Principal of genetic engineering & its applications

2. Principal of genetic engineering
& its applications in medicines
BY
Dr. Laraib Jamil Rph
department of pharmaceutics
University Of Balochistan

3. Genetic Engineering
• Genetic engineering is a process that alters
the genetic make-up of an organism by either
removing or introducing DNA.
• DNA can be introduced directly into the host
organism or into a cell that is
then fused or hybridized with the host.
(Hybridize: cross-breed (individuals of two
different species or varieties).

4. • Genetic engineering, sometimes called genetic
modification, is the process of altering
the DNAin an organism’s genome.
• This may mean changing one base pair (A-T or
C-G), deleting a whole region of DNA, or
introducing an additional copy of a gene.
• It may also mean extracting DNA from another
organism’s genome and combining it with the
DNA of that individual.

5. • Plants, animals or micro organisms that have been
changed through genetic engineering are
termed genetically modified organisms or GMOs.
• If genetic material from another species is added to
the host, the resulting organism is called transgenic.
• If genetic material from the same species or a species
that can naturally breed with the host is used the
resulting organism is called cisgenic.
• If genetic engineering is used to remove genetic
material from the target organism the resulting
organism is termed a knockout organism.

6. Example

7. History
• Genetic engineering as the direct
manipulation of DNA by humans
outside breeding and mutations
has only existed since the 1970s.
The term "genetic engineering"
was first coined by Jack
Williamson in his science
fiction novel Dragon's Island,
published in 1951.

8. • The first genetically modified organism to be
created was a bacterium, in 1973.
• In 1974, the same techniques were applied to
mice.
• In 1994 the first genetically modified foods
were made available.

9. • Genetic engineering has a number of useful
applications, including scientific research, agriculture
and technology.
• In plants, genetic engineering has been applied to
improve the resilience(illness), nutritional value and
growth rate of crops such as potatoes, tomatoes and
rice.
• In animals it has been used to develop sheep that
produce a therapeutic protein in their milk that can be
used to treat cystic fibrosis, or worms that glow in the
dark to allow scientists to learn more about diseases
such as Alzheimer’s.

10. • Host organism : The organism that is modified in
a genetic engineering experiment is referred to as
the host. Depending on the goal of the genetic
engineering experiment, the host could range
from a bacterial cell to a plant or animal cell or
even a human cell.
• Vector : The vehicle used to transfer genetic
material into a host organism is called a vector.
Scientists typically use plasmids, viruses,
cosmids(cos+plasmids), or artificial chromosomes
in genetic engineering experiments.

11. How Does Genetic Engineering
Works?
• To help explain the process of genetic engineering lets take
the example of insulin, a protein that helps regulate the
sugar levels in our blood.
• Normally insulin is produced in the pancreas, but in people
with type 1 diabetes there is a problem with insulin
production.
• People with diabetes therefore have to inject insulin to
control their blood sugar levels.
• Genetic engineering has been used to produce a type of
insulin, very similar to our own, from yeast
and bacteria like E. coli.
• This genetically modified insulin, ‘Humulin’ was licensed for
human use in 1982.

12. The Genetic Engineering Process
1. A small piece of circular DNA called a plasmid is
extracted from the bacteria or yeast cell.
2. A small section is then cut out of the circular
plasmid by restriction enzymes, ‘molecular
scissors’.
3. The gene for human insulin is inserted into the
gap in the plasmid. This plasmid is now
genetically modified.
4. The genetically modified plasmid is introduced
into a new bacteria or yeast cell.

13. 5. This cell then divides rapidly and starts making insulin.
6. To create large amounts of the cells, the genetically
modified bacteria or yeast are grown in large
fermentation vessels that contain all the nutrients they
need. The more the cells divide, the more insulin is
produced.
7. When fermentation is complete, the mixture is filtered
to release the insulin.
8. The insulin is then purified and packaged into bottles
and insulin pens for distribution to patients with
diabetes.

15. Application of genetic engineering in
medicines :
• Genetic engineering has many applications to
medicine that include the manufacturing of
drugs, creation of model animals that mimic
human conditions and gene therapy. One of the
earliest uses of genetic engineering was to mass-
produce human insulin in bacteria. This
application has now been applied to, human
growth hormones, follistim (for treating
infertility), human albumin, monoclonal
antibody, antihemophilic factors, vaccines and
many other drugs.

