Molecular Targets and Early Response Biomarkers for the Prediction of Developmental Toxicity In Vitro

2007 ◽  
Vol 35 (3) ◽  
pp. 335-342 ◽  
Author(s):  
Michael Stigson ◽  
Kim Kultima ◽  
Måns Jergil ◽  
Birger Scholz ◽  
Henrik Alm ◽  
...  

There is an urgent need for new in vitro methods to predict the potential developmental toxicity of candidate drugs in the early lead identification and optimisation process. This would lead to a reduction in the total number of animals required in full-scale developmental toxicology studies, and would improve the efficiency of drug development. However, suitable in vitro systems permitting robust high-throughput screening for this purpose, for the most part, remain to be designed. An understanding of the mechanisms involved in developmental toxicity may be essential for the validation of in vitro tests. Early response biomarkers — even a single one — could contribute to reducing assay time and facilitating automation. The use of toxicogenomics approaches to study in vitro and in vivo models in parallel may be a powerful tool in defining such mechanisms of action and the molecular targets of toxicity, and also for use in finding possible biomarkers of early response. Using valproic acid as a model substance, the use of DNA microarrays to identify teratogen-responsive genes in cell models is discussed. It is concluded that gene expression in P19 mouse embryocarcinoma cells represents a potentially suitable assay system, which could be readily used in a tiered testing system for developmental toxicity testing.

Author(s):  
Danlei Wang ◽  
Maartje H. Rietdijk ◽  
Lenny Kamelia ◽  
Peter J. Boogaard ◽  
Ivonne M. C. M. Rietjens

AbstractDevelopmental toxicity testing is an animal-intensive endpoints in toxicity testing and calls for animal-free alternatives. Previous studies showed the applicability of an in vitro–in silico approach for predicting developmental toxicity of a range of compounds, based on data from the mouse embryonic stem cell test (EST) combined with physiologically based kinetic (PBK) modelling facilitated reverse dosimetry. In the current study, the use of this approach for predicting developmental toxicity of polycyclic aromatic hydrocarbons (PAHs) was evaluated, using benzo[a]pyrene (BaP) as a model compound. A rat PBK model of BaP was developed to simulate the kinetics of its main metabolite 3-hydroxybenzo[a]pyrene (3-OHBaP), shown previously to be responsible for the developmental toxicity of BaP. Comparison to in vivo kinetic data showed that the model adequately predicted BaP and 3-OHBaP blood concentrations in the rat. Using this PBK model and reverse dosimetry, a concentration–response curve for 3-OHBaP obtained in the EST was translated into an in vivo dose–response curve for developmental toxicity of BaP in rats upon single or repeated dose exposure. The predicted half maximal effect doses (ED50) amounted to 67 and 45 mg/kg bw being comparable to the ED50 derived from the in vivo dose–response data reported for BaP in the literature, of 29 mg/kg bw. The present study provides a proof of principle of applying this in vitro–in silico approach for evaluating developmental toxicity of BaP and may provide a promising strategy for predicting the developmental toxicity of related PAHs, without the need for extensive animal testing.


1995 ◽  
Vol 23 (4) ◽  
pp. 491-496
Author(s):  
Hanna Tähti ◽  
Leila Vaalavirta ◽  
Tarja Toimela

— There are several hundred industrial chemicals with neurotoxic potential. The neurotoxic risks of most of these chemicals are unknown. Additional methods are needed to assess the risks more effectively and to elucidate the mechanisms of neurotoxicity more accurately than is possible with the conventional methods. This paper deals with general tasks concerning the use of in vitro models in the evaluation of neurotoxic risks. It is based on our previous studies with various in vitro models and on recent literature. The induction of glial fibrillary acidic protein in astrocyte cultures after treatment with known neurotoxicants (mercury compounds and aluminium) is discussed in more detail as an important response which can be detected in vitro. When used appropriately with in vivo tests and with previous toxicological data, in vitro neurotoxicity testing considerably improves risk assessment. The incorporation of in vitro tests into the early stages of risk evaluation can reduce the number of animals used in routine toxicity testing, by identifying chemicals with high neurotoxic potential.


2015 ◽  
Vol 13 (1) ◽  
pp. nrs.13005 ◽  
Author(s):  
James G. MacKrell ◽  
Benjamin C. Yaden ◽  
Heather Bullock ◽  
Keyue Chen ◽  
Pamela Shetler ◽  
...  

