In March 2017, researchers announced that an experimental gene therapy using stem cells was used to treat a boy in France with sickle-cell disease. Two years earlier, the researchers had removed stem cells from his bone marrow, modified them, then infused them back into his body. Today, he now has enough normal red blood cells to declare his condition cured!
In fact, as Technology Review reports, gene therapy is having quite the time lately. It’s recently been used in clinical trials and treatments to help build new skin, restore sight, and treat blood disorders like hemophilia.
And there’s more. One recent study assessed gene therapy for patients with severe beta thalassemia, a blood disorder caused by a mutation in a specific gene that affects the production of hemoglobin. It often requires those affected to receive regular blood transfusions.
But after three-and-a-half years of gene therapy, 15 of 22 patients achieved transfusion-free status, while others needed transfusions less often. Great news both for the patients and for the scientific community at large!
Gene therapy explained
Genes act like a blueprint for our bodies, telling our cells which proteins to make, when to make them, and how much to make. However, when a genetic mutation disrupts these instructions, our cells either don’t make enough protein or they make the wrong proteins altogether. These mutations, whether inherited or spontaneous, can cause a wide range of conditions. Gene therapy hopes to correct these disease-causing changes.
How does gene therapy work?
Gene therapy works by targeting a gene whose instructions have been disrupted by a mutation, then replaces it with a working copy containing the correct instructions.
The first step is identifying the mutation that’s responsible for the illness, and which cells are affected. Then the gene with the correct instructions is delivered to the cells that need a little help.
Enter stem cells. They’re “immature” cells that can assume different roles as they grow and help deliver the right instructions to damaged parts of the body.
A patient could potentially use their own stem cells, or closely matched donor cells, to inactivate a faulty gene or replace it with a healthy, working copy.
Why use newborn stem cells?
Blood-producing stem cells like those found in cord blood are ideal for a couple reasons.
First, because they can be easily collected at birth. Unlike adult stem cells, they are collected in a non-invasive way, harmless to the donor.
Second, since cord blood stem cells can differentiate, or change into any cell type found in the blood and immune system, corrections made via gene therapy can be replicated through all following cell lines. This means that corrections can potentially cascade through the the entire blood and immune system.
Third, more people could possibly be helped in situations where donors are hard to find. For example, say that someone has a genetic disorder but either (a) no siblings, (b) no siblings who match, or (c) are a hard-to-match ethnicity. By applying gene therapy to cord blood banked at birth, we could potentially help patients who may not have had access to a cure.
One day, we hope gene therapy may someday provide greater application for umbilical cord blood and its potential uses. In the future, individuals with beta thalassemia (and potentially other conditions) may be able to use their own cord blood stem cells instead of relying on a matched donor, like a sibling. Add gene therapy to the list of potential uses for cord blood stem cells!