Cystic Fibrosis Stem Cells Open Door to Promising Treatment
Stem cell researchers have created the specific lung tissue involved in the majority of cases of cystic fibrosis, an inherited chronic, lethal disease that affects approximately 30,000 children and adults in the United States. The research “opens up the door to identifying new small molecules [drugs] to treat lung disease,” according to one of the study’s authors, Hongmei Mou, PhD.
Treatments for cystic fibrosis needed
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.
Cystic fibrosis is caused by a defective gene and its protein byproduct that prompt the body to produce abnormally thick mucus that blocks the lungs and causes life-threatening lung infections. The pancreas is also obstructed, which interrupts enzymes from helping the body metabolize food and absorb nutrients.
The combination of these attacks on the lungs and pancreas result in a variety of symptoms, including chronic cough, shortness of breath, frequent lung infections, poor growth and low weight gain, and bowel problems such as greasy stools or difficult bowel movements.
The tissue created by the stem cell researchers contains the mutated gene, delta-508, which is responsible for 90% of cases of cystic fibrosis in the United States. Another gene mutation, G551D, is also in the tissue, and is the culprit in 2% of cystic fibrosis cases.
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.”
The creation of the specific lung tissue in cystic fibrosis is a major breakthrough because using such human airway tissue is the gold standard for testing drugs. Rajagopal and his team appear to have cleared this hurdle, clearing the way for treatments to control the disease.
Currently, the only other drug that works at a molecular level is Ivacaftor (Kalydeco™), which was approved by the Food and Drug Administration (FDA) on January 31, 2012, for individuals with cystic fibrosis ages 6 years and older who have the G551D genetic defect seen in 2% of cystic fibrosis patients.
Rajagopal noted that because they created lung tissue with both G551D and delta 508, scientists have a way to prove the tissue will be effective in testing drugs to treat cystic fibrosis. “We think this is the near-ideal tissue platform to find a drug for the majority of CF.”
While this new stem cell work is exciting for the field of cystic fibrosis, it also holds promise for other common lung disorders, such as asthma, chronic bronchitis, and lung cancer. For now, however, researchers are moving forward with their cystic fibrosis stem cell work, opening doors to promising treatment for the lethal disease.
Cystic Fibrosis Foundation
Image: Wikimedia Commons