Gene Therapy

Gene Therapy

Aims to treat or cure genetic abnormalities by replacing faulty genes with healthy ones. Single-gene disorders such have the potential to be fixed by correcting the underlying cause  of the disease. The concept of gene therapy is that a vector can be used to deliver desired DNA into a cell..

Vectors in gene therapy

Agents which deliver genes to cells. Often plasmids which are circular pieces of DNA from bacteria or viruses. Used as they are:

-extra chromosomal making it easier to introduce foreign DNA into a cell than integrating DNA into chromosome.

-self-replicating (quickly make multiple copies which include the new genetic information)

The DNA from the vector can be incorporated into the cell’s nucleus and undergo transcription and translation to produce the desired protein

Relation to diabetes mellitus

Gene therapy could make it possible to treat type 1 Diabetes by delivering healthy insulin-producing genes to cells in the pancreas.

1) The gene of interest is isolated - a gene that produces the insulin protein

2) The gene is introduced into a vector

3) The vector is injected into the alpha cells of islets of Langerhans in the pancreas

4) The DNA in the nucleus of the cells takes up the functioning gene and uses the information to make the insulin hormone

It may also be possible to stimulate other types of pancreatic cells and liver cells to produce and secrete insulin

Cell Replacement Therapy

Any disorder involving the loss, or injury to, normal cells is a potential candidate for stem cell replacement therapy. Involves replacing damaged cells with healthy cells produced from stem cells (undifferentiated cells)

Alzheimer’s Disease

Most common form of dementia caused by changes in the brain, degeneration and a decrease in neurotransmitters.

Common symptoms:

-Memory loss

- Confusion and disorientation

- Language difficulties

-Difficulty completing tasks

-Changes in mood and behavior

Treatment of Alzheimers

1) stem cells are obtained (pilot studies have used embryonic stem cells)

2) stem cells are induced to become specific cells (neurons)

3) differentiated stem cells are transplanted into the patient’s brain

4) used to replaces lost or injured neurons.

Currently, there are no proven, safe and effective stem cell treatment for this in Australia

Parkinson’s Disease (PD)

Symptoms include uncontrollable movements, such as shaking, and difficulty with balance and coordination. Occurs when nerve cells in the basal ganglia which produce the neurotransmitter dopamine, become impaired and/or die.

Treatment of Parkinson’s Disease (PD)

Can be treated with cell replacement therapy

1) Stem cells obtained and induced to become specific cells (neurons)

2) differentiated stem cells are transplanted into the patient’s brain

3) new nerve cells produce dopamine

Treatments from stem cells are still not approved for PD patients in Australia