MRP4在去势抵抗性前列腺癌中的表达及意义

Expression and significance of MRP4 in castration resistant prostate cancer

目的探讨多药耐药蛋白4(MRP4)在去势抵抗性前列腺癌(CRPC)中的表达及其作用机制。方法首先采用雄激素递减法建立CRPC细胞株(CR-LNCaP),应用RT-PCR及Western-blotting检测雄激素依赖性前列腺癌细胞株(LNCaP)及CR-LNCaP中MRP4基因的表达变化。然后用慢病毒感染RNA干扰技术(RNAi)沉默CR-LNCaP(KD组)中MRP4表达,并设计未感染病毒的细胞株(CON组)及加阴性对照病毒感染细胞株(NC组)作为对照,应用MTS法、流式细胞术检测RNAi-MRP4后3组细胞的增殖活性及凋亡情况。结果 CR-LNCaP中MRP4 mRNA(0. 89±0. 18 vs. 0. 35±0. 10,P <0. 05)和蛋白(0. 92±0. 28 vs.0. 12±0. 05,P <0. 01)明显高于LNCaP。KD组中MRP4 mRNA(0. 15±0. 01)及蛋白表达(0. 09±0. 02)明显低于CON组(mRNA:0. 95±0. 15,P <0. 01;蛋白:0. 91±0. 11,P <0. 01)及NC组(mRNA:0. 85±0. 11,P <0. 05;蛋白:0. 83±0. 09,P <0. 01)组,并伴随细胞增殖能力下降(P <0. 05)及凋亡数目增加(P <0. 01)。结论雄激素依赖性前列腺癌向CRPC转变过程中伴随有MRP4过表达,下调MRP4表达有抑制肿瘤细胞增殖及促凋亡作用,提示MRP4有可能成为CRPC治疗的新靶点。

Objective To investigate the expression and mechanism of MRP4 gene in castration-resistant prostate cancer（ CRPC）. Methods LNCa P cells were cultured via androgen decrement to establish CRPC cell lines（ CR-LNCa P）. MRP4 mRNA and protein levels in these cells were measured by real-time polymerase chain reaction and Western blot,respectively. A lentivirus-mediated RNA interference technique（ RNAi） was used to inhibit the MRP4 expression in CR-LNCa P（ KD group）. CR-LNCa P with non-transfection were assigned in CON group,and negative control virus as NC group. The proliferation and apoptosis were evaluated by flow-cytometry and MTS assay. Results The expression of MRP4 mRNA（ 0. 89 ± 0. 18 vs. 0. 35 ± 0. 1,P〈0.05） and protein（ 0. 92 ± 0. 28 vs. 0. 12 ± 0. 05,P〈0.01） in CR-LNCa P were significantly higher than those in LNCa P. MRP4 mRNA（ 0. 15 ± 0. 01） and protein（ 0. 09 ± 0. 02） expression in the KD group were significantly lower than those in the CON group（ 0. 95 ± 0. 15 and 0. 91± 0. 11,respectively,P〈0.01） and in the NC group（ 0. 85 ± 0. 11 and 0. 83 ± 0. 09,respectively,P〈0.05,0. 01）.The suppression of MRP4 expression significantly inhibited cell proliferation（ P〈0.05） and increased cell apoptosis（ P〈0.01）. Conclusion There is overexpression of MRP4 in the castration resistant prostate cancer（ CRPC）. MRP4 may play an important role in the control of proliferation and apoptosis of CRPC cells,suggesting a potential target for CRPC therapy.