Hormone loss may be involved in colon cancer, study says

Gene replacement therapy could hold promise in treating colon cancer, reveals a study published Friday in the journal Cancer, Epidemiology, Biomarkers & Prevention.

While some cancers, such as breast and prostate cancer, are caused by an increase in hormones such as estrogen and testosterone, scientists have not yet identified a type of cancer driven by a lack of hormones. But researchers at Thomas Jefferson University found that colon cancer cells may become cancerous when they lose the ability to produce a hormone that helps maintain normal biology.

Researchers studied 281 patients with colon cancer. In more than 85 percent of patients, overall production of the hormone guanylin decreased 100 to 1,000 times. Comparing healthy colon tissue with cancerous colon tissue, researchers were unable to detect the hormone in the cancerous tissue.

"The fact that the vast majority of cancers stop producing this hormone leads us to believe that guanylin may be driving the growth of the tumors," senior author Scott Waldman, chair of the Thomas Jefferson University department of pharmacology & experimental therapeutics, said in a news release.

Researchers saw a marked decrease in guanylin production in normal colon cells of patients over age 50. That could explain why colon cancer risk increases in older individuals, researchers noted.

Previous research has shown that guanylin activates a receptor called GUCY2C. The receptor’s signaling helps replenish the skin cells lining the gut and maintains their overall function. Without these signals, aberrant cell division is more likely, which increases the risk of cancer.

Many colon cancers exhibit high numbers of GUCY2C receptors, despite the lack of signaling from guanylin. Scientists found that when guanylin is reduced, colon cells produce more GUCY2C receptors to try to catch any possible signal from outside of the cell.

Waldman said the next step is to analyze whether hormone replacement can prevent colon cancer development in mice and, after that, humans.