前列腺癌Nrf2表达临床意义

Expression and clinical significance of Nrf2 in prostate cancer

目的探讨核转录因子红细胞系-2p45(NF-E2)相关因子2(nuclear factor erythroid-2related factor 2,Nrf2)在良性前列腺增生(benign prostatic hyperplasia,BPH)和前列腺癌(prostate cancer,PCa)组织中的表达及临床意义。方法收集2015-01-10-2016-01-10武汉市第一医院泌尿外科就诊的前列腺癌患者80例,设为前列腺癌组。选择同院同期前列腺增生患者52例,设为对照组。免疫组织化学染色(immunohistochemistry,IHC)检测前列腺癌和前列腺增生组织中Nrf2的表达情况;实时荧光定量PCR(real-time fluorescence quantitative PCR,RT-qPCR)和蛋白质印迹法检测Nrf2mRNA和蛋白的表达水平;分析前列腺癌患者肿瘤组织中Nrf2的表达与患者年龄、肿瘤大小、血清前列腺特异抗原(prostate specific antigen,PSA)含量、Gleason评分、临床分期、是否淋巴结处转移和是否化疗耐药的关系;培养前列腺癌细胞系DU145,采用siRNA敲减DU145细胞中Nrf2的表达,四甲基偶氮唑盐比色法(MTT)检测细胞对多西他赛(docetaxel,DTX)等化疗药物的敏感性。结果前列腺癌组织中Nrf2mRNA相对表达水平为3.61±1.75,高于前列腺增生组织的1.08±0.78,差异有统计学意义,t=3.669,P=0.003 2;前列腺癌组织中Nrf2蛋白相对表达水平为2.55±1.03,高于前列腺增生组织的0.73±0.54,差异有统计学意义,t=3.513,P=0.005 6。前列腺癌组织Nrf2阳性率为71.25%(57/80)高于前列腺增生组织7.69%(4/52),差异有统计学意义,χ2=51.217,P<0.001。前列腺癌患者肿瘤组织中Nrf2阳性率与血清PSA含量(χ2=19.985,P=0.001)、肿瘤大小(χ2=4.665,P=0.031)、Gleason评分(χ2=9.937,P=0.002)、临床分期(χ2=11.446,P=0.003)和有无淋巴结转移(χ2=6.572,P=0.01)有关联,与患者年龄无关(χ2=1.993,P=0.448)。62例患者进行以DTX为基础的化疗,其中化疗敏感37例,化疗耐药25例。化疗敏感组Nrf2阳性20例,阴性17例,阳性率为54.1%,化疗耐药组Nrf2阳性20例,阴性5例,阳性率为80.0%,两组差异有统计学意义,χ2=4.387,P<0.036。siNrf2组24、48和72hDTX、奥沙利铂和5-氟尿嘧啶(5-FU)的IC50明显低于siCtrl组,差异均有统计学意义,均P<0.01。结论 Nrf2在前列腺癌组织中的表达升高,可能参与前列腺癌的发生发展及化疗耐药的产生,可作为肿瘤治疗的潜在靶点。

OBJECTIVE To explore the expression of（NF-E2）-related factor 2（Nrf2）in benign prostatic hyperplasia（BPH）and prostate cancer（PCa）and its clinical significance.METHODS Pathological sections and tumor tissues were collected from 80 patients with prostate cancer and prostate hyperplasia tissue biopsy from 52 patients from January10,2015 to January10,2016.The expression of Nrf2 was detected by immunohistochemical staining.The expression of Nrf2 mRNA and protein were detected by real-time fluorescence quantitative PCR（RT-qPCR）and western blot.The relationship of the expression of Nrf2 in tumor tissue of patients with prostate cancer and age,tumor size,serum PSA content,Gleason score,clinical stage,lymph node metastasis and chemotherapy resistance were analyzed.Culture DU145 cell line and siRNA were uesd to knockdown the expression of Nrf2 and the sensitivity of cells to docetaxel（DTX）was measured by MTT assay.RESULTS The relative expression level of Nrf2 mRNA and protein in prostate cancer tissues（3.61±1.75,2.55±1.03）was higher than that in benign prostatic hyperplasia tissues（1.08±0.78,0.73±0.54）,the difference was statistically significant（t=3.669,P =0.003 2）.The positive rate of Nrf2 in prostate cancer（71.25%,57/80）was higher than that in benign prostatic hyperplasia（7.69%,4/52）,the difference was statistically significant（χ^2=51.217,P〈0.001）.The positive rate of Nrf2 in tumor tissue of patients with prostate cancer was correlated with serum PSA level,tumor size,Gleason score,clinical stage and lymph node metastasis（χ^2=19.985,P=0.001;χ^2=4.665,P=0.031;χ^2=9.937,P=0.002;χ^2=11.446,P=0.003,χ^2=6.572,P=0.01）,regardless of age（χ^2=1.993,P=0.448）.Sixty-two patients underwent DTX-based chemotherapy,of which 37 were chemotherapy sensitive and 25 were chemotherapy resistance.The positive rate of Nrf2 in chemotherapy sensitive group was 54.1%and 80.0%in chemotherapy resistance group,the difference was statistically significant（χ^2=4.387,P〈0.036）.The IC50 of docetaxel,oxaliplatin and 5-fluorouracil at siNrf2 group were significantly lower than that of siCtrl group at 24,48 and 72 h,the differences were statistically significant,all P〈0.01.CONCLUSION Increased expression of Nrf2 in prostate cancer may be involved in the development and progression of prostate cancer and may serve as a target for tumor therapy.