Combination of a Novel Photosensitizer DTPP with 650 nm Laser Results in Efficient Apoptosis and Cytoskeleton Collapse in Breast Cancer MCF-7 Cells

Abstract

Luminal A type breast cancer was suitable for Photodynamic therapy (PDT) as its strong adhesion ability, low malignancy and easily being exposed to laser. To examine the novel photosensitizer agent 5-5-(4-N, N-diacetoxylphenyl-10, 15, 20-tetraphenylporphyrin)(DTPP) mediate PDT in breast cancer cell, Luminal A type breast cancer MCF-7 cells were used in this study, various concentrations of DTPP (0, 2, 4, 6, 8, 10, 12, 15, 20, 25, 30 μg/mL) and different time intervals (0, 0.5, 1, 2, 4, 6, 8 min) of laser exposure at 650 nm wavelength (power of 20 mW) were tested in PDT. The survival rates of MCF-7 cells were measured using a sensitive cell proliferation assay (MTT) to establish optimal semilethal dose and optimal time exposure, a further study of effects on cytoskeleton and apoptosis were also performed. Cell cycle and apoptosis variation were assayed by flow cytometry. Microtubule, microfilament, and nuclei were observed using laser scanning confocal microscopy. Oncoproteins Bcl-2, beta-tubulin, and beta-catenin were detected by means of electrophoresis. The novel DTPP showed an efficient growth inhibition of MCF-7 during PDT, effective combinations in MCF-7 cells were shown to be 4 μg mL(-1) PS irradiated for 8 min at least or 15 μg mL(-1) irradiated for 2 min at least. Microtubule, microfilament, and nucleus staining demonstrated that cytoskeletal collapse occurs at 0.5 h after PDT. Bcl-2 and skeleton adhesion proteins beta-catenin were reduced in the level of expression; whereas, skeleton proteins beta-tubulin and actin maintained similar levels of expression 12 h after PDT. These results provided a better understanding of DTPP-PDT in MCF-7 cells.

The role of cytoskeleton and adhesion proteins in the resistance to photodynamic therapy. Possible therapeutic interventions

“…Actin has been identified as the main cytoskeleton component affected by PDT either at the early or at the late stages of photodamage. [3][4][5][6][7][8][9]22,23,27,28 However, the changes induced in the structure of actin filaments seem to depend on the initial morphology of the cell. The 5-aminolevulinic acid (ALA)-PDT has been proven to increase the number of stress fibres on human adenocarcinoma WiDr cells, which grow in dense colonies, whereas it caused loss of fibrillar actin structures in growth cones of D54Mg cells, which grow separately.…”

“…In vitro, a decreased invasive and migratory phenotype of PDT-treated cells has been reported for a wide range of photosensitisers. 16,23,27,101,[104][105][106][107][108] On the other hand, the migration of mesenchymal stem cells towards glioblastoma cells was enhanced after ALA-PDT treatment. 109 HPD-PDT decreased adhesiveness of cancer cells to endothelial cells in vitro, has been found to correlate with a decreased metastatic potential of HPD-PDT treated cells injected into rats.…”

Enhanced Oxygen Singlet Production by Hybrid System of Porphyrin and Enriched (6,5) Single-Walled Carbon Nanotubes for Photodynamic Therapy

“…Photodynamic therapy (PDT) is a technique currently used to treat malignant tumors , and microbial parasites . It is based on three key components: a photosensitizer, a light source, and tissue oxygen.…”

Photodynamic therapy induced cell cycle arrest and cancer cell synchronization: review

“…Their data have shown that DTPP arrested CC at S phase, leading to cytoskeleton collapse. Moreover, they investigated DTPP on MCF-7 cells and concluded that DTPP arrests growth and microtubule alteration of MCF-7 cells at 4 μg/ml concentration ( 129 , 130 ). Moreover, tetra-(4-carboxyphenoxy) phthalocyanine zinc (TαPcZn), a novel hydrophilic/lipophilic PS designed and synthesized by Xia et al.…”