Effect of photodynamic therapy with hypocrellin B on apoptosis, adhesion, and migration of cancer cells

Abstract

Purpose: In the present study, we investigated effects of photodynamic therapy with hypocrellin B on apoptosis, adhesion, and migration of cancer cells in vitro.

Materials and methods: Human ovarian cancer HO-8910 cell as a cancer model cell was incubated with hypocrellin B at a concentration of 2.5 μM for 5 h and irradiated by light from a light-emitting diodes (LED) source. Cell apoptosis was analyzed by flow cytometry with annexin V/propidium iodide (PI) staining and nuclear staining 6 h after hypocrellin B photoirradiation. Cell adhesion was assessed using the 3-(4, 5-dimthylthiazol-2-yl)-2, 5 diphenyl-tetrazolium bromide (MTT) assay 4 h after photodynamic treatment. Cell migration was measured 48 h after photodynamic treatment.

Results: Flow cytometry with annexin V/PI staining showed that early apoptotic and late apoptotic (necrotic) rates following photodynamic therapy with hypocrellin B markedly increased to 16.40% and 24.67%, respectively. Nuclear staining found nuclear condensation and typical apoptotic body in the treated cells. The number of cell migration was significantly decreased to 183 ± 28 after photodynamic therapy with hypocrellin B (p < 0.01). Light irradiation alone and hypocrellin B alone had no significant effect on cell migration. The cell adhesion inhibitory rate due to photodynamic action of hypocrellin B was 53.2 ± 1.8%, significantly higher than 2.7 ± 2.1% of light treatment alone and 1.0 ± 0.4% of hypocrellin B treatment alone (p < 0.01).

Conclusion: The findings demonstrated that photodynamic therapy with hypocrellin B remarkably induced apoptosis and inhibited adhesion and migration of cancer cells in vitro.

Keywords::

• Hypocrellin B
• photodynamic therapy
• apoptosis
• adhesion
• migration
• ovarian cancer

Acknowledgements

This work was supported by the general research fund (GRF) from Hong Kong Research Grants Council (RGC) (476912), the Direct Grant from the Chinese University of Hong Kong (4053026), and Innovation and Technology Fund of Shenzhen (CXZZ20120619150627260). We express our sincere thanks to Professor Faqi Li, Mr Jianyong Wu, Mr Jingchuan Fan, and Mr Kejian Wang for their helpful assistance.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.