2.2.

1 (**)
Conclusion Questions
5. Many athletes and administrators fear the widespread use of gene doping
the use of gene therapy to modify genes that improve athletic performance.
Describe at least two genetic modifications that would improve the
performance of an athlete. Make sure to mention the body system(s) affected
as well as the specific goal of the therapy.
One genetic modification is introducing an additional erythropoietin (EPO)
gene to the human genome. This modification would raise the red blood cell
count in the body, allowing for more oxygen and increasing endurance. It
affects the circulatory system primarily. Cyclists also have been known to
dope with synthetic EPO. Another genetic modification is insertion of the
insulinlike growth factor-1 (IGF-1 gene). IGF-1 produces a growth factor that
repairs muscles and supports muscles growth, making the doper stronger. It
affects primarily the muscular system, but also the skeletal system. It has
long been banned from being used as a PED.
Nasr, Susan L. (2008, December 3). How Gene Doping Works. Retrieved on
December 14, 2015 from http://science.howstuffworks.com/life/genetic/genedoping.htm
6. Do you believe gene doping should be considered cheating? Why or why
not?
Gene doping is cheating because it gives an unfair advantage to those who
are able to afford gene doping. Sporting does not become a test of ones own
ability and hard work, but about money and those who can pay for gene
doping. Gene doping is like taking steroids to enhance performance, and
steroids are banned.
7. Why do you think testing for gene doping would be extremely difficult?
Testing for gene doping would be extremely difficult because whatever
performance enhancing substances made from genes is produced by your
own body, so it seems completely natural. To test for the gene would require
a biopsy, which no athlete would let you do. Also, if there were some kind of
test, it might negatively hurt those who were born with a naturally mutated
enhancing gene.
Space Doctor

Patient Name: Balderfum

Species: Oof-a-loof
Disorder: Sisslic Dilliosis
It is caused by a mutation of the SLOO gene. (4443 bp). The gene codes for
a channel that moves slooide ons through cells. The channels causes slooide
ions to move out of the cell and into the mucus, where the ions attracts water
to the mucus. The mutation causes too little slooide ions to move into the
mucus layer and too much gidium into the cells. The water then flow back
into the cells, which causes the mucus layer to dry out and become thick and
sticky. It leads to a higher susceptibility to infection. The most lifethreatening complication is infection in the breathing organ (tungs).
Blockages are also seen in the larryous (produces digestive enzymes) and
millines (absorption organ).
Tissue: Tungs because it is the most life-threatening complication, also
divides very slowly
Vector: Adeno-associated virus
Any vector can hold 5000 bp, so thats not a restriction. The retrovirus and
herpes simplex virus infect only dividing cells or nerve cells respectively, so
thats not an option. The adenovirus does not associate into the hosts
genome, so it wears off in two weeks. The adeno-associated virus does so it
is the best option.
Consensus
We agree that gene therapy should be used, but only in the case of improving
the life of someone with a genetic disorder. Gene therapy has some great
potential; it can cure deafness, blindness, SCID, and more. However, there
are many risk that come with gene therapy. Potential candidates should be
fully informed of these side effects and risks.
Bioethics could also become a concern with this new research. Gene therapy
should also not be used to somehow enhance a person, such as increasing
their height, muscle content, etc. Alternatives to gene therapy like zinc finger
nucleases and TALENs and CRISPR should also follow the same ethical
concerns as gene therapy.
Articles Read
http://www.nytimes.com/2003/01/17/us/2nd-cancer-is-attributed-to-geneused-in-fda-test.html

http://www.nytimes.com/2002/10/04/us/trials-are-halted-on-a-genetherapy.html
http://abcnews.go.com/Health/Story?id=3421869&page=1
Gene Therapy Debate Notes
http://www.nytimes.com/2003/01/17/us/2nd-cancer-is-attributed-to-geneused-in-fda-test.html
2nd Cancer Is Attributed To Gene Used in French Test
Gene therapy patient in France has leukemia-like disease
gene put into cell caused a cancer-causing gene to be switched on
The second therapeutic gene for growth of lymphocytes activated the
oncogene
If this hypothesis is confirmed, it would indicate that gene therapy
treatments in which the inserted gene is not a growth-promoting one
would not face the same risk, he said.
http://www.nytimes.com/2002/10/04/us/trials-are-halted-on-a-genetherapy.html
trying to cure SCID
contracted leukemia like disease
In US and France
http://abcnews.go.com/Health/Story?id=3421869&page=1
treatment for active inflammatory arthritis - death
not sure if gene therapy was the cause of death, but its very likely

Others:
http://query.nytimes.com/gst/fullpage.html?
sec=health&res=9E06EED8173EF93AA1575AC0A96F958260
Jesse Gelsinger- Deceased

