From Science Fiction to Science Fact: Gene Editing May Make Personalized Therapies for Blindness

Have you seen the movie Elysium? It’s a 2013 futuristic science fiction film starring one of my favorite actors Matt Damon. The plot centers on the economic, social and political disparities between two very different worlds: one, an overpopulated earth where people are poor, starving, and have little access to technology or medical care, the other, a terraformed paradise in earth’s orbit that harbors the rich, the beautiful, and advanced technologies.

Med-Bays.

Med-Bays.

The movie is entertaining (I give it 4 stars, Rotten Tomatoes says 67%), but as a scientist, one of the details that stuck out most was the Med-Bays. They’re magical, medical machines that can diagnose and cure any disease, regrow body parts, and even make people young again.

Wouldn’t it be wonderful if Med-Bays actually existed? Unfortunately, we currently lack the capabilities to bring this technology out of the realm of science fiction. However, recent efforts in the areas of personalized stem cell therapies and precision medicine are putting paths for creating potential cures for a wide range of diseases on the map.

One such study, published in Scientific Reports, is using precision medicine to help cure patients with a rare eye disease. Scientists from the University of Iowa and Columbia University Medical Center used CRISPR gene editing technology to fix induced pluripotent stem cells (iPS cells) derived from patients with an inherited form of blindness called X-linked retinitis pigmentosa (XLRP). The disease is caused by a single genetic mutation in the RPGR gene, which causes the retina of the eye to break down, leaving the patient blind or with very little vision. (For more on RP and other diseases of blindness, check out our Stem Cells in your Face video.)

CRISPR is a hot new tool that allows scientists to target and change specific sequences of DNA in the genome with higher accuracy and efficiency than other gene editing tools. In this study, researchers were concerned that it would be hard for CRISPR to correct the RPGR gene mutation because it’s located in a repetitive section of DNA that can be hard to accurately edit. After treating patient stem cells with the CRISPR modifying cocktail, the scientists found that the RPGR mutation had a 13% correction rate, which is comparable to other iPS cell based CRISPR editing studies.

Skin cells from a patient with X-linked Retinitis Pigmentosa were transformed into induced pluripotent stem cells and the blindness-causing point mutation in the RPGR gene was corrected using CRISPR/Cas9. Image by Vinit Mahajan.

Stem cells derived from a patient with X-linked Retinitis Pigmentosa. (Image by Vinit Mahajan)

The authors claim that this is the first study to successfully correct a genetic mutation in human stem cells derived from patients with degenerative retinal disease. The study is important because it indicates that XLRP patients can benefit from personalized stem cell therapy where scientists make individual patient iPS cell lines, use precision medicine to genetically correct the RPGR mutation, and then transplant healthy retinal cells derived from the corrected stem cells back into the same patients to hopefully give them back their sight.

Senior author on the study, Vinit Mahajan explained in a University of Iowa news release:

Vinit Mahajan

Vinit Mahajan

“With CRISPR gene editing of human stem cells, we can theoretically transplant healthy new cells that come from the patient after having fixed their specific gene mutation. And retinal diseases are a perfect model for stem cell therapy, because we have the advanced surgical techniques to implant cells exactly where they are needed.”

It’s important to note that this study is still in its early stages. Stephen Tsang, a co-author on the study, commented:

“There is still work to do. Before we go into patients, we want to make sure we are only changing that particular, single mutation and we are not making other alterations to the genome.”


Related Links:

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s