The high regenerative capacity of adult skeletal muscle relies on a self-renewing depot of adult stem cells, termed muscle satellite cells (MSCs). Androgens, known mediators of overall body composition and specifically skeletal muscle mass, have been shown to regulate MSCs. The possible overlapping function of androgen regulation of muscle growth and MSC activation has not been carefully investigated with regards to muscle regeneration. Therefore, the aim of this study was to examine coinciding androgen-mediated genetic changes in an in vitro MSC model and clinically relevant in vivo models. A gene signature was established via microarray analysis for androgen-mediated MSC engagement and highlighted several markers including follistatin (FST), IGF-1, C-X-C chemokine receptor 4 (CXCR4), hepatocyte growth factor (HGF) and glucocorticoid receptor (GR/Nr3c1). In an in vivo muscle atrophy model, androgen re-supplementation significantly increased muscle size and expression of IGF-1, FST, and HGF, while significantly decreasing expression of GR. Biphasic gene expression profiles over the 7-day re-supplementation period identifed temporal androgen regulation of molecular targets involved in satellite cell engagement into myogenesis. In a muscle injury model, removal of androgens resulted in delayed muscle recovery and regeneration. Modifications in the androgen signaling gene signature, along with reduced Pax7 and MyoD expression, suggested that limited MSC activation and increased inflammation contributed to the delayed regeneration. However, enhanced MSC activation in the androgen-deplete mouse injury model was driven by an androgen receptor (AR) agonist. These results provide novel in vitro and in vivo evidence describing molecular targets of androgen signaling, while also increasing support for translational use of AR agonists in skeletal muscle recovery and regeneration.


Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 702 ◽  
Author(s):  
Christian T. Stackhouse ◽  
James R. Rowland ◽  
Rachael S. Shevin ◽  
Raj Singh ◽  
G. Yancey Gillespie ◽  
...  

Accurate patient-derived models of cancer are needed for profiling the disease and for testing therapeutics. These models must not only be accurate, but also suitable for high-throughput screening and analysis. Here we compare two derivative cancer models, microtumors and spheroids, to the gold standard model of patient-derived orthotopic xenografts (PDX) in glioblastoma multiforme (GBM). To compare these models, we constructed a custom NanoString panel of 350 genes relevant to GBM biology. This custom assay includes 16 GBM-specific gene signatures including a novel GBM subtyping signature. We profiled 11 GBM-PDX with matched orthotopic cells, derived microtumors, and derived spheroids using the custom NanoString assay. In parallel, these derivative models underwent drug sensitivity screening. We found that expression of certain genes were dependent on the cancer model while others were model-independent. These model-independent genes can be used in profiling tumor-specific biology and in gauging therapeutic response. It remains to be seen whether or not cancer model-specific genes may be directly or indirectly, through changes to tumor microenvironment, manipulated to improve the concordance of in vitro derivative models with in vivo models yielding better prediction of therapeutic response.


2008 ◽  
Vol 31 (4) ◽  
pp. 9
Author(s):  
Adam D Durbin ◽  
Gino R Somers ◽  
Michael Forrester ◽  
Gregory E Hannigan ◽  
David Malkin

