Rate Limiting Steps of AAV
Transduction and Implications for Human Gene Therapy Pp. 137-147
S. Sanlioglu, M. M. Monick, G.
Luleci4, G. W. Hunninghake and J. F. Engelhardt
Adenoviral Vector-Mediated Gene
Transfer for Human Gene Therapy Pp. 149-162
Benjamin Breyer, Wei Jiang,
Hongwei Cheng, Lan Zhou, Ronjon Paul, Tao Feng, and Tong-Chuan He
Imaging Methods in Gene Therapy
of Cancer Pp. 163-182
Uwe Haberkorn2 and Annette
Altmann
Viral Based Gene Therapy for
Prostate Cancer Pp. 183-200
Yi Lu
Nonviral Gene Therapy Pp 201-226
Song Li and Zheng Ma
Transplantation-Based Gene
Therapy for Inflammatory Diseases: Focus on Glomerulonephritis Pp 227-235
T. Yokoo and T. Ohashi
[Back to top] Rate Limiting Steps of AAV Transduction and Implications
for Human Gene Therapy
Despite the fact that adeno-associated virus type 2 (AAV2) is an
extremely attractive gene therapy vector, its application has been limited to
certain tissues such as muscle and the brain. In an attempt to broaden the
array of target organs for this vector, molecular studies on the mechanism(s)
of AAV transduction have expanded over the past several years. These studies
have led to the development of innovative strategies capable of overcoming
intracellular barriers to AAV2 transduction. The basis of these technologic
breakthroughs has stemmed from a better understanding of the molecular
processes that control AAV entry and intracellular trafficking to the nucleus.
This review will focus on the identification of molecular components important
for recombinant AAV (rAAV) transduction while highlighting the techniques used
to discover them and potential clinical application of research findings.
[Back to top] Adenoviral Vector-Mediated
Gene Transfer for Human Gene Therapy
Human gene therapy promises to change the practice of medicine by
treating the causes of disease rather than the symptoms. Since the first
clinical trial made its debut ten years ago, there are over 400 approved
protocols in the United States alone, most of which have failed to show
convincing data of clinical efficacy. This setback is largely due to the lack
of efficient and adequate gene transfer vehicles. With the recent progress in
elucidating the molecular mechanisms of human diseases and the imminent arrival
of the post genomic era, there are increasing numbers of therapeutic genes or
targets that are available for gene therapy. Therefore, the urgency and need
for efficacious gene therapies are greater than ever. Clearly, the current
fundamental obstacle is to develop delivery vectors that exhibit high efficacy
and specificity of gene transfer. Recombinant adenoviruses have provided a
versatile system for gene expression studies and therapeutic applications. Of
late, there has been a remarkable increase in adenoviral vector-based clinical
trials. Recent endeavors in the development of recombinant adenoviral vectors
have focused on modification of virus tropism, accommodation of larger genes,
increase in stability and control of transgene expression, and down-modulation
of host immune responses. These modifications and continued improvements in
adenoviral vectors will provide a great opportunity for human gene therapy to
live up to its enormous potential in the second decade.
[Back to top] Imaging Methods in Gene Therapy
of Cancer
Clinical gene therapy needs non ínvasive tools to evaluate the
efficiency of gene transfer. This includes the evaluation of infection
efficiency as well as the verification of successfull gene transfer in terms of
gene transcription. These informations can be used for therapy planning, follow
up studies in treated tumors and as an indicator of prognosis. Therapy planning
is performed by the assessment of gene expression for example using
radiolabeled specific substrates to determine the activity of suicide enzymes
as the Herpes Simplex Virus thymidine kinase or cytosine deaminase.
Furthermore, other in vivo reporter genes as receptors, antigens or transport
proteins may be used in bicistronic vector systems for the evaluation of gene
transduction and expression. This is done using radiolabeled ligands, antigens
or substrates. Follow up studies with magnetic resonance imaging, single photon
emission tomography or positron emission tomography may be done to evaluate
early or late effects of gene therapy on tumor volume, metabolism or
proliferation. Finally, enhancement of radioactive isotope accumulation in
tumors by transfer of the appropriate genes may be used for the treatment of
malignant tumors.
[Back to top] Viral Based Gene Therapy for
Prostate Cancer
In the last few years, significant advances in gene therapy have
been made as a result of advances in many areas of molecular and cell biology,
including the improvement of both viral and nonviral gene delivery systems,
discovery of new therapeutic genes, better understanding of mechanism of
disease progression, exploration of tissue specific promoter, receptor- and
antibody-mediated targeting delivery, and development of better prodrug
enzyme/prodrug systems. In this article, viral based gene therapy for prostate
cancer will be reviewed and discussed. The areas of emphasis in this review
are: choice of viral vectors, comparison of delivery routes, development of
prostate-targeted viruses, choice of therapeutic genes and strategies including
corrective gene therapy (tumor suppressor gene and anti-oncogene gene
approaches), suicide gene therapy, programmed cell death therapy,
immunomodulation therapy, and conditional oncolytic virus approach. Among them,
several examples will be discussed in detail for the scientific basis and
therapeutic applications. In addition, prostate cancer gene therapy clinical
trials, unresolved problems and future directions in this field will also be
described.
[Back to top] Nonviral Gene Therapy
The last 10 years have seen substantial progress in the
development and application of nonviral vectors in gene therapy. Several novel
nonviral methods have been developed that approach viruses with respect to
transfection efficiency. A variety of nonviral delivery systems that can be
used for gene therapy in different clinical settings are also available. In
this review article, we will detail all of the major nonviral vectors that are
currently used in gene therapy while highlighting some recent developments,
particularly the progress towards the understanding of the cellular and in vivo
barriers in gene transfer. Recent advancement in achieving sustained and
regulated gene expression will also be addressed. Finally, this review will
briefly cover targeted gene repair using nonviral delivery systems. Their
impact in gene therapy will also be discussed.
[Back to top] Transplantation-Based Gene
Therapy for Inflammatory Diseases: Focus on Glomerulonephritis
Over the past decade, bone marrow transplantation has come to be
considered an ideal therapeutic strategy for the treatment of certain diseases
affecting the hematopoietic system such as hemophilia, and several clinical
trials have been performed. Although traditionally used for the treatment of
lethal diseases, it is speculated that this approach could also be used in the
treatment of non-lethal but much more common diseases, which are resistant to
conventional therapies, and affect a large number of patients physically and
even financially.
Inflammation may be one target for transplantation-based gene
therapy, since macrophages and neutrophils, which are basically derived from
hematopoietic stem cells, have been identified as key determinants in the
development of diseases.
This article focuses on the glomerulonephritis as a model of local
inflammation and reviews recent investigations on transplantation-based gene
therapy for inflammatory disease.