Objectives: To construct a prediction model for the prognosis of bladder cancer patients based on the expression of ion channel-related genes (ICRGs).
Methods: ICRGs were obtained from the existing researches. The clinical information and the expression of ICRGs mRNA in breast cancer patients were obtained from the Cancer Genome Atlas database. Cox regression analysis, minimum absolute shrinkage and selection operator regression analysis were used to screen breast cancer prognosis related genes, which were verified by immunohistochemistry and qRT-PCR. The risk scoring equation for predicting the prognosis of patients with bladder cancer was constructed, and the patients were divided into high-risk group and low-risk group according to the median risk score. Immune cell infiltration was compared between the two groups. Kaplan-Meier survival curve and receiver operating characteristic (ROC) curve were used to evaluate the accuracy and clinical application value of the risk scoring equation. The factors related to the prognosis of bladder cancer patients were analyzed by univariate and multivariate Cox regression, and a nomogram for predicting the prognosis of bladder cancer patients was constructed.
Results: By comparing the expression levels of ICRGs in bladder cancer tissues and normal bladder tissues, 73 differentially expressed ICRGs were dentified, of which 11 were related to the prognosis of bladder cancer patients. Kaplan-Meier survival curve suggested that the risk score based on these 11 genes was negatively correlated with the prognosis of patients. The area under the ROC curve of the risk score for predicting the prognosis of patients at 1, 3 and 5 year was 0.634, 0.665 and 0.712, respectively. Stratified analysis showed that the ICRGs-based risk score performed well in predicting the prognosis of patients with American Joint Committee on Cancer (AJCC) stage Ⅲ-Ⅳ bladder cancer (P<0.05), while it had a poor value in predicting the prognosis of patients with AJCC stage Ⅰ-Ⅱ (P>0.05). There were significant differences in the infiltration of plasma cells, activated natural killer cells, resting mast cells and M2 macrophages between the high-risk group and the low-risk group. Cox regression analysis showed that risk score, smoking, age and AJCC stage were independently associated with the prognosis of patients with bladder cancer (P<0.05). The nomogram constructed by combining risk score and clinical parameters has high accuracy in predicting the 1, 3 and 5 year overall survival rate of bladder cancer patients.
Conclusions: The study shows the potential value of ICRGs in the prognostic risk assessment of bladder cancer patients. The constructed prognostic nomogram based on ICRGs risk score has high accuracy in predicting the prognosis of bladder cancer patients.
目的: 基于离子通道相关基因（ICRG）构建膀胱癌患者预后风险评估模型。方法: 首先从已有研究中获得ICRG。患者临床信息和信使RNA表达均从癌症基因组图谱数据库膀胱癌数据集下载。接着，采用Cox回归分析和最小绝对收缩与选择算子回归分析筛选预后相关基因并通过免疫组织化学及定量逆转录量聚合酶链反应结果验证相关基因的表达。然后，构建预测膀胱癌患者预后的风险评分方程并根据风险评分的中位数将患者分为高风险组和低风险组，比较两组免疫细胞浸润丰度差异。应用Kaplan-Meier生存曲线及应用受试者操作特征曲线（ROC曲线）评估风险评分方程的准确性以及临床应用价值。最后，通过单因素和多因素Cox回归筛选与膀胱癌患者预后相关的影响因素构建膀胱癌患者预后的列线图。结果: 通过比较膀胱癌组织与健康膀胱组织中ICRG的表达水平，发现共有73个ICRG差异表达，其中11个与膀胱癌患者的预后相关。Kaplan-Meier生存曲线结果提示，基于这11个基因构建的风险评分与患者预后呈负相关；随时间变化的ROC曲线结果显示，风险评分预测患者1、3、5年预后的曲线下面积分别为0.634、0.665、0.712。分层分析发现，基于ICRG的风险评分在预测美国癌症联合委员会（AJCC）Ⅲ~Ⅳ期膀胱癌患者的预后方面表现良好（P<0.05），但在预测Ⅰ~Ⅱ期膀胱癌患者预后时表现一般（P>0.05）。高风险组与低风险组浆细胞、活化的NK细胞、静息的肥大细胞和M2型巨噬细胞的浸润水平差异有统计学意义。Cox回归分析结果显示，风险评分、吸烟、年龄和AJCC分期与膀胱癌患者的预后独立相关（均P<0.05）。结合风险评分和临床参数构建的列线图预测膀胱癌患者1、3、5年总存活率的准确性较高。结论: 本研究初步证实了ICRG在膀胱癌患者预后风险评估中的价值，基于ICRG风险评分所构建的膀胱癌患者预后列线图对于膀胱癌患者预后预测的准确性较高。.
Keywords: Bladder cancer; Gene; Ion channel; Prognosis; Risk assessment.