Cell Biology and Toxicology ( IF 5.3 ) Pub Date : 2022-09-07 , DOI: 10.1007/s10565-022-09756-8 Yujuan Zhan 1, 2 , Qiugu Chen 1, 2 , Yue Song 1, 2 , Xianli Wei 3 , Tingxiu Zhao 4 , Bonan Chen 5 , Chengxi Li 2 , Wenbo Zhang 2, 4 , Yanjun Jiang 6 , Yuhui Tan 1 , Biaoyan Du 4 , Jianyong Xiao 1 , Kun Wang 4
|
Autophagy is typically activated in cancer cells as a rescue strategy in response to cellular stress (e.g., chemotherapy). Herein, we found that Berbamine Hydrochloride (Ber) can act as an effective inhibitor of the late stage of autophagic flux, thereby potentiating the killing effect of chemotherapy agents. Lung carcinoma cells exposed to Ber exhibited increased autophagosomes, marked by LC3-II upregulation. The increased level of p62 after Ber treatment indicated that the autophagic flux was blocked at the late stage. The lysosome staining assay and cathepsin maturation detection indicated impaired lysosomal acidification. We found that Nox2 exhibited intensified co-localization with lysosomes in Ber-treated cells. Nox2 is a key enzyme for superoxide anion production capable of transferring electrons into the lysosomal lumen, thereby neutralizing the inner protons; this might explain the aberrant acidification. This hypothesis is further supported by the observed reversal of lysosomal cathepsin maturation by Nox2 inhibitors. Finally, Ber combined with cisplatin exhibited a synergistic killing effect on lung carcinoma cells. Further data suggested that lung carcinoma cells co-treated with Ber and cisplatin accumulated excessive reactive oxygen species (ROS), which typically activated MAPK-mediated mitochondria-dependent apoptosis. The enhanced anti-cancer effect of Ber combined with cisplatin was also confirmed in an in vivo xenograft mouse model. These findings indicate that Ber might be a promising adjuvant for enhancing the cancer cell killing effect of chemotherapy via the inhibition of autophagy. In this process, Nox2 might be a significant mediator of Ber-induced aberrant lysosomal acidification.
Graphical abstract
中文翻译：
盐酸小檗胺通过激活 Nox2 抑制溶酶体酸化，通过 ROS-MAPK 途径增强化疗诱导的人肺癌细胞凋亡
自噬通常在癌细胞中被激活，作为响应细胞应激（例如化疗）的救援策略。在此，我们发现盐酸小檗胺（Ber）可以作为自噬流后期的有效抑制剂，从而增强化疗药物的杀伤作用。暴露于 Ber 的肺癌细胞表现出自噬体增加，以 LC3-II 上调为标志。Ber处理后p62水平升高表明自噬流在后期被阻断。溶酶体染色测定和组织蛋白酶成熟检测表明溶酶体酸化受损。我们发现 Nox2 在 Ber 处理的细胞中表现出与溶酶体增强的共定位。Nox2 是超氧阴离子产生的关键酶，能够将电子转移到溶酶体腔中，从而中和内部质子；这可能解释了异常酸化。观察到的 Nox2 抑制剂对溶酶体组织蛋白酶成熟的逆转进一步支持了这一假设。最后，Ber与顺铂联合对肺癌细胞表现出协同杀伤作用。进一步的数据表明，用 Ber 和顺铂联合处理的肺癌细胞积累了过量的活性氧 (ROS)，这通常会激活 MAPK 介导的线粒体依赖性细胞凋亡。Ber 与顺铂联合使用的增强抗癌作用也在体内异种移植小鼠模型中得到证实。这些发现表明 Ber 可能是一种有前途的佐剂，通过抑制自噬来增强化疗对癌细胞的杀伤作用。在此过程中，Nox2 可能是 Ber 诱导的异常溶酶体酸化的重要介质。
京公网安备 11010802027423号