Hederagenin potentiated cisplatin- and paclitaxel-mediated cytotoxicity by impairing autophagy in lung cancer cells.
Kun WangXiaodong LiuQuanmeng LiuIdy Ht HoXianli WeiTing YinYujuan ZhanWenjing ZhangWenbo ZhangBonan ChenJiangyong GuYuhui TanLin ZhangMatthew Tv ChanWilliam Ka Kei WuBiaoyan DuJianyong XiaoPublished in: Cell death & disease (2020)
Autophagy inhibition has been demonstrated to increase the efficacy of conventional chemotherapy. In this study, we identified hederagenin, a triterpenoid derived from Hedera helix, as a potent inhibitor of autophagy and then hypothesized that hederagenin might synergize with chemotherapeutic drugs (e.g., cisplatin and paclitaxel) to kill lung cancer cells. Firstly, we observed that hederagenin induced the increased autophagosomes in lung cancer cells concomitantly with the upregulation of LC3-II and p62, which indicated the impairment of autophagic flux. The colocalization assay indicated hederagenin could not block the fusion of lysosomes and autophagosomes, whereas the lysosomal acidification might be inhibited by hederagenin as revealed by the reduced staining of acidity-sensitive reagents (i.e., Lysotracker and acridine orange). The aberrant acidic environment then impaired the function of lysosome, which was evidenced by the decrease of mature cathepsin B and cathepsin D. Lastly, hederagenin, in agree with our hypothesis, promoted pro-apoptotic effect of cisplatin and paclitaxel with the accumulation of reactive oxygen species (ROS); while the synergistic effect could be abolished by the ROS scavenger, N-acetyl-L-cysteine. These data summarily demonstrated hederagenin-induced accumulation of ROS by blocking autophagic flux potentiated the cytotoxicity of cisplatin and paclitaxel in lung cancer cells.
Keyphrases
- poor prognosis
- cell death
- reactive oxygen species
- oxidative stress
- dna damage
- diabetic rats
- high glucose
- signaling pathway
- anti inflammatory
- chemotherapy induced
- high throughput
- fluorescent probe
- squamous cell carcinoma
- electronic health record
- mass spectrometry
- cell proliferation
- deep learning
- transcription factor
- flow cytometry
- stress induced
- tandem mass spectrometry