Medical scientists at Stony Brook University have discovered that a gene initially thought only to suppress tumor growth appears to underlie the development of chronic obstructive pulmonary disease — COPD.
COPD rates have risen globally in recent decades mostly because of smoking, industrial exposures, and living in polluted urban areas. But Stony Brook scientists are positing that certain biological conditions may increase vulnerability.
While conducting cancer research, Dr. Ute Moll of Stony Brook’s School of Medicine, made a serendipitous discovery: When the tumor-suppressor gene called p73 was missing in mice, the fine hairlike cells of the respiratory tract no longer functioned properly.
She now postulates that an absence of p73 in people increases the vulnerability to COPD and possibly other respiratory conditions, such as serious lung infections and asthma.
The hairlike cells, known as cilia, are noteworthy for their synchronous sweeping action — brushing debris, infectious agents and toxic obstructive particles that enter the lungs upward to be expelled through the nose and mouth. When cilia are depleted or malfunctioning, the lungs lack their chief guardians.
“COPD is a huge public health problem worldwide,” Moll said. Her genetic research, she said, provides “a breakthrough in our understanding of p73’s essential role.”
Moll, a physician in addition to being a scientist, noted that because her genetic discovery suggests a similar scenario in humans, the door is now open for broad population-based studies of people with chronic lung disease. The aim would be to study defects in p73-controlled airway function.
Another path of the research might lead to the development of a diagnostic capable of spotting people with a defective p73. For those who live in pollution-choked areas, corrective measures could be taken before irreversible lung disease emerged, she said.
Already, the new discovery aided Moll in the development of the world’s first animal model of COPD, an advance that will allow deeper study into a disease that has no cure.
COPD is the third leading cause of death in the United States, according to the American Lung Association, which estimates that more than 11 million people have been diagnosed with the condition. The association also says about 24 million people in the United States are affected but don’t yet realize they have the disorder.
Women die of COPD at a higher rate than men, which the lung association attributes to a variety of factors: Women are more vulnerable to lung damage from cigarette smoke and other pollutants than their male counterparts, a result of smaller lung size and the hormone estrogen, the association’s medical experts say.
Intense cigarette advertising aimed at women in the late 1960s ushered millions into smoking habits that now have made COPD a medical concern associated with aging women, the association contends.
Regardless of gender, COPD is marked by long-term disability and early death.
Dr. Len Horovitz, a pulmonary specialist at Lenox Hill Hospital in Manhattan, a division of Northwell Health, called COPD an extraordinarily complex condition marked most prominently by a loss of the lung’s alveoli, the minuscule air sacs where gas exchange — oxygen and carbon dioxide — occurs.
“Once they’re gone, they’re gone,” Horovitz said of the alveoli.
He said the loss of cilia described by Moll sounded more to him like Katagener syndrome, a rare genetic disorder associated with inflammation and scarring of the bronchial tubes, a result of frequent lung infections. Sufferers have chronic cough and shortness of breath.
Another condition of the hair cells, immotile cilia syndrome, also results in pulmonary inflammation. The alveoli, he said, remain intact.
Moll is certain her work has opened a new window on COPD — and probably other lung conditions as well.
Moreover, this isn’t the first time that she has found an unforeseen role involving a gene associated with tumor suppression.
In 2012, Moll discovered that p53 — the mother of all tumor-suppressor genes — plays an unexpected role in strokes. The finding was so important that the editors of the prestigious journal Cell, where the research was reported, put that major medical advance on its cover.
Moll was the first scientist to recognize that p53 is responsible for a death signal that results in the irrevocable loss of brain cells during a stroke.
P53 mutations are linked to lung, breast, colorectal and ovarian cancers. She calls p73, p53’s “little cousin.”
“P73 belongs to the famous tumor suppressor family, but its function had been somewhat enigmatic,” Moll said.
“We found that p73 sits at the top of a hierarchy and directly turns on more than 50 other key genes that control the architecture and movement of cilia,” she said.