Experimental Study Of The Resistant Mechanisms Of Docetaxol On Prostate Cancer PC-3 Cell In Vitro And In Vivo

Objective:To observe the effect and possible mechanism of drug resistance of docetaxol (Docetaxel, Doc) on castration resistant prostate cancer cell line PC-3 in vitro and in vivo. To provide new ideas and experimental basis in the clinical treatment for castration resistant prostate cancer.Methods:1. PC-3 cells were cultured with RPMI1640 in vitro, screeing the drug-resistant cells with 0.1 umol/L Doc to continue culturing until drugs have no significant side effects to all cells then the drug-resistant cells line PC-3/Doc were selected.The cells morphological variance were examined by ordinary optical microscopy. The cells cycle and apoptosis rates were examined by flow cytometry (FCM).The CD133+ cells were examined by FCM. The expression of Oct4 protein was detected by Western-blotting.2. To establish a nude mice transplantation tumor model of prostate cancer with cells line PC-3. The 10 nude mice ware randomly divided into two groups,there ware 5 nude mice in each group. Doc group:tail intravenous injected once a week (Doc,10mg/kg), a total of four weeks. At the same time,the negative control group:tail intravenous injected the same amount of Doc solvent. To observe the living situation of nude mice every day, and draw tumor growth carve by measure tumors volume.The inhibition rate of the tumor calculated. HE staining to observe morphological characteristics of tumor cells; Immunohistochemical examine the protein expression levels of CD 133 and Oct4 in the tumor tissues of nude mice; Explore the possible mechanism of drug resistance on PC-3cells in vivo.Results:1. The drug-resistant PC-3 cells (PC-3/Doc) was screened successfully. Compared with PC-3,the proportion of CD133+cells increased significantly in PC-3/Doc detected by Flow cytometry (P<0.05),and the Oct4 protein expression in PC-3/Doc cells increased too detected by Western blotting (P<0.05)2. Docetaxol can obviously inhibit the growth of prostate cancer PC-3 cells transplanted tumor, the tumor volume and weight ware significantly reduced, but the tumors ware not completely disappeaed. Compareding with control group, immunohistochemical results showed that the expression of CD 133 and Oct4 protein in tumor tissues ware significantly increased in Doc group (P<0.05)Conclusion:1.The CD 133+cancer stem cells was enriched in the drug resistant PC-3 cells. Compared with parental cells, the expression of Oct4 protein was rise significantly in the PC-3/Doc cells, the Oct4 protein rise may be associated with the drug resistance of prostate cancer.2. Docetaxol can obviously inhibit the growth of prostate cancer PC-3 cells transplanted tumor, the tumor volume and weight ware significantly reduced, but the tumors had not completely disappeas.The expression of CD133and Oct4 protein ware increased in residual tumors, may be associated with the drug resistance of prostate cancer.