肿瘤睾丸抗原45在卵巢癌组织中的表达水平和血清免疫原性与预后的关系

Expression level and immunogenicity of tumor testis antigen 45 in epithelial ovarian cancer tissues and its relationship with prognosis

目的评估肿瘤睾丸抗原45(CT45)在上皮性卵巢癌(EOC)组织中的表达水平和血清免疫原性与预后的关系。方法选取2018年11月至2020年1月在该院妇产科接受手术治疗的121例EOC患者(EOC组)和60例良性卵巢病变患者(对照组)作为研究对象,采集其组织和血清标本。采用实时荧光定量聚合酶链反应和免疫组织化学法检测CT45在EOC组织、正常卵巢组织中的表达水平。采用酶联免疫吸附试验(ELISA)检测血清标本中抗CT45自身抗体水平,采用Western blot试验进一步证实ELISA的检测结果。采用受试者工作特征(ROC)曲线评估血清抗CT45自身抗体对EOC的诊断价值。结果EOC组CT45A1 mRNA表达水平[1.80(1.10,3.65)]明显高于对照组[0.99(0.68,1.32)],差异有统计学意义(Z=11.883,P<0.001)。46.28%(56/121)的EOC组织均表现出CT45蛋白高表达(++/+++)。CT45蛋白高表达水平与高国际妇产科联盟分期和化疗反应均有关(P<0.05)。EOC组血清抗CT45自身抗体水平明显高于对照组,差异有统计学意义(P<0.05)。ROC曲线分析结果显示,当抗CT45自身抗体最佳截断值设置为中位数(0.37)时,39.67%(48/121)的EOC患者血清标本中可检测到抗CT45自身抗体,其鉴别EOC组和对照组的曲线下面积为0.705,灵敏度和特异度分别为72.51%和68.95%。在48份ELISA检测阳性血清样本中,有81.25%(39/48)的EOC组织CT45蛋白呈高表达。Western blot试验证实了ELISA的检测结果与EOC血清中CT45的免疫原性。组织CT45蛋白高表达(P=0.006)或血清抗CT45自身抗体阳性(P=0.029)患者3年累计总生存率明显更低。结论CT45在EOC组织中表达水平上调,并且在EOC患者中诱导体液免疫反应,表明CT45是EOC的潜在预后生物标志物和肿瘤免疫治疗的靶点。

Objective To evaluate the expression level and serum immunogenicity of tumor testis antigen 45(CT45)in epithelial ovarian cancer(EOC)tissues and its relationship with prognosis.Methods A total of 121 patients with EOC(EOC group)and 60 patients with benign ovarian lesions(control group)who underwent surgical treatment in the Department of Obstetrics and Gynecology of the hospital from November 2018 to January 2020 were selected as the research objects,and their tissue and serum specimens were collected.Real-time fluorescent quantitative polymerase chain reaction and immunohistochemistry were used to detect the expression of CT45 in EOC and normal ovarian tissues.Enzyme-linked immunosorbent assay(ELISA)was used to detect the level of anti-CT45 autoantibodies in serum specimens,and Western blot was used to further confirm the ELISA results.Receiver operating characteristic(ROC)curve was used to evaluate the diagnostic value of serum anti-CT45 autoantibodies for EOC.Results The expression level of CT45A1 mRNA in EOC group[1.80(1.10,3.65)]was significantly higher than that in control group[0.99(0.68,1.32)],and the difference was statistically significant(Z=11.883,P<0.001),and 46.28%(56/121)of EOC tissues showed high expression of CT45 protein(++/+++).CT45 high protein expression levels associated with the international union of gynecology and obstetrics staging and chemotherapy response.The level of serum anti-CT45 autoantibody in EOC group was significantly higher than that in control group,and the difference was statistically significant(P<0.05).The results of ROC curve analysis showed that when the optimal cut-off value of anti-CT45 autoantibody was set as the median(0.37),anti-CT45 autoantibody could be detected in 39.67%(48/121)of the serum samples of EOC patients,and the area under the receiver operating characteristic curve of anti-CT45 autoantibody in distinguishing EOC group and control group was 0.705,and the sensitivity and specificity were 72.51%and 68.95%respectively.Among the 48 ELISA positive serum samples,81.25%(39/48)of EOC tissues showed high expression of CT45 protein.Western blot assay confirmed the results of ELISA and the immunogenicity of CT45 in EOC serum.Patients with high tissue CT45 protein expression(P=0.006)or positive serum anti-CT45 autoantibodies(P=0.029)had a significantly lower 3-year cumulative survival rate.Conclusion CT45 is up-regulated in EOC tissues and induces humoral immune responses in EOC patients,suggesting that CT45 is a potential prognostic biomarker and target for tumor immunotherapy of EOC.