Researchers in Baltimore have made a significant discovery concerning the behavior of mesothelioma in varying patients. Their findings may help them to predict patient responses to the disease, and possibly even control those responses in order to improve survival in those with malignant peritoneal mesothelioma.
Peritoneal mesothelioma refers to the formation of cancerous tumors in the mesothelial tissues of the abdominal cavity. Like other forms of mesothelioma, the disease is caused almost exclusively by asbestos fibers and is terminal in the overwhelming majority of cases. Unlike better known forms of the disease such as pleural mesothelioma, or mesothelioma of the lung lining, the mechanism which introduces the asbestos fibers to the area of the tumor is unknown. Some evidence suggests that peritoneal mesothelioma may result from the accidental ingestion of asbestos fibers, whereas pleural mesothelioma results from inhalation of the dangerous materials.
Patients suffering from peritoneal mesothelioma react to the disease in very different ways, a fact which lead researchers to further investigation. According to the Maryland researchers, “There is marked variability in its clinical behavior. Some patients die rapidly, and others survive for many years.”
The researchers believe that the differences in individual responses to the disease may lie in the expression of certain genes which affect the chemical “signals” transmitted to cells. In some patients, these signaling pathways cause cancerous tumors to grow and spread more rapidly, while in other patients the tumors appear to grow far slower. The researchers analyzed forty-one tissue samples from mesothelioma patients, and found that the “signaling chemicals” responsible for RNA production and protein synthesis differed between samples.
In one group the over-expression of certain pathways known as PI3K and the mammalian target of mTOR caused the presence of specific genes associated with a peritoneal mesothelioma survival of around 24 months. In patients where the same pathways and the genes which they are linked to were not present, survival rates were more than twice that time at some 69.5 months. When synthetic means were introduced to inhibit the expression of the PI3K and mTOR pathways, they found that the division and growth of cancerous cells was significantly impeded.
The scientists believed that further research into the significance of specific gene expression in peritoneal malignant mesothelioma patients was warranted. They asserted that the experiments already conducted highlight the importance of analyzing gene expression and further understanding the mechanisms that link these expressions with differing survival rates.
The study concluded: “Targeting the PI3K and mTOR signaling pathways may have significant therapeutic value in patients with MPM.”
This entry was posted on Wednesday, September 22nd, 2010 at 1:55 PM and is filed under Treatments. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.
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