The current successful clinical use of agents promoting robust anti-tumor immunity in cancer patients warrants noting that radiation therapy (RT) induces immunogenic cell death (ICD) of tumor cells, which can generate anti-tumor immune responses. However, breast cancer stem cells (BCSCs) are resistant to RT and RT alone usually failed to mount an anti-tumor immune response. High aldehyde dehydrogenase activity (ALDH)bright and CD44+/CD24−/ESA+ cancer cells, previously shown to have BCSC properties, were isolated from human MDA-MB-231 and UACC-812 breast cancer cell lines by flow cytometer. Flow sorted BCSCs and non-BCSCs were further tested for their characteristic of stemness by mammosphere formation assay. Induction of ICD in BCSCs vs. non-BCSCs in response to different in vitro treatments was determined by assessing cell apoptosis and a panel of damage-associated molecular pattern molecules (DAMPs) by flow and enzyme-linked immunosorbent assay (ELISA). We found that ionizing radiation (IR) triggered a lower level of ICD in BCSCs than non-BCSCs. We then investigated the ability of disulfiram/cooper (DSF/Cu) which is known to preferentially induce cancer stem cells (CSCs) apoptosis to enhance IR-induced ICD of BCSCs. The results indicate that DSF/Cu induced a similar extent of IDC in both BCSCs and non-BCSCs and rendered IR-resistant BCSCs as sensitive as non-BCSCs to IR-induced ICD. IR and DSF/Cu induced ICD of BCSCs could be partly reversed by pre-treatment of BCSCs with a reactive oxygen species (ROS) scavenger and XBP1s inhibitors. DSF/Cu rendered IR-resistant BCSCs as sensitive as non-BCSCs to IR-induced ICD. Our data demonstrate the potential of IR and DSF/Cu to induce ICD in BCSCs and non-BCSCs leading to robust immune responses against not only differentiated/differentiating breast cancer cells but also BCSCs, the root cause of cancer formation, progression and metastasis.

中文翻译：

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通过改变抗酒精中毒药物双硫仑的用途，在抗辐射的乳腺癌干细胞中诱导免疫原性细胞死亡。

目前，在癌症患者中成功使用可促进强大的抗肿瘤免疫力的药物的临床应用证明，放射疗法（RT）会诱导肿瘤细胞的免疫原性细胞死亡（ICD），从而产生抗肿瘤免疫反应。但是，乳腺癌干细胞（BCSCs）对RT有抵抗力，仅RT通常无法引发抗肿瘤免疫反应。通过流式细胞仪从人MDA-MB-231和UACC-812乳腺癌细胞系中分离出高醛脱氢酶活性（ALDH）明亮的CD44 + / CD24- / ESA +癌细胞，这些细胞先前已证明具有BCSC特性。通过乳球形成试验进一步对分流的BCSC和非BCSC的茎干特性进行了测试。BCSCs中ICD的诱导与 通过评估细胞凋亡和通过流动和酶联免疫吸附测定（ELISA）评估一组与损伤相关的分子模式分子（DAMP）来确定对不同体外处理有反应的非BCSC。我们发现电离辐射（IR）触发的BCSC中的ICD水平低于非BCSC。然后，我们研究了二硫仑/库珀（DSF / Cu）的能力，已知它能优先诱导癌症干细胞（CSCs）凋亡，以增强IR诱导的BCSCs的ICD。结果表明，DSF / Cu在BCSC和非BCSC中诱导了相似程度的IDC，并使抗IR的BCSC对IR诱导的ICD的敏感性与非BCSC一样。IR和DSF / Cu诱导的BCSCs的ICD可以通过用活性氧（ROS）清除剂和XBP1s抑制剂预处理BCSCs来部分逆转。DSF / Cu使耐IR的BCSC与非BCSC一样对IR诱导的ICD敏感。我们的数据表明，IR和DSF / Cu可能在BCSC和非BCSC中诱导ICD，从而导致针对分化/分化的乳腺癌细胞以及BCSC的强大免疫反应，而BCSC是癌症形成，发展和转移的根本原因。