上海交通大学学报(医学版) ›› 2021, Vol. 41 ›› Issue (11): 1436-1445.doi: 10.3969/j.issn.1674-8115.2021.11.006

• 论著 · 基础研究 • 上一篇    下一篇

胃癌患者预后相关微RNA预测模型的构建及其应用价值探讨

岳犇(), 王高明, 杨鹿笛, 崔然, 郁丰荣()   

  1. 上海交通大学医学院附属仁济医院胃肠外科,上海 200127
  • 出版日期:2021-11-28 发布日期:2021-12-03
  • 通讯作者: 郁丰荣 E-mail:yueben@163.com;rry77@126.com
  • 作者简介:岳犇(1986—),男,住院医师,博士;电子信箱:yueben@163.com
  • 基金资助:
    上海市核酸化学与纳米医学重点实验室“临床+”卓越项目(2020ZYA008)

Construction and application value of prognosis-associated miRNA prediction model in gastric cancer patients

Ben YUE(), Gao-ming WANG, Lu-di YANG, Ran CUI, Feng-rong YU()   

  1. Department of Gastrointestinal Surgery, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
  • Online:2021-11-28 Published:2021-12-03
  • Contact: Feng-rong YU E-mail:yueben@163.com;rry77@126.com
  • Supported by:
    Shanghai Key Laboratory of Nucleic Acid Chemistry and Nanomedicine "Clinical Plus" Excellence Project(2020ZYA008)

摘要:

目的·通过生物信息学方法建立胃癌患者预后相关微RNA(microRNA,miRNA)的预测模型并探讨其应用价值。方法·收集癌症和肿瘤基因图谱计划(TCGA)数据库中397例胃癌患者的临床病理资料,其中356例临床病理资料完整。397例患者中,男258例,女139例;中位年龄为67岁。将397例患者采用随机抽样法,按7∶3比例分为训练集278例和测试集119例。另从基因表达数据库(Gene Expression Omnibus,GEO)中下载包含20对胃癌及对应癌旁正常组织的miRNA测序数据集GSE93415,从癌组织和癌旁正常组织差异表达的miRNA中筛选出候选差异表达miRNA。基于训练集患者的信息,利用LASSO回归分析,将候选差异表达miRNA拟合成一个可以预测胃癌患者生存率的预后相关miRNA模型。对构建的预后相关miRNA模型的预测效能,分别在训练集和测试集中进行验证,以Log-Rank检验进行生存分析来验证模型的可靠性;以受试者操作特征曲线下面积(area under curve,AUC)分析该模型的预测效能。使用基因表达数据和pRRophetic包中的算法预测患者对化学治疗药物的敏感性。使用Calibration曲线验证恩诺图的准确性。使用一致性指数(consistency index,C-index)检测恩诺图和其他因素建模的一致性。使用决策曲线分析(decision curve analysis,DCA)推测候选因素对于临床决策的帮助。结果·①训练集与测试集患者的临床资料和总体生存率比较,差异均无统计学意义(均P>0.05)。②差异表达miRNA筛选结果:从GSE93415测序数据集中计算得到111个候选差异表达miRNA,其中20个在癌组织中上调,91个在癌组织中下调。对111个候选差异表达miRNA进行过滤后,得到59个候选差异表达miRNA。③构建预后相关miRNA模型:从59个候选miRNA中,筛选出5个与生存相关的miRNA,分别为let-7i-5p、let-7f-5p、miR-708-5p、miR-135b-5p、miR-100-5p,差异表达模式(癌组织对比癌旁组织)均为降低,差异表达倍数分别2.55、2.78、2.17、3.08、3.26倍。由5个与生存相关miRNA构建的预后表达方程为:风险分数=(-0.049×let-7i-5p表达量-0.033 2×let-7f-5p表达量+0.202 9×miR-708-5p表达量-0.088 9×miR-135b-5p表达量+0.016 3×miR-100-5p表达量)。④预后相关miRNA模型的验证:在训练集和测试集中,高风险组患者的总体生存率低于低风险组患者,差异均有统计学意义(均P<0.05)。在训练集中,预后相关miRNA模型的1年、3年、5年生存时间预测概率AUC值分别为0.640、0.763、0.853;在测试集中,则分别为0.631、0.735、0.750。⑤影响胃癌患者预后的相关因素分析:单因素分析结果显示年龄、肿瘤病理分期、T分期、N分期、M分期和预后相关miRNA模型评分是胃癌患者预后的相关因素(HR=1.017、1.633、1.353、1.346、2.652、15.874,95%CI为1.002~1.033、1.333~2.001、1.109~1.650、1.169~1.548、1.553~4.529、5.729~43.985,P<0.05)。多因素分析结果显示年龄、M分期和预后相关miRNA模型评分是胃癌患者预后的独立危险因素(HR=1.03、2.27、18.72,95%CI为1.01~1.05、1.09~4.70、5.96~58.77,P<0.05)。⑥预后相关miRNA模型与临床病理因素预测效能的比较:在356例临床资料完整的胃癌患者中,预后相关miRNA模型对胃癌患者5年生存时间预测的AUC值为0.818,高于年龄、性别、肿瘤病理分期、T分期、N分期、M分期的预测效能。⑦预后相关恩诺图的评估:Calibration验证曲线、C-index以及DCA分析均提示,胃癌患者从预后相关恩诺图中的获益程度高于年龄、性别和肿瘤病理分期。结论·由5个差异表达的miRNA构建了可用于预测胃癌患者生存的预后相关miRNA模型;该模型对胃癌患者的生存状态和预后具有一定的区分预测能力,可为胃癌患者的临床治疗提供参考。

