Department of Urology, The First Affiliated Hospital of Nanchang University, Nanchang, China.
Jiangxi Institute of Urology, Nanchang, China.
Front Immunol. 2023 Sep 18;14:1253586. doi: 10.3389/fimmu.2023.1253586. eCollection 2023.
To identify the molecular subtypes and develop a scoring system for the tumor immune microenvironment (TIME) and prognostic features of bladder cancer (BLCA) based on the platinum-resistance-related (PRR) genes analysis while identifying P4HB as a potential therapeutic target.
In this study, we analyzed gene expression data and clinical information of 594 BLCA samples. We used unsupervised clustering to identify molecular subtypes based on the expression levels of PRR genes. Functional and pathway enrichment analyses were performed to understand the biological activities of these subtypes. We also assessed the TIME and developed a prognostic signature and scoring system. Moreover, we analyzed the efficacy of immune checkpoint inhibitors. Then we conducted real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) experiments to detect the expression level of prolyl 4-hydroxylase subunit beta (P4HB) in BLCA cell lines. Transfection of small interference ribonucleic acid (siRNA) was performed in 5637 and EJ cells to knock down P4HB, and the impact of P4HB on cellular functions was evaluated through wound-healing and transwell assays. Finally, siRNA transfection of P4HB was performed in the cisplatin-resistant T24 cell to assess its impact on the sensitivity of BLCA to platinum-based chemotherapy drugs.
In a cohort of 594 BLCA samples (TCGA-BLCA, n=406; GSE13507, n=188), 846 PRR-associated genes were identified by intersecting BLCA expression data from TCGA and GEO databases with the PRR genes from the HGSOC-Platinum database. Univariate Cox regression analysis revealed 264 PRR genes linked to BLCA prognosis. We identified three molecular subtypes (Cluster A-C) and the PRR scoring system based on PRR genes. Cluster C exhibited a better prognosis and lower immune cell infiltration compared to the other Clusters A and B. The high PRR score group was significantly associated with an immunosuppressive tumor microenvironment, poor clinical-pathological features, and a poor prognosis. Furthermore, the high PRR group showed higher expression of immune checkpoint molecules and a poorer response to immune checkpoint inhibitors than the low PRR group. The key PRR gene P4HB was highly expressed in BLCA cell lines, and cellular functional experiments indicate that P4HB may be an important factor influencing BLCA migration and invasion.
Our study demonstrates that the PRR signatures are significantly associated with clinical-pathological features, the TIME, and prognostic features. The key PRR gene, P4HB, s a biomarker for the individualized treatment of BLCA patients.
基于铂耐药相关（PRR）基因分析，鉴定膀胱癌（BLCA）的肿瘤免疫微环境（TIME）和预后特征的分子亚型，并建立评分系统，同时鉴定 P4HB 作为潜在的治疗靶点。
本研究分析了 594 例 BLCA 样本的基因表达数据和临床信息。我们使用无监督聚类方法根据 PRR 基因的表达水平来鉴定分子亚型。进行功能和通路富集分析以了解这些亚型的生物学活性。我们还评估了 TIME 并开发了预后特征和评分系统。此外，我们分析了免疫检查点抑制剂的疗效。然后我们进行了实时荧光定量聚合酶链反应（RT-qPCR）实验，以检测 BLCA 细胞系中脯氨酰 4-羟化酶亚基β（P4HB）的表达水平。在 5637 和 EJ 细胞中用小干扰核糖核酸（siRNA）转染以敲低 P4HB，并通过划痕愈合和 Transwell 测定评估 P4HB 对细胞功能的影响。最后，在 cisplatin 耐药的 T24 细胞中转染 P4HB 的 siRNA，以评估其对 BLCA 对铂类化疗药物敏感性的影响。
在 TCGA-BLCA（n=406）和 GSE13507（n=188）队列中，通过与 TCGA 和 GEO 数据库中的 BLCA 表达数据以及 HGSOC-Platinum 数据库中的 PRR 基因进行交集，鉴定出 846 个 PRR 相关基因。单因素 Cox 回归分析显示 264 个 PRR 基因与 BLCA 预后相关。我们基于 PRR 基因鉴定了三种分子亚型（Cluster A-C）和 PRR 评分系统。与其他 Cluster A 和 B 相比，Cluster C 表现出更好的预后和更低的免疫细胞浸润。高 PRR 评分组与免疫抑制性肿瘤微环境、不良临床病理特征和预后不良显著相关。此外，高 PRR 组中免疫检查点分子的表达较高，对免疫检查点抑制剂的反应较差。关键的 PRR 基因 P4HB 在 BLCA 细胞系中高表达，细胞功能实验表明 P4HB 可能是影响 BLCA 迁移和侵袭的重要因素。
本研究表明，PRR 特征与临床病理特征、TIME 和预后特征显著相关。关键的 PRR 基因 P4HB 是 BLCA 患者个体化治疗的生物标志物。
