CHAPTER-7-The-Mouse-in-Preclinical-Safety-Studies_2004_The-Laboratory-Mouse

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The mouse has been one of the main mammalian
species used in preclinical studies ranging from phar-
macology and safety assessment. Its’ use came into
effect for various reasons, some of which were quite
mundane such as being considered a pest, ease of
breeding and small size. The latter made it a favorite
animal for mammalian geneticists. Between the 1920s
and the 1950s numerous inbred strains were devel-
oped and characterized. The Jackson Institute was a key
player and an example of the work carried out, such as
providing breeding and research facilities for this work.
Another boost for the mouse as a model was given by
the immunologists, especially after the pioneering work
to develop monoclonal antibodies in this species.
Recently genetics have again made major inroads with
the development of knockout and knock-in mouse
models and strains (Rosenberg, 1997; Rudmann and
Durham, 1999; Hopley and Zimmer, 2001; Lesch,
2001).
The latter technology, by deleting specific genes
out of animals or respectively inserting e.g. human
genes into the mouse genome has expanded exponen-
tially. Transgenic animals are nowadays a major source
of research material (Rudolph and Möhler, 1999). The
variations and extent of genetic manipulation is only
limited by one’s imagination, resources and ethics. In
the first 6 months of 2002 alone, a literature search
restricted to this period using as search criteria ‘trans-
genic mice’ resulted in a listing of over 1400 citations
(Sigmund, 2000). Much of this work involves basic
biology and pharmacology. A complete review would
go beyond the scope of this section. Transgenic animal
technology has recently been combined with another
powerful tool gene chips, in which mice are used as a
model. Expression profiling of mRNA is expanding
rapidly our basic understanding of regulatory pathways
in mammalian systems.
This section will focus however mainly on the
mouse in preclinical safety testing. Here the use of this
species is historic and for the same reasons as above.
The use of mice as models in safety evaluations is cur-
rently required in international guidelines for both
chemicals and pharmaceuticals.
Mice used in these safety studies are often either
random bred albino mice, frequently with a Swiss
strain origin, or hybrids like the B6C3F1 (an F1 hybrid
from the C57Bl and Ch3 strains).
In oncogenicity testing in particular the use of
transgenic animals is being examined and is already
favored by some. These strains have either certain
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7C H A P T E R
The Mouse in Preclinical
Safety Studies
Johannes H Harlemann
Novartis Pharma, Preclinical Safety, Basel, Switzerland
The Laboratory Mouse
Copyright 2004 Elsevier
ISBN 0-1233-6425-6 All rights of production in any form reserved
repair deficiencies and/or carry one or more particular
oncogenes making them potentially more sensitive to
the effects of tumor induction and promotion (Ashby,
2001; Cohen, 2001; Venkatachalam et al., 2001).
Transgenic mice are also been used in special cases for
the testing of biotechnology products in which no other
models exist except man itself or higher apes (Dayan,
1995; Rosenberg, 1997; Griffiths and Lumley, 1998;
Bugelski et al., 2000; Goodman, 2001). These special
applications will be discussed further in the respective
sections. Mice are used in safety testing in the following
types of studies: acute toxicity, subacute/chronic toxi-
city, carcinogenicity, mutagenicity and immune toxicity.
Acute toxicity
Acute toxicity testing is a frequently underestimated
model. The acute toxicity test gives an estimate for the
therapeutic margin and absolute safety of a drug or
chemical. In the past, LD50 tests were used to quantify
exactly and calculate accurately this endpoint. This,
however, used large numbers of animals, which nowa-
days is avoided by approximative dose regimes. The lat-
ter is also used in the classification of chemicals (Chan
and Hayes, 1994).
Acute toxicity testing has one drawback in that a
detailed examination is often not carried out e.g.
histopathology, clinical pathology and kinetics. This can
lead to an underestimation of the toxicity of a test arti-
cle and identification of target organs with those com-
pounds in which repeat dose toxicity dosing is limited
to markedly lower doses e.g. gastrointestinal toxicity
with non-steroidal anti-inflammatory drugs (NSAIDs).
The routes of exposure in acute toxicity tests is gen-
erally similar to the expected exposure in man e.g. oral
as well as parenteral e.g. intravenous or intraperitoneal.
Repeat dose
subacute/chronic
toxicity
Whereas in pharmacology the mouse is a preferred
species because of the plethora of models available and
its inherent small size, this limits the amount of com-
pound used. In toxicology the mouse is in contrast to
the rat, which is not the standard species for toxicity
testing, mostly because of its size, which limits sam-
pling to obtaining clinical pathology samples as well as
kinetic samples only. Hence most repeat dose toxicity
tests use the rat as the standard rodent species. The
mouse is used in certain cases when, for example, the
pharmacological target is only present in man and not
in any other species. In such cases knock-in transgenic
mice have been used as a model (Dayan, 1995; Thomas,
1995; Griffiths and Lumley, 1998). In repeat dose
studies non-rodent species showed a higher prediction
rate of adverse effects in humans (Olson et al., 1998,
2000). However experience in mice is limited because
most studies involve rats. Based on results in carcino-
genicity studies, a lower rate of prediction may be
expected.
