GIANT CELL FORMATION IN BLADDER TUMOR CELLS FOLLOWING HEMATOPORPHYRIN DERIVATIVE-SENSITIZED PHOTOIRRADIATION

Abstract— Giant cell induction was studied in cultured bladder tumor cells (MGH-Ul; commonly referred to as "EJ") following hematoporphyrin derivative (HpD)-sensitized photoirradiation. Eight days after treatment, control colonies (no treatment, HpD alone, light alone) were generally uniform in size and density and contained few giant cells. Colony heterogeneity and giant cell frequency increased with light dose in the presence of HpD. The morphology and frequency of giant cell formation, with respect to survival levels, were comparable to those observed in 280 kVp X-irradiation of the same cells.