Gene May Put People At Risk of Emphysema and Lung Cancer, Regardless of Smoking Habits

Though emphysema and lung cancer are considered smoker’s diseases, a new study indicates that a certain gene may also be a risk factor – whether the person smokes cigarettes or not.

Previously, smoking was the only known risk factor for emphysema and lung cancer.  However, researchers from UT Southwestern Medical Center have discovered a gene, pleiomorphic adenoma gene-like 2 (PLAGL2), which seems to be linked to both disease.

The researchers bred mice to have the human gene and observed that every one developed emphysema afterward.  They also developed lung cancer at rates as high as one in every six.

Interestingly, emphysema and lung cancer develop in very different ways.  Emphysema arises from cell death or injury, while lung cancer is spurred by uncontrolled cell growth.

Dr. Jonathan Weissler, vice chairman of the department of medicine and chief of medicine at UT Southwestern University Hospital and senior author of the study, explained how the two seemingly at-odds diseases could develop in one mouse (or human):

“We think this gene induces emphysema by causing stem cells in the lung to die.  The cells that don’t die would be more likely to have uncontrolled growth and become cancerous.”

PLAGL2 has previously been identified as a driver of sever types of other cancers.  It has also been observed that the degree to which PLAGL2 turns on, or is expressed, can aggravate the progression and severity of the cancer, as well as affect survival rates.

The researchers also observed that there was a higher rate of lung cancer in the male mice.  In humans, it has also been noted that the association between emphysema and lung cancer is stronger in men.  One previous study showed that about 10 percent of male patients with severe emphysema also had lung cancer.

The researchers hope monitoring the expression of PLAGL2 in humans may identify those at risk for developing cancer.

The study will be published in the journal Lung Cancer.