Homoharringtonine promotes BCR-ABL degradation through the p62-mediated autophagy pathway
Homoharringtonine promotes BCR-ABL degradation through the p62-mediated autophagy pathway
复制标题
高三尖杉酯碱通过 p62 介导的自噬途径促进 BCR-ABL 降解
DOI：
10.3892/or.2019.7412
复制
发表时间：
2020-01-01
期刊：
影响因子：
4.2
通讯作者：
Tong, Yin
中科院分区：
文献类型：
--
作者：
Li, Su;Bo, Zhilei;Tong, Yin
对酪氨酸激酶抑制剂（TKI）的耐药性是目前慢性粒细胞白血病（CML）患者的一个临床问题。高三尖杉酯碱（HHT）是一种获批用于治疗对TKI和其他疗法耐药的慢性期或加速期CML成人患者的药物;然而，其潜在机制仍不清楚。MTS法和Western blotting法显示HHT诱导伊马替尼耐药的K562 G细胞凋亡，BCR-ABL蛋白表达减少。CHX追踪实验显示HHT诱导BCR-ABL蛋白降解，自噬溶酶体抑制剂Baf-A1和CQ可逆转HHT诱导BCR-ABL蛋白降解。接下来，HHT处理证实了K562 G细胞中自噬的诱导，并且沉默关键的自噬蛋白ATG 5和Beclin-1抑制了BCR-ABL蛋白的降解和细胞毒性。此外，自噬受体p62/SQSTM 1（p62）参与了HHT诱导的BCR-ABL自噬降解过程，并通过免疫共沉淀证实了这一点，其中HHT增强了BCR-ABL蛋白的泛素化并促进其与p62的结合。总之，HHT诱导p62介导的自噬伊马替尼耐药CML K562 G细胞，从而促进BCR-ABL蛋白的自噬降解，并提供了一种新的策略，用于治疗TKI耐药CML。
Drug resistance to tyrosine kinase inhibitors (TKIs) is currently a clinical problem in patients with chronic myelogenous leukemia (CML). Homoharringtonine (HHT) is an approved treatment for adult patients with chronic- or accelerated-phase CML who are resistant to TKIs and other therapies; however, the underlying mechanisms remain unclear. In the present study, HHT treatment demonstrated induction of apoptosis in imatinib-resistant K562G cells by using MTS assay and western blotting, and BCR-ABL protein was reduced. CHX chase assay revealed that HHT induced degradation of the BCR-ABL protein, which could be reversed by autophagy lysosome inhibitors Baf-A1 and CQ. Next, HHT treatment confirmed the induction of autophagy in K562G cells, and silencing the key autophagic proteins ATG5 and Beclin-1 inhibited the degradation of the BCR-ABL protein and cytotoxicity. In addition, autophagic receptor p62/SQSTM1(p62) participated during the autophagic degradation of BCR-ABL induced by HHT, and this was confirmed by co-immunoprecipitation, in which HHT enhanced the ubiquitination of the BCR-ABL protein and promoted its binding to p62. In conclusion, HHT induced p62-mediated autophagy in imatinib-resistant CML K562G cells, thus promoting autophagic degradation of the BCR-ABL protein and providing a novel strategy for the treatment of TKI-resistant CML.