Industrial Chemical Found to Raise Mesothelioma Risk in Rats
There is new evidence that a chemical used to produce flexible films like Saran Wrap may increase the risk of developing malignant mesothelioma by damaging the immune system and increasing inflammation.
About 80 percent of mesothelioma cases are the result of exposure to asbestos, a fibrous mineral once popular as a flame retardant and insulator. But a newly-published study suggests that an industrial chemical called vinylidene chloride (VDC) may account for a portion of the remaining 20 percent of non-asbestos mesothelioma cases.
NIH scientists in North Carolina’s Research Triangle Park conducted the 2-year study as part of a National Toxicology Program effort to determine the cancer risk associated with certain chemicals. According to the Environmental Protection Agency, VDC is used to produce polyvinyl chloride copolymers which are used in plastic wraps, films, packing materials, coatings, and adhesives.
To determine what qualities of VDC could account for the “marked increase in malignant mesothelioma” among exposed lab rats, the researchers compared cells from the tumors of these rats with mesothelioma cells from rats with no VDC exposure. While these mesothelioma cells shared man of the same characteristics, the team found that those from the VDC-exposed rats showed a greater tendency toward inflammation and immune system dysfunction.
“These data suggest that a chronic, pro-inflammatory environment associated with VDC exposure may exacerbate disturbances in oncogene, growth factor, and cell cycle regulation, resulting in an increased incidence of mesothelioma,” concludes lead investigator Pamela Blackshear with the Cellular and Molecular Pathology Branch of the National Institute of Environmental Health Sciences.
About 2,500 Americans are diagnosed with mesothelioma each year. In addition to asbestos exposure, radiation, certain chemicals, the mineral erionite, and genetic factors have all been found to potentially play a role in mesothelioma development.
Source:
Blackshear, PE et al, “Gene Expressions of Mesothelioma in Vinylidene Chloride-exposed F344/N Rats Reveal Immune Dysfunction, Tissue Damage, and Inflammation Pathways”, June 23, 2014, Toxicologic Pathology, Epub ahead of print