Abstract Background Acute promyelocytic leukemia (APL) is a hematopoietic malignancy driven by promyelocytic leukemia–retinoic acid receptor A (PML-RARA) fusion gene. The therapeutic drugs currently used to treat APL have adverse effects. 20(S)-ginsenoside Rh2 (GRh2) is an anticancer medicine with high effectiveness and low toxicity. However, the underlying anticancer mechanisms of GRh2-induced PML-RARA degradation and apoptosis in human APL cell line (NB4 cells) remain unclear. Methods Apoptosis-related indicators and PML-RARA expression were determined to investigate the effect of GRh2 on NB4 cells. Z-VAD-FMK, LY294002, and C 87, as inhibitors of caspase, and the phosphatidylinositol 3-kinase (PI3K) and tumor necrosis factor-α (TNF-α ) pathways were used to clarify the relationship between GRh2-induced apoptosis and PML-RARA degradation. Results GRh2 dose- and time-dependently decreased NB4 cell viability. GRh2-induced apoptosis, cell cycle arrest, and caspase3, caspase8, and caspase9 activation in NB4 cells after a 12-hour treatment. GRh2-induced apoptosis in NB4 cells was accompanied by massive production of reactive oxygen species, mitochondrial damage and upregulated Bax/Bcl-2 expression. GRh2 also induced PML/PML-RARA degradation, PML nuclear bodies formation, and activation of the downstream p53 pathway in NB4 cells. Z-VAD-FMK inhibited caspase activation and significantly reversed GRh2-induced apoptosis and PML-RARA degradation. GRh2 also upregulated TNF-α expression and inhibited Akt phosphorylation. LY294002, an inhibitor of the PI3K pathway, enhanced the antitumor effects of GRh2, and C 87, an inhibitor of the TNF-α pathway, reversed NB4 cell viability, and GRh2-mediated apoptosis in a caspase-8-dependent manner. Conclusion GRh2 induced caspase-dependent PML-RARA degradation and apoptosis in NB4 cells via the Akt/Bax/caspase9 and TNF-α/caspase8 pathways.

中文翻译：

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20(S)-Ginsenoside Rh2 通过 Akt/Bax/caspase9 和 TNF-α/caspase8 信号级联诱导 NB4 细胞中 caspase 依赖性 PML-RARA 降解

摘要背景急性早幼粒细胞白血病（APL）是一种由早幼粒细胞白血病-维甲酸受体A（PML-RARA）融合基因驱动的造血系统恶性肿瘤。目前用于治疗APL的治疗药物有不良反应。20(S)-人参皂甙Rh2(GRh2)是一种高效、低毒的抗癌药物。然而，GRh2 诱导人 APL 细胞系（NB4 细胞）中 PML-RARA 降解和凋亡的潜在抗癌机制仍不清楚。方法测定细胞凋亡相关指标和PML-RARA表达，探讨GRh2对NB4细胞的影响。Z-VAD-FMK、LY294002 和 C 87 作为半胱天冬酶的抑制剂，以及磷脂酰肌醇 3-激酶 (PI3K) 和肿瘤坏死因子-α (TNF-α) 通路用于阐明 GRh2 诱导的细胞凋亡和PML-RARA 降解。结果 GRh2 剂量和时间依赖性降低 NB4 细胞活力。处理 12 小时后 NB4 细胞中 GRh2 诱导的细胞凋亡、细胞周期停滞和 caspase3、caspase8 和 caspase9 活化。GRh2 诱导的 NB4 细胞凋亡伴随着活性氧的大量产生、线粒体损伤和上调的 Bax/Bcl-2 表达。GRh2 还诱导 NB4 细胞中的 PML/PML-RARA 降解、PML 核小体形成和下游 p53 通路的激活。Z-VAD-FMK 抑制 caspase 活化并显着逆转 GRh2 诱导的细胞凋亡和 PML-RARA 降解。GRh2 还上调 TNF-α 表达并抑制 Akt 磷酸化。LY294002 是一种 PI3K 通路的抑制剂，可增强 GRh2 的抗肿瘤作用，而 C 87 是一种 TNF-α 通路的抑制剂，可逆转 NB4 细胞的活力，和 GRh2 以 caspase-8 依赖性方式介导的细胞凋亡。结论 GRh2通过Akt/Bax/caspase9和TNF-α/caspase8通路诱导NB4细胞中caspase依赖的PML-RARA降解和凋亡。