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Current
Pharmaceutical Biotechnology
ISSN: 1389-2010
Current Pharmaceutical Biotechnology
Volume 10, Number 2, February 2009
Contents
Novel Targets in Cancer Therapy
Guest Editor: Debabrata Banerjee
Editorial Pp. 147
Debabrata Banerjee
[PMID:
19199945 PubMed - indexed for MEDLINE]
Potential Novel Targets in Breast Cancer
Pp. 148-153
Pranela Rameshwar
[Abstract] [Purchase
Article] [PMID:
19199946 PubMed - indexed for MEDLINE]
Notch Inhibitors as a New Tool in the
War on Cancer: A Pathway to Watch Pp. 154-160
Benjamin Purow
[Abstract] [Purchase
Article] [PMID:
19199947 PubMed - indexed for MEDLINE]
Molecular Targets for Epigenetic Therapy
of Cancer Pp. 161-165
Rita Humeniuk, Prasun J. Mishra, Joseph
R. Bertino and Debabrata Banerjee
[Abstract] [Purchase
Article] [PMID:
19199948 PubMed - indexed for MEDLINE]
Targeting the Immune System in Cancer
Pp. 166-184
Devyani Chaudhuri, Robert Suriano, Abraham
Mittelman and Raj K. Tiwari
[Abstract] [Purchase
Article] [PMID:
19199949 PubMed - indexed for MEDLINE]
Targeting the Tumor Stroma in Cancer
Therapy Pp. 185-191
Kevin Anton and John Glod
[Abstract] [Purchase
Article] [PMID:
19199950 PubMed - indexed for MEDLINE]
Tumor Initiating Cells Pp.
192-196
Nitu Bansal and Debabrata Banerjee
[Abstract] [Purchase
Article] [PMID:
19199951 PubMed - indexed for MEDLINE]
Mammalian Mutant Resources for Therapeutic
Challenges
Guest Editor: Koichiro Abe, Co-Guest Editors:
Minoru Kimura & Ken-ichi Yamamura
Editorial
Pp. 197
Koichiro Abe, Minoru Kimura & Ken-ichi Yamamura
[PMID:
19199952 PubMed - indexed for MEDLINE]
Features and Strategies of ENU Mouse Mutagenesis Pp.
198-213
Dian Soewarto, Matthias Klaften and Isabel
Rubio-Aliaga
[Abstract] [Purchase
Article] [PMID:
19199953 PubMed - indexed for MEDLINE]
Rat Resources in Biomedical Research
Pp. 214-220
Tomoji Mashimo and Tadao Serikawa
[Abstract] [Purchase
Article] [PMID:
19199954 PubMed - indexed for MEDLINE]
International Gene Trap Project: Towards
Gene-driven Saturation Mutagenesis in Mice Pp.
221-229
Masatake Araki, Kimi Araki and
Ken-ichi Yamamura
[Abstract] [Purchase
Article] [PMID:
19199955 PubMed - indexed for MEDLINE]
The New Disease Models from Genetic Polymorphisms
of Japanese Wild Mice Pp. 230-235
Yoshibumi Matsushima
[Abstract] [Purchase
Article] [PMID:
19199956 PubMed - indexed for MEDLINE]
The German Mouse Clinic: A Platform for
Systemic Phenotype Analysis of Mouse Models Pp.
236-243
H. Fuchs, et al.
[Abstract] [Purchase
Article] [PMID:
19199957 PubMed - indexed for MEDLINE]
Recombinant DNA Technologies for Construction
of Precisely Designed Transgene Constructs Pp.
244-251
Masato Ohtsuka, Minoru Kimura, Masafumi
Tanaka and Hidetoshi Inoko
[Abstract] [Purchase
Article] [PMID:
19199958 PubMed - indexed for MEDLINE]
Positional Cloning in Mice and Its Use
For Molecular Dissection of Inflammatory Arthritis Pp.
