Water as a tumoricidal agent in bladder cancer. In vitro studies in parental and resistant cell lines.

Abstract

Water is widely used as a tumoricidal agent during transurethral resection of bladder tumour (TURBT). Despite this, recurrences are common. One possible explanation may be that while the parental bladder cancer cells are sensitive to water, their multidrug resistant (MDR) clones which occur commonly, may be resistant to it. If so, is this a preserve of the MDR phenotype or do other mechanisms confer resistance to water? The parental human urothelial cancer cell lines (MGHU-1 and RT112) and their drug-resistant variants (MDR and non-MDR) were exposed to short pulses of water. The MDR status of these cells was verified using confocal microscopy to detect intracellular accumulation of fluorescent drug (epirubicin). A clonogenic assay was used to establish tumoricidal efficacy on cells in suspension. A thiozolyl blue (MTT) assay was used on adherent cells to assess the residual viable biomass. In the MDR clone of cells, colony counts were reduced by 20% after treatment with water as compared to a 60% reduction in the parental cell line. There was a similar reduction in colony counts between the parental RT112 and its non-MDR cisplatin resistant variant. Water is less effective on MDR cells. Resistance to water may be a function of the MDR phenotype.