Study On Apoptosis-inducing Effects Of Photodynamic Therapy Combined With Cisplatin On The Survival Of Human Cervical Carcinoma Hela And Siha Cells In Vitro

In the large number of treatment of cancer, photodynamic therapy(Photodynamic Therapy, PDT) with its effectiveness, safety and less side effects can be synergistic, repeatable, and relatively low cost competitors.PDT provides an opportunity for patients who have advanced cancerand or refuse treatment with traditional cancer therapy.Currently Cisplatin is considered more effective drug of cervical cancer treatment and more widely used in clinic.But the main reason for failure of chemotherapy to overcome drug resistance is cervical cancer cells to chemotherapeutic agents and the inherent nature of acquired drug resistance (multidrug resistance, MDR). How to overcome drug resistance will be the key for increasing 5-year survival rate for cervical cancer.This study will be creative therapy and chemotherapy combined photodynamic therapy with small doses of chemotherapy drugs in order to enhance the photodynamic therapy treatment of tumors.By using flow cytometry, MTT (MMT) method and immunohistochemistry on human cervical adenocarcinoma and squamous cell carcinoma cell line Hela and Siha by low-dose cisplatin, this study explores its mechanism of radiosensitization effect.PART1 Study on apoptosis-inducing effects of photodynamic therapy with 5-Aminolevulinic Acid on the survival of human cervical carcinoma Hela and Siha cells in vitroObjective:To study effects and mechanisms of 5-ALA-PDT 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 performed to investigate the effects of 5-ALA-PDT on proliferation and apoptosis of Hela and Siha cells respectively. Effects of 5-ALA-PDT on the expression of Her-2/neu in tow cells was detected by Immunocytochemistry.Results:Hela cells was more sensitive to 5-ALA-PDT than Siha cells; 2 mmol/L 5-ALA,10J/cm2 light dose were the optimal function parameters for the killing of Hela and Siha cell lines in vitro by 5-ALA-PDT, and in the case, the 50% inhibition concentration (IC50) of 5-ALA-PDT for Hela and Siha cell lines was 0.724 mmol/L and 1.206 mmol/L respectively.5-ALA-PDT induced remarkably apoptosis of Hela and Siha cells and inhibited the expression of Her-2/neu protein in tow cell lines.Conclusion:5-ALA-PDT has the patent anti-proliferative and apoptosis-promoting effects on the cervical carcinoma Hela and Siha cells in vitro. The mechanism may be related with the down-regulation of Her-2/neu expression.PART 2 Enhancement of photodynamic therapy sensitivity by cisplatin in human cervical carcinoma cell linesObjective:To investigate the mechanism of small dose cisplatin in the enhancement of photodynamic therapy sensitivity and apoptosis in human cervical carcinoma cell lines.Methods:The Hela and Siha cells were divided into four groups (control group, photodynamic therapy only, cisplatin only, photodynamic therapy and cisplatin). The effects of four groups on proliferation of hela and siha cells were examined by MTT assay. The expression of Her-2/neu in Hela and Siha cells which received the effects was detected by Immunocytochemistry.Results:The degree of the apoptosis caused by the joint application of cisplatin and photodynamic therapy was greater than caused by cisplatin or photodynamic therapy respectively. And expression of Her-2/neu in cells declined correspondingly. The difference of the effects is not obvious whether first cisplatin and then photodynamic therapy or vice versa the other way round.Conclusion:The proliferation of Hela and Siha cells in vitro is restrained obviously by cisplatin combined with photodynamic therapy,the effect is greater than cisplatin or photodynamic therapy respectively. The mechanism of enhancement of photodynamic therapy sensitivity by cispatin may be related to inhibiting Her-2/neu gene expression.