Repeat dose mouse studies are most often carried
out relatively late in the development or safety testing
of a drug or chemical and then usually as dose range
finding studies for the oncogenicity studies. In these
studies the mixamal tolerated dose (MTD) after repeat
dosing is determined for use in lifetime exposure in the
subsequent carcinogenicity study.
Carcinogenicity
studies
The mouse and the rat are the standard species for the
conduct of carcinogenicity studies (Haseman et al.,
2001). Although these species have been able to help
identify potential human carcinogens, they may also
identify many rodent specific carcinogens (Huff, 1994;
Battershill and Fielder, 1998). The prediction rate of
the mouse model has been widely criticized (Infante,
1993; Alden et al., 1996). It has been proposed that
these models should be replaced by the transgenic
models (Cannon et al., 2000; Carmichael et al., 2001;
Cohen et al., 2001; Usui et al., 2001; Van Kreijl et al.,
2001; Van Steeg et al., 2001). Whatever model is used
for the testing, it is of utmost importance to use a stan-
dardized nomenclature (Keenan et al., 2002). Progress
has been made in international standardization of this
nomenclature, most notably by the RITA-group. Their
nomenclature has been published and is available on
the Internet.
The most widely used models are the p53 strain,
which is primarily used for compounds in a positive
mutagenicity test and the TgH2RAS model which is
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promoted for both mutagenic and non-mutagenic
compounds (Carmichael et al., 2001; Storer et al.,
2001; Tamaoki, 2001; Usui et al., 2001; Van Kreijl
et al., 2001; Van Steeg et al., 2001; Venkatachalam et al.,
2001). The TgAC model is only favored for dermally
applied compounds (Spalding et al., 1999; Eastin et al.,2001; Tennant et al., 1998, 2001; Morton et al., 2002).
Experience with these compounds is still limited, but
these models have been accepted by the regulatory
authorities as alternative models for the mouse lifetime
2-year carcinogenicity testing (Haseman et al., 2001).
Initially it was thought that these models would give
more specific answers, because of their genetic back
ground, predisposing them to tumor development.
This does not always appear to be the case. Some inves-
tigators suggest increasing the number of animals in
each dose group and extend the duration of these stud-
ies from 6 to 9 months. Another issue is the use of pos-
itive control groups in these studies. As positive
controls p-cresidine and benzidine most frequently are
used. However several groups have reported difficulties
in the use of these compounds either not leading to
positive results or having mixed toxicities.
The handling of these known carcinogens within a
testing facility is also not favored. The results of testing
by the ILSI group and the NTP indicated that the use of
these models can identify correctly many known human
carcinogens and also had a lower false positive rate com-
pared with the 2-year models (Van der Laan and
Spindler, 2002). Only a few indirect carcinogens such as
cyclosporin, estradiol, phenobarbital and chloroform
appear to be non-responding in the models tested (Van
der Laan and Spindler, 2002; Van der Laan et al., 2002).
Mutagenicity
studies
The mouse is used in one standard mutagenicity study,
the micronucleus test (Brusick, 1994). In this test high
doses of test material are administered and the effect on
the formation of micronuclei in the bone marrow is
evaluated. This method is either evaluated manually or
by automated morphometric analysis.
Another model, which is used occasionally to detect
mutation in certain organ tissues is the Mutamouse or
Big-blue system (Gossen et al., 1989; Short et al., 1990;
Myhr, 1991). Here a bacterial genome is inserted into
the mouse genes. After treatment with a test material,
the mutation frequency in these inserts is evaluated and
compared with controls indicating a direct effect where
mutations are found.
Immunotoxicity
The mouse is used in two models for the testing for the
immunotoxic potential of a test material. These models
are proposed as a replacement for the Magnusson
Kligman or Buehler test in guinea pigs.
One model, the local lymph node test, has been
widely validated and has been accepted by the regula-
tory authorities as an alternative for the above guinea
pig models (Ulrich and Vohr, 1996; Basketter et al.,
2000; Dean et al., 2001; Kimber, 2001; Ulrich et al.,
2002). The other test, the popliteal lymph node test
has been proposed in the newest Food and Drug
Administration (FDA) guidelines as a possible test for
autoimmunity and allergy. Both tests use the primary
response in the draining lymph node after exposure to
the test material. In the local lymph node this is applied
to the skin of the ear and in the popliteal lymph node
test injected in the foot pad (Gleichmann et al., 1989;
Bloksma et al., 1995; Pieters, 2001; Pieters et al.,
2002). With a modification of the local lymph mode
test (LLN) one can also check compounds for their
photo-sensitization potential (Ulrich et al., 1998; Vohr
et al., 2000).
