epi-Aszonalenin B from Aspergillus novofumigatus inhibits NF-κB activity induced by ZFTA-RELA fusion protein that drives ependymoma
epi-Aszonalenin B from Aspergillus novofumigatus inhibits NF-κB activity induced by ZFTA-RELA fusion protein that drives ependymoma
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DOI：
10.1016/j.bbrc.2022.01.076
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发表时间：
2022-02-04
影响因子：
3.1
通讯作者：
Ohata，Shinya
中科院分区：
文献类型：
--
作者：
Ishikawa，Kazuki;Ishii，Masaki;Ohata，Shinya
核因子-κB (NF-κB) 信号传导是一种细胞内信号传导途径，参与炎症反应和各种癌症的发病机制，包括室管膜瘤，这是一种罕见且化疗耐药的神经胶质瘤。由核蛋白、锌指易位相关蛋白 (ZFTA) 和 RELA (ZFTA-RELA)（一种 NF-κB 信号效应转录因子）组成的融合蛋白的几种亚型会导致 NF-κB 信号通路过度激活，并导致幕上室管膜瘤 (ST-EPN-RELA)。由于 ZFTA-RELA 诱导的 NF-κB 活性抑制剂有望成为 ST-EPN-RELA 的治疗剂，我们建立了 NF-κB 响应性荧光素酶报告细胞系，该细胞系以强力霉素依赖性方式表达最常见的 ZFTA-RELA 亚型。使用该报告细胞系，我们筛选了真菌提取物中可抑制 ZFTA-RELA 表达诱导的 NF-κB 活性的化合物，并鉴定了 Aszonalenin（一种来自 Aspergillus novofumigatus 的生物碱）。我们还纯化了阿索那宁的类似物，即乙酰阿索那宁和表阿索那宁 B 和 C。在使用组成型表达荧光素酶的细胞进行的荧光素酶测定（反测定）中，乙酰阿索那宁和表阿索那宁 C 显示出对荧光素酶活性的非特异性抑制。 Aszonalenin 和 epi-aszonalenin B 通过比反测定中的荧光素酶活性更强烈地表达 ZFTA-RELA 来抑制 NF-κB 响应性荧光素酶活性。 ZFTA-RELA 表达对内源性 NF-κB 反应基因（例如 CCND1、ICAM1 和 L1CAM）的上调被 epi-aszonalenin B 抑制，但不被 aszonalenin 抑制。这项研究表明，epi-aszonalenin B 可能是 ST-EPN-RELA 治疗开发的先导化合物。
Nuclear factor-kappa B (NF-κB) signaling is an intracellular signaling pathway involved in inflammatory responses and the pathogenesis of various cancers, including ependymoma, which is a rare and chemotherapy-resistant glioma. Several isoforms of fusion proteins that consist of a nuclear protein, zinc finger translocation associated (ZFTA), and RELA (ZFTA-RELA), an NF-κB-signaling effector transcription factor, cause excessive activation of the NF-κB signaling pathway and result in supratentorial ependymomas (ST-EPN-RELA). As inhibitors of NF-κB activity induced by ZFTA-RELA are expected to be therapeutic agents for ST-EPN-RELA, we established an NF-κB responsive luciferase reporter cell line that expresses the most common isoform of ZFTA-RELA in a doxycycline-dependent manner. Using this reporter cell line, we screened fungus extracts for compounds that inhibit the NF-κB activity induced by ZFTA-RELA expression and identified aszonalenin, an alkaloid fromAspergillusnovofumigatus. We also purified analogs of aszonalenin, namely acetylaszonalenin andepi-aszonalenin B and C. In a luciferase assay using cells constitutively expressing luciferase (counter assay), acetylaszonalenin andepi-aszonalenin C showed non-specific inhibition of the luciferase activity. Aszonalenin andepi-aszonalenin B inhibited the NF-κB responsive luciferase activity by expressing ZFTA-RELA more strongly than the luciferase activity in the counter assay. The upregulation of endogenous NF-κB responsive genes, such asCCND1,ICAM1, andL1CAM, by ZFTA-RELA expression was inhibited byepi-aszonalenin B, but not by aszonalenin. This study suggests thatepi-aszonalenin B may be a lead compound for the therapeutic development of ST-EPN-RELA.