Effects of photodynamic therapy with 5-aminolevulinic acid on apoptosis of human cervical carcinoma Hela and Siha cells in vitro

Objective To study effects and mechanisms of 5-ALA-PDT(5-aminolevulinic acid-photodynamic therapy) on apoptosis of cervical adenocarcinoma Hela and squamous cell carcinoma Siha cells in vitro. Methods MTT assay and AnnexinⅤ-FITC/PI double staining assay were applied to investigate the effects of 5-ALA-PDT on proliferation and apoptosis of Hela and Siha cells respectively. Effects of 5-ALA-PDT on expression of Her-2/neu in the two cell lines were detected by immunocytochemistry. Results Hela cells were more sensitive to 5-ALA-PDT than Siha cells. 2mmol/L 5-ALA and a light dose of 10J/cm2 were the optimal condition for killing of the Hela and Siha cell lines in vitro by 5-ALA-PDT,under which,the 50% inhibition concentrations (IC50) of 5-ALA-PDT for the Hela and Siha cell lines were 0.724mmol/L and 1.206mmol/L respectively. 5-ALA-PDT remarkably induced apoptosis of Hela and Siha cells and inhibited expression of Her-2/neu protein in the two cell lines. Conclusion 5-ALA-PDT has patent proliferation-inhibiting and apoptosis-promoting effects on the cervical carcinoma Hela and Siha cells in vitro. The mechanism may be related to the down-regulation of Her-2/neu expression.