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A. Gene Therapy
Recessive
forms of EB:
The aim is to
introduce normal copies of the genes into the skin.
Over the last
few years skin cells from EB patients have been grown in the laboratory.
These cells can be genetically modified to make normal protein.
Skin cells are
continuously being shed and renewed so the effect of genetically
modifying most types of skin cells would be short lived. Stem cells
are the cells in skin and other tissues that replenish the body's
cells. If stem cells are used for gene therapy they should allow
the new gene to produce normal protein for a long time.
Professor Michele
De Luca intended to trial gene therapy on a patient with non-Herlitz
junctional EB in mid-2002.
The idea was
to take a skin biopsy from this person, grow the skin in the laboratory
and insert a normal copy of the deficient gene into the stem cells
in this culture.
A skin graft
would then be prepared and it would be transplanted back to the
patient. The graft would be a few square centimetres. An outer layer
of non-blistered skin would be removed with a laser and the new
skin would be placed on the wound bed. As the new skin would come
from the same individual the graft should not be rejected. The gene
has been corrected in the stem cells so the replacement protein
should continue to be made in the long term.
They were expecting
to monitor the graft for several months and I have not yet found
any information about the outcome of this trial.
Professor Hovnanian
has used human artificial chromosomes to introduce a gene has achieved
sustained functioning of type V11 collagen for more than 35 weeks
in the laboratory.
Dominant
forms of EB:
Professor Roop
has developed a mouse model of dominant EB in which the condition
can be switched on and off by applying a cream.
Dr McLean has
been developing methods of 'switching off the bad gene' and will
be working with Professor Roop.
B. Wound
Healing:
Scarring is
an important problem in some forms of EB and may be the cause of
cancers in recessive dystrophic EB. Wounds in the foetus do not
lead to scars and, if this could be mimicked in adults, it may reduce
scarring following injury. A collaboration is being organised to
test this theory in EB.
C. Dressings:
A number of
new dressings, developed for more common conditions, are coming
onto the market and are being trialled for use in EB patients.
D. Cancers:
If gene therapy
and wound healing strategies are effective there may be fewer cancers
in EB patients. Cancers from EB and non-EB patients are being compared
by Dr Mallipeddi in the UK. Cancer research is set to become a major
focus of Debra's research activities.
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