ENHANCEMENT OF RADIATION RESPONSE OF PROSTATIC-CARCINOMA BY LONIDAMINE

Potential application of lonidamine (LND) to enhance radiation toxicit y in prostate cancer was investigated using human prostate cancer line s and a rat tumor model (Dunning MAT LyLu). LND alone was cytoxic with 50% inhibition concentration (IC50) between 0.5 and 0.8 mM. Preincuba tion with LND increased clonogenic toxicity of radiation. The sensitiz er enhancement ratio was 1.8 to 2.2, depending on the cell line tested and it was consistent with inhibition of repair from potentially leth al damage. LND has limited effect in vivo on the Dunning model, consis tent with its in vitro effect on the same cell line. LND did not alter the primary growth of the tumor growth. LND injection (50 mg/kg) befo re fractionation did not cause any further decrease in tumor growth. R adiation dose fractionation and the combination treatment significantl y reduced tumor metastasis in lungs.