School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China; Shaanxi Engineering Research Center of Cardiovascular Drugs Screening & Analysis, Xi'an 710061, China.
Department of Neurosurgery, Shaanxi Provincial People's Hospital, Xi'an 710068, China.
Cell Signal. 2020 Jul;71:109598. doi: 10.1016/j.cellsig.2020.109598. Epub 2020 Mar 9.
Recent evidence has demonstrated that the signal transducer and activator of transcription 3 (STAT3) gene are abnormally active in glioblastoma multiforme (GBM), and this change is crucial for the tumor survival and chemotherapy-resistant. Certain preclinical pharmacology studies have focused on STAT3 phosphorylation and homodimerization, and have developed a class of salicylic acid-based inhibitors, which blocks the nuclear translocation-dependent canonical STAT3 signaling. In the present study, we demonstrated that the salicylic acid-based compound SH-4-54 was quite toxic to temozolomide (TMZ)-resistant GBM cells and could trigger apoptosis in these cells via enhancing mitochondrial translocation-dependent non-canonical STAT3 pathway. We demonstrated that incubation of TMZ-resistant GBM cells with SH-4-54 led to mitochondrial STAT3 (mitoSTAT3) activation and respiratory dysfunction reflected by disrupted (or suppressed) activities of oxidative phosphorylation complexes and oxygen consumption rate. Mechanistically, we proved that SH-4-54 could increase mitoSTAT3 transmembrane import via GRIM-19 and reinforce the association between mitoSTAT3 and mitochondrial transcription factor A (TFAM), indicating that SH-4-54 could facilitate the binding of mitoSTAT3 to mitochondria DNA (mtDNA) and negatively regulate mitochondrial-encoded genes, thus leading to the abnormal oxidation respiratory. Lastly, using GRIM-19 knockout cell line and subcutaneous xenotransplanted tumor model, we elaborately showed the enrichment of SH-4-54 in mitochondria by LC-MS/MS analysis. In conclusion, our data demonstrate thatthe salicylic acid-based compound SH-4-54 is quite effective in killing TMZ-resistant GBM cells and this cytotoxicity is attributed to mitoSTAT3 activation.
最近的证据表明，信号转导子和转录激活子 3（STAT3）基因在多形性胶质母细胞瘤（GBM）中异常活跃，这种变化对于肿瘤的存活和化疗耐药至关重要。某些临床前药理学研究集中在 STAT3 的磷酸化和同源二聚化上，并开发了一类以水杨酸为基础的抑制剂，该抑制剂阻断了核转位依赖的经典 STAT3 信号通路。在本研究中，我们证明了基于水杨酸的化合物 SH-4-54 对替莫唑胺（TMZ）耐药的 GBM 细胞具有很强的毒性，并通过增强线粒体转位依赖的非经典 STAT3 途径在这些细胞中引发细胞凋亡。我们证明，用 SH-4-54 孵育 TMZ 耐药的 GBM 细胞会导致线粒体 STAT3（mitoSTAT3）激活和呼吸功能障碍，表现为氧化磷酸化复合物活性和耗氧量的破坏（或抑制）。从机制上讲，我们证明 SH-4-54 可以通过 GRIM-19 增加 mitoSTAT3 的跨膜导入，并增强 mitoSTAT3 与线粒体转录因子 A（TFAM）之间的关联，表明 SH-4-54 可以促进 mitoSTAT3 与线粒体 DNA（mtDNA）的结合，并负调控线粒体编码基因，从而导致异常的氧化呼吸。最后，通过 GRIM-19 敲除细胞系和皮下异种移植肿瘤模型，我们通过 LC-MS/MS 分析详细显示了 SH-4-54 在线粒体中的富集。总之，我们的数据表明，基于水杨酸的化合物 SH-4-54 非常有效地杀死 TMZ 耐药的 GBM 细胞，这种细胞毒性归因于 mitoSTAT3 的激活。
