| Objective:To investigate the effect of dexamethasone(Dex)on the progression of castrated resistant prostate cancer(CRPC)through glucocorticoid receptor(GR).Methods:1.RT-PCR and Western Blot were used to detect the differential expression of GR and AR in different prostate cancer cells C4-2B,DU145,and PC-3.2.Prostate cancer cells C4-2B,DU145,and PC-3 were pretreated in a full culture medium containing 10% carbon adsorbed serum FCS for 72 hours to remove the effects of corticosteroids in the serum.After 48 hours of treatment with 100 nM Dex,the effects of Dex on the proliferation ability of prostate cancer cell lines of different stages were analyzed by cell cloning experiments and CCK8 experiments,the effect of invasion and metastasis ability were analyzed by cell scratch and Transwell experiments.3.To confirm that GR plays an important role in the regulation of prostate cancer,GR was silenced by siRNA in DU145 and PC-3 cell lines treated with 100 nM Dex,and the effect of GR expression on the growth,proliferation,invasion and metastasis of prostate cancer cells were observed by cell cloning,CCK 8,cell scratch and Transwell experiments4.According to the literature and pre-experimental results,after the DU145 cell line was treated with Dex concentrations of 0,10,100,and 1000 nM for 48 hours,the expression changes of downstream proteins were detected by RT-PCR and Western Blot,and the intracellular location distribution of target proteins was observed by immunofluorescence.Results:1.RT-PCR and Western Bolt results showed that GR was highly expressed in DU145 and PC-3 cells,almost non-expressed in androgen dependent cell line C4-2B,and AR was highly expressed in C4-2B,almost undetectable in DU145 and PC-3 cells,indicating a negative correlation between GR expression and AR expression.2.The results of cell cloning experiment and CCK8 experiment showed that compared to the control group,DU145 and PC-3 treated with 100 nMDex showed a decrease in cell proliferation ability and colony formation ability(P<0.05).The proliferation ability and colony formation ability of androgen dependent cell C4-2B were not affected(P>0.05).The cell scratch test and Transwell results showed that compared with the control group,DU145 and PC-3showed a decrease in cell invasion and metastasis ability(P<0.05),the invasion and metastasis ability of C4-2B were not affected(P>0.05).3.Silencing GR in Dex-treated DU145 and PC-3 cells can reverse the reduced proliferation,colony formation,invasion and metastasis ability of DU145 and PC-3 caused by Dex treatment.4.The expression of VEGF-C and p-P65 in DU145 cell line treated with Dex was significantly reduced in a dose-dependent manner(P<0.05).The expression of IκBα increased in a dose-dependent manner(P<0.05),and after silencing P65,the expression of VEGF-C significantly decreased(P<0.005).Dex significantly inhibits intracellular NF-κB nuclear transfer(P<0.05).Conclusion:Dexamethasone can inhibit the proliferation,invasion and metastasis of CRPC cells and slow the progression of CRPC by regulating NF-κB/VEGF-C signaling pathway by mediating glucocorticoid receptors. |
