  
Bioactive Molecules ◽  
Bioactive Materials ◽  
In Vivo Models ◽  
Tumor Subtypes ◽  
Gas Streams

For two decades, methods for the synthesis and characterization of dendrimers based on [1,3,5]-triazine have been advanced by the group. Motivated by the desire to generate structural complexity on the periphery, initial efforts focused on convergent syntheses, which yielded pure materials to generation three. To obtain larger generations of dendrimers, divergent strategies were pursued using iterative reactions of monomers, sequential additions of triazine and diamines, and ultimately, macromonomers. Strategies for the incorporation of bioactive molecules using non-covalent and covalent strategies have been explored. These bioactive materials included small molecule drugs, peptides, and genetic material. In some cases, these constructs were examined in both in vitro and in vivo models with a focus on targeting prostate tumor subtypes with paclitaxel conjugates. In the materials realm, the use of triazine dendrimers anchored on solid surfaces including smectite clay, silica, mesoporous alumina, polystyrene, and others was explored for the separation of volatile organics from gas streams or the sequestration of atrazine from solution. The combination of these organics with metal nanoparticles has been probed. The goal of this review is to summarize these efforts.

scholarly journals Characterization of bone resorption in novel in vitro and in vivo models of oral squamous cell carcinoma

Oral Oncology ◽  
2012 ◽  
Vol 48 (6) ◽  
pp. 491-499 ◽  
Author(s):  
Chelsea K. Martin ◽  
Wessel P. Dirksen ◽  
Sherry T. Shu ◽  
Jillian L. Werbeck ◽  
Nanda K. Thudi ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Bone Resorption ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
In Vivo Models

scholarly journals Toward a Better Testing Paradigm for Developmental Neurotoxicity: OECD Efforts and Regulatory Considerations

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 86
Author(s):  
Magdalini Sachana ◽  
Timothy J. Shafer ◽  
Andrea Terron
Keyword(s):  
Adverse Outcome ◽  
Developmental Neurotoxicity ◽  
Adverse Outcome Pathway ◽  
Guidance Document ◽  
Chemical Safety ◽  
In Vivo Models ◽  
Animal Data

Characterization of potential chemical-induced developmental neurotoxicity (DNT) hazard is considered for risk assessment purposes by many regulatory sectors. However, due to test complexity, difficulty in interpreting results and need of substantial resources, the use of the in vivo DNT test guidelines has been limited and animal data on DNT are scarce. To address challenging endpoints such as DNT, the Organisation for Economic Co-Operation and Development (OECD) chemical safety program has been working lately toward the development of integrated approaches for testing and assessment (IATA) that rely on a combination of multiple layers of data (e.g., in vitro, in silico and non-mammalian in vivo models) that are supported by mechanistic knowledge organized according to the adverse outcome pathway (AOP) framework. In 2017, the OECD convened a dedicated OECD expert group to develop a guidance document on the application and interpretation of data derived from a DNT testing battery that relies on key neurodevelopmental processes and is complemented by zebrafish assays. This review will provide a brief overview of the OECD DNT project and summarize various achievements of relevance to the project. The review also presents an opportunity to describe considerations for uptake of the DNT in an in vitro battery in a regulatory context.

scholarly journals Abstract LB-363: Characterization of in vitro and in vivo models generated from disseminated tumor cells of patients without manifest metastasis

2018 ◽  
Author(s):  
Christian Werno ◽  
Kathrin Weidele ◽  
Steffi Treitschke ◽  
Catherine Botteron ◽  
Sebastian Scheitler ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Disseminated Tumor Cells ◽  
In Vivo Models

scholarly journals Applying Bioinformatic Platforms, In Vitro, and In Vivo Functional Assays in the Characterization of Genetic Variants in the GH/IGF Pathway Affecting Growth and Development

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2063
Author(s):  
Sabina Domené ◽  
Paula A. Scaglia ◽  
Mariana L. Gutiérrez ◽  
Horacio M. Domené
Keyword(s):  
In Silico ◽  
Growth And Development ◽  
Genetic Variant ◽  
Modeling Tools ◽  
In Vivo Models ◽  
Bioinformatic Tools ◽  
Functional Assays

Heritability accounts for over 80% of adult human height, indicating that genetic variability is the main determinant of stature. The rapid technological development of Next-Generation Sequencing (NGS), particularly Whole Exome Sequencing (WES), has resulted in the characterization of several genetic conditions affecting growth and development. The greatest challenge of NGS remains the high number of candidate variants identified. In silico bioinformatic tools represent the first approach for classifying these variants. However, solving the complicated problem of variant interpretation requires the use of experimental approaches such as in vitro and, when needed, in vivo functional assays. In this review, we will discuss a rational approach to apply to the gene variants identified in children with growth and developmental defects including: (i) bioinformatic tools; (ii) in silico modeling tools; (iii) in vitro functional assays; and (iv) the development of in vivo models. While bioinformatic tools are useful for a preliminary selection of potentially pathogenic variants, in vitro—and sometimes also in vivo—functional assays are further required to unequivocally determine the pathogenicity of a novel genetic variant. This long, time-consuming, and expensive process is the only scientifically proven method to determine causality between a genetic variant and a human genetic disease.