References
Abelson, P.H. (1990). Science 249(4975), 1357.
Alden, C.L., Smith, P.F., Piper, C.E. and Brej, L. (1996).
Acritical appraisal of the value of the mouse cancer bioas-
say safety assessment. Toxcol. Pathol. 24, 722–725.
Ashby, J. (2001). Toxicol. Pathol. 29(Suppl.) 177–182.
Basketter, D.A., Balikie, L., Dearman, R.J., Kimber, I.,
Ryan, C.A., Gerberick, G.F., Harvey, P., Evans, P.,
White, I.R. and Rycroft, R.J. (2000). Contact Dermatitis
42, 344–348.
Battershill, J.M. and Fielder, R.J. (1998). Hum. Exp. Toxicol.
17, 193–205.
Bloksma, N., Kubicka-Muranyi, M., Schuppe, H.C.,
Gleichmann, E. and Gleichmann, H. (1995). Crit. Rev.
Toxicol. 25, 369–396.
Brusick, D. (1994). In Principles and Methods of Toxicology
(ed. W.A. Hayes), pp. 545–577. Raven Press, New York.
113
D
EV
ELO
PM
EN
T
O
F
TH
E
M
O
U
SE
A
S
A
L
A
B
O
RATO
RY
M
O
D
EL
T
H
E
M
O
U
SE
IN
P
R
EC
LIN
IC
A
L
S
A
FET
Y
S
TU
D
IES
Bugelski, P.J., Herzyk, D.J., Rehm, S., Harmsen, A.G.,
Gore, E.V., Williams, D.M., Maleeff, B.E., Badger, A.M.,
Truneh, A., O’Brien, S.R., Macia, R.A., Wier, P.J.,
Morgan, D.G. and Hart, T.K. (2000). Hum. Exp. Toxicol.
19, 230–243.
Cannon, R.E., Graves, S., Spalding, J.W., Trempus, C.S. and
Tennant, R.W. (2000). Mol. Carcinog. 29, 229–235.
Carmichael, P.L., Mills, J.J., Campbell, M., Basu, M.
and Caldwell, J. (2001). Toxicol. Pathol. 29(Suppl.),
155–160.
Chan, P.K. and Hayes, A.W. (1994). In Principles and
Methods of Toxicology (ed. W.A. Hayes), pp. 579–647.
Raven Press, New York.
Cohen, S.M. (2001). Toxicol. Pathol. 29(Suppl.), 183–190.
Cohen, S.M., Robinson, D. and MacDonald, J. (2001).
Toxicol. Sci. 64, 14–19.
Dayan, A.D. (1995). Toxicology 105, 59–68.
Dean, J.H., Twerdok, L.E., Tice, R.R., Sailstad, D.M.,
Hattan, D.G. and Stokes, W.S. (2001). Regul. Toxicol.
Pharmacol. 34, 258–273.
Eastin, W.C., Mennear, J.H., Tennant, R.W., Stoll, R.E.,
Branstetter, D.G., Bucher, J.R., McCullough, B.,
Binder, R.L., Spalding, J.W. and Mahler, J.F. (2001).
Toxicol. Pathol. 29(Suppl.), 60–80.
Gleichmann, E., Klinkhammer, C. and Gleichmann, H.
(1989). Arch. Toxicol. Suppl. 13, 188–190.
Goodman, J.I. (2001). Toxicol. Pathol. 29(Suppl.), 173–176.
Gossen, J., de Leeuw, W., Tan, C., et al. (1989). Proc. Natl.
Acad. Sci. USA 86, 7971–7975.
Griffiths, S.A. and Lumley, C.E. (1998). Hum. Exp. Toxicol.
17, 63–83.
Haseman, J., Melnick, R., Tomatis, L. and Huff, J. (2001).
Food Chem. Toxicol. 39, 739–744.
Hopley, R. and Zimmer, A. (2001). BioTechniques 30,
130–132.
Huff, J. (1994). In Carcinogenesis (eds M.P. Waalkes and
J.M. Ward), pp. 25–37. Raven Press, New York.
Infante, P.F. (1993). Environ. Health Perspect. 101(Suppl. 5),
143–148.
Keenan, C., Hughes-Earle, A., Case, M., Stuart, B., Lake, S.,
Mahrt, C., Halliwell, W., Westhouse, R., Elwell, M.,
Morton, D., Morawietz, G., Rittinghausen, S., Deschl, U.
and Mohr, U. (2002). Toxicol. Pathol. 30(1), 75–79.
