Department of Pancreatic Surgery, Shanghai Cancer Center, Fudan University, 270 DongAn Road, Xuhui, Shanghai, 200032, People's Republic of China.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
BMC Gastroenterol. 2023 Apr 6;23(1):113. doi: 10.1186/s12876-023-02748-w.
Pancreatic adenocarcinoma (PAAD) remains a lethal malignancy making the detection of novel prognostic biomarkers urgent. Limited studies have investigated the predictive capability of immune checkpoints in PAAD.
Gene expression data and correlative clinical information of PAAD cohort were obtained from public databases, including TCGA, ICGC, GTEX and GEO databases. Risk factors were screened and used to establish a risk score model through LASSO and Cox regression analyses. The prognostic ability of the risk score model was demonstrated. The association between risk score with immune cells infiltration, immune checkpoint genes expression, immunogenic cell death, somatic mutations and signaling pathways enrichment were analysed. scRNA-seq data were collected to confirmed the immune checkpoints expression in PAAD samples. The prognosis prediction ability of OX40/TNFRSF4 was identified. The mRNA and protein expression of OX40 in our clinical specimens were examined by RT-PCR and IHC method and its prognosis ability was verified.
First of all, the difference of immune microenvironment between pancreatic cancer and adjacent tissues was shown. A risk score system based on three immune checkpoints (OX40, TNFSF14 and KIR3DL1) was established. The risk score model was an independent prognostic factor and performed well regarding overall survival (OS) predictions among PAAD patients. A nomogram was established to facilitate the risk model application in clinical prognosis. Immune cells including naive B cells, CD8 T cells and Tregs were negatively correlated with the risk score. The risk score was associated with expression of immune checkpoint genes, immunogenic cell death related genes and somatic mutations. Glycolysis processes, IL-2-STAT5, IL-6-STAT3, and mTORC1 signaling pathways were enriched in the high-risk score group. Furthermore, scRNA-seq data confirmed that TNFRSF4, TNFSF14 and KIR3DL1 were expressed on immune cells in PAAD samples. We then identified OX40 as an independent prognosis-related gene, and a higher OX40 expression was associated with increased survival rate and immune environment change. In 84 PAAD clinical specimens collected from our center, we confirmed that higher OX40 mRNA expression levels were related to a good prognosis. The protein expression of OX40 on tumor-infiltrating immune cells (TIICs), endothelial cells and tumor cells was verified in PAAD tissues by immunohistochemistry (IHC) method.
Overall, our findings strongly suggested that the three-immune checkpoints score system might be useful in the prognosis and design of personalized treatments for PAAD patients. Finally, we identified OX40 as an independent potential biomarker for PAAD prognosis prediction.
胰腺导管腺癌（PAAD）仍然是一种致命的恶性肿瘤，因此迫切需要检测新的预后生物标志物。有限的研究调查了免疫检查点在 PAAD 中的预测能力。
从公共数据库（TCGA、ICGC、GTEx 和 GEO 数据库）中获取 PAAD 队列的基因表达数据和相关临床信息。通过 LASSO 和 Cox 回归分析筛选风险因素，并建立风险评分模型。验证风险评分模型的预后能力。分析风险评分与免疫细胞浸润、免疫检查点基因表达、免疫原性细胞死亡、体细胞突变和信号通路富集的关系。收集 scRNA-seq 数据以确认 PAAD 样本中的免疫检查点表达。鉴定 OX40/TNFRSF4 的预后预测能力。通过 RT-PCR 和免疫组化方法检测我们临床标本中 OX40 的 mRNA 和蛋白表达，并验证其预后能力。
首先，显示了胰腺癌和相邻组织之间免疫微环境的差异。建立了基于三个免疫检查点（OX40、TNFSF14 和 KIR3DL1）的风险评分系统。该风险评分模型是 PAAD 患者总体生存（OS）预测的独立预后因素，表现良好。建立了列线图以促进风险模型在临床预后中的应用。幼稚 B 细胞、CD8 T 细胞和 Tregs 等免疫细胞与风险评分呈负相关。风险评分与免疫检查点基因、免疫原性细胞死亡相关基因和体细胞突变相关。在高风险评分组中富集了糖酵解过程、IL-2-STAT5、IL-6-STAT3 和 mTORC1 信号通路。此外，scRNA-seq 数据证实 TNFRSF4、TNFSF14 和 KIR3DL1 在 PAAD 样本中的免疫细胞上表达。我们随后确定 OX40 是一个独立的预后相关基因，较高的 OX40 表达与生存率提高和免疫环境改变有关。在我们中心收集的 84 例 PAAD 临床标本中，我们证实较高的 OX40 mRNA 表达水平与良好的预后相关。通过免疫组化（IHC）方法在 PAAD 组织中验证了肿瘤浸润免疫细胞（TIIC）、内皮细胞和肿瘤细胞上 OX40 的蛋白表达。
总的来说，我们的研究结果强烈表明，三个免疫检查点评分系统可能有助于 PAAD 患者的预后和个性化治疗方案的设计。最后，我们确定 OX40 是 PAAD 预后预测的一个独立的潜在生物标志物。