18 year old who suffered from insufficient metabolism of ammonia

o

gene mutated after birth

rare form

Him and another (unaffected of disorder) received highest dose

in trial

adenovirus was inserted into main arteries of the liver to deliver

highest possible dose of a corrective gene to the cells where it
was needed

adenovirus main causes of the common cold and usually causes

only a mild fever

timing of the treatment and death have relationship

died couple after treatment

vital signs decreased after two days and was taken off life
support

Blood clotting and hepatitis

http://www.foxnews.com/story/2007/12/18/boy-living-in-bubble-developsleukemia-from-experimental-therapy.html
3 year old boy

Leukemia resulted from treatment of gene therapy

Born with X-linked severe combined immunodeficiency (X-SCID)

o

immune system fails to develop

Bubble baby syndrome

Corrected faulty DNA that causes X-SCID

inserting the replacement DNA can trigger another gene that

promotes cancer

fatal without treatment

bone marrow transplant

http://www.bbc.com/news/magazine-25687002
Gene Doping

Armstrong and Pantani both injected EPO hormone

alter genetic makeup

o

make us faster or stronger

Add synthetic gene to the patients genome and reintroduce it

into the bone marrow via disabled virus

acts like a medicine in the patients cells and permanently

incorporated in the bone marrow

Treatments for neuromuscular diseases

EPO Erythropoietin- controls production of red blood cells

too many RBC and blood thickens and sludge

Temporary results by injecting straight into the muscle

IGF-1 gene injected into the muscles to promote muscle growth

Very hard to detect/ test for

http://www.nytimes.com/2003/01/17/us/2nd-cancer-is-attributed-to-geneused-in-fda-test.html
2nd Cancer Is Attributed To Gene Used in French Test
Gene therapy patient in France has leukemia-like disease
gene put into cell caused a cancer-causing gene to be switched on
The second therapeutic gene for growth of lymphocytes activated the
oncogene

If this hypothesis is confirmed, it would indicate that gene therapy

treatments in which the inserted gene is not a growth-promoting one
would not face the same risk, he said.
http://www.nytimes.com/2002/10/04/us/trials-are-halted-on-a-genetherapy.html
trying to cure SCID
contracted leukemia like disease
In US and France
http://abcnews.go.com/Health/Story?id=3421869&page=1
treatment for active inflammatory arthritis - death
not sure if gene therapy was the cause of death, but its very likely
http://www.biologynews.net/archives/2009/02/23/gene_therapy_shows_promi
se_as_weapon_against_hiv.html

cell-delivered gene transfer

o

study discovered that there is a possibility that it could be a onetime treatment that reduces the viral load and does not hurt the
immune system

could be used to cure HIV

first study shows patients with modified cells could better sapress HIV
replication compared to constant antiretrovirus treatments

no adverse effects from gene therapy in trial

although it was not long-lasting, there is possibility to engineer it to be

so

very positive effect in patients where the gene was successfully

installed

https://www.newscientist.com/article/dn2124-gene-therapy-cures-bubble-boy

child with SCID

x linked

affects immune protein interleukin 2

faulty gene stops T cells from developing

children with this disease must be kept in isolation, usually die young

cure in form of bone marrow transplant, but only found in of cases

How?

stem cells taken from boys bone marrow

modified form of retrovirus found in gibbons used to put normal

copy of gene in stem cells

virus altered to better bind to stem cells and transfer genes to

them more efficiently

2 children were cured

http://www.newscientist.com/article/dn7003 (Links to an external site.)

Possibility of curing deafness

The possibility comes from the possible regrowth of hair cells in the ear

worked in guinea pigs

gene therapy can be used to help the regrowth of hair cells in

the cochlea

this test used adenoviruses and inserted the Atoh1 gene into the
cochlea

allowed hair cells to grow in the cochlea

Stem cells
o

embryonic cells were also used for the regrowth of hair cells

Cells were chemically altered to produce hair cells and

implanted on test subjects (chickens)

This was also successful

http://www.eurekalert.org/pub_releases/2005-12/sumc-gtf122205.php (Links
to an external site.)

