Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Branch of National Clinical Research Center for Laboratory Medicine, Nanjing, China.
Cancer Med. 2024 Feb;13(4):e7055. doi: 10.1002/cam4.7055.
CD2-associated protein (CD2AP) is a podocyte-associated gene and its reduced expression is associated with the development of proteinuria and glomerulosclerosis. However, few studies have focused on the correlation between the expression and prognosis of CD2AP in renal clear cell carcinoma (ccRCC). Therefore, we aimed to assess the regulation of CD2AP expression and prognostic value in ccRCC.
Multiple databases were employed to examine the expression of CD2AP in ccRCC. RT-qPCR, Western Blot and immunohistochemistry were used to validate CD2AP expression in different cell lines and tissue samples. Kaplan-Meier analysis and ROC curve analysis were performed on the predictive prognostic performance of CD2AP. COX regression was used to construct CD2AP-related prognostic models. The TIMER and TISIDB databases were used to analyze the correlation of tumor-infiltrating immune cells with gene expression, mutations, somatic copy number variation, and immune molecules. Mass spectrometry was used to detect methylation status of the promoter CpG site of CD2AP in multiple cells.
We found that CD2AP expression was downregulated in ccRCC and its lower expression level was correlation with worse patient prognosis, higher tumor stage and grade and distant metastasis through analysis of databases, ccRCC cell lines and clinical tissue samples. Moreover, database and mass spectrometry techniques identified and validated cg12968598 hypermethylation as one of the key reasons for the downregulation of CD2AP expression. CD2AP expression was also associated with macrophage and neutrophil infiltration.
Taken together, our results suggest that CD2AP can be used as a diagnostic and prognostic biomarker in ccRCC patients and that DNA hypermethylation plays an important role in reducing CD2AP expression.
CD2 相关蛋白（CD2AP）是一种足细胞相关基因，其表达降低与蛋白尿和肾小球硬化的发展有关。然而，很少有研究关注 CD2AP 在肾透明细胞癌（ccRCC）中的表达与预后的相关性。因此，我们旨在评估 CD2AP 在 ccRCC 中的表达调控及其预后价值。
利用多个数据库检测 CD2AP 在 ccRCC 中的表达。采用 RT-qPCR、Western Blot 和免疫组织化学方法验证不同细胞系和组织样本中 CD2AP 的表达。对 CD2AP 的预测预后性能进行 Kaplan-Meier 分析和 ROC 曲线分析。COX 回归用于构建 CD2AP 相关的预后模型。利用 TIMER 和 TISIDB 数据库分析肿瘤浸润免疫细胞与基因表达、突变、体细胞拷贝数变异和免疫分子的相关性。利用质谱技术检测多个细胞中 CD2AP 启动子 CpG 位点的甲基化状态。
通过数据库、ccRCC 细胞系和临床组织样本分析，我们发现 CD2AP 在 ccRCC 中表达下调，其低表达水平与患者预后不良、肿瘤分期和分级较高以及远处转移相关。此外，数据库和质谱技术鉴定并验证了 cg12968598 超甲基化是 CD2AP 表达下调的关键原因之一。CD2AP 表达还与巨噬细胞和中性粒细胞浸润相关。
综上所述，我们的研究结果表明，CD2AP 可作为 ccRCC 患者的诊断和预后生物标志物，DNA 超甲基化在降低 CD2AP 表达中起重要作用。
