Jiang Lei, Zhao Yi-Ming, Yang Ming-Zhen
Department of Haematology, The Fourth Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230012, P.R. China.
Oncol Lett. 2021 Feb;21(2):109. doi: 10.3892/ol.2020.12370. Epub 2020 Dec 11.
Bortezomib is a novel proteasome inhibitor, which has been successfully used to treat mantle cell lymphoma and multiple myeloma. However, the direct effects of bortezomib on acute promyelocytic leukaemia (APL) have not been fully investigated. In the present study, the WST-8 assay, western blotting, flow cytometry, monodansylcadaverine staining and transmission electron microscopy were performed. It was demonstrated that bortezomib treatment induced a time- and dose-dependent decrease in the viability of NB4 cells. Bortezomib treatment induced cell apoptosis in NB4 cells, as assessed by Annexin V/propidium iodide analysis, and the detection of cleaved caspase-3, cleaved poly(ADP-ribose) polymerase, Bax and Bcl-2 expression. Furthermore, bortezomib treatment induced autophagy in NB4 cells, as indicated by autophagosome formation, p62 degradation, LC3-I to LC3-II conversion and formation of acidic autophagic vacuoles. Notably, autophagy induced by bortezomib was initiated prior to apoptosis. Inhibition of autophagy by knocking down Beclin-1 expression increased bortezomib-induced apoptosis in NB4 cells. Therefore, the present study revealed that the combination of bortezomib and autophagy inhibition may be a potential treatment strategy for APL.
硼替佐米是一种新型蛋白酶体抑制剂，已成功用于治疗套细胞淋巴瘤和多发性骨髓瘤。然而，硼替佐米对急性早幼粒细胞白血病（APL）的直接作用尚未得到充分研究。在本研究中，进行了WST-8检测、蛋白质印迹法、流式细胞术、单丹磺酰尸胺染色和透射电子显微镜检查。结果表明，硼替佐米处理诱导NB4细胞活力呈时间和剂量依赖性下降。通过膜联蛋白V/碘化丙啶分析以及检测裂解的半胱天冬酶-3、裂解的聚（ADP-核糖）聚合酶、Bax和Bcl-2表达评估，硼替佐米处理诱导NB4细胞凋亡。此外，硼替佐米处理诱导NB4细胞自噬，表现为自噬体形成、p62降解、LC3-I向LC3-II转化以及酸性自噬泡形成。值得注意的是，硼替佐米诱导的自噬在凋亡之前启动。通过敲低Beclin-1表达抑制自噬可增加硼替佐米诱导的NB4细胞凋亡。因此，本研究表明硼替佐米与自噬抑制相结合可能是APL的一种潜在治疗策略。
