The Experimental Study Of 20(S)-Protopanaxadiol On Mouse Prostate Cancer RM-1 Cells In Vitro

Prostate cancer is the first most prevalent cancer in males in the United States and Europe, which is only second to the mortality of lung cancer In our country, the incidence of prostate cancer is far less than the one of western countries. However, as aging and the change of life-style .the prevalence of prostate cancer in population has increased significantly, the majority of that has been diagnosed as advanced terminally cancer and die in few months. Although the conventional therapies such as castration or blockade androgen with chemical drugs can initially alleviate the clinical symptoms and decrease PSA(prostate specific antigen) in peripheral blood serum,the most of that will progress to androgen-independent prostate cancer in 18 months(average). So, it is a meaningful research that developing a novel drug which can block the progression from ADPC to AIPC.20(S)-Protopanaxadiol (PPD) is a saponin extracted from ginseng, which has excellent protection for our body's system such as nervous system, immune systerm , endocrine system, blood systerm and so on.PPD has play a significant role in killing cancer cells and inducing apoptosis. It is comfirmed that PPD can induce apoptosis of some cancer cells such as breast cancer cells, pulmonary cancer cells.In this study,we observed the effect of PPD on mouse prostate cancer RM-1 cells in vitro,and briefly analysis of probable mechanism of PPD induce apoptosis of RM-1 cells in vitro,which may pave the way for the treatment of prostate cancer.Objective:To observe the effect of PPD on prostate cancer RM-1 cells in vitro experimental and briefly analysis of probable mechanism of PPD induce apoptosis of RM-1 cells Methods:After the RM-1 cells were treated with different dose of PPD,the cell viability was examined by MTT assay test.The changes of morphology in apoptotic cells were observed by AO/EB staining and TUNEL assay kit. The apoptosis effect of PPD on prostate cancer RM-1 cells was tested by Annexin V assay kit .The expression of bcl-2, bax, caspase-3 and AR mRNA was detected by RT-PCR.Immunocytochemisty stain was done to detect the expression of bax and caspase-3 proteinResults:1.MTT experiment showed that PPD can inhibit RM-1 cell growth in a dose-dependent manner2.We observed the changes of cells under the confocal microscopy ,PPD treated cells showed retarded proliferation and less division, suspension cell and collapse cell also appeared3.We observed the changes of morphology in apoptotic cells treated with PPD by AO/EB staining under the Fluorescence microscope, PPD treated cells showed \ nuclear pyknosis, nuclear density enhanced .4 We used FCM to examine cell apoptosis in expreriment,the result revealed that the percentage of apoptotic cell increased obviously after treated with PPD.5 We also observed the changes of morphology in apoptotic cells treated with PPD by TUNEL staining under Laser scanning confocal microscope,the result showed that nuclear was stimulated green fluorescent and nuclear pyknosis, nuclear density enhanced too.6 After the treatment of PPD for 24h,The mRNA expression of bax, caspase-3 in treated groups are higher than control, meanwhile the level of bcl-2,AR mrRNA was less than control (p<0.05).7 Immunocytochemistry stain showed that expression of bax,caspase-3 was upregulated in treated groups,some show the expression of caspase-3 in nuclear. Conclusion: PPD can inhibit the proliferation of RM-1 cells in vitro,which may be caused by downregulation the expression of AR; PPD can induce the apotosis of RM-1 prostatic cancer cells, this effect may be caused by downregulation bcl-2/bax ratio and upregulation the level of caspase-3.