Junk DNA Research Leads to Lung Cancer Discovery

Your body’s blueprint, the human genome, consists of DNA that codes for proteins, which tells cells what to do. Laced between are other bits of genetic material that, until recently, had long been considered non-functioning. These bits are often referred to as “junk DNA.”

“Just because a gene doesn’t make a protein, doesn’t make it junk,” says Mick D. Edmonds, PhD, an assistant professor at the University of Alabama at Birmingham School of Medicine. In fact, he recently discovered a new, non-coding gene called microRNA-31 (miR-31) that may play a key role in causing lung cancer.

“It didn’t make any sense to me that it [miR-31] was junk DNA. I knew it was important and had to prove it,” Edmonds says. “We have a pretty good understanding now that these non-coding microRNAs are changing cancer.”

Edmonds and colleagues are the first to show that miR-31 prompts cells lining an organ to turn into cancer. In studies of lung cancer patients, they found that over 75% had increased miR-31 levels. The finding represents a surprising shift in miR-31 function: Other studies have noted reduced levels in breast, ovarian, prostate, bladder, and skin cancers, suggesting that the genetic material typically stops tumors from growing.

The team published their discovery in the January 2016 issue of the Journal of Clinical Investigation. Their research was funded by the American Cancer Society (made possible by a donation from the Kirby Foundation) and the National Institutes of Health.

“This Gene is Important”

Lung cancer is the No. 1 cause of cancer-related death for men and women. Every year, more people die of it than colon, breast, and prostate cancers combined. The disease is especially challenging to treat because scientists do not know what drives many cases of lung cancer to grow and spread.

“That makes it really hard for us to target,” says Edmonds. “We’ve shown this [miR-31] gene is important. Now we are working on showing proof of concept. What happens when we take miR-31 away from lung cancer? Does it affect tumor growth? Then, we will see if we can target it” to develop new treatments.

Why Research Funding is Critical

Edmonds originally trained to become a breast cancer researcher. His area of focus shifted as his career grew and he realized the great need for lung cancer research. “It’s so under studied,” he says.

The American Cancer Society grant that supported Edmonds’ lung cancer project positioned him to become an independent investigator and keep the lung cancer research pipeline going. Had it not been for the funding, he admits, he likely would have pursued something else.

“I am studying this because I really do want to make an impact on patient outcomes,” says Edmonds. “The ACS and Kirby Foundation allowed me to stay in the field and it paid off. We made a huge discovery.”

Edmonds continues to research microRNAs and their role in lung cancer, breast cancer, and other epithelial cancers. He is also investigating if they can be used as biomarkers to predict a patient’s outcome.