Researchers Discover Protein Linking Exposure to Asbestos and Mesothelioma

A new study has linked a specific type of protein released after asbestos exposure to mesothelioma, which may be the long sought after mechanism of action that explains the cause of the deadly cancer.

Researchers from the University of Hawaii Cancer Center indicate that the protein HMGB1 begins the inflammatory process that leads to the eventual development of mesothelioma, according to findings published last week in the Proceedings of the National Academy of Sciences of the U.S.

The study focused on identifying the primary cell type responsible for inflammation leading to mesothelioma after asbestos exposure. Researchers created genetically modified mice with regulated HMGB1 expression in different cell types and exposed the mice to asbestos.

The findings indicate mesothelial cells released HMGB1 during the early phases of inflammation after asbestos exposure. Mesothelial cells form the lining of the abdomen, the chest, and internal organs and later by macrophages, which are inflammatory cells.

The data suggests the release of the protein HMGB1 leads to the production of another protein, TNFa, or tumor necrosis factor. In previous studies TNFa was identified as a contributor to the inflammatory response in the body, and is linked to some autoimmune diseases.

The combination of the two proteins after asbestos exposure start a chronic inflammatory process that promotes mesothelioma development, the researchers concluded.

“Altogether, our study provides a biological explanation for HMGB1 as a driver of asbestos-induced mesothelioma,” they wrote.

Asbestos Exposure and Mesothelioma Risks

Asbestos is a naturally occurring fibrous mineral resistant to heat and corrosion commonly used in building industries and commercial products such as automotive brakes, insulation, wallboard materials, and fireproofing materials.

Mesothelioma is a rare, aggressive type of cancer that affects the thin tissue lining of the chest and abdomen. It causes roughly 3,200 deaths every year in the United States. Most people diagnosed with mesothelioma will live for only 18 to 31 months.

The only known cause of mesothelioma is prior exposure to asbestos, leading to bans on most uses of the fiber in 1972. However, it has taken decades since the ban for rates of mesothelioma from asbestos to decline, given the long latency period before a diagnosis.

The invasive cancer can take many years, sometimes decades, before symptoms begin to appear. As a result, it is often not diagnosed until the cancer is at an advanced stage, leading to a short life expectancy.

Mesothelioma lawsuits are part of the largest mass-tort in U.S. history, with more than 600,000 people having filed a case against more than 6,000 defendants due to injuries caused by inhaling asbestos fibers. In addition to individuals directly exposed to asbestos, a growing number of the lawsuits filed in recent years have involved second-hand exposure among individuals who inhaled fibers carried on on the clothes or in the hair of their parents when they were children.

Researchers hope the results of the new study’s findings may help lead to the development of more effective preventive and therapeutic strategies for those at risk of developing mesothelioma from asbestos exposure.