COMBINED ANTITUMOR EFFECT OF RADIATION AND IBUPROFEN IN HUMAN PROSTATE CARCINOMA-CELLS

Recent clinical observations indicate that ibuprofen may alleviate the radiation-induced dysuria that almost invariably occurs during radiat ion therapy for prostate cancer, Because the use of ibuprofen could co nsequently become common during radiation therapy for prostate cancer, we have been interested in the potential interactions between ibuprof en and ionizing radiation on prostate tumor cells, The effects of gamm a-irradiation and/or ibuprofen on PC3 and DU-145 human prostate carcin oma cells were evaluated in vitro using three model systems, Clonogeni c survival was determined by plating cells 24 h after treatment of nea rly confluent monolayers. Analysis of cell growth, cell detachment, an d apoptotic cell death was carried out over a period of up to 9 days a fter treatment of PC3 and DU-145 monolayers, The effect of ibuprofen a nd/or radiation was also probed by observing the inhibition of growth of established PC3 and DU-145 colonies that were treated on the 14th d ay of colony growth. Ibuprofen enhanced the radiation response of pros tate cancer cells in all three in vitro models, Both the cytotoxic and radiosensitizing effects of ibuprofen seem to require concentrations that are higher than those reported to inhibit prostaglandin synthesis , suggesting that other molecular mechanisms may be responsible for ib uprofen cytotoxicity.