A team of Japanese researchers believe they may have found another piece of the puzzle explaining why asbestos causes malignant mesothelioma.
Asbestos is a naturally occurring soil mineral, mined for decades for use in various industrial applications. Since its use was first linked to deadly malignant mesothelioma around the middle of the century, researchers around the world have been trying to uncover exactly what makes the material so toxic.
Now, a new laboratory study of several types of asbestos may have found part of the answer. Using an advanced system known as ‘matrix-assisted laser desorption ionization-time of flight mass spectrometry’, the Japanese team identified a number of cellular proteins that tend to attach themselves to the surface of asbestos molecules once those molecules enter the body. These proteins include chromatin/nucleotide/RNA-binding proteins, ribosomal proteins, cytoprotective proteins, cytoskeleton-associated proteins, histones and hemoglobin.
By acting as a magnet for these critical cell proteins, asbestos molecules have the power to disrupt the inner workings of cells – including their ability to replicate normally – and potentially trigger cancerous changes that lead to mesothelioma.
The worse culprits for stealing cell proteins were the most iron-rich types of asbestos, crocidolite and amosite, giving credence to the theory that the danger of asbestos may stem partially from its iron content. Although it contains less iron, chrysotile asbestos may trigger mesothelioma by attracting hemoglobin to its surface, and acting as a catalyst to induce oxidative DNA damage.
In discussing their results regarding asbestos and mesothelioma, the authors reported, “Our results suggest a novel hypothetical mechanism causing genetic alternations during asbestos-induced carcinogenesis.”
Every year, more than 2,500 Americans are diagnosed with mesothelioma. Although highly technical, the Japanese findings may provide valuable data to translational researchers searching for ways to protect against or even reverse DNA damage and reduce mesothelioma risk.
Nagai, H et al, “asbestos surface provides a niche for oxidative modification, September 2, 2011, Cancer Science, Epub ahead of print.