252-260
Koichiro Abe and Philipp Yu
[Abstract] [Purchase
Article] [PMID:
19199959 PubMed - indexed for MEDLINE]
The Utilization of Gene Targeting Models
During in Preclinical Study of Drug Discovery Process - Example
of Phenotypic and Functional Analysis of Cacna1β
Gene Product Pp. 261-267
Norimasa Miyamoto, Kana Namiki, Naoki Tokuhara,
Mai Uesugi, Eiki Takahashi, Junro Kuromitsu and Yoshitoshi
Kasuya
[Abstract] [Purchase
Article] [PMID:
19199960 PubMed - indexed for MEDLINE]
Abstracts
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[PMID:
19199945 PubMed - indexed for MEDLINE]
Editorial: Novel Targets in Cancer Therapy
Debabrata Banerjee
In this special issue six articles on current developments
in the field of cancer research with special emphasis on novel
approaches and or novel targets in cancer chemotherapy are
presented. These include identification of novel targets in
breast cancer such as the bone marrow microenvironment and
the interaction with subsets of tumor cells including tumor
stem cells (see article by Rameshwar), the notch signaling
pathway (see article by Purow BJ), epigenetics (Humeniuk et
al.), novel ideas regarding targeting the immune system
for cancer immunotherapy (see Chaudhury et al.),
targeting the tumor stromal interaction (article by Anton
and Glod) and lastly targeting the tumor initiating cells
or tumor stem cells (see article by Bansal and Banerjee).
Rameshwar discusses a new way of thinking for identifying
the breast cancer stem cells and other subsets in bone marrow.
Following entry of breast cancer cells in the marrow, it is
proposed that the first step involves formation of gap junctional
intercellular communication between cancer cells and stromal
cells close to the endosteum. An understanding of the mechanisms
by which cancer cell subsets interact with other cells of
the bone marrow could lead to an understanding of cancer behavior
in bone marrow and may lead to identification of novel therapeutic
targets.
Chaudhury et al. propose that the immunosuppressive
tumor environment can be altered to become immune activating,
thus facilitating the infiltration of myeloid and lymphoid
cells that can act in concert leading to tumor regression.
In this regard, immunotherapeutic approaches such as DNA vaccines,
dendritic cell based vaccines, HSP based vaccines and gene
transfer technology, are being developed and further refined
to overcome their inherent limitations. They argue that careful
evaluation of the suppressive nature of the tumor microenvironment
accompanied by qualitative and quantitative measurements of
lymphocyte responses in patients may lead to development of
more meaningful therapeutic strategies. Combined with development
of advanced genetic technologies and continuous identification
of novel tumor antigens, the field of cancer immunotherapy
is poised to make major advances.
The Notch signaling pathway has been found to play central
roles in humans in stem cell maintenance, cell fate decisions,
and in cancer as well. Notch family members are now being
recognized as oncogenes in an ever-increasing number of cancers
making them attractive therapeutic targets. Purow makes the
case that although significant progress has been made in dissecting
the complex workings of this signaling pathway, there are
very limited options available for clinical use of Notch inhibitors.
The review addresses current state-of-the-art, newer notch
targeting agents in the pipeline, and potential strategies
for use of future Notch inhibitors in the clinic as anticancer
agents.
Humeniuk et.al. propose that epigenetic modifications can
be transmitted to the next generation and used to turn off
and/or on certain genes or pathways that may confer survival
benefit to a cancer cell. As the epigenetic changes are readily
reversible, strong arguments can be made in favor of “epigenetic
therapy”. They are quick to point out that a potential
problem in this therapeutic approach is the lack of specificity
as epigenetic modifications are used by both normal and cancer
cells to regulate expression of various genes. They refer
to ongoing studies to identify genes that are differentially
expressed in cancer cells vs. normal cells are providing valuable
information about molecular targets for epigenetic therapy.
Humeniuk et al. summarize some of these studies and
discus the differences between conventional and epigenetic
therapy utilizing epigenetic drugs like DNA methyltransferase
inhibitors or histone deacetylase inhibitors. Current thoughts
on the future of epigenetic therapy are also discussed.
