Medical Research: What is the background for this study?
Dr. Brackenbury: Metastasis, the spread of cancer cells from the primary tumour to secondary sites, e.g. the lungs or bones, is the main cause of deaths from cancer. However, there are no effective treatments available to slow or stop this devastating aspect of the disease. We and others have found that sodium channels, normally present in neurons and muscle cells, are up-regulated in metastatic breast cancer cells. Sodium channels appear to regulate the behaviour of these cancer cells, helping them to move and squeeze their way out of the primary tumour as they invade and metastasise on their way to distant sites. This suggests that sodium channels might be useful new therapeutic targets for drugs that could slow metastasis.
Medical Research: What are the main findings?
Dr. Brackenbury: Sodium channels are important drug targets for treating epilepsy. We have found that the antiepileptic drug phenytoin, which is a sodium channel blocker, reduces tumour growth and metastasis in a preclinical model of breast cancer. We found that phenytoin reduces proliferation of cancer cells within the primary tumour. It also reduces local invasion of cancer cells into the surrounding fat and muscle, and reduces the number of cells metastasising to distant sites in the liver, lungs and spleen.
Medical Research: What should clinicians and patients take away from your report?
Dr. Brackenbury: This is the first study to show that phenytoin reduces both the growth and spread of breast cancer tumour cells. This indicates that re-purposing antiepileptic drugs is worthy of further study as a potentially novel anti-cancer therapy. Re-purposing existing drugs to metastasis is particularly attractive because it may be considerably cheaper and faster than developing entirely new therapies.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Brackenbury: We do not yet know whether other types of sodium channel-inhibiting drug work better than phenytoin as anti-metastatic agents.
Michaela Nelson, Ming Yang, Adam A Dowle, Jerry R Thomas, William J Brackenbury. The sodium channel-blocking antiepileptic drug phenytoin inhibits breast tumour growth and metastasis. Molecular Cancer, 2015; 14 (1) DOI: 10.1186/s12943-014-0277-x
MedicalResearch.com Interview with William J. Brackenbury, Ph.D. (2015). Study Attacks Breast Cancer Metastases With Seizure Medication MedicalResearch.com