A gene most often associated with breast cancer may also play a vital role in the effectiveness of mesothelioma treatment.
BRCA1 has been shown to be closely linked to the risk of breast cancer and a number of other malignancies. But a new study out of Ireland suggests that there may also be a connection between BRCA1 expression and sensitivity to vinorelbine, an antimitotic chemotherapy drug, in mesothelioma tumors. Classified as a plant alkaloid, vinorelbine attacks tumor cells by interfering with their ability to properly divide the chromosomes in their nuclei (mitosis).
To test the connection between BRCA1 and vinorelbine sensitivity in mesothelioma, the researchers tested 144 mesothelioma tissue specimens for their level of BRCA1 expression. They found that 38.9% of the samples exhibited a loss of BRCA1 protein expression which was directly correlated with lower vinorelbine resistance. The opposite was also true: The team confirmed “the reactivation of vinorelbine induced apoptosis (cell death) following re-expression of BRCA1 in resistant cells.”
Currently, there are a limited number of therapeutic options for mesothelioma, which is caused by inhaling or ingesting asbestos and mesothelioma tends to spread quickly once it takes hold. Chemotherapy is often a primary treatment modality, but choosing the right drug is key since, as this study demonstrates, individual mesothelioma patients respond differently to different drugs. Genetic studies like this one could eventually allow doctors to customize mesothelioma treatments based on the results of a simple blood test.
In a report of their findings in the Journal of Pathology, the researchers from the Centre for Cancer Research and Cell Biology at Queens University in Belfast concluded, “This data suggests BRCA1 plays a critical role in mediating apoptosis (cell death) by vinorelbine in mesothelioma, warranting its clinical evaluation as a predictive biomarker.”
Busacca, S et al, “BRCA1 is an essential mediator of vinorelbine induced apoptosis in mesothelioma”, December 21, 2011, Journal of Pathology, Epub ahead of print.
Vinorelbine information from Drugs.com.