Study on application of photodynamic therapy for the treatment of cervical cancer

Objective: To evaluate the inhibition function of Photodynamic Therapy mediated by Tetrakismethylpiridiniumylporphine (TMPyP4-PDT) in cervical cancer cell lines (Hela and Caski) in vitro and its effects on the expression levels of c-myc and hTERC, analyzing the advantages of TMPyP4-PDT for the treatment of cervical cancer. Methods: The cervical cancer cell lines (Hela and Caski) in vitro irradiated by photosensitizer (TMPyP4) at various concentrations and laser energy densities were classified into the normal control group, the PDT group, the TMPyP4 group and the TMPyP4-PDT group in terms of treating methods. The inhibition effects of PDT on the proliferation of the cervical cancer cell lines were detected by MTT colorimetry. Meanwhile, the apoptosis rates of the cell lines were detected by flow cytomerty and the expression of c-myc and hTERC in the cell lines by the Western blot method. Results: With the increase in TMPyP4 concentration and laser energy density, the inhibition rate and apoptosis rate of cervical cancer cell lines (Hela and Caski) also increased. At the same laser energy density, some statistically significant differences (P < 0.05) were found in cell inhibition rate and apoptosis rate between Hela cell lines and Caski ones at different TMPyP4 concentrations; at the same concentration of TMPyP4, some statistically significant differences (P < 0.05) were also found in cell inhibition rate and apoptosis rate between Hela cell line and Caski cell line mediated by TMPyP4 at different laser energy densities. With the same concentration of TMPyP4 and the same laser energy density, the inhibition rate of Caski cells was higher than that of Hela cells, without statistically significant difference (P < 0.05); while the apoptosis rate of Caski cells was higher than that of Hela cells with statistically significant difference (P < 0.05). The expression levels of c-myc and hTERC in the cervical cancer cell lines Hela and Caski detected by the Western blot method decreased. Conclusion: TMPyP4-PDT has inhibitory effects on cervical cancer cell lines (Hela and Caski) in vitro and induces their apoptosis dependent on concentration of photosensitizers. The possible mechanism of TMPyP4 maybe related with degrading the expression levels of hTERC and c-myc mRNA.