Biomedical Engineering Reference
In-Depth Information
X
Mutant (disease) gene - loss of function
D
Mutant (disease) gene - dominant gain of function
1 Gene augmentation therapy
Functional
gene
X
X
2 Gene inhibition therapy
Antisense
gene etc.
D
D
3 Gene targeting
Homologous
f
unctional gen
e
X
or
D
4 Assisted killing
Antigen,
cytokine etc.
D
Death
D
Immune system
stimulated
5 Prodrug therapy
TK etc
Ganciclovir
D
Death
D
Fig. 14.9
Overview of gene-therapy
strategies.
Confers
sensitivity
The
ex vivo
approach can be applied only to certain
tissues, such as bone marrow, in which the cells are
amenable to culture. Gene therapy can be used to
treat diseases caused by mutations in the patient's
own DNA (inherited disorders, cancers), as well as
infectious diseases, and is particularly valuable in
cases where no conventional treatment exists or
where that treatment is inherently risky. Strategies
include the following (Fig. 14.9):
• Gene-augmentation therapy (GAT), where DNA is
added to the genome with the aim of replacing a
missing gene product.
• Gene targeting to correct mutant alleles.
• Gene-inhibition therapy, using techniques such
as antisense RNA expression or the expression of
intracellular antibodies to treat dominantly acting
diseases.
• The targeted ablation of specific cells.
