adenanthin and Leukemia--Promyelocytic--Acute

To investigate the differentiation of acute promyelocytic leukemia (APL) cells induced by adenosine targeting Prx III.. HL-60 cells were divided into four groups: control group, all-trans retinoic acid (ATRA) group, adenanthin group and ATRA+adenanthin group. Cell morphologic changes were observed under optical microscope. The influence of adenanthin on the differentiation of HL-60 was observed by nitro blue tetrazolium chloride (NBT) test. Cell surface differentiation antigens CD11b expression was measured by flow cytometry. The protein expression of Prx III was detected by immunohistochemical assay.. Adenanthin could induce the differentiation of HL-60 cells; the NBT reduction positive rate in ATRA+adenanthin group was significantly higher than that in ATRA group and adenanthin group (P＜0.05). The percentage of CD11b positive cells in ATRA+adenanthin group (43.62％±1.38％) was higher than that in adenanthin group (28.15％±1.78％), ATRA group (36.72％±1.33％) and control group (7.99％±1.78％) (P＜0. 05). The content of Prx Ⅲ protein in adenanthin group was significantly higher than that in control group and ATRA group (P＜0.05).. Adenanthin and ATRA have a synergistic effect on the differentiation and maturation of HL-60 cells, and its mechanism may be related with regulation of Prx III expression.. 腺花素通过靶向 Prx III 诱导急性早幼粒白血病细胞分化的研究.. 探讨腺花素（Adenanthin）靶向Prx III 诱导急性早幼粒白血病（acute promyelocyticleukemia，APL）细胞分化.. 以HL-60细胞株作为研究对象，取对数生长期细胞，分为对照、全反式维甲酸（ATRA）、Adenanthin和ATRA+Adenanthin，共4组。观察各组细胞形态的变化；用NBT还原实验分析细胞分化能力的变化；流式细胞术检测细胞表面分化抗原CD11b的表达变化；采用Western blot 检测Prx III表达的变化.. Adenanthin可诱导HL-60细胞分化；ATRA+Adenanthin组NBT还原阳性率明显高于ATRA组和Adenanthin组（P＜0.05）；ATRA+Adenanthin组CD11b阳性细胞百分率（43.62％±1.38％）均明显高于Adenanthin组（28.15％±1.78％）、ATRA组（36.72％±1.33％）及空白对照组（7.99％±1.78％）（P＜0.05）；Adenanthin组Prx Ⅲ蛋白水平明显高于空白对照组及ATRA组（P＜0.05）.. 腺花素能协同ATRA使HL-60细胞分化成熟，其作用机制可能与调控 Prx III的表达有关.

Topics: Cell Differentiation; Diterpenes, Kaurane; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Peroxiredoxin III; Tretinoin

Although 1,25‑dihydroxyvitamin D3 (VD3) is regarded as a promising inducing agent for leukemia cell differentiation, it is not as effective an agent as all‑trans‑retinoic acid, and its usefulness is also limited by the adverse effects of hypercalcemia. The aim of the present study was to determine whether combining VD3 with adenanthin, a peroxiresoxin I (Prx I)‑targeting natural compound, improves the efficacy of VD3. Cell viability was assessed using a trypan blue exclusion assay and flow cytometry was used to evaluate the expression of cell surface markers, CD11b/CD14, and the level of reactive oxygen species (ROS). Wright's staining was used to examine morphological changes and RNA‑interference was used to knockdown Prx I and p65 gene expression. Protein expression was determined by western blot analysis. The results demonstrated that adenanthin markedly enhanced VD3‑induced cell differentiation of leukemia NB4 cells, as evidenced by the increased percentage of CD11b‑ and CD14‑positive cells, the mature morphology of the monocytes and the increased phagocytic ability. Consistent with these results, knockdown of Prx I, but not nuclear factor‑κB (p65), enhanced VD3‑induced cell differentiation. The combinatorial effects of adenanthin and VD3 were shown to be associated with the ROS‑CCAAT‑enhancer‑binding protein (C/EBP)β axis, since N‑acetylcysteine, a ROS scavenger, was able to abrogate the differentiation‑enhancing effects of adenanthin, and the knockdown of C/EBPβ also inhibited the combinatorial effects of adenanthin and VD3. In addition, co‑treatment with adenanthin and VD3 was able to induce differentiation in other non‑acute promyelocytic leukemia cells and primary leukemia cells. In conclusion, the results of the present study revealed a novel role for Prx I in VD3‑induced cell differentiation, and suggested that targeting Prx I may represent a novel strategy to enhance VD3‑induced leukemia cell differentiation.

Topics: Adult; Calcitriol; CCAAT-Enhancer-Binding Protein-beta; Cell Differentiation; Cell Line, Tumor; Diterpenes, Kaurane; Female; Gene Knockdown Techniques; Humans; Leukemia, Promyelocytic, Acute; Monocytes; Peroxiredoxins; Reactive Oxygen Species

Peroxiredoxins (Prxs) are potential therapeutic targets for major diseases such as cancers. However, isotype-specific inhibitors remain to be developed. We report that adenanthin, a diterpenoid isolated from the leaves of Rabdosia adenantha, induces differentiation of acute promyelocytic leukemia (APL) cells. We show that adenanthin directly targets the conserved resolving cysteines of Prx I and Prx II and inhibits their peroxidase activities. Consequently, cellular H(2)O(2) is elevated, leading to the activation of extracellular signal-regulated kinases and increased transcription of CCAAT/enhancer-binding protein β, which contributes to adenanthin-induced differentiation. Adenanthin induces APL-like cell differentiation, represses tumor growth in vivo and prolongs the survival of mouse APL models that are sensitive and resistant to retinoic acid. Thus, adenanthin can serve as what is to our knowledge the first lead natural compound for the development of Prx I- and Prx II-targeted therapeutic agents, which may represent a promising approach to inducing differentiation of APL cells.

Topics: Animals; Antineoplastic Agents; CCAAT-Enhancer-Binding Protein-beta; Cell Differentiation; Cysteine; Diterpenes; Diterpenes, Kaurane; Extracellular Signal-Regulated MAP Kinases; Humans; Hydrogen Peroxide; Leukemia, Promyelocytic, Acute; Mice; Peroxiredoxins; Tretinoin; Tumor Cells, Cultured