Providence, RI - A particular enzyme is significantly higher in cancer cells that have been exposed to acid, leading to the overproduction of hydrogen peroxide, and offering a possible explanation for how acid reflux may lead to cancer of the esophagus, according to a recent study in the Journal of Biological Chemistry.
The study found that the enzyme NOX5-S is affected by exposure to acid and that it produces stress on cells, activating genes that lead to DNA damage. For the first time, researchers have outlined the signaling pathway from cells damaged by acid, to the progression of esophageal cancer. They believe the same process may happen in the body when cells are exposed to acid reflux.
"The role of acid is controversial. But we show that by exposing cells to acid for short periods of time, that affects a particular enzyme, triggering a chain of events that possibly leads to cancer of the esophagus. Now that we have a better understanding of the signaling pathway, we can possibly identify who is at risk of developing cancer by determining the levels of this enzyme," says senior author Weibiao Cao, a researcher at Rhode Island Hospital and an assistant professor of medicine and surgery at Brown Medical School.
The study looked at human cancer cells and biopsies from patients with Barrett's esophagus (BE), a condition where cells in the esophagus have been altered by gastroesophageal reflux disease (GERD), or acid reflux. Acid reflux is believed to be a major risk factor for cancer in people with Barrett's esophagus.
However, the mechanisms of the progression to cancer have not been fully understood. In this study, researchers found that the enzyme NOX5-S is significantly higher in Barrett's esophageal tissues, which creates a pre-cancerous condition, as well as in esophageal cancer. Acid exposure leads to an increase in calcium in Barrett's esophageal cancer cells, thus activating a cAMP response element binding protei
Contact: Nicole Gustin