胃癌组织CUL4B表达临床意义

Expression of CUL4B in gastric cancer and its clinical significance

目的Cullin蛋白家族CUL4A在胃癌的临床预后中扮演着重要角色,其蛋白家族CUL4B目前在胃癌中研究较少。本研究意在探讨CUL4B在胃癌组织中的表达及其与临床病理和预后之间的关系。方法采用实时荧光定量PCR(quantitative real-time PCR,q-PCR)和蛋白质印迹法,检测2017-05-01-2017-11-15武警安徽省总队医院的26对新鲜配对的胃癌组织和癌旁正常组织中CUL4B mRNA和蛋白表达情况。收集2006-06-01-2009-03-15武警安徽省总队医院的98例石蜡包埋的胃癌组织和31例癌旁正常组织并将其构建成组织芯片,采用免疫组织化学方法检测组织芯片中CUL4B在肿瘤组织和癌旁正常组织中的表达情况,并且分析CUL4B蛋白的表达与胃癌患者临床病理以及临床预后之间的关系。结果在26对新鲜配对的组织中,q-PCR结果显示胃癌组织CUL4B mRNA中位相对表达水平为0.011(0.042),高于配对的癌旁正常组织的0.002(0.038),差异有统计学意义,Z=-3.111,P=0.002;蛋白质印迹结果显示,CUL4B蛋白在胃癌组织中的表达强度高于癌旁正常组织。在组织芯片中,免疫组化结果显示胃癌组织中CUL4B蛋白表达阳性率(70.41%,69/98)高于癌旁正常组织(35.48%,11/31),差异有统计学意义,P<0.0010 CUL4B蛋白表达与肿瘤淋巴结转移(P=0.014)、组织分化程度(P=0.001)以及TNM分期(P=0.046)有关联。单因素Cox回归分析显示,组织分化程度(HR=1.798,95%CI为1.105~2.927)、肿瘤浸润深度(HR=1.819,95%CI为1.050~3.153)、淋巴结转移(HR=2.050,95%CI为1.268~3.313)、TNM分期(HR=2.688,95%CI为1.666~4.337)以及CUL4B蛋白表达水平(HR=1.817,95%CI为1.093~3.022)是影响总生存时间(overall survival,OS)的风险因子。多因素Cox回归分析显示,组织分化程度(HR=1.745,95%CI为1.059~2.875)和CUL4B蛋白表达水平(HR=1.766,95%CI为1.041~2.994)是影响OS的独立风险因子。经Kaplan-Meier生存分析以及Log-Rank检验结果显示,CUL4B蛋白表达阳性组患者的中位生存时间(48个月)低于阴性组患者(66个月),差异有统计学意义,P=0.014。结论CUL4B蛋白表达参与胃癌的发生发展,可能成为预测胃癌患者预后的重要分子标志物,并为胃癌靶向分子治疗提供重要的理论依据。

OBJECTIVE In Cullin protein family CUL4A plays an important role in the clinical prognosis of gastric cancer,and its protein family CUL4B is seldom studied in gastric cancer.The purpose of this study was to investigate the expression of CUL4B in gastric cancer and its relationship with clinical pathology and prognosis.METHODS Quantitative real-time PCR(q-PCR)and Western blotting were used to detect the expression of CUL4B mRNA and protein in 26 pairs of fresh gastric cancer tissues and adjacent normal tissues from the Armed Police Corps Hospital of Anhui from May 1,2017 to November 15,2017.A total of 98 paraffin-embedded GC tissues and 31 randomly selected normal gastric tissues from June 01,2006 to March 15,2009 in the Armed Police Corps Hospital of Anhui were collected and constructed into tissue microarray(TMA).Immunohistochemistry were performed on TMA to detect the expression of CUL4B,and correlation of CUL4B protein expression with clinicopathological features and clinical prognosis of GC patients were analyzed.RESULTS In 26 pairs of fresh paired tissues,the results of q-PCR showed that the median relative expression level of CUL4B mRNA in GC tissues(0.011,range:0.042)was higher than that in matched normal tissues(0.002,range:0.038),Z=-3.111,P=0.002,with statistical significance;western blot results showed that the expression of CUL4B protein in GC tissues was higher than that in matched controls.In TMA,immunohistochemistry results showed that the positive rate of CUL4B protein expression in GC tissues(70.41%,69/98)was higher than in matched controls(35.48%,11/31),PV0?001,with statistical significance.CUL4B protein expression was significantly correlated with lymph node metastasis(P=0.014),histological differentiation degree(P=0.001)and TNM stage(P=0.046).Univariate Cox regression analysis revealed that histological differentiation degree(HR=1.798,95%CI:1.105-2.927),depth of invasion(HR=1.819,95%CI:1.050-3.153),lymph node metastasis(HR=2.050,95%CI:1.268-3.313),TNM stage(HR=2.688,95%CI:1.666-4.337)and CUL4B expression(HR=1.817,95%CI:1.093-3.022)were prognostic factors for GC.Multivariate Cox regression analysis revealed that histological differentiation degree(HR=1.745,95%CI:1.059-2.875)and CUL4B expression(HR=1.766,95%CI:1.041-2.994)to be the independent prognostic factors for GC.Kaplan-Meier survival analysis and Log-Rank test results showed that CUL4B positive GC patients had a shorter survival time(median 48 months)than CUL4B negative GC patients(median 66 months),P=0.014,with statistical significance.CONCLUSION CUL4B protein expression may be realted to the tumorigenesis,prognostic biomarkers and theoretical basis of therapeutic targets for GC.