It is now recognized that the stroma plays a role in processes
such as nutritional support, the removal of waste products,
and the creation of a barrier regulating the exchange of fluids,
gases, and cells. The stroma provides support with growth
factors and cytokines and promotes angiogenesis, tissue invasion,
and metastasis. More recently, it has become evident that
the stroma provides a chemoresistant capability to the tumor,
preventing chemotherapeutics from reaching their target. Anton
and Glod discuss the recent developments in targeting the
various players involved in the tumor stroma interactions
and argue that future development of more specific targets
will depend upon further characterization of the cellular
and molecular interactions in the tumor microenvironment.
Although there is evidence supporting the existence of cancer
stem cells, tumor induction from a single cell has yet to
be shown. Therefore scientists prefer to describe these as
“tumor initiating cells” (TIC) that define a subset
of cancer cells that have the ability to form tumors. Several
groups have reported on the isolation and separation of cancer
stem cells. Methods used in the isolation of hematopoietic
stem cells played an important role in the evolution of techniques
involved in identification of cancer stem cells. Bansal and
Banerjee suggest that a very small percentage of tumor initiating
cells are present in the tumor mass and make up approximately
0.2 to 1%. Importantly, these cells are thought to contribute
to the overall chemotherapy and radiation resistance encountered
in the clinic. Thus, combination therapies using conventional
chemotherapy agents and novel drugs that target essential
pathways in the tumor initiating cells could be more effective
in cancer cell kill.
I am confident that these articles will be of interest to
readers of CPB and will provoke new ideas and discussions
in developing novel strategies to combat cancer.
Debabrata Banerjee
Guest Editor
Department of Pharmacology and Medicine,
The Cancer Institute of New Jersey,
Robert Wood Johnson Medical School,
UMDNJ, 195 Little Albany Street, Room 3035, New Brunswick
NJ 08903
USA
Tel: (732) 235 6458;
Fax: (732) 235 8181;
E-mail: banerjed@umdnj.edu
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[Purchase Article] [PMID:
19199946 PubMed - indexed for MEDLINE]
Potential Novel Targets in Breast Cancer
Pranela Rameshwar
This review focuses on the properties of different breast
cancer cell subsets, including cancer stem cells (CSCs) and
cancer progenitors. The premise is that an understanding of
self-renewal, the effects of aging microenvironment on the
behavior of cancer cell subsets will map the path of development
from CSCs to progenitors. The basic characterization of different
cancer cell subsets will lead to their signatures and open
the field to novel methods of prognosis and diagnosis. The
identification of cancer progenitors would allow scientists
to modify the cells genetically for dedifferention to CSCs.
This will benefit the field to understand the method by which
CSCs are developed. The review discusses a reductionist approach
for identifying the CSCs and other subsets in bone marrow.
An understanding of the mechanisms by which cancer cell subsets
interact with other cells of the bone marrow could lead to
an understanding of cancer behavior in bone marrow. A protective
role of mesenchymal stem cells after the cancer cells enter
the marrow is proposed as the first step in the cancer cells
forming gap junctional intercellular communication with stromal
cells close to the endosteum. It is possible that microRNAs
could be shared between the cancer cells and stroma. The review
recapitulates two stages of breast cancer: an early stage
when the cancer cells enter bone marrow, perhaps prior to
clinical detection and during the stage of heavy tumor burden
when a subset of cancer cells survive and can resurge years
after remission. This review argues for new approaches to
identify breast cancer stem cells, and to understand how this
population of cells interacts with the bone marrow microenvironment.
In summary, the presented approach could lead to the development
of new drug targets and approaches to treat breast cancer.
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[Purchase Article] [PMID:
19199947 PubMed - indexed for MEDLINE]
Notch Inhibitors as a New Tool in the War on Cancer: A Pathway
to Watch
Benjamin Purow
Notch was first recognized as an important developmental
pathway in Drosophila in the first half of the 20th
century. Many decades later, this pathway has been found to
play central roles in humans in stem cell maintenance, cell
fate decisions, and in cancer as well. Notch family members
are being revealed as oncogenes in an ever-increasing number
of cancers. Though significant progress has been made in dissecting
the complex workings of this signaling pathway, there are
very limited options available for Notch inhibitors. However,
the pioneering class of Notch inhibitors is already in clinical
trials for two cancer types. This review will address the
current state-of-the-art, agents in the pipeline, and potential
strategies for future Notch inhibitors. Successful development
of Notch inhibitors in the clinic holds great promise as a
new anti-cancer strategy.
