TPX2在肾透明细胞癌中的表达及其临床意义

Expression of TPX2 in kidney renal clear cell carcinoma and its clinical significance

目的分析Xklp2靶蛋白(TPX2)在肾透明细胞癌(KIRC)组织中的表达及其临床意义。方法收集2017年7月至2019年6月在蚌埠医学院第一附属医院泌尿外科收治的54例KIRC患者术后组织标本。利用免疫组织化学法检测TPX2在KIRC组织和癌旁组织的蛋白表达。利用TIMER数据库分析TPX2 mRNA在KIRC组织与正常组织的表达差异,验证免疫组织化学结果。使用UALCAN数据库和Kaplan-Meier plotter数据库对TPX2 mRNA表达与KIRC患者临床分期、分子亚型、淋巴结转移及预后的关系进行分析。通过STRING数据库进行蛋白互作网络构建获得TPX2相关蛋白,将相关蛋白对应的基因进行KEGG通路富集。利用TIMER数据库对TPX2的表达与免疫细胞浸润、免疫检查点的关系进行研究。结果免疫组织化学结果显示,癌组织中的TPX2蛋白的阳性表达率(48.15%,26/54)高于癌旁组织中阳性表达率(20.37%,11/54)(χ^(2)=9.25,P=0.002)。生物信息学分析结果显示,TPX2 mRNA表达水平在KIRC中显著上调[癌组织:1.89(1.49,2.42),正常组织:0.35(0.24,0.57),U=2 297.00,P<0.001];TPX2 mRNA表达与KIRC患者的临床分期(χ^(2)=34.36,P<0.001)、分子亚型(χ^(2)=30.15,P<0.001)及淋巴结转移状态(χ^(2)=27.21,P<0.001)均有关;TPX2高表达患者的5年生存率(53.80%)低于TPX2低表达患者(74.40%,χ^(2)=18.87,P<0.001);STRING数据库蛋白互作网络构建获得20个TPX2相关蛋白,其相关蛋白对应的基因富集于细胞周期;TPX2的表达与B细胞(r=0.30,P<0.001)、CD8+ T细胞(r=0.23,P<0.001)、CD4+ T细胞(r=0.18,P<0.001)、巨噬细胞(r=0.20,P<0.001)、中性粒细胞(r=0.31,P<0.001)、树突状细胞(r=0.39,P<0.001)浸润及其大部分生物标志物(均P<0.05)呈正相关,与免疫检查点PD-1(r=0.31,P<0.001)、CTLA-4(r=0.27,P<0.001)呈正相关,与PD-L1无相关性(r=0.07,P=0.146)。结论 TPX2在KIRC中高表达,并与患者不良预后密切相关,有望成为KIRC新的治疗靶点。

Objective To analyze the expression of targeting protein for Xklp2(TPX2)in kidney renal clear cell carcinoma(KIRC)and its clinical significance.Methods The postoperative tissue samples of 54 patients with KIRC admitted to the Department of Urology,the First Affiliated Hospital of Bengbu Medical College from July 2017 to June 2019 were collected.Immunohistochemistry was used to detect the protein expression of TPX2 in renal carcinoma and paracancerous tissues.The difference of TPX2 mRNA expression between KIRC tissues and normal tissues was analyzed by using the TIMER database,which verified the immunohistochemical results.The UALCAN database and the Kaplan-Meier plotter database were used to analyze the relationship between TPX2 mRNA expression and clinical stage,molecular subtypes,lymph node metastasis,and prognosis of patients with KIRC.The protein interaction network was constructed by STRING database to obtain TPX2-related proteins,and the genes corresponding to the related proteins were enriched for the KEGG pathway.The relationship between TPX2 expression and immune cell infiltration and the immune checkpoint was studied by using the TIMER database.Results Immunohistochemical results showed that the positive expression rate of TPX2 protein was 48.15%(26/54)in cancer tissues,which was higher than that in paracancerous tissues(20.37%,11/54)(χ^(2)=9.25,P=0.002).The results of bioinformatics analysis showed that TPX2 mRNA expression was significantly up-regulated in KIRC[cancer tissue:1.89(1.49,2.42),normal tissue:0.35(0.24,0.57),U=2297.00,P<0.001].The expression of TPX2 mRNA was related to the clinical stage(χ^(2)=34.36,P<0.001),molecular subtypes(χ^(2)=30.15,P<0.001),and lymph node metastasis status(χ^(2)=27.21,P<0.001)of KIRC patients.The 5-year survival rate(53.80%)in patients with high TPX2 expression was lower than that in patients with low TPX2 expression(74.40%,χ^(2)=18.87,P<0.001).STRING database protein interaction network construction obtained 20 TPX2-related proteins,and the genes corresponding to the related proteins were enriched in the cell cycle.The expression of TPX2 was positively correlated with B cells(r=0.30,P<0.001),CD8+T cells(r=0.23,P<0.001),CD4+T cells(r=0.18,P<0.001),macrophages(r=0.20,P<0.001),neutrophils(r=0.31,P<0.001),dendritic cells(r=0.39,P<0.001)infiltration and most of its biomarkers(all P<0.05).It was positively correlated with immune checkpoint PD-1(r=0.31,P<0.001)and CTLA-4(r=0.27,P<0.001),but not correlated with PD-L1(r=0.07,P=0.146).Conclusion TPX2 is highly expressed in KIRC and is closely associated with poor prognosis.It is expected to be a new therapeutic target for KIRC.