Possible long-term fix for muscular dystrophy

o

The mutated gene should be able to produce a healthy

dystrophin protein

Must provide enough protein to fix entire muscle cell

This technique was successful in mice

-The gene gets inserted into the cells own DNA (makes a
permanent correction)

- Does NOT rely on a virus to spread the DNA which avoids

further complications and risks

-Travels through the bloodstream to get to cells

http://www.usatoday.com/tech/science/2008-04-28-3714044875_x.htm (

Improved Vision among the Blind

o

injected working genes into the retina of patients (only 1 eye)

vision improved in patients tested in italy; two women and a

man age 26

no reported serious side effects

Gene Therapy Notes

What is Gene Therapy?

add a corrected copy of a defective gene

treats the genetic problem, not the symptom
uses a vector (usually virus) to deliver gene
creates proteins that fixes the problem
Candidates:
single genes, not multifactorial
able to determine the gene
need to remove the defective gene in some conditions
deliver to cell using molecular signatures
accesibility of tissues
Gene Delivery: Tools of the Trade
must target the right cells
integrates the gene into the DNA
activate the gene
no side effects
Viruses:
can target and enter cells
can be specific
can modified not to replicate
limited amount of genetic material
causes immuen response - sickness, immune system prevents
gene therapy
Not Viruses:

plasmids - larger, but not good at getting into cells, dont usually
trigger immune response
packaged inside liposomes
virosomes - liposomes with viral surface proteins combines
plasmid and viral advantages
Ex vivo vs. In vivo
in vivo: directly inject vector
ex vivo: deliver genes to culture, then put cells in patient
less likely to trigger an immune response
alternative to bone marrow transplants
bone marrow transplants (stem cells) from donors used to treat
genetic disorders
ADA deficiency
SCID
sickle cell disease
TALENs (Transcription activator-like effector nucleases)
includes TAL effector DNA-binding domain and cleavage domain
TAL effector protein from bacteria show correlation between
amino acids and nucleotide recog
similar to zinc finger nuclease
have been used in vitro for sickle cell and another stuff
easier and cheaper than zinc
danger: off-target cuts, bulky unknown immunogenicity,
uncertain binding specificity
CRISPR (clustered regularly interspaced short palindromic repeats/cas
9)
immune system for prokaryotes: short repeated sequences
followed by spacer from foreign plasmids (memory)
applications: can edit 5 genes at a time, can methylate genes to
turn off, turn genes to turn on, bacterial strain identification/isolation
comparing spacers
affordable, easy to engineer, easier to deliver to cells
might make off-target cuts
Vectors

Vectors
Retrovirus

Adenovirus

Genetic
Material
Max base pairs
Advantages

RNA

2x-strand
DNA
7.5k bp
Infects
dividing and
non-dividing
cells
Can be
specific

Disadvantages

Infects only
dividing cells
RNA must be
converted to
DNA
May disrupt
other

8k bp
Can target
specific cells
Integrates into
genome

Does not
integrate
May trigger
immune
response

AdenoAssociated
Virus
Single-strand
DNA
5k bp
Infects
dividing and
non-dividing
Can be
specific
Integrates
usually on
chromosome
19 (less
chance of
disruption)
Does not
cause immune
response
(usu.)
Small

Herpes
Simplex Virus

Liposomes

Naked DNA

2x-strand DNA

2x-strand DNA

20k bp
Large
Does not
integrate, but
is replicated
with the cell
Does not
disrupt any
genes

No max
Infinitely-sized
gene
No immune
response

Plasmid (it is
one)
No max
Infinitely-sized
gene
No immune
response

Only infects
nerve cells
May trigger
immune
response

May be
poisonous
Does not
integrate
Not good at
entering cells

May be toxic
Very
ineffective at
entering cells
Difficult to
make

functioning
genes
May trigger
immune
response

Wiskott-Aldrich Syndrome

abnormal immune system function, reduced ability to form blood clots

microthrombocytopenia - lack of platelets

X-linked, tho not necessarily recessive, males have harsher form

mutation in the WAS gene which makes WASP

abnormal white blood cells

WASP is used in signalling between blood cells to the actin skeleton,

causes adhesion to other cells

in white blood cells, the signalling causes the actin skeleton to create
the immune synapse between the foreign invader and lymphocyte

cannot form immune synapses, impairs development in platelets

can be cured using hematopoietic stem cell transplantation - but no

donors
o

difficult to find donor

hematopoietic stem cells: stem cells that can produce any type
of blood cell

used retroviruses and lentiviruses ex vivo (lv has less risk for leukemia)

high rate of success

Rettner, Rachael. (2013, July 11). 6 Children with Rare Disorders Helped by
Gene Therapy. Retrieved on December 14, 2015 from
http://www.livescience.com/38118-gene-therapy-rare-disorders.html
Bosticardo, M, Ferrua, F., Cavazzana, M., Aitui, A. (2014). Gene Therapy for
Wiskott-Aldrich Syndrome. Current Gene Therapy, 14(6), 413-421. Retrieved
on December 14, 2015 from http://www.ncbi.nlm.nih.gov/pubmed/25245089

Wiskott-Aldrich syndrome. (2013, February). Retrieved on December 14, 2015

from http://ghr.nlm.nih.gov/condition/wiskott-aldrich-syndrome