[Back to top]
[Purchase Article] [PMID:
19199948 PubMed - indexed for MEDLINE]
Molecular Targets for Epigenetic Therapy of Cancer
Rita Humeniuk, Prasun J. Mishra, Joseph
R. Bertino and Debabrata Banerjee
Recent advances in cancer research showed that changes
of the cell “epigenome” contribute significantly
to the development and progression of cancer. Similar to genetic
alterations, epigenetic modifications can be transmitted to
the next generation and used to turn off and/or on certain
genes or pathways that may confer survival benefit to a malignant
cell. However, epigenetic changes are readily reversible raising
the possibility of “epigenetic therapy”. A potential
problem in this therapeutic approach is the lack of specificity,
as epigenetic modifications are used by both normal and cancer
cells to regulate expression of various genes. Ongoing studies
to identify genes that are differentially expressed in cancer
cells vs. normal cells are providing valuable information
about molecular targets for epigenetic therapy. The present
article will focus on summarizing some of these studies and
will discus the differences between conventional chemotherapy
and epigenetic therapy utilizing epigenetic drugs like DNA
methyltransferase inhibitors or histone deacetylase inhibitors.
Current perspectives on the future of epigenetic therapy are
also discussed.
[Back to top]
[Purchase Article] [PMID:
19199949 PubMed - indexed for MEDLINE]
Targeting the Immune System in Cancer
Devyani Chaudhuri, Robert Suriano, Abraham
Mittelman and Raj K. Tiwari
The concept of cancer immunotherapy provides a fresh
perspective as it is not associated with many of the drawbacks
of conventional therapies such as chemotherapy, radiotherapy
and surgery. When fully activated the immune system has immense
potential as is evident from mis-matched transplanted organs
undergoing rapid immunological attack and rejection. However,
the development of immune strategies for cancer therapy has
been associated with challenges of their own. Early attempts
at cancer vaccination were carried out in an empirical manner
that did not always lead to reproducibility. This led to a
search of tumor associated antigens with the belief that specific
targeting of these antigens would lead to successful tumor
elimination. Active vaccination with TAA peptides or passive
vaccination with specific lymphocytes against these TAAs did
not however demonstrate encouraging results in clinical trials.
This was mainly because of the lack of an activating immune
response which is required for continuous stimulation of lymphocytes
and also because of the selection of tumor escape variants
that did not express the particular TAA. On the positive side,
attempts at characterizing TAAs illuminated the molecular
changes that attribute a malignant phenotype to cancer cells.
Attempts at cytokine therapy were also met with challenges
of high systemic toxicity and a lack of specific lymphocyte
activation. It was therefore realized that an ideal vaccinating
agent should be able to combine the effects of both these
therapeutic strategies, i.e., it should be able to induce
an innate immune response which can be tailored to a tumor
specific adaptive immune response. By this, the immunosuppressive
tumor environment can be altered to become immune activating,
thus facilitating the infiltration of myeloid and lymphoid
cells that can act in concert leading to tumor regression.
In this regard, immunotherapeutic approaches such as DNA vaccines,
dendritic cell based vaccines, HSP based vaccines and gene
transfer technology, are being developed and further refined
to overcome their inherent limitations. Animal experiments
with these therapeutic modalities have demonstrated exciting
results, although their evaluation in clinical trials has
not indicated exceptional tumor protection in a large percentage
of the patients. These observations only further underscore
the multivariate and dynamic nature of the immune system and
the many ways in which tumor cells modulate themselves and
their surroundings to escape immune surveillance. Assessment
of successful therapeutic intervention will require periodic
evaluations of the suppressive nature of the tumor microenvironment
accompanied by qualitative and quantitative measurements of
lymphocyte responses in patients. With the development of
advanced genetic technologies and continuous identification
of tumor antigens, the field of cancer immunotherapy is progressing
at an exciting pace giving us hope for the advent of effective
treatment modalities that will prolong tumor free survival
and enhance the quality of life in patients with malignant
disease.
