Ethical Stem Cells Provide Hope for Cystic Fibrosis Patients

Bioethics   |   Rebecca Taylor   |   Apr 10, 2012   |   3:40PM   |   Washington, DC

Cystic fibrosis (CF) is a genetic disease caused by mutations in a gene called the CFTR gene. If a person has a mutation in both copies of their CFTR gene (one mutation inherited from their father, one from their mother) then the CFTR protein that they produce does not function properly. Without a functioning CFTR protein, the patient produces abnormally thick mucus that collects in the lungs and pancreas causing serious breathing and digestive problems. The average life span for someone with CF is about 30 years with some living into their 40s and beyond.

CF is a common genetic disease. It is estimated that 1 in 29 Caucasians carry a mutation in one of their two copies of the CFTR gene. Those that have only one CF mutation do not suffer from CF but are called carriers because they can pass this gene onto their children. There are over 1500 documented mutations in the CFTR gene and counting. Approximately 30,000 Americans, both adults and children, inherited a CF mutation from both of their parents and suffer with CF symptoms.

Thanks to induced pluripotent stem cell technology, there is hope for those that suffer with CF. Induced pluripotent stem cells (iPSCs) are mature cells, like skin cells, that have been reprogrammed back to an embryonic-like state. They are an ethical alternative to cloning or destroying IVF embryos for pluripotent stem cells. Pluripotent stem cells are cells that can become most or all of the 200 cell types in the body.

IPSCs have been a tremendous boon for researchers that want to study diseases like CF. Scientists are able to take a skin cell from a patient with a disease, reprogram it back to a pluripotent state, and then get those embryonic-like pluripotent stem cells to grow into whatever tissue they want to study. These iPSCs are grown and maintained in the lab and have the genetic make-up of the patient.

Before iPSC technology, scientists had a hard time growing lung tissue in the lab and so had a hard time studying possible therapies for CF. Now using iPSC technology, researchers in Boston were able to take a skin cell from someone with CF, make induced pluripotent stem cells and then grow those into lung tissue. This lung tissue has the most common CF mutation, delta F508. Scientists are hopeful that now they have lung tissue with the most common CF mutation, they will be able to test new drugs on those cells to see which would be the most promising to treat CF. From

A team of Harvard stem cell researchers at Massachusetts General Hospital, under direction of Jayaraj Rajagopal, MD, Harvard Medical School assistant professor of medicine, began with the skin cells of individuals with cystic fibrosis and eventually ended up creating the lung tissue that harbors the genes which cause the damage that is characteristic of the disease….

The results of this new work is generated much excitement among the researchers. According to Doug Melton, PhD, co-director of the Harvard Stem Cell Institute, they can now “produce millions of cells for drug screening, and for the first time human patients’ cells can be used as the target.”

Rajagopal pointed out that their discovery means “we’re talking about a drug that hits the major problem in the disease. This is the enabling technology that will allow that to happen in a matter of years.”

And this technique of reprogramming skin cells back to a pluripotent state and then growing lung tissue has great promise not just for CF, but for many other diseases of the lungs like asthma, bronchitis and even lung cancer.

Induced pluripotent stem cell technology was developed as a response to the ethics of destroying embryos for pluripotent stem cells. The idea of reprogramming an adult cell back to a pluripotent state is credited to Japanese scientist who wanted another way to get patient-specific pluripotent stem cells without creating and destroying embryos. Dr. Shinya Yamanaka, stated in the New York Times:

“When I saw the embryo, I suddenly realized there was such a small difference between it and my daughters, I thought, we can’t keep destroying embryos for our research. There must be another way.”

Dr. Yamanaka and embryonic stem cell pioneer James Thomson independently created the first iPS cells. James Thomson also recognized that destroying embryos for research was problematic. Thomson told the New York Times:

“If human embryonic stem cell research does not make you at least a little bit uncomfortable, you have not thought about it enough.”

And now iPSCs are coming into their own giving hope to those with CF proving that ethics and science make good partners.