The primary subcellular localization of Zinc phthalocyanine and its cellular impact on viability, proliferation and structure of breast cancer cells (MCF-7)

The development of curative techniques which are selective for neoplasms is one of the main focal areas in cancer research. The mechanism of cell damage due to Zinc phthalocyanine (ZnPcSmix)-mediated photodynamic therapy (PDT) in a breast cancer cell line (MCF-7) was assessed by inverted light microscopy for morphology, the Trypan blue exclusion assay and adenosine triphosphate (ATP) luminescence assay for cell viability, alamarBlue for proliferation, Lactate Dehydrogenase (LHD) membrane integrity for cytotoxicity and fluorescent microscopy for ZnPcSmix localization. Fluorescent microscopy revealed that ZnPcSmix was localized in both mitochondria and lysosomes, and PDT treated cells showed damaging structural changes and decreased cell viability and proliferation. The light-dependent ZnPcSmix displayed appreciable photosensitivity and the intensity of damage was directly related to its concentration.

► ZnPcSmix is an effective photodynamic agent in vitro.
► ZnPcSmix localizes in mitochondria, lysosomes and Golgi apparatus.
► ZnPcSmix in its inactive form, showed no apparent destructive effects in breast cancer cells.