Combination of a novel photosensitizer DTPP with 650 nm laser results in efficient apoptosis and cytoskeleton collapse in breast cancer MCF-7 cells

Cell Biochem Biophys. 2014 Jul;69(3):549-54. doi: 10.1007/s12013-014-9830-x.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Apoptosis / radiation effects*
  • Breast Neoplasms / pathology*
  • Cell Cycle Checkpoints / drug effects
  • Cell Cycle Checkpoints / radiation effects
  • Cytoskeletal Proteins / metabolism
  • Cytoskeleton / drug effects*
  • Cytoskeleton / radiation effects*
  • DNA Breaks, Single-Stranded / drug effects
  • DNA Breaks, Single-Stranded / radiation effects
  • Dose-Response Relationship, Drug
  • Gene Expression Regulation, Neoplastic / drug effects
  • Gene Expression Regulation, Neoplastic / radiation effects
  • Humans
  • Lasers*
  • MCF-7 Cells
  • Photochemotherapy
  • Photosensitizing Agents / pharmacology
  • Porphyrins / pharmacology*
  • Time Factors

Substances

  • 5-(4-N,N-diacetoxylphenyl)-10,15,20-tetraphenylporphyrin
  • Cytoskeletal Proteins
  • Photosensitizing Agents
  • Porphyrins