肿瘤相关成纤维细胞作为预测非肌层浸润性膀胱癌复发的生物标志物的评估

Assessment of tumor-associated fibroblast as a biomarker for predicting recurrence of non-muscle invasive bladder cancer

摘要:

目的 探究肿瘤相关成纤维细胞作为生物学标志物预测非肌层浸润性膀胱癌（non-muscle invasive bladder cancer，NMIBC）患者术后复发的临床意义。方法 从基因表达综合（Gene Expression Omnibus，GEO）数据库下载转录组数据以及对应的临床信息，分析原发性和复发性膀胱癌样本中ACTA2的表达差异。免疫组织化学法（immunohistochemistry，IHC）检测56例膀胱癌样本中α-平滑肌肌动蛋白（α-smooth muscle actin，α-SMA）表达。绘制无复发生存曲线（recurrence-free survival，RFS）和时间依赖性受试者工作特征曲线（time-dependent receiver operating characteristic curves，tdROC）。采用单变量和多变量Cox比例风险回归模型分析α-SMA作为膀胱癌患者术后复发的预测因素的可行性。结果 GSE13507、GSE120739和GSE128959数据集复发组中ACTA2的表达均高于原发组（P<0.05）。IHC结果显示，α-SMA蛋白定位在肿瘤间质，复发组中α-SMA阳性/强阳性占比56.52%，而在原发组中占比16.13%，差异有统计学意义（P<0.001）。α-SMA蛋白表达与年龄、性别、病理分期、分级、肿瘤数量和大小等指标无明显相关性。α-SMA高表达组患者术后RFS较低表达组患者明显缩短[风险比（hazard ratio，HR）=2.76，95%可信区间（confidence interval，CI）=1.21~6.30，P=0.016]。多变量Cox分析显示，α-SMA蛋白表达水平是影响患者术后RFS的独立危险因素（HR=2.47，95%CI=1.02~5.97，P=0.045）。tdROC曲线提示α-SMA对复发的预测能力优于其他临床因素。结论 肿瘤间质的α-SMA蛋白表达水平与膀胱癌复发密切相关，可作为临床预测NMIBC患者术后复发的标志物。

Abstract:

Objective To investigate the clinical significance of tumor-associated fibroblast as a biomarker in predicting postoperative recurrence of non-muscle invasive bladder cancer（NMIBC）.Methods Transcriptomic data were downloaded from the Gene Expression Omnibus database along with corresponding clinical information to analyze the differences in ACTA2 expression in primary and recurrent bladder cancer samples. Immunohistochemistry（IHC） was used to determine α-smooth muscle actin（α-SMA） expression in 56 bladder cancer samples. Recurrence-free survival（RFS） curves and time-dependent receiver operating characteristic（tdROC） curves were plotted. Univariate and multivariate Cox proportional hazard regression models were used to analyze the feasibility of α-SMA as a predictor of postoperative recurrence of bladder cancer.Results The expression of ACTA2 was significantly higher in the recurrence group than in the primary group in the GSE13507，GSE120739，and GSE128959 datasets（P<0.05）. IHC results showed that α-SMA protein was localized in the tumor stoma，and the percentage of positive/strongly positive α-SMA was 56.52% in the recurrence group and 16.13% in the primary group，with a significant difference between the two groups（P<0.001）. There was no significant correlation between α-SMA protein expression and age，gender，pathological stage，grade，tumor number，and size. Postoperative RFS was significantly shorter in patients with high α-SMA expression than in those with low α-SMA expression [hazard ratio（HR）=2.76，95% confidence interval（CI）=1.21~6.30，P=0.016]. Multivariate Cox analysis showed that α-SMA protein expression level was an independent risk factor for postoperative RFS in patients（HR=2.47，95%CI=1.02~5.97，P=0.045）. tdROC curves suggested that α-SMA was a better predictor of recurrence than other clinical factors.Conclusion α-SMA protein expression level in the tumor stroma is closely related to the recurrence of bladder cancer and can be used as a clinical marker to predict postoperative recurrence of NMIBC.