[Back to top]
[Purchase Article] [PMID:
19199950 PubMed - indexed for MEDLINE]
Targeting the Tumor Stroma in Cancer Therapy
Kevin Anton and John Glod
Increasing evidence shows that the interaction between
neoplastic cells and the surrounding stroma is a critical
factor in solid tumor growth. The tumor stroma is made up
of diverse cellular populations including macrophages, lymphocytes,
vascular cells, and carcinoma-associated fibroblasts. The
complex interactions between the stroma and neoplastic cells
are largely unexplored. Initial therapies aimed at disrupting
angiogenesis within the tumor microenvironment have met with
success in a number of tumor types. An improved understanding
of stromal signaling pathways is likely to identify additional
novel therapeutic targets.
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[Purchase Article] [PMID:
19199951 PubMed - indexed for MEDLINE]
Tumor Initiating Cells
Nitu Bansal and Debabrata Banerjee
Cancer Stem cells (CSC) are defined as a population of
cells found within a tumor that have characteristics similar
to normal stem cells. Like normal stem cells they have the
potential to self renew and differentiate. The cellular origin
of these cancer stem cells - whether they originate from stem
cells that have lost the ability to regulate proliferation,
or they arise from more differentiated population of progenitor
cells that have acquired abilities to self-renew is still
unclear. Investigators have reported isolation of cancer stem
cells or tumor initiating cells using techniques developed
for isolating hematopoietic stem cells and assays that identify
a small subset of tumor initiating cells. The TICs are thought
to play an important role in tumor development, progression
as well response to therapy and relapse. Strategies that combine
conventional therapies with newer approaches that target the
TICs may be more effective in tumor cell kill are discussed.
Mammalian Mutant Resources for Therapeutic Challenges
Guest Editor: Koichiro Abe, Co-Guest Editors:
Minoru Kimura & Ken-ichi Yamamura
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[PMID:
19199952 PubMed - indexed for MEDLINE]
Editorial:Mammalian Mutant Resources for Therapeutic Challenges
Koichiro Abe, Minoru Kimura & Ken-ichi Yamamura
After the publication of the draft human genome sequence,
now complete or partial genome sequences of 25 mammalian species
are available in public genome databases. Obviously, sequence
comparisons among the species are crucial for identification
of similarities and differences between humans and other mammals
in genome evolution. In the post genomic era, however, attention
has been paid to uncovering gene function and identifying
gene products that might possess therapeutic value. Although,
systems biology and in silico analysis will help
to predict in vivo gene function in the future, genetic
modification using model organisms are necessary to confirm
the predictions experimentally in vivo. Because of experimental
limitation in human, other mammalian models are essential
for this purpose.
The laboratory mouse (Mus musclus) has a long history
as a human model in biomedical research since early days of
genetics. For most of the 20th century, production, identification,
and analysis of mouse mutant strains were carried out independently
in small scale. During this period, the spontaneous or induced
mutant strains were archived and maintained by individual
institution or scientist. Through the development of transgenic
and gene targeting techniques in mice, the situation changed
dramatically. The number of scientists working with mice rapidly
increased. Engineering of mouse genome attracted many molecular
biologists, because it seemed the most efficient way to study
functions of gene in vivo and to generate models
for human diseases. During same period, several large integrated
projects were undertaken. They include the sequencing of the
mouse genome, the production of numerous new mutations using
chemical mutagens or by gene trap, and systematic phenotyping
of many inbred and mutant strains. Despite the large body
size and technical inabilities, chemical mutagenesis projects
in rats are in progress. The resources also contain increased
number of genetically engineered mutants and gene targeted
ES clones from the knockout mouse project, which is a high-throughput
international effort to produce knockout ES cells for all
mouse genes. These precious and valuable resources, however,
are not connected to efficient systems to produce novel therapeutic
strategies or drug development.
