摘要
目的探究Ⅳ型胶原蛋白A4(collagen typeⅣalpha 4 chain,COL4A4)在肾透明细胞癌(clear cell renal cell carcinoma,ccRCC)中的表达及其与临床预后和免疫浸润的关系。方法利用癌症基因组图谱(The Cancer Genome Atlas,TCGA)和高通量基因表达(Gene Expression Omnibus,GEO)数据库分析COL4A4在ccRCC组织和癌旁正常组织中的表达差异。Western blot实验探究COL4A4在人ccRCC细胞株(786-O、OS-RC-2、Caki-1、SW839和RCC4)和人正常肾小管上皮细胞株HK-2中的表达差异。Kaplan-Meier曲线用于分析COL4A4表达与ccRCC患者的临床总生存期、无进展生存期和疾病特异性生存期的关系,并用受试者工作特征(receiver operating characteristic,ROC)曲线评价COL4A4对预测ccRCC发生的诊断价值。利用cBioPortal和COSMIC数据库分析COL4A4在ccRCC中的突变情况。采用STRING数据库构建COL4A4的蛋白互作(protein-protein interaction,PPI)网络。采用LinkedOmics数据库构建COL4A4的共表达基因网络。采用R软件进行基因本体(Gene Ontology,GO)功能富集分析和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)信号通路富集分析。基于TCGA数据的单样本基因集富集分析(single sample gene set enrichment analysis,ssGSEA)分析ccRCC中COL4A4表达与免疫浸润的相关性。结果TCGA和GEO数据库均显示,COL4A4在ccRCC组织中低表达(均P<0.05)。Western blot实验证实,COL4A4在ccRCC细胞株(786-O、OS-RC-2、Caki-1、SW839和RCC4)中均低表达(均P<0.05)。高表达COL4A4的患者具有更好的总生存期、无进展生存期和疾病特异性生存期(均P<0.01)。COL4A4是ccRCC患者的独立危险因素(HR=0.562,95%CI:0.352~0.898,P<0.05)。COSMIC数据库发现,COL4A4突变频率较低,在ccRCC中稳定表达。PPI网络显示,COL4A4与整合素家族密切相关。功能富集分析发现,COL4A4参与GTP酶活性调节、细胞核分裂、细胞周期转换、自噬和T细胞激活等生物学过程。信号通路富集分析提示,COL4A4主要参与沙门氏菌感染和细胞间的紧密连接。免疫浸润分析发现,COL4A4表达与调节性T细胞浸润呈负相关(r=-0.428,P<0.05)。结论COL4A4是ccRCC的潜在生物预后标志物和治疗靶点。
Objective To explore the expression of collagen typeⅣalpha 4 chain(COL4A4)in clear cell renal cell carcinoma(ccRCC)and its relationship with prognosis and immune infiltration.Methods The differential expression of COL4A4 in ccRCC and adjacent normal tissues was analyzed using The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)databases.Western blot was used to examine the difference of COL4A4A expression in different human ccRCC cell lines including 786-O,OS-RC-2,Caki-1,SW839,and RCC4,and human normal renal epithelial cell line HK-2.Kaplan-Meier method was used to analyze the correlation between the ex-pression of COL4A4 and the overall survival(OS),progression-free survival(PFS),and disease-specific survival of the patients.Receiver operating characteristic(ROC)curve was used to evaluate the diagnostic value of COL4A4 expression for ccRCC.The gene mutation land-scape of COL4A4 was analyzed by the cBioPortal and COSMIC databases.The protein-protein interaction(PPI)network of COL4A4 was conducted by STRING.The co-expression network of COL4A4 in ccRCC was analyzed by the LinkedOmics database and used to perform the Gene Ontology(GO)annotations and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis by R software.The single sample gene set enrichment analysis(ssGSEA)was used to analyze the correlation of COL4A4 expression and immune infiltra-tion in ccRCC based on TCGA database.Results The analysis in TCGA and GEO databases showed that COL4A4 expression was lower in ccRCC tissues(both P<0.05).Western blot confirmed the low expression of COL4A4 in all ccRCC cell lines(all P<0.05).Patients with high COL4A4 expression had better OS,PFS and disease-specific survival(all P<0.01).COL4A4 expression was an independent risk fac-tor for ccRCC(HR=0.562,95%CI:0.352-0.898,P<0.05).The analysis in the COSMIC database found that COL4A4 had a low mutation frequency and was stably expressed in ccRCC.The PPI network results showed that COL4A4 was closely related to the integrin family.The GO annotations showed that COL4A4 was mainly involved in the biological processes of the regulation of GTPase activity,nuclear division,the regulation of cell cycle phase transition,autophagy,and T cell activation.The KEGG pathway enrichment analysis showed that COL4A4 mainly participated in the salmonella infection and tight junction pathways.The ssGSEA results showed that COL4A4 expression was neg-atively associated with regulatory T cell infiltration(r=-0.428,P<0.05).Conclusions COL4A4 may serve as a novel prognostic marker and a potential therapeutic target for ccRCC.
作者
杨泽中
岳阳阳
姜云中
范晋海
王吉昌
张孟钊
Yang Zezhong;Yue Yangyang;Jiang Yunzhong;Fan Jinhai;Wang Jichang;Zhang Mengzhao(Department of Urology,First Affi liated Hospital,Medical School of Xi'an JiaoTong University,Xi'an 710061,China;Department of Vascular Surgery,First Affi liated Hospital,Medical School of Xi'an JiaoTong University,Xi'an 710061,China)
出处
《实用肿瘤杂志》
CAS
2024年第4期332-343,共12页
Journal of Practical Oncology
基金
国家自然科学基金项目(81572520,82103563)。
关键词
肾透明细胞癌
Ⅳ型胶原蛋白A4
预后
生物信息学
免疫细胞浸润
clear cell renal cell carcinoma
collagen typeⅣalpha 4 chain
prognosis
bioinformatics
immune cell infiltration
