Anti-pain agent capsazepine has been found to shrink oral cancer in mouse models, without damaging the surrounding tissues.
Oral squamous cell carcinoma is the eighth most common cancer in the US, and 16th most common cancer in the UK. First author of the study, Cara Gonzales from The University of Texas Health Science Center at San Antonio, said: “These tumours develop primarily on the side of the tongue. Unfortunately, 60 per cent of patients have large tumours before seeking help, and their five-year survival rate is as low as 30 per cent.”
Capsazepine was developed to block TRPV1, a calcium channel found in pain-sensing neurons. When TRPV1 is activated, a ‘pain signal’ is sent to the brain. Capsazepine may reduce oral cancer pain because it blocks tumour-secreted factors from stimulating TRPV1 on these neurons.
Dr Gonzales found that capsazepine also has anti-cancer activity that may be associated with its ability to increase oxidative damage in tumours. The researchers theorise that enhanced oxidative stress leads to auto-destruction of tumour cells.
Dr Gonzales said: “Capsazepine kills cancers selectively, leaving normal tissues alone, and also acts on neurons to block pain, a desirable combination in a potential medication.”