Background:The integrin-linked kinase (ILK) is a protein kinase involved in the regulation of pathogenic cancer cell behaviours, such as proliferation, survival and invasion. ILK appears to be pro-oncogenic in vitro and in vivo models of tumorigenesis. Rhabdomyosarcoma (RMS) is a primitive mesenchyme-derived tumor and is subclassified into primarily embryonal (ERMS) and alveolar (ARMS) variants. Patients who present with metastatic RMS tumors have a less than 20% chance of cure, suggesting a need to define novel targets for chemotherapeutic intervention. Methods: We used cell culture, murine xenografts and primary human tumors to examine ILK expression and functionality. RNAi and adenoviruses were used to knock down or over expressproteins, and SP600125 was used to inhibit JNK kinase activity. ERMS cells stablye xpressing PAX3-FOXO1A we regenerated using pcDNA3.1 with the full length PAX3-FOXO1A cDNA insert. Results: RNAi-mediated ablation of ILK induced stimulation of ERMS and inhibition of ARMS cell growth in vitro and in vivo. Overexpression of ILK, but not the ILK-R211A mutant reversed these effects. High-throughput screening of multiple tumor cell lines and mesenchymal progenitor cells demonstrated similar ILK anti-growth effects. Consistent with these results, clinical correlations made between ILK immunohistochemical staining intensity and patterns on an ERMS tumor tissue microarray revealed downregulation of ILK in stage III/IV primary tumors. Mechanistically, ILK silencing induced selective phosphorylation of the c-jun amino terminal kinase (JNK) and its target c-Jun in ERMS cells with attenuated phosphorylation in ARMS cells. ERMS cells express higher levels of JNK1 isoforms than ARMS cells. Introduction of the ARMS-associated PAX3-FOXO1A fusion gene into ERMS cells restored the oncogenic function of ILK and downregulated of JNK1. Coupling ILK siRNA with inhibition of the JNK-c-Jun signaling pathway in ERMS cells resulted in growth reductions and apoptotic induction. In contrast, coupling ILK knockdown with overexpression of JNK1 in ARMS cells resulted in growth and c-jun phosphorylation. Conclusion: In summary, these data suggest a model whereby the effect of ILK as an oncogene or tumor suppressor is determined by JNK1. Finally, this data suggests that ILK kinase inhibition may be warranted in ARMS tumors, and may be contraindicated in ERMS.


1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 11-18 ◽  
Author(s):  
Oliver P. Flint

The fullest potential for in vitro evaluation of toxicity will be realised in the context of the process of assessing the risk of human toxicity. This article is an attempt to clarify what contributions can be made by in vitro tests and what types of in vitro test can best be used. In vitro tests are clarified according to the type of biological endpoint evaluated, first into tests for general (‘basal’) cytotoxicity and, secondly, into tests for differentiated cell function. The role of each type of test is analysed and it is suggested that tests for general cytotoxicity, as opposed to differentiated function, are difficult to interpret in terms of in vivo toxicity. A general approach to evaluating in vitro tests is described, and a strategy for using these tests is proposed.


Author(s):  
Francesca Pistollato ◽  
Federica Madia ◽  
Raffaella Corvi ◽  
Sharon Munn ◽  
Elise Grignard ◽  
...  

AbstractThe EU Directive 2010/63/EU   on the protection of animals used for scientific purposes and other EU regulations, such as REACH and the Cosmetic Products Regulation advocate for a change in the way toxicity testing is conducted. Whilst the Cosmetic Products Regulation bans animal testing altogether, REACH aims for a progressive shift from in vivo testing towards quantitative in vitro and computational approaches. Several endpoints can already be addressed using non-animal approaches including skin corrosion and irritation, serious eye damage and irritation, skin sensitisation, and mutagenicity and genotoxicity. However, for systemic effects such as acute toxicity, repeated dose toxicity and reproductive and developmental toxicity, evaluation of chemicals under REACH still heavily relies on animal tests. Here we summarise current EU regulatory requirements for the human health assessment of chemicals under REACH and the Cosmetic Products Regulation, considering the more critical endpoints and identifying the main challenges in introducing alternative methods into regulatory testing practice. This supports a recent initiative taken by the International Cooperation on Alternative Test Methods (ICATM) to summarise current regulatory requirements specific for the assessment of chemicals and cosmetic products for several human health-related endpoints, with the aim of comparing different jurisdictions and coordinating the promotion and ultimately the implementation of non-animal approaches worldwide. Recent initiatives undertaken at European level to promote the 3Rs and the use of alternative methods in current regulatory practice are also discussed.


2019 ◽  
Vol 24 (6) ◽  
pp. 615-627 ◽  
Author(s):  
Tijmen H. Booij ◽  
Leo S. Price ◽  
Erik H. J. Danen

The introduction of more relevant cell models in early preclinical drug discovery, combined with high-content imaging and automated analysis, is expected to increase the quality of compounds progressing to preclinical stages in the drug development pipeline. In this review we discuss the current switch to more relevant 3D cell culture models and associated challenges for high-throughput screening and high-content analysis. We propose that overcoming these challenges will enable front-loading the drug discovery pipeline with better biology, extracting the most from that biology, and, in general, improving translation between in vitro and in vivo models. This is expected to reduce the proportion of compounds that fail in vivo testing due to a lack of efficacy or to toxicity.


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