Photodynamic therapy with non-porphyrin photosensitizers in breast cancer and non-cancer cells

Abstract

Breast cancer is a major cause of morbidity and mortality in women worldwide. Conventional therapies have undesirable side effects and in some cases are ineffective; therefore, the search for alternative therapies, such as photodynamic therapy (PDT), is essential. In this work, the effect of PDT on two breast cancer cell lines and one non-cancerous breast cell line was investigated using non-porphyrin photosensitizers (PS), such as methylene blue (MB) and rose bengal (RB). The efficacy of each treatment was evaluated by measuring cell viability with the MTT assay and by morphological observations. Before evaluating the effects of PDT, the intracellular uptake of each PS was measured in the cell lines studied. The results showed that the MDA-MB-231 cell line exhibited the highest sensitivity to PDT for both PS. The T47D cell line showed almost 50% inhibition in both cases. Surprisingly, the non-cancerous cell line MCF10A showed a selective response to PDT. In particular, no significant inhibition was observed with MB-PDT treatment. However, inhibition was observed with RB-PDT treatment. The morphological changes supported the cytopathic effect induced by PDT, it was found that non-cancerous MCF10A cells showed remarkable changes only with the highest dose of RB-PDT. In conclusion, this study presents, to the best of our knowledge, for the first time the effect of PDT using RB as a PS for the inhibition of MDA-MB-231, T47D and MCF10A breast cells, and using MB for PDT inhibition onT47D cells. Furthermore, no direct relationship was observed between the effect of PDT and the intracellular concentration of PS. Finally, these findings highlight the potential of MB and RB as effective PS in PDT and suggest the importance of considering cell line-specific responses and characteristics in optimizing PDT efficacy and selectivity