Background

Britannin, a Sesquiterpene Lactone isolated from Inula aucheriana, has recently gained attraction in the therapeutic fields due to its anti-tumor properties. This study was designed to evaluate the effect of this agent on Acute Lymphoblastic Leukemia (ALL) cell lines, either as a monotherapy or in combination with Vincristine (VCR).

Methods and Results

To determine the anti-leukemic effects of Britannin on ALL-derived cell lines and suggest a mechanism of action for the agent, we used MTT assay, Annexin-V/PI staining, ROS assay, and real-time PCR analysis. Moreover, by using a combination index (CI), we evaluated the synergistic effect of Britannin on Vincristine. We found that unlike normal Peripheral Blood Mononuclear Cells (PBMCs) and L929 cells, Britannin reduced the viability of NALM-6, REH, and JURKAT cells. Among tested cells, NALM-6 cells had the highest sensitivity to Britannin, and this agent was able to induce p21/p27-mediated G1 cell cycle arrest and Reactive Oxygen Specious (ROS)-mediated apoptotic cell death in this cell line. When NALM-6 cells were treated with Nacetyl-L-Cysteine (NAC), a scavenger of ROS, Britannin could induce neither apoptosis nor reduce the survival of the cells suggesting that the cytotoxic effect of Britannin is induced through ROS-dependent manner. Moreover, we found that a low dose of Britannin enhanced the effect of Vincristine in NALM-6 cells by inducing apoptotic cell death via altering the expression of apoptotic-related genes.

Conclusions

Overall, our results proposed a mechanism for the cytotoxic effect of Britannin, either as a single agent or in combination with Vincristine, in NALM-6 cells.

中文翻译：

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Britannin，一种倍半萜内酯在 NALM-6、REH 和 JURKAT 细胞系中诱导 ROS 依赖性细胞凋亡，并与长春新碱产生协同作用

背景

Britannin 是一种从 Inula aucheriana 中分离出来的倍半萜内酯，由于其抗肿瘤特性，最近在治疗领域受到了关注。本研究旨在评估该药物对急性淋巴细胞白血病 (ALL) 细胞系的影响，无论是作为单一疗法还是与长春新碱 (VCR) 联合使用。

方法和结果

为了确定 Britannin 对 ALL 衍生细胞系的抗白血病作用并提出该试剂的作用机制，我们使用了 MTT 测定、Annexin-V/PI 染色、ROS 测定和实时 PCR 分析。此外，通过使用组合指数 (CI)，我们评估了 Britannin 对长春新碱的协同作用。我们发现，与正常外周血单个核细胞 (PBMC) 和 L929 细胞不同，Britannin 降低了 NALM-6、REH 和 JURKAT 细胞的活力。在测试的细胞中，NALM-6 细胞对 Britannin 的敏感性最高，并且该试剂能够在该细胞系中诱导 p21/p27 介导的 G1 细胞周期停滞和活性氧 (ROS) 介导的细胞凋亡。当 NALM-6 细胞用 ROS 清除剂 N乙酰-L-半胱氨酸 (NAC) 处理时，Britannin既不能诱导细胞凋亡，也不能降低细胞的存活率，这表明Britannin的细胞毒作用是通过ROS依赖性方式诱导的。此外，我们发现低剂量的 Britannin 通过改变凋亡相关基因的表达诱导凋亡细胞死亡，从而增强了长春新碱在 NALM-6 细胞中的作用。

结论

总体而言，我们的结果提出了在 NALM-6 细胞中 Britannin 的细胞毒作用机制，无论是作为单一药物还是与长春新碱联合使用。