Therapeutical Effects Of DIM With IDA On Prostate Carcinoma In Mice

Objective:To investigate the therapeutical effects and the mechanism of the 3,3'-diindolylmethane (DIM) and Idamycin(IDA) on subcutaneous prostate cancer of mice.Methods:①The MTT assay was used to measure the proliferation of mouse prostate cancer cell RM-1.Apoptosis of the RM-1 was measured by the flow cytometry and acridine orange staining method,and then the expression of apoptosis relative gene Bcl-2,Bax and Caspase-3 was detected by RT-PCR.②The xenografted C57 mice model with prostate cancer was established.Forty of the C57 mice bearing RM-1cell were randomly divided into five groups (eight in each group),control group(0.9%sodium chloride 0.2 mL·d^-1),IDA group(IDA 1mg·kg^-1·d^-1),DIM low -dose group(DIM 5mg·kg^-1·d^-1),DIM high-dose group(DIM 10mg·kg^-1·d^-1) and DIM+IDA group(IDA lmg·kg^-1·d^-1+ DIM 5mg·kg^-1·d^-1),and the mice were given intraperitoneal injection once every three days after four days inoculation of RM-1 cell.And volume of the xenografts was measured once every five days.On the 25th day after tumor inoculability,all the mice were killed.The xenografts were weighed and the inhibitory rates of tumor were calculated.The expression of apoptosis gene Bcl-2,Bax and Caspase-3 was detected by RT-PCR,and then the expression of Caspase-3 and Bcl-2 protein was detected by immunohistochemistry and western blot.Results:①Compared with the controlled group,IDA and DIM decreased proliferation and and induced apoptosis for the RM-1 cells in vitro,and the therapeutic effects were more obvious in the combined group than in the single work of low-dose group.RT-PCR results showed that IDA and DIM can either regulate the expression of Bcl-2 downwards or the expression of Bax and Caspase-3 upwards,and the defference was statistically significant(P＜0.05).and the therapeutic effects had more advantage obvious in the combined group than in the single work of low-dose group.②The xenografted tumors were significantly inhibited in the IDA group,DIM group and DIM+IDA group than in the control group in vivo(P＜0.05),and the inhibitory rate was 23.7%,34.2%,47.7%,66.9%,respectively.The RT-PCR results showed that treatment group could regulate the expression of Bcl-2 downwards and the expression of Bax and Caspase-3 upwards.Immunohistochemistry results showed that the expression of Caspase-3 protein was increased after the treatment.Western blot results showed that treatment group could regulate the expression of Bcl-2 protein downwards and the expression of Caspase-3 protein upwards.And all experiments were showed that therapeutic effects in the combined group were more significant.Conclusion:DIM with IDA inhibits proliferation and induces apoptosis in mouse Prostate Cancer Cell RM-1.Meanwhile,DIM with IDA may obviously improve the anti-tumor effects in mice in vivo.The mechanism is related with block cell cycle,DNA splitting increase, inhibit DNA synthesis,and the expression of apoptosis relative gene was regulated and increasing apoptosis-inducing effect.