Kimber, I. (2001). Toxicology 158, 59–64.
Lesch, K.P. (2001). Pharmacogenomics J. 1, 187–192.
Morton, D., Alden, C.L., Roth, A.J. and Usui, T. (2002).
Toxicol. Pathol. 30(1), 139–146.
Myhr, B. (1991). Environ. Mol. Mutagen. 18, 308–315.
Olson, H., Betton, G., Stritar, J. and Robinson, D. (1998).
Toxicol. Lett. 102–103, 535–538.
Olson, H., Betton, G., Robinson, D., Thomas, K., Monro, A.,
Kolaja, G., Lilly, P., Sanders, J., Sipes, G., Bracken, W.,
Dorato, M., van Deun, K., Smith, P., Berger, B. and
Heller, A. (2000). Regul. Toxicol. Pharmacol. 32, 56–67.
Pieters, R. (2001). Toxicology 158, 65–69.
Pieters, R., Ezendam, J., Bleumink, R., Bol, M. and
Nierkens, S. (2002). Toxicol. Lett. 127, 83–91.
Popp, J.A. (2001). Toxicol. Pathol. 29(Suppl.), 20–23.
Rosenberg, M.P. (1997). Mol. Carcinog. 20, 262–274.
Rudmann, D.G. and Durham, S.K. (1999). Toxicol. Pathol.
27(1), 111–114.
Rudolph, U. and Möhler, H. (1999). Eur. J. Pharmacol. 375,
327–337.
Sigmund, C.D. (2000). Arterioscler. Thromb. Vasc. Biol. 20,
1425–1429.
Spalding, J.W., French, J.E., Tice, R.R., Furedi-Machacek, M.,
Haseman, J.K. and Tennant, R.W. (1999). Toxicol. Sci.
49, 241–254.
Short, J.M., Kohler, S.W., Provost, G.S., Ferik, A. and
Kretz, P.L. (1990). In Mutation and the Environment (eds
M. Mendelsohn and R. Albertini), pp. 355–367. Wiley
and Liss, New York.
Storer, R.D., French, J.E., Haseman, J., Hajian, G.,
LeGrand, E.K., Long, G.G., Mixson, L.A., Ochoa, R.,
Sagartz, J.E. and Soper, K.A. (2001). Toxicol. Pathol.
29 (Suppl.),30–50.
Tamaoki, N. (2001). Toxicol. Pathol. 29(Suppl.), 81–89.
Tennant, R.W., Tice, R.R. and Spalding J.W. (1998). Toxicol.
Lett. 102–103, 465–471.
Tennant, R.W., Stasiewicz, S., Eastin, W.C., Mennear, J.H. and
Spalding J.W. (2001). Toxicol. Pathol. 29(Suppl.), 51–59.
Thomas, J.A. (1995). Toxicology 105, 7–22.
Ulrich, P. and Vohr, H.W. (1996). Eur. Cytokine Netw. 7,
401–407.
Ulrich, P., Homey, B. and Vohr, H.W. (1998). Toxicology
125, 149–168.
Ulrich, P., Grenet, O., Bluemel, J., Vohr, H.W., Wiemann, C.,
Grundler, O. and Suter, W. (2002). Arch. Toxicol.
76, 62.
Usui, T., Mutai, M., Hisada, S., Takoaka, M., Soper, K.A.,
McCullough, B. and Alden, C. (2001). Toxicol. Pathol.
29(Suppl.), 90–108.
Van der Laan, J.W. and Spindler, P. (2002). Regul. Toxicol.
Pharmacol. 35, 122–125.
Van der Laan, J.W., Lima, B.S. and Snodin, D. (2002).
Toxicol. Pathol. 30(1), 157–159.
Van Kreijl, C.F., McAnulty, P.A., Beems, R.B., Vynckier, A.,
van Steeg, H., Fransson-Steen, R., Alden, C.L., Forster, R.,
van der Laan, J.W. and Vandenberghe, J. (2001). Toxicol.
Pathol. 29(Suppl.), 117–127.
Van Steeg, H., de Vries, A., van Oostrom, C.T.M.,
van Benthem, J., Beems, R.B. and van Kreijl, C.F. (2001).
Toxicol. Pathol. 29(Suppl.), 109–116.
Venkatachalam, S., Tyner, S.D., Pickering, C.R., Boley, S.,
Recio, L., French, J.E. and Donehower, L.A. (2001).
Toxicol. Pathol. 29(Suppl.), 147–154.
Vohr, H.W., Blumel, J., Blotz, A., Homey, B., and Ahr, H.J.
(2000). Arch. Toxicol. 73, 501–509.
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