Piperlongumine increases the sensitivity of bladder cancer to cisplatin by mitochondrial ROS

• Published in: Journal of clinical laboratory analysis 2022-06, Vol.36 (6), p.e24452-n/a
• Main Authors: Pan, Xiaobo, Chen, Guangyao, Hu, Wenhao
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate; Annexin V; Apoptosis; Bladder cancer; Cancer; Cancer therapies; Cell death; Cell survival; Chemotherapy; Cholecystokinin; Cisplatin; Cisplatin - pharmacology; cisplatin resistance; Dioxolanes; Fluorescent indicators; Gene expression; Humans; Kinases; MAP kinase; Metastasis; Mitochondria; Mitochondrial DNA; Necroptosis; Neoplasm Recurrence, Local; piperlongumine; Plasmids; Protein kinase; Proteins; Reactive oxygen species; Reactive Oxygen Species - metabolism; Reactive Oxygen Species - pharmacology; Receptor-Interacting Protein Serine-Threonine Kinases - genetics; Receptor-Interacting Protein Serine-Threonine Kinases - metabolism; receptor‐interacting protein kinase 1; siRNA; Sulfonamides; Urinary Bladder Neoplasms - drug therapy; Urinary Bladder Neoplasms - genetics; Western blotting
• ISSN: 0887-8013; 1098-2825
• DOI: 10.1002/jcla.24452

Background The development of cisplatin resistance often results in cisplatin inefficacy in advanced or recurrent bladder cancer. However, effective treatment strategies for cisplatin resistance have not been well established. Methods Gene expression was measured by qRT‐PCR and Western blotting. CCK‐8 assay was performed to detect cell survival. The number of apoptotic cells was determined using the Annexin V‐PI double‐staining assay. The level of reactive oxygen species (ROS) was measured using 2’,7'‐dichlorodihydrofluorescein diacetate fluorescent dye, and the ATP level was detected using an ATP measurement kit. Results The expression of receptor‐interacting protein kinase 1 (RIPK1), a key regulator of necroptosis, gradually decreased during cisplatin resistance. We first used piperlongumine (PL) in combination with cisplatin to act on cisplatin‐resistant BC cells and found that PL‐induced activation of RIPK1 increased the sensitivity of T24 resistant cells to cisplatin treatment. Furthermore, we revealed that PL killed T24 cisplatin‐resistant cells by triggering necroptosis, because cell death could be rescued by the mixed lineage kinase domain‐like (MLKL) protein inhibitor necrotic sulfonamide or MLKL siRNA, but could not be suppressed by the apoptosis inhibitor z‐VAD. We further explored the specific mechanism and found that PL activated RIPK1 to induce necroptosis in cisplatin‐resistant cells by stimulating mitochondrial fission to produce excessive ROS. Conclusions Our results demonstrated the role of RIPK1 in cisplatin‐resistant cells and the sensitization effect of the natural drug PL on bladder cancer. These may provide a new treatment strategy for overcoming cisplatin resistance in bladder cancer. In the process of cisplatin resistance in bladder cancer cells, RIPK1 expression was gradually lost. PL promotes mitochondrial fission by activating DRP‐1, which results in excessive ROS production. Then, ROS induces necroptosis of resistant cells by activating the expression of RIPK1, thereby enhancing the effect of cisplatin on bladder cancer cells.