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Colgate-Palmolive In Vitro Annual Meeting Lectures
2010Toxicity Testing in the 21st Century: The Vision and Some Questions, Kim Boekelheide, M.D., Ph.D., Brown University, Providence, RI
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The purpose of this event for postdoctoral scholars, graduate students, undergraduate students, and other invited guests is to focus on the importance of animal research to biomedical sciences and toxicology and the ethical obligations of the scientific community to follow the “3Rs” of animal testing (refine, reduce, replace) whenever it is feasible.
In the future, toxicity testing will utilize emerging technologies from the ongoing revolution in understanding biological processes to identify the effects of chemicals on toxicity pathways, using in vitro approaches. The interpretation of chemically-induced alterations in toxicity pathways will depend upon sophisticated modeling that extrapolates from the measured dose-response in cell-based systems to human exposure.
After providing an overview of the National Academy of Sciences report entitled “Toxicity testing in the 21st Century—A Vision and a Strategy,” this presentation will turn to a discussion of issues raised by this new approach. The audience will be asked to think about and respond to the following questions:
- Is focus on environmental agents important for the design criteria?
- How long will it take to implement this new toxicity testing paradigm?
- Is the focus on “toxicity pathways” useful or distracting?
- Does a test for neurodevelopmental effects have to look at neurons?
- How do we distinguish adaptive versus adverse (toxic) responses?
- Is this a screening tool or a stand-alone system?
- How is the new paradigm validated?
- What about epigenetics and other new biology?
- How do regulators handle the transition in testing?
- How does the apical definition of adversity work in the new toxicity testing paradigm?
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2009The 3Rs in Animal Use and a Prospective In Vitro Screening Tool for Identifying Potential Immunotoxicants, Courtney E. W. Sulentic, Wright State University, Dayton, OH
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The purpose of this lecture is to discuss the importance of animal research to biomedical sciences and toxicology and the ethical obligations of the scientific community to follow the “3Rs” of animal testing (refine, reduce, replace) whenever it is feasible. Following this discussion the remainder of the lecture will briefly describe Dr. Sulentic’s current research utilizing an in vitro alternative to understand mechanisms in altered immune function. The immune system is critical to human survival but also plays a contributing role in various mechanisms of toxicity. Assessing alterations of immune function by potential immunotoxicants is complicated by the diffuse nature of the immune system which is composed of various effector cells each with differing functions. Current immunotoxicity testing relies heavily on animal studies underscoring the need to develop and implement alternative approaches. Dr. Sulentic will discuss a cell line model developed to provide an in vitro alternative to animal studies in identifying immunotoxicants that specifically target B-cell function (i.e., alteration of immunoglobulin expression and antibody secretion) as well as elucidating the mechanisms of altered B-cell function. |
2008Development of In Vitro
Screening Tools to Test for Drug-Induced Mitochondrial Toxicities, Yvonne Will, Pfizer, Inc., San Diego, CA
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It is estimated that only 50% of the animal studies predict human efficacy and more importantly human toxicity. In addition, the use of animals should be minimized as much as possible for ethical reasons. Today, there are vigorous, ongoing national and international research and policy efforts to develop alternatives to animal testing. The efforts focus on both in vitro and in silico approaches and methods. For example, the National Toxicology Program (NTP) at the National Institute of Environmental Health Sciences (NIEHS) created the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM) in 1998.
Mitochondrial dysfunction is a common mechanism of drug-induced toxicity for a variety of therapeutics, such as certain antiviral drugs, lipid-lowering drugs, NSAIDs and certain cancer chemotherapeutics. Therefore, the early identification of drug candidates that potentially disrupt mitochondrial function is of significant importance in drug discovery. In the past few years we have developed organelle and cell based in vitro screens to detect potential mitochondrial toxicities. These include oxygen sensors to measure mitochondrial respiration in isolated mitochondria and cells, immunocapture of individual electron transport chain proteins that can identify inhibitors of mitochondrial electron transport, and metabolic profiling using oxygen and pH measurements. We discuss the strength and limitations of new applicable high throughput screens and provide recommendations of where to position these assays within the drug development process. |
2007Integration of Exploration of the Genome to Refine In Vitro
Screening Models, Cynthia A. Afshari, Amgen Inc., Thousand
Oaks, CA.
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The goal of the In Vitro Lecture
series is to feature important research using in vitro and alternative
techniques to study basic mechanisms, and to illustrate how these test
methods benefit animal welfare by refining and reducing animal use.
The advent of microarray technology into non-clinical studies has demonstrated
impact in several avenues. For example, whole genome analysis of the
transcriptional effects of drug exposures has allowed elucidation of
mechanism of action, potential off-target indication, and discovery
of promising new biomarkers of pharmacological effect or possible adverse
indications. For this latter goal, the integration of genomic, proteomic,
and metabolomic-based technologies has led to a blossoming of the field
known as “toxicogenomics.” One of the early promises of
integrating these molecular approaches was that new genomics based
models would provide for accurate prediction of toxicity. This talk
will focus on examples where analysis of in vivo gene expression data
derived from early nonclinical screening studies led to the elucidation
of a new in vitro screen for aiding selection of molecules during lead
optimization. The characterization of this model will be presented.
