ABSTRACT
Objective To study the effects of curcumin mediated photodynamic therapy (PDT)on the growth and proliferation in human cervical cancer cell line H8 in vitro and in vivo,and to investigate its antitumor mechanisms.Methods The effects of curcumin mediated PDT on proliferation of human cervical cancer H8 cell by MTT assay was used to screen the optimal parameter.Changes in cell morphology were observed by May-Gr ünwald-Farbstoff Giemsa staining.The apoptosis rate was estimated by flow cytometry.The effect of PDT by curcumin on the expressions of Bcl-2,P53 and survivin in H8 cells was detected by fluorescence real-time reverse transcription-polymerase chain reaction (RT-PCR).Forty BALB/C nude mice underwent subcutaneous injection of H8 cell line so as to establish animal models,and then were randomly divided into four equal groups:control group,irradiation alone group,curcumin alone group,curcumin PDT group.HE staining and pathological examination were performed.Immunohistochemical study was conducted to detect the protein expression of the apoptosis inhibiting genes of Bcl-2.Results The proliferation inhibition of H8 cells was obvious after PDT when curcumin 5μmol/L with irradiation 100 J/cm2,and with dose dependent manner.Typical morphologic features of apoptosis appeared characterizedly by marked chromatin condensation,nuclear pyknosis and fragmentation,and the appearance of apoptotic bodies.The total apoptosis rate was higher in PDT group [(47.21 ± 4.11)％]than in control group(1.71 ±0.16) ％ (P＜0.01).The mRNA expression of Bcl-2,P53 and survivin in H8 cells were suppressed significantly.HE staining showed remarkable subcutaneous necrosis in the PDT group.Immunohistochemistry showed remarkable down-regulation of protein expression of Bcl-2(P＜0.01).Conclusions Curcumin-mediated photodynamic therapy has a significant killing effect on H8 cells in vivo and in vitro.Its antitumor effect might be related to induction of Tumor cell apoptosis and suppression of Bcl-2 mRNA and protein expression.