BACKGROUND The epigenome plays a key role in cancer heterogeneity and drug resistance. Hence, a number of epigenetic inhibitors have been developed and tested in cancers. The major focus of most studies so far has been on the cytotoxic effect of these compounds, and only few have investigated the ability to revert the resistant phenotype in cancer cells. Hence, there is a need for a systematic methodology to unravel the mechanisms behind epigenetic sensitization. RESULTS We have developed a high-throughput protocol to screen non-simultaneous drug combinations, and used it to investigate the reprogramming potential of epigenetic inhibitors. We demonstrated the effectiveness of our protocol by screening 60 epigenetic compounds on diffuse large B-cell lymphoma (DLBCL) cells. We identified several histone deacetylase (HDAC) and histone methyltransferase (HMT) inhibitors that acted synergistically with doxorubicin and rituximab. These two classes of epigenetic inhibitors achieved sensitization by disrupting DNA repair, cell cycle, and apoptotic signaling. The data used to perform these analyses are easily browsable through our Results Explorer. Additionally, we showed that these inhibitors achieve sensitization at lower doses than those required to induce cytotoxicity. CONCLUSIONS Our drug screening approach provides a systematic framework to test non-simultaneous drug combinations. This methodology identified HDAC and HMT inhibitors as successful sensitizing compounds in treatment-resistant DLBCL. Further investigation into the mechanisms behind successful epigenetic sensitization highlighted DNA repair, cell cycle, and apoptosis as the most dysregulated pathways. Altogether, our method adds supporting evidence in the use of epigenetic inhibitors as sensitizing agents in clinical settings.

中文翻译：

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药物筛选方法结合了表观遗传学敏化和免疫化学疗法治疗癌症。

背景技术表观基因组在癌症异质性和耐药性中起关键作用。因此，已经开发出多种表观遗传抑制剂并在癌症中进行了测试。迄今为止，大多数研究的主要重点是这些化合物的细胞毒性作用，只有极少数研究了恢复癌细胞抗性表型的能力。因此，需要一种系统的方法来阐明表观遗传致敏背后的机制。结果我们开发了一种高通量的方案来筛选非同时药物组合，并用于研究表观遗传抑制剂的重编程潜力。我们通过在弥漫性大B细胞淋巴瘤（DLBCL）细胞上筛选60种表观遗传化合物证明了我们方案的有效性。我们确定了几种与阿霉素和利妥昔单抗协同作用的组蛋白脱乙酰基酶（HDAC）和组蛋白甲基转移酶（HMT）抑制剂。这两类表观遗传抑制剂通过破坏DNA修复，细胞周期和凋亡信号转导而实现了致敏作用。通过我们的结果浏览器可以轻松浏览用于执行这些分析的数据。另外，我们显示这些抑制剂以比诱导细胞毒性所需的剂量低的剂量实现致敏作用。结论我们的药物筛选方法为测试非同时药物组合提供了系统的框架。该方法确定了HDAC和HMT抑制剂是在耐治疗性DLBCL中成功的致敏化合物。对成功的表观遗传致敏机制的进一步研究强调了DNA修复，细胞周期，和凋亡是最失调的途径。总之，我们的方法为在临床环境中使用表观遗传抑制剂作为敏化剂增加了支持证据。