环状RNA FLI1在肝细胞癌患者中的表达及其与预后的关系

目的探讨环状RNA FLI1(circ FLI1)在肝细胞癌(HCC)患者中的表达及意义。方法收集2013年1月-2018年1月于西南医科大学附属医院经手术切除的45例HCC患者的癌组织及配对癌旁组织和血清样本(HCC组)。同时收集45例健康体检者的血清标本(对照组)。人肝癌细胞株HepG2、SMMC7721、HB611均来自中国科学院生物化学与细胞生物学研究所。real-time PCR法检测circ FLI1在肝癌细胞及45例肝癌组织、血清标本中的表达。计量资料2组间比较采用t检验。采用Kaplan-Meier法分析circ FLI1表达与患者生存时间的关系,采用受试者工作特征曲线(ROC曲线)分析血清circ FLI1 E2-4及circ FLI1 E2-5作为诊断HCC生物标志物的潜能,应用单因素及多因素Cox比例风险模型分析影响HCC预后的因素。结果 circ FLI1 E2-5及circ FLI1 E2-4在3种肝癌细胞中高表达。circ FLI1 E2-4(7.09±0.26 vs 1.14±0.20,t=19.970,P<0.001)及circ FLI1 E2-5(7.50±0.25 vs 1.29±0.30,t=16.640,P<0.001)在HCC患者血清中的表达明显高于对照组;在HCC患者癌组织中的表达明显高于癌旁组织(7.62±1.33 vs 1.55±0.32,t=15.560,P<0.001;7.92±0.35 vs 1.42±0.39,t=21.170,P<0.001)。高表达circ FLI1 E2-5的患者中位无进展生存时间(11.17±0.49)个月vs (23.35±1.27)个月,χ^2=28.480,P<0.001]及总生存时间(19.75±0.76)个月vs(37.44±1.57)个月,χ^2=21.750,P<0.001]均较低表达者明显缩短;高表达circ FLI1 E2-4的患者中位无进展生存时间(10.29±0.42)个月vs(24.65±1.58)个月,χ^2=19.620,P<0.001]及总生存时间(21.32±0.55)个月vs(35.69±1.74)个月,χ^2=19.730,P<0.001]亦较低表达者明显缩短。血清circ FLI1 E2-4作为诊断HCC血清标志物的ROC曲线下面积为0.91095%可信区间(95%CI):0.621~0.970,P<0.001],灵敏度和特异度分别为84.3%和90.5%。血清circ FLI1 E2-5作为诊断HCC血清标志物的ROC曲线下面积为0.760(95%CI:0.650~0.860,P<0.001),灵敏度和特异度分别为80.5%和87.3%。Cox多因素回归模型分析提示,血清circ FLI1 E2-4(风险比=3.060,95%CI:1.630~5.870,P=0.001)及circ FLI1 E2-5(风险比=2.560,95%CI:1.250~6.460,P=0.008)表达是HCC患者预后的独立影响因素。结论 circ FLI1在HCC患者组织及血清中高表达,与患者的预后相关,可能是潜在的HCC患者预后标志物和治疗靶点。

Expression of circular RNA FLI1 in patients with hepatocellular carcinoma and its association with prognosis

Objective To investigate the expression and significance of circular RNA FLI1( circ FLI1) in patients with hepatocellular carcinoma( HCC).Methods A total of 45 HCC patients who underwent surgical resection in The Affiliated Hospital of Southwest Medical University from January 2013 to January 2018 were enrolled as HCC group,and the samples of cancerous tissue,adjacent tissue,and serum were collected.A total of 45 healthy individuals who underwent physical examination were enrolled as control group,and their serum samples were collected.Human hepatoma cell lines HepG2,SMMC7721,and HB611 were obtained from Shanghai Institute of Biochemistry and Cell Biology,Chinese Academy of Sciences.qRT-PCR was used to measure the expression of circ FLI1 in hepatoma cells and 45 samples of cancerous tissue and serum.The t-test was used for comparison of continuous data between groups.The Kaplan-Meier method was used to analyze the association between circ FLI1 expression and survival time;the receiver operating characteristic( ROC) curve was used to evaluate the potential of serum circ FLI1 E2-4 and circ FLI1 E2-5 as the biomarkers for the diagnosis of HCC;univariate and multivariate Cox proportional hazards model analyses were used to investigate the influencing factors for the prognosis of HCC.Results There was high expression of circ FLI1 E2-5 and circ FLI1 E2-4 in the three hepatoma cell lines.Compared with the control group,the HCC group had sig-nificantly higher serum levels of circ FLI1 E2-4( 7.09 ± 0.26 vs 1.14 ± 0.20,t = 19.970,P<0.001) and circ FLI1 E2-5( 7.50 ±0.25 vs 1.29 ± 0.30,t = 16.640,P<0.001).For the HCC patients,the expression of circ FLI1 E2-4 and circ FLI1 E2-5 in cancerous tissue was significantly higher than that in adjacent tissue( circ FLI1 E2-4: 7.62 ± 1.33 vs 1.55 ± 0.32,t = 15.560,P<0.001;circ FLI1 E2-5: 7.92 ± 0.35 vs 1.42 ± 0.39,t = 21.170,P<0.001).The patients with high expression of circ FLI1 E2-5 had significantly shorter median progression-free survival time and overall survival time than those with low expression( median progression-free survival time: 11.17 ± 0.49 months vs 23.35 ± 1.27 months,χ^2= 28.480,P<0.001;overall survival time: 19.75 ± 0.76 months vs 37.44 ± 1.57 months,χ^2= 21.750,P<0.001).The patients with high expression of circ FLI1 E2-4 had significantly shorter median progression-free survival time and overall survival time than those with low expression( median progression-free survival time: 10.29 ± 0.42 months vs 24.65 ± 1.58 months,χ^2= 19.620,P<0.001;overall survival time: 21.32 ± 0.55 months vs 35.69 ± 1.74 months,χ^2= 19.730,P<0.001).As a serum marker for the diagnosis of HCC,serum circ FLI1 E2-4 had an area under the ROC curve of 0.910( 95% confidence interval CI]: 0.621-0.970,P<0.001),with a sensitivity of 84.3% and a specificity of 90.5%.As a serum marker for the diagnosis of HCC,serum circ FLI1 E2-5 had an area under the ROC curve of 0.760( 95% CI: 0.650-0.860,P<0.001),with a sensitivity of80.5% and a specificity of 87.3%.The multivariate Cox proportional hazards model analysis showed that serum circ FLI1 E2-4( hazard ratio HR]= 3.060,95% CI: 1.630-5.870,P<0.05) and circ FLI1 E2-5( HR = 2.560,95% CI: 1.250-6.460,P<0.05) were independent influencing factors for the prognosis of HCC patients.Conclusion Circ FLI1 is highly expressed in the tissue and serum of HCC patients,which is associated with the prognosis of patients.It may be a potential biomarker for prognosis and a therapeutic target for HCC.