16. • Mouse hybridomas, cells fused together to
create monoclonal antibodies, have been
humanised through genetic engineering to
create human monoclonal
antibodies. Genetically engineered viruses are
being developed that can still confer
immunity, but lack the infectious sequences.

17. • Genetic engineering is used to create animal
models of human diseases. They have been
used to study and model cancer (oncomouse),
obesity, heart disease, diabetes, arthritis,
substance abuse, anxiety, aging and Parkinson
disease.

18. • Potential cures can be tested against these
mouse models. Also genetically modified pigs
have been bred with the aim of increasing the
success of pig to human organ transplantation.
• Gene therapy is the genetic engineering of
humans, generally by replacing defective genes
with effective ones. Clinical
researchers using somatic gene therapy has been
conducted with several diseases, including X-
linked SCID, chronic lymphocytic
leukemia (CLL), and Parkinson's disease.

19. • There are also concerns that the technology could be used
not just for treatment, but for enhancement, modification
or alteration of a human beings' appearance, adaptability,
intelligence, character or behavior.
• Right now, scientists are working on designing foods that
contain vaccines.
• Vaccines create immunity, where our body recognizes a
virus and is able to fight it off without us getting sick.
Instead of getting injections, which can be tough to
transport and administer to remote countries where
disease is most prevalent, scientists want to put it into their
food.

20. • One vaccine being studied is for hepatitis B.
Hepatitis B is a virus that affects the liver.
Tobacco plants have been engineered to make
part of the virus, which when consumed by
mice, causes immunity to the virus, just like a
vaccine.

21. Research being done on potatoes, show that genes can
be put successfully into potato plants that will
make vaccines against cholera, diarrhea and hepatitis
B. Scientists hope to be able to genetically engineer
bananas to have vaccines in them. The bananas would
then be grown in developing countries, where disease
such as cholera and diarrhea are very prevalent. This
would be a much cheaper alternative to the wasteful
process of a series of shots, throwing away costly
syringes after every injection. About 300 million people
are carriers of hepatitis B, which can cause liver failure
and liver cancer. Diarrhea is a common cause of death
in young children.

22. Alzheimer disease
• Scientists are using a special type of cell, called a
stem cell, to grow new organs and replace
damaged tissue.
• Stem cells are cells that are basically a blank slate
and can become any other type of cell. They can
be found in both embryos and adults. Scientists
take the stem cells, put in healthy, normal DNA,
and then put them into patients to replace their
cells that have defective DNA. Manipulating stem
cells is probably one of the most recognizable
form of genetic engineering in medicines.

23. • In Alzheimer’s disease nerve
cells or neurons start to be die
off due to defective DNA. If
doctors grow new neurons from
patient’s stem cells, they could
replace the dying cells in the
brain with cell engineered to
have normal DNA curing the
disease.

24. Anemia
• The children with ADA (adenosine deaminase)
deficiency die before they are two years old.
Bone marrow cells of the child after removal
from the body were invaded by a harmless
virus into which ADA has been inserted.
• Erythropoetin, a genetically engineered
hormone is used to stimulate the production
of red blood cells in people suffering from
severe anaemia.

25. Production of blood clotting factor
• Normally heart attack is caused when
coronary arteries are blocked by cholesterol or
blood clot. plasminogen is a substance found
in blood clots. Genetically engineered tissue
plasminogen activator (tPA) enzyme dissolves
blood clots in people who have suffered heart
attacks. The plasminogen activator protein is
produced by genetech company which is so
potent and specific that it may even arrest a
heart attack underway.

26. Cancer
• Cancer is a dreaded disease. Antibodies cloned
from a single source and targetted for a specific
antigen (monoclonal antibodies) have proved
very useful in cancer treatment. Monoclonal
antibodies have been target with radioactive
elements or cytotoxins like Ricin (Ricin is a highly
toxic, naturally occurring lectin produced in the
seeds of the castor oil plant, Ricinus communis. A
dose of purified ricin powder the size of a few
grains of table salt can kill an adult human). Such
antibodies seek cancer cells and specifically kill
them with their radioactivity or toxin.