Protein Linked to Tissue Inflammation Suggests New Approach To Treating Mesothelioma, University of Hawaii Researchers Say

• Nancy Meredith
• Asbestos Exposure, Cancer, Mesothelioma, Research, Treatments

Asbestos was used extensively at the Pearl Harbor shipyards during World War II and the decades afterward. Today, Hawaii has some of the highest rates of mesothelioma in the nation, according to cancer researchers at the University of Hawaii.

For more than a decade, researchers at the University of Hawaii  Cancer Center have been deciphering the molecular processes that cause normal cells to tranform into malignant mesothelioma cells. In a study in the July issue of the scientific journal Cancer Research, they report that malignant mesothelioma relies on a particular protein known as HMGB1 to fuel the growth of tumors. Suppressing the protein may be key to a new approach for treating mesothelioma, which is notoriously difficult for doctors to manage.

Mesothelioma is a cancer of the lining of the chest and abdominal cavities. It develops from inhaling microscopic asbestos fibers that lodge in the thin tissue lining the body cavity causing inflammation that leads to cancer. People in jobs in which asbestos exposure is an occupational hazard such as mining, shipbuilding, maintenance, plumbing and electrical work have a higher incidence of asbestos-related disease.

Medical researcher Haining Yang, an assistant professor at the University of Hawaii,  and colleagues have studied asbestos-related disease for more than a decade. In a series of research papers, the Hawaii cancer researchers have detailed how asbestos damages and kills cells through a process called programmed cell necrosis that leads to the release of a protein molecule called HMGB1.

Patients with mesothelioma have elevated levels of the protein in their blood. The researchers suggest the protein may play a critical role in transforming healthy mesothelial cells into cancer cells and fueling the growth of malignant tumors.

In the most recently published study, the researchers treated mice with malignant mesothelioma with antibodies aimed at suppressing the protein HMGB1. They observed that inhibiting HMGB1 reduced the growth of cancer cells and extended the lives of the mice. Their findings suggest that mesothelioma cells rely on HMGB1 and that removal of the protein may produce a therapeutic response in mesothelioma patients, suggesting a new approach for malignant mesothelioma treatment.

Mesothelioma takes the lives of about 3,000 people a year in the U.S. People typically develop mesothelioma symptoms 20 years to 50 years after exposure to asbestos. The incidence of mesothelioma has risen steadily in the last decade in some parts of the world, including Europe and China.