蛋白激酶Cα对浅表膀胱癌分化及阿霉素内源性耐药的作用  

The role of protein kinase C alpha in recurrence of superficial bladder carcinoma

作　　者：朱育焱[1] 王海明 孔垂泽[1] 柳东辉[1] 李泽良[1] 孙志熙[1] 刘革非[3] 

机构地区：[1]中国医科大学附属第一医院泌尿外科,沈阳110001 [2]内蒙古自治区赤峰平庄矿务局西露天矿医院 [3]中国医科大学卫生部国家重点实验室细胞生物学教研室

出　　处：《中华外科杂志》2005年第10期662-666,共5页Chinese Journal of Surgery

基　　金：卫生部科研基金资助项目(981189)

摘　　要：目的探讨蛋白激酶C(PKC)α与浅表膀胱癌细胞分化及内源性耐药的关系。方法采用蛋白印迹法检测76例临床标本(浅表膀胱癌及正常组织)中PKCα的表达水平,对所有患者行标准化疗后随访4～24个月,分析PKCα表达及活化与复发的关系。应用人浅表膀胱癌细胞系RT4细胞,建立能够稳定表达PKCα绿色荧光蛋白(GFP)的人膀胱癌细胞系RT4/PKCαGFP。用四甲基偶氮唑蓝比色法(MTT)测定RT4/PKCαGFP和亲代细胞对阿霉素的敏感性。分别检测PKCα激活和抑制状态下RT4/PKCαGFP对阿霉素敏感性的差异。结果在癌组织中,PKCα总体表达水平和胞膜、胞浆中表达水平的比值(M/C值),均显著高于正常组织(癌组织为正常组织的2.2倍,t=1.98,P<0.05;M/C值癌组织为0.84±0.12,正常组织为0.23±0.11,t=2.62,P<0.01)。随着肿瘤分级的升高,胞膜中PKCα的相对表达的水平显著升高(P<0.01),胞浆中的相对表达水平显著下降(P<0.01),PKCα的M/C值显著升高(P<0.01),总体PKCα相对表达水平显著升高(P<0.01)。70例获随访,共复发38例。多因素分析表明,高PKCαM/C值是影响化疗后近期复发的独立预后因素(相对危险度3.98,95%可信区间1.22～5.68,P=0.03)。转染PKCα基因后,RT4细胞对阿霉素的耐药性增强(耐药指数6.97,t=3.24,P<0.01)。Objective To investigate the relationship of protein kinase C-alpha(PKCα) expression /activation with tumor differentiation and resistance to chemotherapy drugs in superficial bladder carcinoma. Methods Expression of PKCα was measured by Western-blot analysis in 76 samples including tumor and normal tissues, respectively. A human RT4 bladder cancer cell line stably expressing green fluorescent protein(GFP)-PKCα (RT4/PKCα) was established. The sensitivity of the RT4/PKCα and parental cells to adriamycin (ADM) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide(MTT)assay. The change of sensitivity of the RT4/PKCα to ADM were observed under the conditions of PKC activation and inhibition, respectively. Results Total level of PKCα expression and the ratio of the amount of PKCα expression or PKC activity in membrane to that in cytosol (M/C) were all more higher in cancerous tissues than in normal tissues(P<0.01); With the increase of tumor grade, the relative level of PKCα expression significantly increased in membrane (P<0.01) and decreased in cytosol(P<0.01), M/C of PKCα was significantly elevated(P<0.01), and total relative level of PKCα expression significantly increased(P<0.01). Thirty-eight cases recurred during the follow-up period in total seventy cases. Multivariate analysis showed that high M/C of PKCα was independent prognostic factor for tumor recurrence after standard ADM treatment in the 2-year follow-up (RR=3.98, 95%CI 1.22—5.68, P=0.03). Transfection of PKCα increased resistance of RT4 cells to ADM [resistance index(RI):6.97, t=3.24, P<0.01].PKCα activation further greatly promoted the resistance (RI:148.11, t=5.18, P<0.001) while inhibition of PKCα did conversely (RI:1.6, t=1.29, P>0.05). Conclusion The abnormal activation and expression level of PKCα closely correlate with both tumor grade and intrinsic resistance to ADM in patients with superficial bladder carcinoma. afte

关 键 词：浅表膀胱癌 阿霉素 内源性 蛋白激酶CΑ 蛋白激酶C(PKC) 四甲基偶氮唑蓝比色法 膀胱癌细胞系 RT4细胞 PKCα 正常组织 绿色荧光蛋白 相对表达 耐药指数 癌细胞分化 蛋白印迹法 多因素分析 相对危险度 癌组织 临床标本 稳定表达 

分 类 号：R737.14[医药卫生—肿瘤] R979.1[医药卫生—临床医学]