Objective  his study aims to evaluate the efficacy of carcinophotorin(PSD-007) photosensitization on the apoptosis-induced response in human breast cancer cells and analyze the mechanisms of PSD-007 involved in this process.

  Methods  Methyl thiazolyl tetrazolium(MTT) assay and in situ labeling were performed to examine the effects of the photodynamic therapy(PDT) on the proliferation and apoptosis of the cancer cells MDA-MB-231, respectively.Changes in cellular morphology were assessed using an optical microscope.Real-time polymerase chain reaction and Western blot analysis were conducted to clarify the underlying mechanisms.

  Results  The MTT assay revealed that at a concentration of 10 μg/mL and in combination with 9.0 J/cm² laser radiation power 24 h after cell culture, PSD-007 markedly inhibited the proliferation of breast tumor cells, with an inhibition rate of 97.01%. "Under a fluorescent microscope, apoptotic cells in the treatment groups with 5 and 10 μg/mL PSD-007-PDT were observed to have dramatically outnumbered the control groups.The dead cells after PSD-007-PDT mainly consisted of necrotic and late apoptotic cells.Caspase-3, caspase-8, P65, and P53 expression was upregulated in the treatment groups compared with the control group, with 5 and 10 μg/ml PSD-007 therapies, whereas no significant alteration in Bcl-2 and Bcl-x was found.

  Conclusion  PDT inhibits the proliferation and induces the apoptosis of cancer cells MDA-MB-231 by upregulating the caspase-3, caspase-8, P53, and NF-KB pathways, indicating a new strategy for treating breast cancer in the future.