Daurisoline (DS) is an isoquinoline alkaloid that exerts anticancer activities in various cancer cells. However, the underlying mechanisms through which DS affects the survival of breast cancer cells remain poorly understood. Therefore, the present study was undertaken to investigate the potential anticancer effect of DS on breast cancer cells and reveal the mechanism underlying the enhanced tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis by DS. Cell counting kit-8 (CCK-8) and 5-ethynyl-2-deoxyuridine (EdU) assay were used to evaluate the ability of cell proliferation. Flow cytometry was selected to examine the cell cycle distribution. TUNEL assay was used to detect the cell apoptosis. The protein expression was measured by Western blot analysis. DS was found to reduce the cell viability and suppress the proliferation of MCF-7 and MDA-MB-231 cells by causing G1 phase cell cycle arrest. DS could trigger apoptosis by promoting the cleavage of caspase-8 and PARP. The phosphorylation of ERK, JNK, and p38MAPK was upregulated clearly following DS treatment. Notably, SP600125 (JNK inhibitor) pretreatment significantly abrogated DS-induced PARP cleavage. DS inactivated Akt/mTOR and Wnt/β-catenin signaling pathway and upregulated the expression of ER stress-related proteins. Additionally, DS amplified TRAIL-caused viability reduction and apoptosis in breast cancer cells. Mechanismly, DS upregulated the protein level of DR4 and DR5, and knockdown of DR5 attenuated the cotreatment-induced cleavage of PARP. Inhibition of JNK could block DS-induced upregulation of DR5. This study provides valuable insights into the mechanisms of DS inhibiting cell proliferation, triggering apoptosis, and enhancing TRAIL sensitivity of breast cancer cells.

中文翻译：

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Daurisoline 通过上调 DR5 抑制增殖、诱导细胞凋亡并增强乳腺癌细胞的 TRAIL 敏感性


Daurisoline (DS) 是一种异喹啉生物碱，在多种癌细胞中发挥抗癌活性。然而，DS 影响乳腺癌细胞存活的潜在机制仍知之甚少。因此，本研究旨在探讨 DS 对乳腺癌细胞的潜在抗癌作用，并揭示 DS 增强肿瘤坏死因子相关凋亡诱导配体 (TRAIL) 介导的细胞凋亡的机制。使用细胞计数试剂盒-8（CCK-8）和5-乙炔基-2-脱氧尿苷（EdU）测定法评估细胞增殖能力。选择流式细胞术来检查细胞周期分布。 TUNEL 检测用于检测细胞凋亡。通过蛋白质印迹分析测量蛋白质表达。 DS 被发现可通过引起 G1 期细胞周期停滞来降低细胞活力并抑制 MCF-7 和 MDA-MB-231 细胞的增殖。 DS可以通过促进caspase-8和PARP的裂解来引发细胞凋亡。 DS 处理后，ERK、JNK 和 p38MAPK 的磷酸化明显上调。值得注意的是，SP600125（JNK 抑制剂）预处理显着消除了 DS 诱导的 PARP 裂解。 DS 使 Akt/mTOR 和 Wnt/β-catenin 信号通路失活，并上调 ER 应激相关蛋白的表达。此外，DS 放大了 TRAIL 导致的乳腺癌细胞活力降低和细胞凋亡。从机制上讲，DS 上调 DR4 和 DR5 的蛋白水平，敲低 DR5 减弱了共处理诱导的 PARP 裂解。抑制 JNK 可以阻止 DS 诱导的 DR5 上调。这项研究为 DS 抑制细胞增殖、触发细胞凋亡和增强乳腺癌细胞 TRAIL 敏感性的机制提供了有价值的见解。