National Institut for Medical Research (INSERM), Cordeliers Research Center (UMRS 872), University of Pierre and Marie Curie and University of Paris Descartes, Paris, France.
Int J Oncol. 2013 Oct;43(4):1011-8. doi: 10.3892/ijo.2013.2021. Epub 2013 Jul 18.
In spite of the growing importance of endothelial protein C receptor/active protein C (EPCR/aPC) in tumor biology, their impact on immunological homeostasis remains largely unexplored. The objective of this study was to assess whether soluble plasma endothelial protein C receptor (sEPCR), which is a regulator of circulating aPC, is involved in innate immune response in cancer patients. In the Ovcar-3 ovarian cancer line, the role of aPC in secretion of cytokines was analyzed. In parallel, in 33 patients, with a diagnosis of ovarian epithelial cancer, sEPCR was quantified, blood immune cell phenotypes were determined by flow cytometry and plasma cytokines were evaluated using a protein array. Spearman's rank correlation coefficients (r) and coefficient significance was determined by a statistical hypothesis test (α=0.05). Our results show that i) aPC induced the secretion of several cytokines in Ovcar-3 cells; ii) 61% of patients exhibited a concentration of plasma sEPCR well above the baseline (normal plasma level, 100 ± 28 ng/ml); iii) comparing immune cell phenotypes in patients having a normal level of sEPCR with those having a high level of sEPCR, it was found that sEPCR levels were correlated with high intensity of cells expressing CD45ra, CD3, CD8, CD25 and low intensity of cells expressing CD56 (NK cells), CD294 (TH2 cells), IL-2, IL-10, IL-17a (TH17 cells), IL-21 (TH21 cells) and CD29 markers (r ≥ 0.60); and iv) high levels of sEPCR correlate with high levels of plasma bioactive proteins such as insulin-like growth factor-2 (IGFII), IL-13rα, macrophage inflammatory protein (MIP1α) and matrix metalloproteinase-7 (MMP-7) that have already been proposed as biomarkers for ovarian cancer and particularly those with poor prognosis. In conclusion, sEPCR produced by ovarian cancer cells, by modulating circulating aPC, influences the secretory behavior of tumor cells (cytokines and interleukins). Consequently, sEPCR in turn acts on the innate immune response by decreasing effector cells such as natural killer and T helper cells (TH2, TH17 and TH21).
尽管内皮蛋白 C 受体/活性蛋白 C（EPCR/aPC）在肿瘤生物学中的重要性日益增加，但它们对免疫稳态的影响在很大程度上仍未得到探索。本研究旨在评估循环中 aPC 的调节因子可溶性血浆内皮蛋白 C 受体（sEPCR）是否参与癌症患者的固有免疫反应。在 Ovcar-3 卵巢癌细胞系中，分析了 aPC 在细胞因子分泌中的作用。同时，在 33 名卵巢上皮癌患者中，定量了 sEPCR，通过流式细胞术测定了血液免疫细胞表型，并使用蛋白质阵列评估了血浆细胞因子。采用统计学假设检验（α=0.05）确定斯皮尔曼等级相关系数（r）和系数显著性。我们的结果表明：i）aPC 诱导 Ovcar-3 细胞分泌多种细胞因子；ii）61%的患者血浆 sEPCR 浓度明显高于基线（正常血浆水平为 100±28ng/ml）；iii）比较 sEPCR 水平正常和 sEPCR 水平高的患者的免疫细胞表型，发现 sEPCR 水平与表达 CD45ra、CD3、CD8、CD25 的细胞强度高和表达 CD56（NK 细胞）、CD294（TH2 细胞）、IL-2、IL-10、IL-17a（TH17 细胞）、IL-21（TH21 细胞）和 CD29 标志物的细胞强度低相关（r≥0.60）；iv）高水平的 sEPCR 与高水平的血浆生物活性蛋白相关，如胰岛素样生长因子-2（IGFII）、IL-13rα、巨噬细胞炎症蛋白（MIP1α）和基质金属蛋白酶-7（MMP-7），这些蛋白已被提议作为卵巢癌的生物标志物，特别是那些预后不良的标志物。总之，卵巢癌细胞产生的 sEPCR 通过调节循环中的 aPC 影响肿瘤细胞（细胞因子和白细胞介素）的分泌行为。因此，sEPCR 通过减少自然杀伤细胞和辅助性 T 细胞（TH2、TH17 和 TH21）等效应细胞，反过来作用于固有免疫反应。
