There are many diseases caused by genetic abnormalities. A defect of a specific gene can cause the production of thick, sticky mucus associated with cystic fibrosis. People missing functional genes needed for tumor suppression may be more susceptible to cancer.
However, a lot of illnesses are complex and develop as a consequence of both genetics and the environment. Malignant mesothelioma may be one such disease. The inhalation of asbestos fibers is the only proven cause of this cancer, but not all individuals who are exposed to asbestos develop the disease. Some scientists infer that people who do get sick have certain genes that make them prone to developing malignant mesothelioma after coming into contact with the hazardous mineral.
One international team of scientists from Australia, Italy and Canada tried to find these genes, as reported in the journal Lung Cancer.
What are ‘snips?’
For their new study, the researchers were studying a phenomenon known as single nucleotide polymorphisms, which are also known as SNPs or snips.
DNA is a long sequence of millions of molecules known as bases, which come in four varieties. Experts from the National Institutes of Health describe snips as occurring when a single base is replaced by another one.
Most of these snips happen in areas of the DNA that have no function. However, if a snip occurs in a gene that has a function, this can directly affect a person’s health. The medical community hopes some day to be able to use snips to measure patients’ risk of certain diseases, predict patients’ reactions to certain drugs or assess individuals’ vulnerability to environmental toxins.
Scientists look for snips in mesothelioma patients
To find out whether snips play a role with asbestos in who develops mesothelioma, the international research team conducted a study in which the investigators analyzed DNA samples that they collected from mesothelioma patients in two countries. First, in Australia, they collected DNA from 428 malignant mesothelioma patients, 1,269 healthy controls and 778 controls who were exposed to asbestos, but showed no sign of disease.
From this initial analysis, the researchers found the snips that appeared to have the strongest associations to disease, and they conducted another round of DNA analysis in Italy, with samples collected from 392 mesothelioma patients and 367 disease-free controls who either were and were not exposed to asbestos, respectively.
The initial results suggested that snips associated with malignant mesothelioma may be found in three specific genes. The Italian study was not able to replicate these associations. However, the second round of analysis did suggest that one gene in particular may be a promising candidate to look at.
In the future, researchers will need to conduct further experiments in order to verify these results or find other genes that may be responsible for the link between asbestos exposure and malignant mesothelioma.
Experts from the Environmental Working Group estimate that malignant mesothelioma claims the lives of more than 2,500 individuals in the U.S. every year. So far, there is no real way of telling who will and will not develop this cancer among people who have been exposed to asbestos. Until then, public health efforts to eliminate the use and production of asbestos remain crucial.