EFFECTS OF 2.45-GHZ MICROWAVE-RADIATION AND PHORBOL ESTER 12-O-TETRADECANOYLPHORBOL-13-ACETATE ON DIMETHYLHYDRAZINE-INDUCED COLON-CANCER INMICE

The purpose of this study was to investigate the effects of 2.45 GHz m icrowave (MW) radiation on dimethylhydrazine (DMH)-induced colon cance r in mice. The subjects were 115 Balb/c mice 4 weeks of age. The anima ls were divided into group A (control), group B (DMH), group C (DMH MW), and group D [DMH + 12-O-tetradecanoylphorbol-13-acetate (TPA)]. R adiation (10 mW/cm(2)) was delivered dorsally with the E field paralle l to the mouse's long body axis in an anechoic chamber. Radiations wer e administered 3 hr daily, 6 days per week, over a period of 5 months. The average SAR was estimated to be 10-12 W/kg. During the course of radiation treatments, DMH was injected once per week. The tumor promot er TPA was administered once per week for 10 weeks, from the third wee k on, after the initial treatment. The incidence of tumors did not sig nificantly differ between the three test groups (groups B, C, and D; P > 0.25). However, the number of tumors, the size of the tumors, and t he incidence of protuberant and infiltrative types in tumor-bearing an imals were higher in group D compared to groups B and C (P <0.05). No difference was found between groups B and C (P > 0.25). The study indi cates that 2.45 GHz microwave radiation at 10 mW/cm(2) power density d id not promote DMH-induced colon cancers in young mice. The study also showed that TPA could accelerate colon tumor production if a tumor wa s initiated. (C) 1994 Wiley-Liss, Inc.