Endoplasmic reticulum (ER) stress can trigger various cell death mechanisms beyond apoptosis, providing promise in cancer treatment. Oncosis, characterized by cellular swelling and increased membrane permeability, represents a non-apoptotic form of cell death. In our study, we discovered that Arnicolide D (AD), a natural sesquiterpene lactone compound, induces ER stress-mediated oncosis in hepatocellular carcinoma (HCC) cells, and this process is reactive oxygen species (ROS)-dependent. Furthermore, we identified the activation of the PERK-eIF2α-ATF4-CHOP pathway during ER stress as a pivotal factor in AD-induced oncosis. Notably, the protein synthesis inhibitor cycloheximide (CHX) was found to effectively reverse AD-induced oncosis, suggesting ATF4 and CHOP may hold crucial roles in the induction of oncosis by AD. These proteins play a vital part in promoting protein synthesis during ER stress, ultimately leading to cell death. Subsequent studies, in where we individually or simultaneously knocked down ATF4 and CHOP in HCC cells, provided further confirmation of their indispensable roles in AD-induced oncosis. Moreover, additional animal experiments not only substantiated AD’s ability to inhibit HCC tumor growth but also solidified the essential role of ER stress-mediated and ROS-dependent oncosis in AD’s therapeutic potential. In summary, our research findings strongly indicate that AD holds promise as a therapeutic agent for HCC by its ability to induce oncosis.

内质网 (ER) 应激可引发细胞凋亡以外的各种细胞死亡机制，为癌症治疗提供了希望。肿瘤的特征是细胞肿胀和膜通透性增加，代表细胞死亡的非凋亡形式。在我们的研究中，我们发现 Arnicolide D (AD) 是一种天然倍半萜内酯化合物，可在肝细胞癌细胞 (HCC) 中诱导内质网应激介导的肿瘤沉着，并且该过程依赖于活性氧 (ROS)。此外，我们还发现 ER 应激期间 PERK-eIF2α-ATF4-CHOP 通路的激活是 AD 诱导的肿瘤形成的关键因素。值得注意的是，蛋白质合成抑制剂放线菌酮（CHX）被发现可以有效逆转 AD 诱导的肿瘤，这表明 ATF4 和 CHOP 可能在 AD 诱导肿瘤中发挥关键作用。这些蛋白质在内质网应激期间促进蛋白质合成中发挥着至关重要的作用，最终导致细胞死亡。随后的研究中，我们单独或同时敲低 HCC 细胞中的 ATF4 和 CHOP，进一步证实了它们在 AD 诱导的肿瘤形成中不可或缺的作用。此外，额外的动物实验不仅证实了 AD 抑制 HCC 肿瘤生长的能力，而且还巩固了 ER 应激介导和 ROS 依赖性肿瘤病在 AD 治疗潜力中的重要作用。总之，我们的研究结果强烈表明，AD 由于其诱导肿瘤的能力而有望成为 HCC 的治疗剂。