This approach will provide an additional filter to discriminate compounds
that are selected for in vivo studies and should impact the number
of animals used in a screening paradigm. The potential challenges that
still need to be surpassed in order to allow progressive development
of these models will also be addressed. |
2006Application
of Genomic Technology to Toxicology: Identifying Predictive Biomarkers
and Assessing the Impact of Chemicals on Cell Signaling Networks, Russell
Thomas, CIIT Centers for Health Research, Research Triangle Park,
NC. (Large file format, may take a few minutes to download).
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The lecture will review an important application of in
vitro toxicology
to the study of basic mechanistic processes and provide examples of how
new test methods have benefited animal welfare by refining experimental
procedures and reducing animal use. Recent developments in genomics
technology now allow for the comprehensive screening of the impact of
chemicals and pharmaceuticals on complex cell signaling networks without
the use of whole animal systems. The high-throughput requirement of
these approaches necessitates use of in vitro cell culture systems.
These high throughput screens provide enormous amounts of data in the
context of mechanistic and predictive toxicology. The tools for this
type of research include a combination of receptor-based reporter gene
assays, gene expression analysis using genome-wide microarrays and
large-scale, loss-of-function and gain-of-function studies using
inhibitory RNA libraries and libraries of full-length genes,
respectively. From results obtained with these tools, a cell signaling
pathway can be constructed and a more comprehensive and mechanistic
understanding of the impact of chemicals on biological systems can be
developed. Elucidation of signaling pathways at the cellular level is
not possible in intact animals and identification of mode of action at
the molecular level is often important in explaining disease states or
toxicities identified in vivo. |
2005Using In Vitro Toxicology
to Protect Human Health and Advance Animal Welfare, William
S. Stokes, NIEHS.
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The lecture will discuss the application
of in vitro toxicology to regulatory safety assessment and provide
examples of how recently adopted in vitro test methods have benefited
animal welfare by refining and reducing animal use while providing
for the protection of human health. The process by which new technological
methods evolve from development to regulatory acceptance will be discussed,
including the validation process necessary to determine their usefulness
and limitations for defined specific purpose. Dr. Stokes will also
discuss expected opportunities for an expanded role for in vitro toxicology
in an integrated approach to safety assessment. |
2004In Vitro Methods
for Dermatotoxicology Studies, Robert Bronaugh, U.S.
FDA.
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The lecture will address in vitro methods
for skin corrosivity, skin sensitization, skin phototoxicity and
skin absorption that are widely used in the safety assessment
of topical products. These alternative methods can reduce and sometimes replace
the need for animals. Methods for skin corrosivity and skin sensitization have
been validated by both the Interagency Coordinating Committee on the
Validation of Alternative Methods (ICCVAM) and European Centre for Validation
of Alternative Methods (ECVAM). ECVAM is ready to begin a validation study to assess
the adequacy of three methods for dermal irritation measurement. Further efforts
are being made to clarify controversial areas in skin absorption methodology
with regard to the skin reservoir, skin metabolism, and other issues. |
2003In Vitro Methods:
Are They Really Alternatives? Rodger D. Curren,
Institute for In
Vitro Sciences.
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The lecture will examine
how in vitro methods have struggled to gain respectability within
the toxicological community, and how companies now routinely use
in
vitro data as they make major product development and safety assessment decisions.
Dr. Curren will discuss how several new in vitro test procedures have gained
international regulatory approval, which he believes will make in vitro methods
an “alternative” no longer.
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2002The
3Rs of Alternatives: Humane Science—The
Best Science,
Alan Goldberg, Johns Hopkins University Center for
Alternatives to Animal
Testing.
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The lecture will examine
the ethical background to the concept of the 3Rs of alternatives
and will examine the concept that humane science is the best science,
providing some specific examples. Included will be a discussion of what each
of us can do to practice humane science.
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2001Alternatives
to Skin Sensitization Testing: the Local Lymph Node Assay and Beyond,
Ian Kimber, Syngenta Central Toxicology Laboratory.
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Dr. Kimber helped develop the local lymph node assay,
one of the two alternative tests currently approved by the Interagency
Coordinating Committee on the Validation of Alternative Methods (ICCVAM).
His presentation will explore how an increasingly sophisticated understanding
of the cellular and molecular mechanisms through which chemicals induce
skin sensitization and allergic contact dermatitis has translated into
new approaches for hazard identification and risk assessment. The evolution
of the local lymph node assay (LLNA) and its evaluation, validation,
and application will be described. This method was developed originally
as an alternative approach to hazard identification. More recently,
however, it has been found that in modified form this method can determine
accurately the relative potency of skin sensitizing chemicals; an important
first step in the risk assessment process. Finally, recent approaches
to the development of in vitro methods for the identification of skin
sensitization hazard will be described. |
2000In Vitro Technologies
in the 90s and Beyond, Chuck Ruegg, In
Vitro Technologies, Inc.
The presentation will review the history of in vitro techniques in toxicology and the rapid changes that have occurred over the last few years, leading us to the future use of these technologies.
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