In this special issue of Current Pharmaceutical Biotechnology,
we aimed to enhance and increase interaction between the mammalian
mutant resource projects and pharmaceutical science. For this
purpose, we selected three categories for review articles:
1) introduction of mammalian resource projects; 2) technology
aspects for developing the resources; 3) applications of the
mammalian resources to human diseases. First, chemically induced
mutant resources are described; Soewarto et al. and
Mashimo & Serikawa reviewed recent progress of
ethyl nitrosourea (ENU) mutagenesis projects in the mouse
and the rat, respectively. Araki et al. introduced
ES cell based gene-driven mutagenesis projects, the gene trap
project, and the usage of web-based database to obtain the
information on trapped clones. Matsushima introduces
that genetic variation in wild mice derived strains is also
a valuable source for mutations. In addition to these four
reviews on mutant resources, two reviews were selected to
expand on technological usage of mutant resources. Fuchs
et al. described the German Mouse Clinic, a large phenotyping
centre for mutant mice, and its output. The standardization
of the phenotyping is becoming more and more important in
order to share phenotype information in the future. Ohtsuka
et al. focused on recent progress and improvement on
techniques in DNA construction for genetic engineering. The
developing techniques are critical for production of genetically
engineered animals in a high-throughput manner. Finally, usages
and application of the mutant resources for human disease
are described. Abe & Yu reviewed a positional
cloning strategy for mutant strains with inflammatory arthritis.
Miyamoto et al. focused on analysis of genetic engineered
mice for preclinical studies.
Many examples show that mutants of experimental animals are
used as in vivo confirmation for pathogenesis of
human diseases. More frequently, aspects from analysis of
various mammalian mutants could be applied to development
of new treatments and drugs in next decades. Thus mammalian
mutant resources hold vast potential to accelerate the novel
therapeutic challenges and thereby contribute to human health.
We hope that this issue helps to the bridging and development
of the interaction among different fields for the aspiration.
Koichiro Abe
Guest Editor
Department of Basic Medical Science and Molecular Medicine
Shimokasuya 143, Isehara, School of Medicine, Tokai University
Kanagawa 259-1193
Japan
E-mail: abeko@is.icc.u-tokai.ac.jp
Minoru Kimura
Co-Guest Editor
Department of Basic Medical Science and Molecular Medicine
Shimokasuya 143, Isehara, School of Medicine, Tokai University
Kanagawa 259-1193
Japan
Ken-ichi Yamamura
Co-Guest Editor
Institute of Molecular Embryology and Genetics
Kumamoto University
Honjo 2-2-1
Kumamoto 860-0811
Japan
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Article] [PMID:
19199953 PubMed - indexed for MEDLINE]
Features and Strategies of ENU Mouse
Mutagenesis
Dian Soewarto, Matthias Klaften and Isabel
Rubio-Aliaga
Aim of this review is to demonstrate the relevance of
animal models created by ENU mutagenesis for the pharmaceutical
community to understand diseases and the modulation of disease
status by pharmaceutical compounds. We give an overview of
what ENU mutagenesis in mice implies and introduce the main
research centers running ENU mutagenesis projects. The different
strategies of ENU mutagenesis screens are explained as well
as the latest advances in mapping and mutation detection strategies,
which until recently have been the main limiting step in forward
genetics/ phenotype-driven approaches. ENU mutagenesis in
mice has shown its power by providing animal models for human
monogenic diseases. Moreover, the development of modifier
and sensitized screens extended this resource to models for
multigenic diseases and thereby opened the perspective to
understand the modulation of disease states. Finally, we provide
information about the accessibility and availability of these
models for academic research.
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[Purchase Article] [PMID:
19199954 PubMed - indexed for MEDLINE]
Rat Resources in Biomedical Research
Tomoji Mashimo and Tadao Serikawa
The laboratory rat is obviously an important model for
physiology, pathology, pharmacology, toxicology, and transplantation
experiments. The value for pharmacological research is immense
since virtually every drug approved for human treatment passes
through the body of laboratory rats. Hundreds of unique rat
models have been developed to mimic pathological and physiological
human clinical conditions, especially in the case of complex
diseases. Many of the model rats are deposited into rat resource
centers, from which researchers can use and share animals
and rat related resources in biomedical research. Recent progressing
technologies for genetically engineered rats, such as traditional
transgenesis, chemical ENU mutagenesis, and transposon insertional
mutagenesis, will provide thousands of useful rat models for
functional genomics and human diseases. Globally acting rat
resource centers are prerequisites for successful and sustainable
research in the biomedical field where the rats are used as
model species.
