No matter what you study about DNA technology, ethics and morals are almost always connected. Check out me and Keira Cruickshank‘s presentation to learn all about DNA technology, Gene Therapy, and the ethical questions that surround this fascinating topic!
Since our presentation is mostly pictures, here are our speaking notes so you can learn a little more about what we’re talking about!
- Gene therapy: the introduction of beneficial genes into an afflicted individual (human) for therapeutic purposes
- The DNA is carefully selected to correct the effect of a mutated gene that is causing disease
- First developed in 1972
- 2 different kinds of gene therapy:
- Somatic gene therapy
- Effects won’t be passed on to offspring b/c the changes aren’t in the sex cells
- Germline gene therapy
- Changes made in sperm or egg cells → effects will be passed onto offspring
- Somatic gene therapy
Gene augmentation therapy
- Used to treat diseases caused by a mutation that stops a gene from producing a functioning product/protein
- Adds DNA sequence containing a functional version of the lost gene into the cell → produces a functioning product to replace the protein that was originally missing
Gene inhibition therapy
- Introduce a gene whose product either:
- inhibits the expression of the mutated gene
- interferes with the activity of the mutated product/protein produced by the defective gene
- Eliminates the activity of a gene that encourages the growth of disease-related cells
Killing of specific cells
- Cancer can be treated by destroying certain groups of cells
- Insert DNA sequence into a diseased cell that causes that cell to die
- This can be achieved in one of two ways:
- “suicide” gene, kills the diseased cell
- the inserted DNA causes expression of a protein that marks the cancer cells so that they are attacked by the body’s natural immune system
Specific example: SCID: Severe Combined Immunodeficiency
- Bone marrow cells don’t create important protein because of defective gene
- Insert working gene into cells affected by defective gene –> cells are able to make proteins
- Clone correct gene, insert RNA version into virus
- Harmless retrovirus cells are introduced into bone marrow (has correct functional protein)
- SCID cases were used in some of the first gene therapy trials
- Been used to treat other issues including: a degenerative nerve disease, progressive blindness, a blood disorder
- Bacteria have adaptive immune system called CRISPR
- Detect viral DNA and destroy it
- Protein called CAS9 allows cells to record viruses that the cell has been exposed to
- CAS9 makes an RNA copy of the viral DNA to store
- Searches through DNA and snips out DNA sites that match
- CAS9 can be programmed with specific DNA sequences and will make cuts at that specific site
- Guide RNA (gRNA) which is read to determine correct sequence of DNA to cut
- Can repair breaks or errors in DNA
- Allows cells to repair genome mutation
- We can harness and program CAS9 to delete or insert bits of DNA w/ precision into affected/harmfull cells and DNA
- Could remove DNA from HIV affected cells
- CRISPR: clustered regularly interspaced short palindromic repeats
- If we can program CRISPR to break the DNA at or on the mutated DNA site that’s causing a disease, we can trigger the cell to fix that mutation cuz it will sense the break in DNA and fix it!
- Relatively simple technology
- CRISPR easily programmed using little bits of RNA
- Examples: can correct mutations that cause sickle cell anemia or huntington’s disease
- Is it moral to tamper with human genes?
- Could this technology lead to the creation of ‘the perfect human being’?
- Would this technology allow people to choose the most “populat” genes for their children?
- “Designer humans,” “engineering humans,” kind of like playing God…
- What would happen to genetic diversity?
- Does the price of the technology make it so that only the wealthy will be able to benefit from this?