关键词: 胃癌, LASSO回归模型, 微RNA, 预测模型, 受试者操作特征曲线

Abstract:

Objective·To construct a prognosis-associated microRNA (miRNA) prediction model in gastric cancer patients based on bioinformatics analysis and evaluate its application value.

Methods·The clinicopathological data of gastric cancer patients were downloaded from the Cancer Genome Atlas (TCGA). There were 258 males and 139 females with a median age of 67 years. Three hundred and fifty-six of the 397 patients had complete clinicopathological data. The 397 patients were allocated into training cohort consisting of 278 patients and validation cohort consisting of 119 patients using the random sampling method, with a ratio of 7∶3. A miRNA sequencing dataset GSE93415 containing 20 pairs of gastric cancer and corresponding adjacent normal tissue was downloaded from Gene Expression Omnibus database. The candidate miRNAs were selected from differentially expressed miRNAs in gastric cancer and adjacent tissue. A prognosis associated miRNA prediction model was constructed upon survival-associated miRNAs which were selected from candidate miRNAs through LASSO-Cox regression analysis. The performance of prognosis-associated miRNA prediction model was validated in the training cohort and validation cohort. The reliability of the model was evaluated by using Log-Rank test, and the accuracy of the model was evaluated by using the area under curve (AUC) of the receiver operating characteristic curves. Gene expression profiles and algorithms in the pRRophetic package were utilized to predict patients' sensitivity to chemotherapy drugs. Calibration curves were used to verify the accuracy of the nomogram. Consistency index (C-index) was used to check the consistency of the nomogram and other factors. Decision curve analysis (DCA) was employed to predict the contribution of candidate factors to clinical decision making.

Results·① There was no significant difference in the baseline and overall survival between the training cohort and validation cohort (P>0.05). ② There were 111 differentially expressed miRNAs calculated from GSE93415 dataset, of which 20 were up-regulated in tumor tissue while 91 were down-regulated. Fifty-nine miRNAs were selected as candidate miRNAs after filtration. ③ Among the 59 candidate miRNAs, 5 survival-associated miRNAs were selected, including let-7i-5p, let-7f-5p, miR-708-5p, miR-135b-5p and miR-100-5p. The differential expression patterns of gastric cancer to adjacent tissue were all down-regulation, with the fold change of 2.55, 2.78, 2.17, 3.08 and 3.26. Risk score = (-0.049×let-7i-5p expression level -0.033 2×let-7f-5p expression level +0.202 9×miR-708-5p expression level -0.088 9×miR-135b-5p expression level +0.016 3×miR-100-5p expression level). ④ In the training cohort and the validation cohort, the overall survival rate of patients in the high-risk group was lower, and the difference was statistically significant (P<0.05) . The AUC of the prognosis-associated miRNA model for 1-, 3- and 5-year survival prediction was 0.640, 0.763 and 0.853, and was 0.631, 0.735 and 0.750 in validation cohort. ⑤Results of univariate analysis showed that age, tumor pathological stage, T stage, N stage, M stage and prognosis-associated miRNA model score were related factors for prognosis of gastric cancer patients (HR=1.017, 1.633, 1.353, 1.346, 2.652, 15.874; 95%CI 1.002?1.033, 1.333?2.001, 1.109?1.650, 1.169?1.548, 1.553?4.529, 5.729?43.985; P<0.05). Results of multivariate analysis showed that age, M stage and prognosis-associated miRNA model score were independent risk factors for prognosis of gastric cancer patients (HR=1.03, 2.27, 18.72; 95%CI 1.01?1.05, 1.09?4.70, 5.96?58.77; P<0.05). ⑥The AUC of the prognosis-associated miRNA model for 5-year survival prediction was 0.818 in 356 gastric cancer patients with complete clinicopathological data, higher than that of age, gender, tumor pathological stage, T stage, N stage, M stage and merged clinical factors. ⑦The results of Calibration curves, C-index, and DCA all indicated that patients with gastric cancer may get more net benefits from the prognostic nomogram than age, gender and tumor pathological stage.

Conclusion·A prognosis-associated miRNA prediction model that can be used to predict the survival of gastric cancer patients is constructed based on 5 miRNAs, which has a certain predictive ability to distinguish the survival status and prognosis of gastric cancer patients and can provide reference for clinical treatment.

Key words: gastric cancer, LASSO regression model, microRNA, prediction model, receiver operating characteristic curve

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