The therapeutic strategy of drug re-positioning to induce autophagic cell death in brain malignancy
The therapeutic strategy of drug re-positioning to induce autophagic cell death in brain malignancy
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DOI：
10.1007/s10495-020-01617-1
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发表时间：
2020-06
期刊：
影响因子：
7.2
通讯作者：
G. J. Yoshida
中科院分区：
文献类型：
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作者：
G. J. Yoshida
我饶有兴趣地阅读了Omoruyi et al.[1]的研究，作者发现抗精神病药物吩噻嗪（DS00329）的衍生物在自噬的同时诱导细胞凋亡。DS00329治疗导致多形胶质母细胞瘤（GBM）细胞在细胞周期的G1期阻滞，部分依赖于细胞周期蛋白依赖性激酶（CDK）抑制剂p21。裂解型caspase 3/9经PTZ合成衍生物处理后激活多聚（adp -核糖）聚合酶（PARP），导致凋亡细胞死亡[1]。一些研究已经揭示了药物重新定位治疗脑肿瘤的疗效[1-4]。例如，已经确定针对GBM自噬的新治疗策略侧重于突触中的内源性神经递质以及常规药物[2]。事实上，Dolma等人使用患者来源的GBM神经干细胞（GNS）进行了多达680种神经化学化合物的化学筛选，并随后鉴定了多巴胺受体D4 （DRD4）拮抗剂作为GNS增殖的选择性抑制剂和正常神经干细胞分化和LC-3点形成的诱导剂[2]。体内实验表明，DRD4拮抗剂与替莫唑胺（temozolomide， TMZ）协同作用，激活自噬，抑制GNS增殖。DRD4拮抗剂抑制血小板衍生生长因子（PDGF）受体-β/ERK1/2 （p44/p42-MAPK）信号轴，破坏GBM癌干细胞的自噬通量，通过caspase-3介导的PARP[2]切割导致细胞凋亡。此外，嘌呤能受体P2Y12抑制剂噻氯匹定是一种广泛用于预防短暂性脑缺血发作（TIA）和中风的抗凝药物，可增加低级别胶质瘤和高级别星形细胞瘤细胞内cAMP水平，并促进自噬通量[3]。值得注意的是，三环类抗抑郁药如丙咪嗪与噻氯匹定协同作用，通过进一步增加细胞内cAMP浓度来促进胶质瘤细胞的自噬。在图6d中，作者展示了DS00329[1]处理对LC-3转化有时间依赖性的促进作用。然而，考虑到这种抗精神病药物的衍生物可能会损害自噬通量，他们应该对选择性自噬的主要底物p62/SQSTM1进行Western blot分析。p62/SQSTM1下调表明atg5 /7依赖性自噬确实被激活，而p62/SQSTM1上调表明自噬通量受损（即自噬体形成受到抑制）。在图6a中，作者还对酸性囊泡细胞器（AVO）进行了染色，得出OS00329通过激活自噬[1]增加了酸性囊泡细胞器的数量。然而，仅仅通过AVO染色很难区分自噬溶酶体（自噬体和溶酶体的融合体）和完整的溶酶体。Omoruyi等人[1]的报道表明，DS00329存在时，凋亡细胞死亡和自噬通量都被激活，与此相反，人们普遍认为，自噬-溶酶体通路的破坏诱导凋亡主要是由过度内质网（ER）应激[4]介导的。TMZ是一种烷基化剂，它在DNA链中诱导o6 -甲基鸟嘌呤的形成，在随后的DNA复制周期中诱导与胸腺嘧啶的错配对。在对氯喹（CQ）处理的反应中，TMZ引起的基因组应激与内质网累积应激协同诱导细胞凋亡[4]。考虑到两者同时激活…
I read with great interest the work of Omoruyi et al.[1], in which the authors showed that a derivative of the antipsychotic drug phenothiazine (DS00329) induced apoptosis in parallel with autophagy. DS00329 treatment led to glioblastoma multiforme (GBM) cells arresting in the G1 phase of the cell cycle partly depending on the cyclin-dependent kinase (CDK) inhibitor p21. Cleaved caspase 3/9 activated poly (ADP-ribose) polymerase (PARP) after the treatment with a PTZ synthesized derivative, which led to the promotion of apoptotic cell death [1]. Several investigations have revealed the therapeutic effectiveness of drug re-positioning for the treatment of brain tumors [1–4]. For instance, it has been identified that the novel therapeutic strategy targeting autophagy in GBM focuses on endogenous neurotransmitters in the synapse as well as conventional drugs [2]. Indeed, Dolma et al. performed the chemical screening of as many as 680 neurochemical compounds using patient-derived GBM neural stem cells (GNS) and the subsequent identification of dopamine receptor D4 (DRD4) antagonists as selective inhibitors of GNS proliferation and inducers of normal neural stem cell differentiation and LC-3 puncta formation [2]. In vivo experiments revealed that a DRD4 antagonist acted synergistically with temozolomide (TMZ) to activate autophagy and inhibited GNS proliferation. DRD4 antagonists suppressed the platelet-derived growth factor (PDGF) receptor-β/ERK1/2 (p44/p42-MAPK) signaling axis and disrupted autophagy flux in GBM cancer stem cells, leading to apoptosis via caspase-3-mediated cleavage of PARP [2]. Furthermore, the purinergic receptor P2Y12 inhibitor ticlopidine, which is an anticoagulant drug widely used to prevent transient ischemic attacks (TIA) and stroke, increased intracellular cAMP levels in low-grade glioma and high-grade astrocytoma and promotes autophagic flux [3]. Notably, tricyclic antidepressants such as imipramine acted synergistically with ticlopidine to promote autophagy in glioma cells by further increasing intracellular cAMP concentrations. In Fig. 6d, the authors showed that LC-3 conversion was promoted in time-dependent manner by the treatment with DS00329 [1]. However, considering the possibility that autophagic flux can be impaired by this derivative of the antipsychotic drug, they should perform Western blot analysis of p62/SQSTM1, the major substrate of selective autophagy. Whereas downregulation of p62/SQSTM1 indicates that Atg5/7-dependent autophagy was really activated, upregulation of p62/SQSTM1 suggests the impaired autophagic flux (ie the inhibition of the autophagosome formation). In Fig. 6a, the authors also stained acidic vesicular organelles (AVO) to conclude that OS00329 increased the number of AVO with the activated autophagy [1]. However, it seems to be quite difficult to distinguish autophagolysosomes (the fusion of autophagosomes and lysosomes) from intact lysosomes just by staining AVO. In contrast to the report by Omoruyi et al.[1], which demonstrated that both apoptotic cell death and autophagic flux are activated in the presence of DS00329, it is widely accepted that disruption of the autophagy-lysosome pathway induces apoptosis mainly mediated by excessive endoplasmic reticulum (ER) stress [4]. TMZ is an alkylating agent which induces the formation of O6-methylguanine in DNA strands, which in turn induces mismatch pair with thymine during the following cycle of DNA replication. Genome stress due to TMZ synergistically induces apoptosis in collaboration with accumulated ER stress in response to chloroquine (CQ) treatment [4]. Given the simultaneous activation of both …