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[Purchase Article] [PMID:
19199955 PubMed - indexed for MEDLINE]
International Gene Trap Project: Towards Gene-driven Saturation
Mutagenesis in Mice
Masatake Araki, Kimi Araki and
Ken-ichi Yamamura
While the human genome project has been completed, analysis
of functions of each gene is still underway. Knockout and
knock down of gene products offer useful tools to understand
functions of a single gene in vivo. Production of
knockout mice using homologous recombination in embryonic
stem (ES) cells is a powerful and established strategy. However,
it is laborious, time-consuming and expensive if expanding
large scale. In mice, the gene trap is an alternative strategy
to disrupt gene functions by random disruption of gene. The
functions of a gene in vivo can be analyzed by production
of mice from trapped ES clones. Large-scale gene trap projects
have been started in some research centers of the world, and
the International Gene Trap Consortium (IGTC) was established
to strengthen interactions among centers involved. Moreover,
the website of the IGTC has been constructed to integrate
information of trap clones from each gene trap project. The
database of the IGTC is expanding rapidly because of accumulation
of information about gene trap clones from ongoing gene trap
projects; approximately 135,000 trapped ES lines are registered
in June, 2008. These clones are freely available to academic
community. At moment, the IGTC cell lines have covered approximately
10,000 genes in the mouse genome database. Therefore, it is
recommended to check the IGTC database before starting knockout
experiment, even when annotations of genes are not available.
In this review, we introduce principle and short history of
gene trap, and then use of the IGTC database is described
to obtain trapped ES clones for the experiments.
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[Purchase Article] [PMID:
19199956 PubMed - indexed for MEDLINE]
The New Disease Models from Genetic Polymorphisms of Japanese
Wild Mice
Yoshibumi Matsushima
Personalized medicine offers a custom-made treatment
for each patient directed by information of individual's genetic
variation. Despite plenty of information about human single
nucleotide polymorphisms (SNPs) and gene expression profile,
predicting functions of genetic variations in humans is still
a difficult task. Genetic analysis using experimental animals
is possible to provide information about the functions of
genetic polymorphisms over experimental invention in humans.
In particular, inbred strains established from wild mice are
valuable resources for analyzing functions of genetic polymorphisms.
In this article, first I describe history of inbred strains
derived from Japanese wild mice, Mus musuclus molossinus.
Next, I discuss a mouse model for hyperlipidemia, which was
isolated from a colony of Japanese wild mice. Interestingly,
the hyperlipimic phenotypes are varied in congenic strains
on other genetic backgrounds, reflecting phenotype variation
of hyperlipidemia in human populations. Thus, further genetic
analysis of Japanese wild mice can contribute to functional
analysis of human genetic variation leading to personalized
medicine.
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19199957 PubMed - indexed for MEDLINE]
The German Mouse Clinic: A Platform for Systemic Phenotype
Analysis of Mouse Models
H. Fuchs, et al.
The German Mouse Clinic (GMC) is a large scale phenotyping
center where mouse mutant lines are analyzed in a standardized
and comprehensive way. The result is an almost complete picture
of the phenotype of a mouse mutant line – a systemic
view. At the GMC, expert scientists from various fields of
mouse research work in close cooperation with clinicians side
by side at one location. The phenotype screens comprise the
following areas: allergy, behavior, clinical chemistry, cardiovascular
analyses, dysmorphology, bone and cartilage, energy metabolism,
eye and vision, host-pathogen interactions, immunology, lung
function, molecular phenotyping, neurology, nociception, steroid
metabolism, and pathology. The German Mouse Clinic is an open
access platform that offers a collaboration-based phenotyping
to the scientific community (www.mouseclinic.de).
More than 80 mutant lines have been analyzed in a primary
screen for 320 parameters, and for 95% of the mutant lines
we have found new or additional phenotypes that were not associated
with the mouse line before. Our data contributed to the association
of mutant mouse lines to the corresponding human disease.
