Scientists discover immune-boosting LIGHT cytokine reduces colon cancer tumors

Colorectal cancer, or cancer of the colon and rectum, is the third most common cancer, and the second-leading cause of cancer-related death in both men and women in the United States. Its prognosis can be bleak too; of the 136,119 people diagnosed with colorectal cancer in 2013, 51,813 died. An exciting new study by researchers from the University of Illinois at Chicago, the University of Texas Southwestern, and the National Cancer Institute, published in the journal Cancer Research, might be the breakthrough that could turn the tide in the fight against this deadly form of cancer.

Many studies have been undertaken to examine the effects of immunotherapy – treatments designed to either elicit or amplify the body’s own immune response – in the treatment of different cancers. However, no such study had previously looked into immunotherapy in the treatment of patients whose cancer has metastasized (spread) to the liver. This is a grave condition, and one for which no treatment exists.

“For most patients with colon cancer that has spread to the liver, current treatments are palliative and not curative,” said Dr. Ajay Maker, one of the authors of the paper, and an associate professor of surgery at the UIC College of Medicine. “And while studies have suggested that immunotherapy may be a promising approach for advanced cancers, the use of such treatments for advanced gastrointestinal metastases have not yet been very successful.”

This exciting new study provides hope for such patients, as it confirmed that at least one immunotherapy treatment would seem to be beneficial in fighting this type of previously unresponsive gastrointestinal cancer.

For their animal trial, the scientists used two groups of mice, all of which had colon cancer tumors and normal, functional immune systems. The scientists activated the cytokine LIGHT (a chemical which activates the immune system’s own cancer-killing T-cells) in one group of mice, while the other group served as a control for comparison purposes. Interestingly, in previous studies, scientists had found that patients whose colon cancer has metastasized usually have low levels of the LIGHT cytokine.

The tumors of the mice which had the LIGHT cytokine-activated shrank quickly when the immune system engulfed them in T-cells. The tumors stayed smaller even after they were no longer exposed to the cytokine. Even in mice whose cancer had metastasized, the LIGHT cytokine-triggered the T-cell immune response, and their tumors were also reduced in size.

“We demonstrated that delivery of a therapeutic immune-stimulating cytokine caused T-cells to traffic to tumors and to become activated tumor-killing cells,” Dr. Maker explained. “This activity is especially exciting because it resulted in a profound anti-tumor immune response without any other chemotherapy or intervention. The treatment manipulates our natural defenses to fight off the tumor in the same way it has been trained to attack other foreign invaders in our body.”

The researchers were also able to establish that the specific type of T-cell which was causing the tumors to shrink was the CD8 cell.

While this study is certainly good news, and it is encouraging to see scientists looking for ways in which the body can use its own immune system to fight off cancer rather than turning to chemical poisons like chemotherapy, ultimately, prevention is always better than cure. There are several ways to reduce the risk of developing colon cancer in the first place.

Fiber is tremendously important, as it moves substances that could potentially cause cancer out through your digestive system more quickly. Rule of thumb: If you’re having less than one really good bowel movement a day, you need to up your fiber intake.

Water serves multiple functions, all of which reduce colon cancer risk. For one thing, it flushes cancer-causing compounds out of the body, and for another, it prevents constipation. Rule of thumb: If you aren’t urinating at least every two or three hours, or your urine is dark and has a strong smell, you need to increase your intake of clean, filtered water.

Sources include:

ScienceDaily.com

CDC.gov