METHODS: We compared the expression discrepancy of PTTG1 mRNA in BLCA and normal bladder tissue, using the BLCA transcriptomic datasets from GEO, ArrayExpress, TCGA, and GTEx. In-house immunohistochemical staining was implemented to determine the PTTG1 protein intensity. The prognostic value of PTTG1 was evaluated using the Kaplan-Meier Plotter. CRISPR screen data was utilized to estimate the effect PTTG1 interference has on BLCA cell lines. We predicted the abundance of the immune cells in the BLCA tumor microenvironment using the microenvironment cell populations-counter and ESTIMATE algorithms. Single-cell RNA sequencing data was applied to identify the major cell types in BLCA, and the dynamics of BLCA progression were revealed using pseudotime analysis. PTTG1 target genes were predicted by CistromeDB.
RESULTS: The elevated expression level of PTTG1 was confirmed in 1037 BLCA samples compared with 127 non-BLCA samples, with a standardized mean difference value of 1.04. Higher PTTG1 expression status exhibited a poorer BLCA prognosis. Moreover, the PTTG1 Chronos genetic effect scores were negative, indicating that PTTG1 silence may inhibit the proliferation and survival of BLCA cells. With PTTG1 mRNA expression level increasing, higher natural killer, cytotoxic lymphocyte, and monocyte lineage cell infiltration levels were observed. A total of four candidate targets containing CHEK2, OCIAD2, UBE2L3, and ZNF367 were determined ultimately.
CONCLUSIONS: PTTG1 mRNA over-expression may become a potential biomarker for BLCA prognosis. Additionally, PTTG1 may correlate with the BLCA tumor microenvironment and exert transcriptional activity by targeting CHEK2, OCIAD2, UBE2L3, and ZNF367 in BLCA tissue.
方法:我们比较了PTTG1mRNA在BLCA和正常膀胱组织中的表达差异,使用来自GEO的BLCA转录组数据集,ArrayExpress,TCGA,还有GTEx.实施内部免疫组织化学染色以确定PTTG1蛋白强度。使用Kaplan-Meier绘图仪评估PTTG1的预后价值。利用CRISPR筛选数据来估计PTTG1干扰对BLCA细胞系的影响。我们使用微环境细胞群体计数器和估计算法预测了BLCA肿瘤微环境中免疫细胞的丰度。单细胞RNA测序数据用于识别BLCA中的主要细胞类型,使用假时间分析揭示了BLCA进展的动力学。通过CistromeDB预测PTTG1靶基因。
结果:与127个非BLCA样本相比,在1037个BLCA样本中证实了PTTG1的表达水平升高,标准化平均差值为1.04。较高的PTTG1表达状态显示较差的BLCA预后。此外,PTTG1Chronos遗传效应评分为阴性,表明PTTG1沉默可抑制BLCA细胞的增殖和存活。随着PTTG1mRNA表达水平的升高,更高的自然杀手,细胞毒性淋巴细胞,观察单核细胞浸润水平。最终确定了包含CHEK2、OCIAD2、UBE2L3和ZNF367的总共四个候选靶标。
结论:PTTG1mRNA过表达可能成为BLCA预后的潜在生物标志物。此外,PTTG1可能与BLCA肿瘤微环境相关,并通过靶向BLCA组织中的CHEK2,OCIAD2,UBE2L3和ZNF367发挥转录活性。