Tag Archives: gene therapy

Gene therapy, newly developed treatment approved in Europe

Genes (composed of deoxyribonucleic acid, also known as DNA) function as the biological determinants of heredity that exhibit traits, such as eye color and they are located on chromosomes inside cells.

Gene therapy

Gene therapy is an experimental treatment that involves introducing genetic material (DNA or RNA) into a person’s cells to fight or prevent disease. It facilitates our body by providing the genes in needs, or correct copies of defective genes that may potentially cause genetic disorders. So far, researchers are studying gene therapy in clinical trials to suit different types of cancer and other various diseases, such as hemophilia B, Parkinson’s disease, and HIV.

Several approaches are being attempted in order to cure diseases via gene therapy. First of all, mutated genes that cause diseases are replaced with healthy copies of the genes. Also, mutated genes that are functioning improperly are inactivated. Finally, new genes are introduced into the body to help fighting against diseases.

Generally, a gene cannot be directly inserted into a person’s cell. So, a vector, which is used to deliver a gene to a person’s cell, is used. Virus is the most commonly used vector in gene therapy. Although the viruses are genetically altered to be safe and carry normal human DNA, some risks still exist with gene therapy.

Gene therapy was not available outside a clinical trial until recently. Since 1990, hundreds of clinical trials have been conducted and most have failed as it was difficult to deliver the genes and keep them activated for a long time. Also, the incident of a teenager’s death during a clinical trial at the University of Pennsylvania in 1999 brought the safety concerns on the surface. However, researchers have been slowly overcoming the obstacles and in the last few years there have been reports of successes in attempts to treat cancer, hemophilia B, certain immune diseases and a condition that causes blindness.

After all, gene therapy was first officially approved in Europe. The European Medicines Agency has recommended the application of a gene therapy to treat rare genetic diseases. This was actually the very first regulatory approval of a gene therapy drug in the Western world. Also, a gene therapy to treat cancer won an approval in China in 2003.

As illustrated, a gene therapy has been a controversial topic and it was successful in establishing realistic procedure in the world. Still it is not such a common method that we encounter in the medical field. As it was proven to be beneficial and effective in treating number of symptoms, our deeper attention and acknowledgement regarding this content would be an advantageous step in discovering a new tool to cure diseases.

Here is a video more detailed descriptions about the gene therapy.

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KiWon Min

Online reference

http://www.genetherapynet.com/

http://www.ema.europa.eu/ema/

http://www.sciencedaily.com/news/health_medicine/gene_therapy/

http://www.nytimes.com/2012/07/21/health/european-agency-recommends-approval-of-a-gene-therapy.html?_r=0

 

Are HIV Medications a Thing of the Past?

Being diagnosed with human immunodeficiency virus (HIV) is one of the most devastating things a person can hear.  This virus which breaks down a person’s immune system and eventually leads to acquired immune deficiency (AIDS) is still one of Earth’s incurable tragedies.  However, new research has come to light where gene therapy  may be used as an alternative to medications for patients with HIV.

HIV gains entry into the body by attaching to the surface proteins CCR5 and CXCR4 of a person’s immune cells, also known as T-cells.  The current medication treatment of HIV is called highly active antiretroviral therapy (HAART) which is a mixture of pharmaceutical drugs.  HAART acts to prevent the spread of HIV in the body.   However,  researchers at the Stanford University of Medicine have found a way to halt further HIV infection in the body without requiring patients to take medications.

A model of HIV that was on display at the Smithsonian Museum of Natural History in July of 2012. Image from Fickr user dctim1.

Many different gene therapy research approaches are being investigated, but Dr. Matthew Porteus and his team at Stanford made a unique adjustment to the other research.  The Stanford scientists utilized zinc finger nucleases in order to break open the CCR5 receptor protein’s DNA found on T-cells.  From there, they added three genes that are resistant to HIV in a process known as stacking.  Stacking the genes is what differs between the various teams of gene therapy research.  Faced with the resistant genes, HIV has less of a chance of entering the cell.  In order to test this, the scientists inserted either one, two or the three genes and then exposed the T-cells to HIV.  They found that the cells with the combination of the three genes were the most resistant.

Some people in the world actually have a resistance to HIV because of a mutation in their CCR5 receptors.  Thus, if this new gene therapy can mimic this resistance hopefully HIV will not be as daunting.  Below is a video displaying the research done at the University of Pennsylvania , which is similar to what is being done at the Stanford School of Medicine.  The video is from February of 2011.

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Although this research appears very promising, it is by no means perfect yet. There are certain problems that could arise including the cells not responding to the genes and breakages in the other areas possibly causing cancer or other problems.  This research is extremely new and still has a lot of work to be done before it is ready to be tested on the general public.

Brittany Maxwell