Download Activity 2.2.1: Gene Therapy Introduction

Activity 2.2.1: Gene Therapy
Introduction
In Lesson 2.1, you explored the science behind genetic testing and screening. You
saw how DNA sequencing technology and bioinformatics have opened the door to
identifying specific genes in our genome. Faulty genes are often at the heart of
devastating illnesses and disorders. But what if scientists could penetrate our cells
and replace a gene that is malfunctioning? With a working copy of the gene, the
proper protein could be produced and the disease could be eliminated. It may sound
like science fiction, but scientists have already opened the door to this molecular
treatment known as gene therapy.
Gene therapy is the practice of inserting functional genes into a person’s genome to
replace faulty genes. Doctors and medical researchers are working to restore
function to cells that are affected by genetic disorders. To accomplish this goal,
scientists have to get the right gene to the right cells in the right tissue. This is not an
easy task. Many vectors, or delivery systems, for gene therapy are actually viruses.
The idea of using viruses to deliver treatment may sound frightening, but these tiny
pathogens can be used as an effective way to target our cells and insert new genes.
In this activity, you will investigate how gene therapy works and learn about the
vectors currently being investigated as possible transport systems for new genes.
You will read current research on gene therapy trials and gather evidence for and
against this type of disease treatment. Ultimately, you will develop a policy for
regulating and controlling future gene therapy research.
Equipment
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Computer with Internet access and Inspiration® software
Activity 2.2.1 Student Response Sheet
Laboratory journal
Procedure
Part I: Mechanics of Gene Therapy
1. With a partner, brainstorm diseases that you feel could be cured using gene
therapy. Refer back to the genetic testing scenarios from Lesson 2.1 and to
genetic disorders you discussed in PBS for ideas. Identify the faulty gene in at
least one of the diseases on your list.
2. Visit the Genetic Science Learning Center (GSLC) Gene Therapy site at
http://learn.genetics.utah.edu/content/tech/genetherapy/ and read the three
sections listed below. Take notes in your laboratory journal.
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MI Activity 2.2.1 Gene Therapy – Page 1
o What is Gene Therapy?
o Choosing Targets for Gene Therapy
o Gene Delivery: The Key to Gene Therapy
3. Use Inspiration software to create a concept map summarizing what you have
learned about gene therapy. Include the disease and the faulty gene you
identified in Step 1 as an example.
4. Answer Conclusion question 1.
5. Return to the GSLC site and open the Tools of the Trade interactive.
6. Obtain a Student Response Sheet from your teacher.
7. Note that for gene therapy to be successful, a DNA delivery system, or vector, is
necessary. Click the toolbox to explore possible vectors for gene therapy. Record
information about these vectors on the Student Response Sheet.
8. Answer Conclusion question 2.
9. Use the information you have compiled on your Student Response Sheet to
complete the GSLC Space Doctor interactive found at
http://learn.genetics.utah.edu/content/tech/genetherapy/spacedoctor/.
Choose and treat one patient. Note that the interactive may take a few minutes to
load. As you complete the interactive and treat your patient, think about the
following questions:
o Will the gene of interest fit into the vector?
o Will the vector target the right type of tissue?
o What type of cells does the therapy need to target (dividing/nondividing)?
10. Document the case from the interactive in your laboratory journal and describe
the evidence you used to choose the proper vector. Make sure to list the patient
by name and provide a description of the fictional condition, including information
about the gene affected, the cells in question and the overall prognosis of the
patient. If you choose a vector that does not work, explain why it did not work in
your laboratory journal and describe how you altered your treatment plan.
