Gene Therapy

Done By: Abeer Al-TaweelAlbatool Bin Ajlan Amal Alblwi Atheer Hakami Rawan Almugbel Shaikha Aldukhail

Supervised by: Dr. Amina Alshibani

What is Gene therapy? It is an experimental technique that uses genes to treat or prevent

disease. In the future, this technique may allow doctors to treat a

disorder by inserting a gene into a patient’s cells instead of using

drugs or surgery. Researchers are testing several approaches to

gene therapy, including:

Replacing a mutated gene that causes disease with a healthy copy

of the gene.

Inactivating, or “knocking out,” a mutated gene that is functioning

improperly.

Introducing a new gene into the body to help fight a disease.

Definition

Types Of Gene Therapy Germ Line gene therapy. Somatic Gene Therapy.

Types

Gene Therapy Applications: Before gene therapy can be used to treat a certain

genetic condition or disorder, certain requirements need to be met:

The faulty gene must be identified and some information about how it results in the condition or disorder must be known so that the vector can be genetically altered for use and the appropriate cell or tissue can be targeted.

The gene must also be cloned so that it can be inserted into the vector.

Once the gene is transferred into the new cell, its expression (whether it is turned on or off) needs to be controlled.

There must be sufficient value in treating the condition or disorder with gene therapy - that is, is there a simpler way to treat it?

Applications

The balance of the risks and benefits of gene therapy

for the condition or disorder must compare favorable

to other available therapies.

Sufficient data from cell and animal experiments are

needed to show that the procedure itself works and is

safe.

Once the above are met, researchers may be given

permission to start clinical trials of the procedure,

which is closely monitored by institutional review

boards and governmental agencies for safety.(1)

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1-cancer: There are different possibilities which can be used to treat cancer with

gene therapy; Genes can be inserted into the cancerous cells so that they become sensitive

and can be destroyed with chemotherapy. genes can be inserted into the cancer cells, they will release toxin which will

completely disable them to function in a negative way.  Genes can also make the cancerous cells unstable. Usually cancer cells do not

allow the faulty DNA to repair which results in the rapid growth of abnormal cells.

As cancer is caused due to the mutations in the genes, that is why if healthy genes are added in place of abnormal or missing genes, they will start

working in a normal way. Gene therapy can make immune system so strong that it

can easily recognize the cancerous cells in the body and

completely destroy them

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2-down syndrome: Recent findings indicate that gene therapy strategies-based on the

introduction of genetic elements by means of delivery vectors-

toward the correction of phenotypic abnormalities in DS are also

very promising tool to identify HSA21 and non-HSA21 gene

candidates, contributing to DS phenotype.

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3-AIDS:  scientists in California show that a single injection — which inserted

the DNA for an HIV-neutralizing antibody into the muscle cells of live mice — completely protected the animals against HIV transmission.

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4 -Cystic fibrosis:

Gene therapy involves the transfer of correct copies of cystic fibrosis transmembrane conductance regulator (CFTR) DNA to the epithelial cells in the airways.

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5- Diabetes Mellitus 1: In Canada, researchers developed a protocol to treat type I

diabetes. Doctors use ultrasound to guide a small catheter through the upper abdomen and into the liver. Pancreatic islet cells are then injected through the catheter into the liver. In time, islets are established in the liver and begin releasing insulin.

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6- Sjogren’s syndrome (SS) : SS is characterized by the presence of a focal lymphoid cell infiltration in the

salivary and lacrimal glands,. In the absence of any suitable conventional treatments, they have suggested

that gene therapy may be beneficial for SS patients. They have hypothesized that transfer of immunomodulatory genes into SGs may reduce the autoimmune sialadenitis and lead to increased salivation as well as symptomatic relief. For example, the transfer of genes encoding anti-inflammatory cytokines such as interleukin-10 (IL-10) or vasoactive intestinal peptide could lead to a decrease in the expression of proinflammatory cytokines, and thus, protect SGs and preserve their secretory function.

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7- X-linked severe combined immunodeficiency (X-SCID):

It's a disease where a baby lacks both T and B cells of the immune system and is

vulnerable to infections.

The current treatment is bone marrow transplant from a matched sibling, which

is not always possible or effective in the long term.

most children die from infection in their first two years of life.

One exception was David Vetter, a Texas boy born in 1971. Vetter lived in a

specially constructed sterile plastic bubble from birth until his death at age 12

He became famous as the “bubble boy,” and his story made

many people aware of SCID for the first time.

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Nine years after getting gene therapy for a rare, inherited immune system

disorder often called “bubble boy disease,” 14 out of 16 children are doing well,

researchers report.

The 16 children with SCID who got the gene therapy ranged in age from 6

months to 3 years. Four of them had the ADA-deficiency type of SCID. The other

kids had the X1 form of SCID. Those are the two most common types of SCID.

One problem occurred at that time !

For most of the children, gene therapy was a success. But one boy who had the

X1 form of SCID developed treatment-related Leukemia.

The clinical trials were put on hold until a safer method can be designed and

tested.

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Future Of Gene Therapy

First FDA-approved gene therapy for cancer may be on its way !

Advexin is being studied in the third phase of the trials that are enrolling patients with recurrent, refractory head and neck squamous cell carcinoma.

Gene therapy may reverse congenital hearing loss.

Future

“Indeed, within 20 years, I expect that gene therapy will be

used regularly to ameliorate —and

even cure — many ailments.”

W. French Anderson