Late last year, Science News magazine published an article about how scientists used genetic modification to save the life of a young boy. He had a skin condition in which the upper layer of his skin would blister and separate from the layers underneath if he was just touched or rubbed gently. Children with this condition are called “butterfly children” because their skin “is as fragile as butterfly wings.” At the time of his treatment, the boy had lost 80% of his skin and was close to death.
People with this condition have a mutation in one of three genes. The doctors identified which one was the problem for this child, took a section of good skin, and used a retrovirus to insert good copies of the bad gene into the skin cells. (No, retroviruses don’t wear leisure suits and enjoy disco music. They’re not that kind of “retro.”) The scientists grew patches of skin containing stem cells and other kinds of cells in the lab and transplanted them onto the boy. Over time, that treated skin grew to cover the rest of his body, and today he’s in school, playing soccer, and leading an apparently normal life.
This is just one example of a growing field called personalized medicine, in which doctors use cells from a patient’s own body in some way to treat a disease. This approach is gaining wider and wider use in cancer therapies, for example, where doctors modify the patient’s own disease-fighting cells. The modified cells once again recognize cancer cells and attack and kill them. Usually this involves changing the immune cells’ genes in some targeted way so that they will either ignore the signals the tumor uses to hide from the immune system, or to recognize some protein on a cancer cell’s surface that is unique to that kind of cell.
An example of this uses specially modified T cells, part of the immune system, to target specific cancer cells, including a kind of lymph cancer and a form of childhood leukemia. These “chimeric antigen receptor T cell,” or CAR-T cell, therapies currently have some pretty severe, but usually controllable, side effects, like very low blood pressure and very high heart rates, but they also cure the cancers they’re targeted against.
In 2013, the husband of a friend of mine was diagnosed with pancreatic cancer, the same kind that recently killed Aretha Franklin. Dennis’ treatment included being injected with specially modified mouse cells that were meant to make his immune system react to his cancer. While this is not the same kind of treatment I just mentioned, the mouse cells had to be genetically modified in some way so Dennis’ immune system wouldn’t attack them. While the doctors determined that this experimental treatment probably did not help him, his other treatments did, and five years later he’s cancer free.
Side-Effects and Other Concerns
Side-effects, like those I mentioned above, are always a concern, and research scientists do want to minimize them. Of course, chemotherapy and radiation have pretty severe side effects too, but given the choice between feeling lousy for a while after each round of treatment and dying, most patients choose to feel lousy until the treatment either works or it’s clear that it won’t. The same appears to be true when it comes to these gene-mod treatments.
It’s interesting to me that there’s been little push-back against these kinds of treatments, which involve modifying a cell’s genes, as compared to the other kinds of genetic modifications scientists are experimenting with. See my previous post for some examples of this. Maybe it’s because there’s a perception that these kinds of treatments are isolated to one individual, whereas the others release gene-modded animals into the wild. The former case assumes a degree of control over the modified cells that may or may not exist.
What Would You Do?
So if you had a disease that could be cured, or at least treated, by some kind of gene therapy, would you take it? I’m pretty sure I would, especially if the cells that were going to be modified were my own.
Please leave your thoughts in the comments box below.