A HYDROXYPYRIDINONE (CP94) ENHANCES PROTOPORPHYRIN-IX FORMATION IN 5-AMINOLEVULINIC ACID-TREATED CELLS

Different cell lines were given photodynamic treatment with 5-aminolae vulinic acid (ALA) and light. In addition, the iron chelator 1,2-dirth yl-3-hydroxypyridin-4-one (CP94) was used. The porphyrin species produ ced was spectrofluorimetrically identified as protoporphyrin M. All th e cell lines responded to treatment, including a multidrug resistance gene expressing bladder cancer line and, to a lesser degree, cells der ived from untransformed human skin fibroblasts. CP94 enhanced both por phyrin fluorescence, total porphyrin content and photosensitivity of t he cells. CCD fluorescence microscopy showed a granular extranuclear p orphyrin fluorescence distribution for all the cell lines involved? bu t the untransformed cells showed a distribution pattern different from the ones seen in the other cells, (C) 1997 Elsevier Science S.A.