Environmental Toxicology Research Laboratory, NIH-Center for Environmental Health College of Science, Engineering and Technology, Jackson State University, 1400 Lynch Street, Box 18540, Jackson, MS, 39217, USA.
Exp Hematol Oncol. 2014 Mar 25;3(1):9. doi: 10.1186/2162-3619-3-9.
Arsenic trioxide (ATO) is a novel form of therapy that has been found to aid acute promyelocytic leukemia (APL) patients. Our laboratory has demonstrated that ATO-induced cytotoxicity in human leukemia (HL-60) cells is mediated by oxidative stress. Pro-oxidants have been known to play a role in free radical-mediated oxidative stress. Vitamin D3, (Vit D3) an active metabolite of vitamin D has been reported to inhibit the growth of number neoplasms such as prostate, breast, colorectal, leukemia, and skin cancers. The goal of the present research was to use (HL-60) cells as an in vitro test model to evaluate whether low doses of Vit D3 potentiate the toxicity of ATO and whether this toxic action is mediated via apoptotic mechanisms.
HL-60 cells were treated either with a pharmacologic dose of ATO alone and with several low doses of Vit D3. Cell survival was determined by MTT assay. Cell apoptosis was measured both by flow cytometry assessment, and DNA laddering assay.
MTT assay indicated that Vit D3 co-treatment potentiates ATO toxicity in HL-60 cells in a dose dependent manner. A statistically significant and dose-dependent increase (p <0.05) was recorded in annexin V positive cells (apoptotic cells) with increasing doses of Vit D3 in ATO-treated cells. This finding was confirmed by the result of DNA laddering assay showing clear evidence of nucleosomal DNA fragmentation in vitamin and ATO co-treated cells.
The present study indicates that Vit D3 potentiates the antitumor effects of ATO. This potentiation is mediated at least in part, through induction of phosphatidylserine externalization and nucleosomal DNA fragmentation. These findings highlight the potential impact of Vit D3 in promoting the pharmacological effect of ATO, suggesting a possible future role of Vit D3/ATO combination therapy in patients with acute promyelocytic leukemia (APL).
三氧化二砷（ATO）是一种新型的治疗方法，已被发现有助于急性早幼粒细胞白血病（APL）患者。我们的实验室已经证明，ATO 在人白血病（HL-60）细胞中的细胞毒性是由氧化应激介导的。促氧化剂已被证明在自由基介导的氧化应激中发挥作用。维生素 D3（Vit D3）是维生素 D 的一种活性代谢物，据报道可抑制前列腺、乳腺、结直肠、白血病和皮肤癌等多种肿瘤的生长。本研究的目的是使用（HL-60）细胞作为体外测试模型，评估低剂量的 Vit D3 是否增强 ATO 的毒性，以及这种毒性作用是否通过凋亡机制介导。
HL-60 细胞单独用药物剂量的 ATO 处理，并用几种低剂量的 Vit D3 处理。通过 MTT 测定法确定细胞存活率。通过流式细胞术评估和 DNA 梯状电泳法测定细胞凋亡。
MTT 测定法表明，Vit D3 与 ATO 联合治疗以剂量依赖的方式增强 HL-60 细胞的毒性。在 ATO 处理的细胞中，随着 Vit D3 剂量的增加， Annexin V 阳性细胞（凋亡细胞）的数量呈统计学显著和剂量依赖性增加（p<0.05）。Vit D3 和 ATO 联合处理细胞中核小体 DNA 片段化的 DNA 梯状电泳法结果证实了这一发现。
本研究表明，Vit D3 增强了 ATO 的抗肿瘤作用。这种增强至少部分是通过诱导磷脂酰丝氨酸外翻和核小体 DNA 片段化介导的。这些发现强调了 Vit D3 在促进 ATO 药理作用方面的潜在影响，表明 Vit D3/ATO 联合治疗在急性早幼粒细胞白血病（APL）患者中的可能未来作用。
Zotero 插件
