A new report in the medical journal Cancer Gene Therapy says treatments that are based on genetic manipulation with the aid of modified viruses may be the wave of the future for combatting malignant pleural mesothelioma.
The report comes from scientists at the Chiba Cancer Center Research Institute and Chiba University Medical School in Japan, where the incidence of mesothelioma is still increasing. Mesothelioma is an asbestos-linked cancer for which there is currently no standard cure. The Japanese team’s analysis of current global research on gene and virotherapy suggests that treatments that impact a particular genetic abnormality in the DNA of mesothelioma cells may have the greatest impact on the disease. They explain the process this way:
“Preclinical studies targeting the genetic abnormality with adenoviruses showed that restoration of the p53 pathways induced pRb dephosphorylation and subsequently produced anti-tumor effects.” The authors go on to note that a number of clinical and preclinical studies using different modified viruses as delivery or ‘vector’ systems to deliver various gene-altering therapies into cells have “raised the possibility of gene therapy in clinical settings.” P53 is a tumor suppressor gene and its suppression is widely implicated in many different cancers.
Recently, several studies have explored the advantages and challenges of delivering those viral vectors directly into the intrapleural space around the lungs where pleural mesothelioma tumors are located. While this method has the advantage of putting the treatment in close proximity to the tumor, the authors point out that intrapleural administration has also been shown to rapidly activate antibody production, which can block expression of the desirable genes. Intrapleural gene therapy also has other “distinct aspects” which set it apart from other treatments for mesothelioma.
Mesothelioma is the cancer most closely associated with exposure to asbestos fibers, usually in construction or an industrial setting. While asbestos use and production has been banned among European Union countries because of its link to mesothelioma, asbestosis and lung cancer, many countries, including the U.S., have resisted the idea of a comprehensive ban. There are an estimated 2,500 Americans diagnosed with mesothelioma annually.