In addition, the systemic phenotype analysis accounts for
pleiotropic gene functions and refines previous phenotypic
characterizations. This is an important basis for the analysis
of underlying disease mechanisms. We are currently setting
up a platform that will include environmental challenge tests
to decipher genome–environmental interactions in the
areas nutrition, exercise, air, stress and infection with
different standardized experiments. This will help us to identify
genetic predispositions as susceptibility factors for environmental
influences.
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19199958 PubMed - indexed for MEDLINE]
Recombinant DNA Technologies for Construction of Precisely
Designed Transgene Constructs
Masato Ohtsuka, Minoru Kimura, Masafumi
Tanaka and Hidetoshi Inoko
Genetically modified animals have been used as models
in broad range of studies including pharmaceutical biology.
Designing and construction of transgene constructs are the
first indispensable task in generating model animals. In addition
to the classical restriction enzyme-based method, still holds
some advantages in generating precise constructs, site-specific
recombinase-based and homologous recombination-based DNA engineering
strategies (e.g. Gateway and Red/ET recombineering, respectively)
have been developed and widely used for vector construction
or BAC modification. In this review, the three construction
methods are described and their applications are discussed
such as tandem assemblies of multiple components and modification
of large DNA molecules. Combinational use of these E.
coli-based recombinant DNA technologies enables the generation
of precisely designed vectors useful for desired genome modification
for future analyses.
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19199959 PubMed - indexed for MEDLINE]
Positional Cloning in Mice and Its Use For Molecular Dissection
of Inflammatory Arthritis
Koichiro Abe and Philipp Yu
One of the upcoming next quests in the field of genetics
might be molecular dissection of the genetic and environmental
components of human complex diseases. In humans, however,
there are certain experimental limitations for identification
of a single component of the complex interactions by genetic
analyses. Experimental animals offer simplified models for
genetic and environmental interactions in human complex diseases.
In particular, mice are the best mammalian models because
of a long history and ample experience for genetic analyses.
Forward genetics, which includes genetic screen and subsequent
positional cloning of the causative genes, is a powerful strategy
to dissect a complex phenomenon without preliminarily molecular
knowledge of the process. In this review, first, we describe
a general scheme of positional cloning in mice. Next, recent
accomplishments on the patho-mechanisms of inflammatory arthritis
by forward genetics approaches are introduced; Positional
cloning effort for skg, Ali5, Ali18, cmo, and lupo
mutants are provided as examples for the application to human
complex diseases. As seen in the examples, the identification
of genetic factors by positional cloning in the mouse have
potential in solving molecular complexity of gene-environment
interactions in human complex diseases.
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[Purchase Article] [PMID:
19199960 PubMed - indexed for MEDLINE]
The Utilization of Gene Targeting Models During in Preclinical
Study of Drug Discovery Process - Example of Phenotypic and
Functional Analysis of Cacna1β
Gene Product
Norimasa Miyamoto, Kana Namiki, Naoki Tokuhara,
Mai Uesugi, Eiki Takahashi, Junro Kuromitsu and Yoshitoshi
Kasuya
Using gene knockout mice of particular genes is one of
the most effective methods in conducting successful study
on the mode of action of target gene products in targeted
organs. So called the knockout technology is now a powerful
tool that can lead us to find clear understanding on difficult
questions such as the effects of full antagonist against target
molecules. Cacna1b (α1B)
gene knockout mouse was generated to study mechanisms of N-type
calcium (Ca2+) channel. The
model was able to overcome physiological obstacles in studies
of N-type Ca2+ channel selective
blockers, such as unspecific binding to structurally similar
molecules, and failed distribution to targeted organs. In
the case of N-type Ca2+ channel
studies, knockout technology was successfully applied to various
cardiovascular, sympathetic, nociceptive, sleep-awake cycles,
metabolic and neurodegenerative experiments using homozygous
mutants of the α1B
gene that turned out to be viable. These studies were able
to confirm not only the predicted phenotypes, but were able
to present completely unexpected phenotypes that are great
interest for future study. Thus the outputs from the knockout
mouse studies lead to gain the proof of concept as a drug
for specific inhibitors of the gene products and enabled us
to make further prediction of side-effects of these inhibitors
in the drug discovery and development process.
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