Altered cellular proteins may reveal clues as to why some people exposed to asbestos get mesothelioma, while others don’t. That is the conclusion of new research conducted in China.
Asbestos has long been known to cause mesothelioma, but the mechanisms by which it does so remain largely a mystery. For instance, scientists have been at a loss to say why some people can work around asbestos for years with no ill effects, while others with the same level of exposure contract malignant mesothelioma. Understanding why this happens may not only help predict who is at higher risk, but may also give doctors new targets for treatments.
Now, research from China is shedding new light on the subject. The researchers focused their attention on cellular proteins, the command ‘signals’ that direct most cellular activity. To conduct the study, the team looked at samples of three kinds of cells: healthy mesothelial cells, healthy mesothelial cells that were exposed to crocidolite asbestos in the lab, and malignant mesothelioma cells. A multiplex immunoblot-based assay test was used to measure the expression levels of 112 different proteins and phosphoproteins in each of the samples.
The levels of 16 proteins and phosophoproteins were altered (7 were decreased, 9 were increased) in the benign mesothelial cells after they were treated with crocidolite asbestos in the lab. Most of the effected proteins were those that involve DNA damage repair and cell cycle regulation. In the malignant mesothelioma cells, 21 proteins were found to be altered (5 were decreased, 16 were increased). The researchers report “substantial overlap” between the proteins affected in the asbestos-treated cell and the mesothelioma cells.
Reporting in the international medical journal Mutation Research, the Chinese scientists conclude that asbestos exposure “has extensive affects on regulatory pathways and networks” and that these altered proteins may be used in the future to indentify people who are at high risk for developing mesothelioma. Medical treatments that target the levels of these key proteins might also be a way to control mesothelioma, which is notoriously difficult to treat with standard therapeutic modalities.
Wang, H et al, “Crocidolite asbestos-induced signal pathway dysregulation in mesothelioma cells”, May 6, 2011, Mutation Research. Epub ahead of print.