scholarly journals Molecular and Functional Characterization of Circulating Tumor Cells: From Discovery to Clinical Application

2019 ◽  
Vol 66 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Luis Enrique Cortés-Hernández ◽  
Zahra Eslami-S ◽  
Klaus Pantel ◽  
Catherine Alix-Panabières
Keyword(s):  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Liquid Biopsy ◽  
Functional Characterization ◽  
Clinical Information ◽  
In Vivo Models ◽  
Functional Studies

Abstract BACKGROUND One of the objectives for the liquid biopsy is to become a surrogate to tissue biopsies in diagnosis of cancer as a minimally invasive method, with clinical utility in real-time follow-ups of patients. To achieve this goal, it is still necessary to achieve a better understanding of the mechanisms of cancer and the biological principles that govern its behavior, particularly with regard to circulating tumor cells (CTCs). CONTENT The isolation, enumeration, detection, and characterization of CTCs have already proven to provide relevant clinical information about patient prognosis and treatment prediction. Moreover, CTCs can be analyzed at the genome, proteome, transcriptome, and secretome levels and can also be used for functional studies in in vitro and in vivo models. These features, taken together, have made CTCs a very valuable biosource. SUMMARY To further advance the field and discover new clinical applications for CTCs, several studies have been performed to learn more about these cells and better understand the biology of metastasis. In this review, we describe the recent literature on the topic of liquid biopsy with particular focus on the biology of CTCs.

Characterization of CGS 8515 as a selective 5-lipoxygenase inhibitor using in vitro and in vivo models

1988 ◽  
Vol 959 (3) ◽  
pp. 332-342 ◽  
Author(s):  
Edmond C. Ku ◽  
Anil Raychaudhuri ◽  
Geetha Ghai ◽  
Earl F. Kimble ◽  
Warren H. Lee ◽  
...  
Keyword(s):  
Lipoxygenase Inhibitor ◽  
In Vivo Models

Creation and characterization of a novel human PDGFRA D842V-mutant GIST cell line.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e22512-e22512
Author(s):  
Lillian Rose Klug ◽  
Gleb Abalakov ◽  
Diana Griffith ◽  
Ajia Town ◽  
Arin McKinley ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Kinase Inhibitors ◽  
Imatinib Resistance ◽  
In Vivo Models ◽  
Biological Aspects ◽  
Novel Model

e22512 Background: Activating PDGFRA mutations are seen in about 10% of gastrointestinal stromal tumors (GIST). Of these, the majority are one specific PDGFRA mutation, D842V, which confers resistance to all clinically approved tyrosine kinase inhibitors (TKI). Much has been learned about the mechanism by which TKIs work in GIST using cell lines derived from human GIST that bear activating KIT mutations. However, despite enormous effort to develop cell lines derived from human tumors over the past 15 years, there are currently no human cell models of PDGFRA D842V GIST. With the development of potent PDGFRA D842V TKI, such as crenolanib, avapritinib, and DCC2618 it is of interest to understand how these drugs affect PDGFRA-mutant GIST biology. Methods: We sought to convert the KIT-driven GIST-T1 cell line to be PDGFRA-driven by transduction with PDGFRA D842V. Endogenous KIT expression was knocked-out using CRISPR Cas9. Knockout was verified at protein and DNA levels. Clonal KIT knockout cell lines were tested for sensitivity to KIT and PDGFRA TKI both in vitro and in vivo models. Kinase dependence was determined by measuring the effect on viability after KIT and/or PDGFRA knockdown by siRNA. Results: GIST-T1 cells transduced with PDGFRA D842V display highly phosphorylated PDGFRA, imatinib resistance, and PDGFRA dependence. Cell lines that express both endogenous mutant KIT and exogenous PDGFRA D842V maintain some dependence on KIT, but less so than the parental KIT-driven GIST-T1 cell line. Complete knockout of KIT protein expression was achieved in GIST-T1 D842V cells using CRISPR-Cas9. GIST-T1 D842V KITko cell lines demonstrate sensitivity to TKI avapritinib, crenolanib, and DCC2618. Xenografts were established using GIST-T1 D842V KITko cell lines and are sensitive to avapritinib in vivo. Conclusions: The GIST-T1 D842V KITko cell line demonstrates ability to switch kinase allegiance resulting in PDGFRA-dependence and KIT-independence. This GIST-T1 D842V KITko cell line represents a novel model of PDGFRA-mutant GIST and can be used to understand the unique biological aspects of these tumors, particularly the response to new potent PDGFRA kinase inhibitors such as avapritinib which will have immense clinical relevance.

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