Phytoestrogen Suppresses Efflux of the Diagnostic Marker Protoporphyrin IX in Lung Carcinoma.

One promising method to visualize cancer cells is based on the detection of the fluorescent photosensitizer protoporphyrin IX (PpIX) synthesized from 5-aminolevulinic acid (ALA), but this method cannot be used in cancers that exhibit poor PpIX accumulation. PpIX appears to be pumped out of cancer cells by the ABC transporter G2 (ABCG2), which is associated with multidrug resistance. Genistein is a phytoestrogen that appears to competitively inhibit ABCG2 activity.

Photodynamic therapy involves an antiangiogenic mechanism and is enhanced by ferrochelatase inhibitor in urothelial carcinoma.

The purpose of the present study was to investigate the mechanism of photodynamic therapy (PDT) supplemented with exogenously added 5-aminolevulinic acid (ALA) on human urothelial cancer (UC). Moreover, we aimed to determine whether the therapeutic effects of ALA-based PDT (ALA-PDT) for UC could be enhanced by deferoxamine (DFX), an inhibitor of ferrochelatase. The efficiency of ALA-PDT on these cells was analyzed using flow cytometry and the type of cell death was also assessed.