S. E. B. McArdle

Treatments for organ‐confined prostate cancer include external beam radiation therapy, radical prostatectomy, radiotherapy/brachytherapy, cryoablation and high‐intensity focused ultrasound. None of these are cancer‐specific and are commonly accompanied by side effects, including urinary incontinence and erectile dysfunction. Moreover, subsequent surgical treatments following biochemical recurrence after these interventions are either limited or affected by the scarring present in the surrounding tissue. Carnosine (β‐alanyl‐L‐histidine) is a histidine‐containing naturally occurring dipeptide which has been shown to have an anti‐tumorigenic role without any detrimental effect on healthy cells; however, its effect on prostate cancer cells has never been investigated. In this study, we investigated the effect of carnosine on cell proliferation and metabolism in both a primary cultured androgen‐resistant human prostate cancer cell line, PC346Flu1 and murine TRAMP‐C1 cells. Our results show that carnosine has a significant dose‐dependent inhibitory effect in vitro on the proliferation of both human (PC346Flu1) and murine (TRAMP‐C1) prostate cancer cells, which was confirmed in 3D‐models of the same cells. Carnosine was also shown to decrease adenosine triphosphate content and reactive species which might have been caused in part by the increase in SIRT3 also shown after carnosine treatment. These encouraging results support the need for further human in vivo work to determine the potential use of carnosine, either alone or, most likely, as an adjunct therapy to surgical or other conventional treatments.