Effects of the flavonoid drug Quercetin on the response of human prostate tumours to hyperthermia in vitro and in vivo

Tumour hyperthermia, although potentially a powerful therapeutic agent and radiation sensitizer, is hindered by a number of considerations including i nhomogeneous heating of deep seated tumours due to energy deposition and pe rfusion issues. One solution is to design hyperthermia sensitizers to ampli fy the effects of hyperthermia, particularly at cold spots within the tumou r undergoing treatment. This study examined the use of Quercetin, a flavono id drug shown previously to antagonize the expression of HSP72 and induce a poptosis as a sensitizer of prostate cancer growth in vivo. Quercetin dose- dependently suppressed PC-3 tumour growth in vitro and in vivo. When combin ed in a treatment protocol with hyperthermia, quercetin drastically inhibit ed tumour growth and potently amplified the effects of hyperthermia on two prostate tumour types, PC-3 and DU-145 in vivo. These experiments, thus, su ggest the use of Quercetin as a hyperthermia sensitizer in the treatment of prostate carcinoma.