How antioxidants can hasten the spread of lung cancer
A few years ago, scientists in Sweden sparked a heated debate when they published research suggesting that taking antioxidant supplements, such as vitamin E, could make cancer more invasive. Their revelations challenged the belief that antioxidants can help fight cancer.
Now, two independent Cell studies, one from the United States and the other from Sweden, reveal how lung cancer cells can use antioxidants to help them fuel their spread to other parts of the body.
The researchers anticipate that these findings will lead to new treatments for lung cancer, which kills more people worldwide than any other cancer.
Cancer cells need lots of sugar, or glucose, to help them grow rapidly and metastasize, or spread. To meet this need, they use an energy-making process that is faster than the one that noncancerous cells use.
The downside of having this faster energy mechanism is that it produces lots of molecules called free oxygen radicals that place significant chemical stress on cells.
The new studies, which the researchers carried out using human tissue and mice, reveal how lung cancer cells use antioxidants to withstand oxidative stress and thrive.
The U.S. study shows how two genetic mutations help the lung cancer cells make their own antioxidants to overcome oxidative stress and metastasize.
The Swedish study shows how lung cancer cells use antioxidants from the diet to achieve the same outcome.
Antioxidants boost metastasis mechanisms
Both studies focus on the effect that reducing oxidative stress has on a protein called BTB domain and CNC homolog 1 (BACH1).
It appears that reducing oxidative stress through antioxidants can raise the stability of BACH1 and boost its accumulation in lung cancer cells.
BACH1 can trigger mechanisms that promote metastasis, one of which helps cancer cells acquire glucose from the blood and convert it into fuel.
"We hope these findings help to dispel the myth that antioxidants like vitamin E help to prevent every type of cancer," says Thales Papagiannakopoulos, Ph.D., an investigator on the U.S. study and an assistant professor in pathology at NYU School of Medicine in New York City.
Lung cancer is cancer that starts in the cells of the lungs. It is not the same as cancers that start elsewhere and then travel to the lungs to form secondary tumors or metastases.
Once cancer that starts in the lungs begins to metastasize, it spreads through the lymph nodes to the brain and other parts of the body.
Metastasis is the main reason why cancer is such a serious disease. Without metastasis, significantly fewer people would die of cancer.
