| Regarding post-complication of convenient therapies against breast cancer, the emergence of effective approaches is
essential. Photodynamic therapy is touted as a novel invasive therapeutic approach by the application of a photosensitizer
promoted by laser irradiation. This study aimed to investigate the combined regime of low-level laser irradiation
with zinc phthalocyanine in human breast cancer ZR-75-1 cell line. Cells were treated with 0.01 and 5 μg/ml of ZnPc for
24 h and exposed to radiation (70 mW) for 60 s. Cell viability was evaluated by MTT and flow cytometry. Cell
migration capacity was monitored by scratch test, Transwell migration insert, and gelatin zymography. The function
of MDR in treated cells was examined by Rhodamine 123 exclusion test. The level of GALNT11 was measured by
ELISA. The expression of Bax and Bcl-2 genes was evaluated by real-time PCR. Laser irradiation and zinc phthalocyanine
induced cell cytotoxicity in a dose-dependent manner. Flow cytometry analysis showed the induction of apoptotic
and necrotic changes in treated cells. We found a reduction in migration rate and MMP-9 activity in cells undergoing the
experimental procedure (p < 0.05). Immunofluorescence imaging revealed the intracellular accumulation of Rhodamine
123 coincided with a reduction in the level of GALNT11 in treated cells, showing the reduction of MDR activity and
tumor cell resistance. Similar to flow cytometry assay, the reduction of Bcl-2 (approximately twofold) and upregulation
of Bax genes were found in treated cells. Photodynamic therapy could be as an effective and alternative method for the
treatment of breast cancer in a human. |