11. Answer Conclusion questions 3 and 4.
Part II: Debating Gene Therapy
12. Form a group of four.
13. Two members of the group will choose and read four of the following articles
describing evidence against the use of gene therapy.
o The New York Times – Patient Dies During a Trial of Therapy Using
Genes
http://query.nytimes.com/gst/fullpage.html?sec=health&res=9E
06EED8173EF93AA1575AC0A96F958260
o Fox News – Boy Living in Bubble Develops Leukemia From
Experimental Therapy
http://www.foxnews.com/story/0,2933,317225,00.html
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MI Activity 2.2.1 Gene Therapy – Page 2
o Newsweek – Juice for Today’s Athlete: Is ‘Gene Doping” the Next
Olympic Threat?
http://www.newsweek.com/id/151988/output/print
o The New York Times – 2nd Cancer is Attributed to Gene Used in
FDA Test
http://query.nytimes.com/gst/fullpage.html?res=9801E7DB1F31
F934A25752C0A9659C8B63
o ABC News – Patient Death Latest Setback for Gene Therapy
http://abcnews.go.com/Health/Story?id=3421869&page=1
o The New York Times – Trials are Halted on a Gene Therapy
http://query.nytimes.com/gst/fullpage.html?res=9C01E7D9163B
F937A35753C1A9649C8B63
14. The two remaining members of the group will choose and read four of the
following articles arguing in favor of gene therapy:
o Biology News Net – Gene Therapy Shows Promise as Weapon
Against HIV
http://www.biologynews.net/archives/2009/02/23/gene_therapy_
shows_promise_as_weapon_against_hiv.html
o New Scientist - Gene Therapy Cures “Bubble Boy”
http://www.newscientist.com/article/dn2124-gene-therapycures-bubble-boy.html
o The New York Times – More Than Human
http://www.nytimes.com/2005/07/03/books/chapters/0703-1stnaam.html
o New Scientist – Gene Therapy is First Deafness ‘Cure’
http://www.newscientist.com/article/dn7003
o Stanford University Medical Center – Gene Therapy for Muscular
Dystrophy Fixes Frail Muscle Cells in Animal Model
http://www.eurekalert.org/pub_releases/2005-12/sumcgtf122205.php
o USA Today – Gene Therapy Experiments Improve Vision in Nearly
Blind http://www.usatoday.com/tech/science/2008-04-283714044875_x.htm
15. Print out the articles you have selected if instructed to do so by your teacher.
16. Read the articles and record evidence in your laboratory journal that supports the
viewpoint you were asked to research.
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MI Activity 2.2.1 Gene Therapy – Page 3
17. Present your evidence to your group members while the other pair takes notes in
their laboratory journals. Switch roles and take notes as the other pair presents
their evidence.
18. Have a discussion with the other pair debating the pros and cons of gene
therapy. Argue for the opposing viewpoint of the articles that you were assigned.
Use only the notes that you took as your partners presented their evidence.
19. When both sides have been argued, come to a consensus as to whether gene
therapy research should be continued. As a group, write a two to three paragraph
statement regarding what you believe to be effective policy for gene therapy
research. Should research continue? If so, with what restrictions? If you decide
research should not be continued, explain why and provide possible alternatives.
20. Explain your group’s decision and policy to the class.
21. Use the Internet to find an article about gene therapy being used for a disease,
disorder or condition NOT discussed in this activity. Bullet key points of the article
in your laboratory journal and share your findings with the class.
22. Answer the remaining Conclusion questions.
Conclusion
1. How do doctors and researchers decide whether a disease is a good candidate
for gene therapy?
2. What are the advantages and disadvantages of using viral vectors for gene
therapy?
3. What factors must be considered when choosing a vector for a gene therapy
trial?
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MI Activity 2.2.1 Gene Therapy – Page 4
4. A young boy suffers from Neurofibromatosis Type 1 (NF1), a genetic nervous
system disorder that causes tumors to grow around nerve cells. The gene for
NF1, approximately 8,400 base pairs long, is located on chromosome 11. What
is the best candidate for a vector for gene therapy in this case? Provide evidence
from your research to support your choice.
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.
6. Do you believe gene doping should be considered cheating? Why or why not?
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MI Activity 2.2.1 Gene Therapy – Page 5
7. Why do you think testing for gene doping would be extremely difficult?
8. Explain why some physicians and clinicians feel that gene therapy is a distant
future consideration.
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MI Activity 2.2.1 Gene Therapy – Page 6