Frequently Asked Questions
ESNATS uses human ES cells to develop in vitro test systems for developmental and acute toxicity. As ES cells can develop into virtually any cell type of the body, they are an ideal source of human cells, thus avoiding problems of interspecies differences. Furthermore, human ES cells offer a unique tissue culture model for developmental processes and can be used for studying developmental toxicity as well.
3R stands for reduction, refinement and replacement (W.M.S. Russell and R.L. Burch (1959). The Principles of Humane Experimental Technique):
- "Reduction" aims to reduce the number of test animals
- "Refinement" of tests, i.e. that alleviate or minimise pain, suffering and distress of test animals
- "Replacement" aims to obtain equivalent results without using animal experiments
REACH is a European Community regulation regarding the Registration, Evaluation, Authorisation and Restriction of CHemical substances. As the majority of chemicals currently used have not undergone safety testing, the REACH regulation will require all manufacturers or importers of chemicals into the European Union in quantities of one ton or more per year to register these substances with a new European Chemicals Agency and to provide results of safety tests. Whereever possible, these tests should not use animals. More information about REACH can be found at http://ec.europa.eu/environment/chemicals/reach/reach_intro.htm
Embryonic stem cells are special in that they can generate all cell types in the body - they are "pluripotent". Under suitable conditions, they can be kept in culture in their pluripotent state indefinitely, i.e. one embryonic stem cell line represents a potentially unlimited source of cells.
Adult stem cells such as the mesenchymal stem cells isolated from bone marrow have a more restricted differentiation potential, i.e. they can differentiate into a more limited set of cell types such as those making up the haematopoietic system (including the bone marrow, red blood cells and lymphocytes). Depending on their source, adult stem cells can have distinct properties. ESNATS aims to build an "all in one" in vitro test system using a single cell type (ES cells) that have the potential to generate all cell types in the body.
Generation of embryonic stem cell lines involves using surplus blastocysts that are the byproduct of in vitro fertilisation. Research using such cell lines is therefore often criticised as immoral as critics claim it involves the killing of human embryos. An in-depth discussion of this problem can be found in the article "The Biological and Ethical Basis of the Use of Human Embryonic Stem Cells for In Vitro Test Systems or Cell Therapy" (ALTEX 25(3), 163-190), http://www.altex.ch/en/index.html?id=16&aid=3.
Mouse ES cells have similar properties as human ES cells and can give rise to all cell types of the mouse. However, for toxicological assays, physiological differences between mouse and human cell types can mean that a substance might be tested negative in the mouse system whereas it has significant toxicity in humans. To avoid such potentially dangerous situations and exclude interspecies differences, the ESNATS project will use human embryonic stem cells for its studies.
The EC does fund research involving ES cells, it is recognised that great differences persist between member states concerning the legislation and control of research involving human stem cells. While the potential benefits of human ES cell research are very high, such research could involve using and destroying embryos. Once the scientific evaluators confirm the necessity of using hESCs in the research proposal, an ethics review panel assesses:
- that the proposal does not include research activities which destroy embryos including for the procurement of stem cells
- whether the consortium has taken into account the legislation, regulations
- ethical rules and/or codes of conduct in place in the country(ies) where the research using hESC is to take place, including the procedures for obtaining informed consent
- the source of the hESC
- the measures taken to protect personal data, including genetic data, and privacy
- the nature of financial inducements, if any.