Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Kent Ridge, Singapore, 119228, Singapore.
Stem Cell Rev Rep. 2017 Dec;13(6):801-816. doi: 10.1007/s12015-017-9767-8.
Strategies that induce immunogenic cell death (ICD) or downregulate CD47 or PD-L1 expression have resulted in successful therapeutic options for tumor eradication. Several groups have reported the tumoricidal effects of human umbilical cord Wharton's jelly stem cells (hWJSCs) or its conditioned medium (hWJSC-CM) on certain cancers but the mechanisms have not been elucidated. Since hWJSCs possess immunomodulatory properties, we investigated whether one of the tumoricidal mechanisms was via ICD. We first concentrated hWJSC-CM into a 3 kDa concentrate and then exposed various concentrations of this concentrate to human lymphoma cells to find out which concentration had the greatest tumoricidal effect. We observed that a 500 µg/ml concentration of the concentrate had the greatest inhibitory effect. Thereafter, lymphoma cells were exposed to 500 µg/ml of the hWJSC-CM-3 kDa concentrate and then subjected to analysis for morphology, viability, apoptosis, mitochondrial and endoplasmic reticulum stress, danger associated molecular patterns (DAMP), extracellular HMGB1, CD47 and PD-L1 markers and dendritic cell phenotype. Extensive nuclear chromatin and mitochondrial changes with significantly decreased cell viability and increased apoptosis were observed in the treated lymphoma cells compared to controls. There were also significant increases in the release of DAMPs, extracellular HMGB1 and dendritic cell activation and maturation, with concomitant decreases in CD47 and PD-L1 expression in the treated cells compared to controls. In other ongoing studies we observed increased expression of specific tumor-suppressor molecules (miRNA-146a and miRNA-126, MCP-1, IL-6, IL-8 and IL-12) in hWJSC-CM suggesting that one or more of these molecules may be the modulators of the ICD.
诱导免疫原性细胞死亡 (ICD) 或下调 CD47 或 PD-L1 表达的策略已为肿瘤消除带来了成功的治疗选择。有几个研究小组报告了人脐带华通氏胶干细胞 (hWJSCs) 或其条件培养基 (hWJSC-CM) 对某些癌症的杀伤作用，但这些机制尚未阐明。由于 hWJSCs 具有免疫调节特性，我们研究了其杀伤肿瘤机制之一是否是通过 ICD。我们首先将 hWJSC-CM 浓缩成 3 kDa 的浓缩物，然后将不同浓度的浓缩物暴露于人淋巴瘤细胞中，以找出具有最大杀伤肿瘤效果的浓度。我们观察到 500 µg/ml 的浓度具有最大的抑制作用。此后，将淋巴瘤细胞暴露于 500 µg/ml 的 hWJSC-CM-3 kDa 浓缩物中，然后进行形态学、活力、凋亡、线粒体和内质网应激、危险相关分子模式 (DAMP)、细胞外 HMGB1、CD47 和 PD-L1 标志物以及树突状细胞表型分析。与对照组相比，处理后的淋巴瘤细胞中观察到广泛的核染色质和线粒体变化，细胞活力显著降低，凋亡增加。处理组细胞中 DAMPs、细胞外 HMGB1 和树突状细胞激活和成熟的释放也显著增加，而与对照组相比，CD47 和 PD-L1 的表达降低。在其他正在进行的研究中，我们观察到 hWJSC-CM 中特定肿瘤抑制分子 (miRNA-146a 和 miRNA-126、MCP-1、IL-6、IL-8 和 IL-12) 的表达增加，这表明这些分子中的一个或多个可能是 ICD 的调节剂。
