PHOTODYNAMIC THERAPY OF BLADDER-CANCER CELL-LINES

Objective To determine the effect of photodynamic therapy mediated by 5-aminolevulinic acid (ALA) on a range of bladder cancer cell lines, i ncluding a squamous cancer cell line and a multi-drug resistant cell l ine. Materials and methods Experiments were performed on cells growing in culture; the cell lines studied were the transitional cell cancer lines RT112, T24 and EJ138, the squamous cancer cell line, SCaBER, and the multi-drug resistant transitional cancer cell line, MGH-U1(R), to gether with its non-resistant parent line, MGH-U1. The kinetics of the ALA-mediated generation of fluorescent photosensitizer were determine d using now cytometry, Photodynamic therapy was performed by incubatin g cells in ALA followed by exposure to various doses of white light. R esults The response of the various transitional cancer cell lines to p hotodynamic therapy depended on dose, The squamous cell line was relat ively resistant to photodynamic therapy. There was some cross-resistan ce of the MGH-U1(R) cell line to photodynamic therapy, although the me chanism of cross-resistance appeared not to be necessarily a property of the drug-resistant phenotype. Conclusion This study suggests that A LA-mediated photodynamic therapy may be effective in transitional cell carcinoma of the bladder. Based on these findings, this therapeutic m ethod should be further evaluated clinically.