In vitro photodynamic therapy of cervical cancer

Abstract

Abstract Objectives: Photodynamic therapy is one of the modern therapeutic techniques, in which cytotoxic effects are induced by light. Currently, investigators show that it can be used to eliminate cervical cancer cells. Aim: In this study we decided to check whether the Low Level Lasers Therapy (LLLT) can induce the phototoxic changes in HeLa cells, after their photosesitization. Material and methods: The studies were performed in vitro on HeLa cervical cancer cell line. Protoporphyrin IX (PpIX) in final concentrations: 0.5, 1.0, 5.0 and 10.0μmol/l was used as photosensitizer. The cells were preincubated with specific concentrations for 6 and 18 hours. After these defined periods of time the cultures were illuminated for 8 minutes by laser light (635nm and 30mW/cm2). The cytotoxic effects were assessed by a colorimetric test XTT, 24 and 48 hours after irradiation. Results: Significantly augmented cytotoxic changes were found in HeLa cells 18 hours after preincubation and 48 hours after illumination. Moreover, biostimulating laser exposure preceded by preincubation with protoporphyrin IX caused the cytotoxic changes in cervical cancer cells. Conclusion: The obtained results allow us to assume that photodynamic therapy of cervical cancer using biostimulating laser light should be performed 18 hours after the application of protoporphyrin IX.