ELECTROPERMEABILIZATION IN BLADDER-CANCER CHEMOTHERAPY

Purpose: Electropermeabilization has been used for the introduction of genes into cells. Using this technique, we introduced the cytotoxic d rug bleomycin (BLM) into cells and examined whether the technique migh t be useful for the treatment of bladder cancer. Materials and methods : For electropermeabilization in vitro, we used YTS-1 cells, a human t ransitional cell carcinoma line. Aliquots of cell suspension were mixe d with a solution of BLM and immediately exposed to electric pulses. A high-power pulse generator was used to supply square-shaped pulses of 1250 V/cm (100 mu s, eight pulses). After a 2-h post-shock incubation , cells were washed and incubated for one further hour. Then the conce ntration of BLM in the cells was measured using a bioassay. For electr opermeabilization of tissue, we used normal male Wistar rats. The blad der was exposed and 10 mg/kg BLM was injected into the caudal vein. A series of eight pulses with a time constant of 100 mu s at an electric field intensity of 1000 V/cm was applied. The bladder, liver and lung s were extracted 1 h later and prepared for quantification of the BLM concentration using the bioassay. Results: Electrotreated cells contai ned significantly higher concentrations of BLM than nonelectrotreated cells. The concentration of BLM 1 h after electrotreatment in bladder tissue was 2.7 times higher than that in nonelectrotreated bladder tis sue. Conclusion: The electropermeabilization technique has the potenti al to serve as a new and effective modality for the treatment of bladd er cancer.