Department of Urology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
J Transl Med. 2022 May 10;20(1):202. doi: 10.1186/s12967-022-03398-4.
Prostatic cancer (PCa) is one of the most common malignant tumors in men worldwide. Emerging evidence indicates significance of hypoxia and immunity in PCa invasion and metastasis. This study aimed to develop a hypoxia- and immune-related gene risk signature and explore the molecular mechanisms to formulate a better prognostic tool for PCa patients.
The hypoxia and immune scores of all PCa patients in The Cancer Genome Atlas (TCGA) dataset were calculated via the maximally selected rank statistics method and the ESTIMATE algorithm. From common genes identified overlapping hypoxia- and immune-related differentially expressed genes (DE-HRGs and DE-IRGs), a hypoxia- and immune-related gene risk signature was developed utilizing univariate and multivariate Cox regression analyses, and validated in the Memorial Sloan Kettering Cancer Centre (MSKCC) database. The immune cell infiltration level of PCa samples were evaluated with ssGSEA algorithm. Differential expression of prognostic genes was evidenced by immunohistochemistry and western blot (WB) in paired PCa samples. Expression levels of these genes and their variations under regular and hypoxic conditions were examined in cell lines. The functional effects of the prognostic gene on PCa cells were examined by wound healing and transwell assays.
A hypoxia- and immune-related gene risk signature constructed by ISG15 and ZFP36 displays significant predictive potency, with higher risk score representing worse survival. A nomogram based on independent prognostic factors including the risk score and Gleason score exhibited excellent clinical value in the survival prediction of PCa. Infiltration levels of eosinophils, neutrophils, Tcm, Tem, TFH, Th1 cells, and Th17 cells were significantly lower in the high-risk group. Conversely, aDC, pDC, T helper cells, and Tregs were significantly higher. Additionally, the two prognostic genes were closely correlated with the tumor-infiltrating immune cell subset in PCa progression. RT-qPCR and WB presented higher and lower expression of ISG15 and ZFP36 in PCa cells, respectively. They were correspondingly increased and decreased in PCa cells under hypoxic conditions. Wound healing and transwell assays showed that over-expression of ISG15 promoted the migration and invasion of PCa cells.
Our study identified a novel hypoxia- and immune-related gene signature, contributing a new perspective to the treatment of PCa.
前列腺癌（PCa）是全球男性中最常见的恶性肿瘤之一。新出现的证据表明，缺氧和免疫在 PCa 的侵袭和转移中具有重要意义。本研究旨在开发一个与缺氧和免疫相关的基因风险特征，并探讨其分子机制，为 PCa 患者制定更好的预后工具。
通过最大选择秩统计方法和 ESTIMATE 算法计算 TCGA 数据集所有 PCa 患者的缺氧和免疫评分。从共同的基因中鉴定重叠的与缺氧和免疫相关的差异表达基因（DE-HRGs 和 DE-IRGs），利用单变量和多变量 Cox 回归分析开发一个与缺氧和免疫相关的基因风险特征，并在 Memorial Sloan Kettering Cancer Centre（MSKCC）数据库中进行验证。利用 ssGSEA 算法评估 PCa 样本的免疫细胞浸润水平。通过免疫组织化学和 Western blot（WB）在配对的 PCa 样本中证实预后基因的差异表达。在细胞系中检查这些基因的表达水平及其在常氧和缺氧条件下的变化。通过划痕愈合和 Transwell 测定检查预后基因对 PCa 细胞的功能影响。
由 ISG15 和 ZFP36 构建的与缺氧和免疫相关的基因风险特征具有显著的预测能力，风险评分越高代表预后越差。基于独立预后因素（包括风险评分和 Gleason 评分）的列线图在 PCa 患者的生存预测中具有优异的临床价值。在高危组中，嗜酸性粒细胞、中性粒细胞、Tcm、Tem、TFH、Th1 细胞和 Th17 细胞的浸润水平显著降低。相反，aDC、pDC、T 辅助细胞和 Tregs 则显著升高。此外，这两个预后基因与 PCa 进展中的肿瘤浸润免疫细胞亚群密切相关。RT-qPCR 和 WB 显示，PCa 细胞中 ISG15 和 ZFP36 的表达水平更高和更低。在缺氧条件下，PCa 细胞中的表达水平相应增加和减少。划痕愈合和 Transwell 测定表明，ISG15 的过表达促进了 PCa 细胞的迁移和侵袭。
本研究鉴定了一个新的与缺氧和免疫相关的基因特征，为 PCa 的治疗提供了新的视角。
