铁死亡相关lncRNA结肠癌预后风险模型的构建及临床应用

Construction and clinical application of colon cancer prognostic risk model of ferroptosis-related lncRNA

目的 基于肿瘤基因图谱计划(TCGA)数据库筛选铁死亡相关长链非编码RNA(lncRNA),建立结肠癌预后风险模型,并探讨其临床应用价值。方法 选取行结肠癌根治术的患者48例,收集术中切除的癌组织及对应的癌旁组织(距离癌组织边缘2~3 cm)。从TCGA数据库中收集结肠癌的转录组数据(结肠癌组织428例、正常结肠组织41例)及对应患者的临床资料。筛选结肠癌组织与正常结肠组织差异表达的铁死亡相关基因,并进行基因本体(GO)富集分析和京都基因与基因组数据库(KEGG)通路分析。筛选与结肠癌预后相关的铁死亡lncRNA,采用共识聚类分析对结肠癌患者进行分组,并比较总体生存率。采用LASSO-Cox回归分析建立预后风险模型。建立用于预测结肠癌患者总体生存率的列线图。采用细胞学实验分析关键lncRNAITGB1-DT在结肠癌中的生物学功能。结果 从TCGA数据库中筛选出72个差异表达的铁死亡相关基因,其中表达上调47个、表达下调25个,GO和KEGG通路分析结果显示这72个基因广泛参与了铁代谢和脂肪酸氧化等生物学过程。共筛选出20个结肠癌组织与正常组织有差异的铁死亡lncRNA。根据共识聚类分析结果分组的2个结肠癌集群之间总体生存率差异有统计学意义(P<0.001)。根据LASSO-Cox回归分析结果筛选出10个lncRNA,并构建预后风险模型,将428例结肠癌患者按7∶3的比例随机分为训练组和验证组。在训练组、验证组和总体结肠癌患者中,高风险组的总体生存率均显著低于低风险组(P<0.001)。结肠癌组织ITGB1-DT相对表达量显著高于癌旁组织(P<0.001)。细胞实验结果显示,ITGB1-DT可促进结肠癌细胞的增殖并抑制其铁死亡。结论 成功构建了基于铁死亡相关lncRNA的结肠癌预后风险模型,并建立了可用于判断结肠癌患者总体生存率的列线图。ITGB1-DT或可促进结肠癌的发展。

Objective Based on the Cancer Genome Atlas(TCGA) database,ferroptosis-related long noncoding RNA(lncRNA) were screened to establish a colon cancer prognostic risk model and to investigate its clinical application role. Methods A total of 48 patients who underwent radical resection of colon cancer were enrolled,and the intraoperatively resected cancer tissues and corresponding paracancerous tissues(2-3 cm from the edge of the cancer tissue)were collected. Transcriptome data of colon cancer(428 cases of colon cancer tissues and 41 cases of normal colon tissues)and clinical data of corresponding patients were collected from the TCGA database. Gene Ontology(GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis were performed for ferroptosis-related genes differentially expressed in colon cancer tissues and normal colon tissues.Screening for ferroptosis-related lncRNA with colon cancer prognosis,consensus clustering analysis was used to classify colon cancer patients and compare overall survival. A prognostic risk model was established by LASSO-Cox regression analysis. A nomogram for predicting overall survival in patients with colon cancer was developed.The biological function of the key lncRNA ITGB1-DT in colon cancer was analyzed by cytological experiments.Results Totally,72 differentially expressed ferroptosis-related genes were screened from the TCGA database,of which 47 cases were up-regulated,and 25 cases were down-regulated. GO enrichment analysis and KEGG pathway analysis showed that these genes were widely involved in biological processes,such as iron metabolism and fatty acid oxidation. A total of 20 ferroptosis-related lncRNA with difference between colon cancer tissues and normal colon tissues were screened. There was statistical significance in overall survival between the 2 colon cancer subgroups classified according to the results of consensus clustering analysis(P<0.001). According to the results of LASSO-Cox regression analysis,10 lncRNA were screened,and a prognostic risk model was constructed. A total of 428 patients with colon cancer were randomly classified into training group and validation group according to the ratio of 7∶3. In the training group,validation group and overall colon cancer patients,the overall survival rate of highrisk group was lower than that of low-risk group(P<0.001). The relative expression of ITGB1-DT in colon cancer tissues was higher than that in adjacent tissues(P<0.001). The results of cytological experiments showed that ITGB1-DT could promote the proliferation of colon cancer cells and inhibit its ferroptosis. Conclusions A colon cancer prognostic risk model based on ferroptosis-related lncRNA has been constructed successfully,and a nomogram that could be used to judge the overall survival rate of colon cancer has been established. ITGB1-DT may promote the development of colon cancer.