The cytostatic and cytotoxic effects of oridonin (Rubescenin), a diterpenoid from Rabdosia rubescens, on tumor cells of different lineage.
The cytostatic and cytotoxic effects of oridonin (Rubescenin), a diterpenoid from Rabdosia rubescens, on tumor cells of different lineage.
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DOI：
10.3892/ijo.26.3.579
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发表时间：
2005-03
影响因子：
5.2
通讯作者：
Sophie S. Chen;Jian Gao;H. Halicka;Xuan Huang;F. Traganos;Z. Darżynkiewicz
中科院分区：
文献类型：
--
作者：
Sophie S. Chen;Jian Gao;H. Halicka;Xuan Huang;F. Traganos;Z. Darżynkiewicz
冬凌草是一种在中国用于治疗食道癌的草药。在这项研究中，倍半萜冬凌草甲素（一种类异戊二烯）从冬凌草中分离出来。使用质谱和碳 13 NMR 光谱来鉴定纯化化合物的结构。然后评估其针对源自前列腺癌（DU-145、LNCaP）、乳腺癌（MCF-7）和卵巢癌（A2780 和 PTX10）的人类细胞系的生物活性。冬凌草甲素对所有测试的癌细胞系均表现出抗增殖活性，通过 MTT 细胞活力测定估计的 IC50 范围为 5.8+/-2.3 至 11.72+/-4.8 microM。流式细胞术分析表明，冬凌草甲素在含有wt p53的雄激素受体阳性LNCaP细胞中诱导G1期停滞，而在含有突变p53的雄激素受体阴性DU-145细胞中阻断G2和M期的细胞周期；通过检查细胞形态和 Ser-10 磷酸化组蛋白 H3 的细胞频率增加来验证 M 的停滞。在用冬凌草甲素处理的肿瘤系中观察到细胞凋亡发生率的增加，这是通过细胞形态的特征性变化来确定的。值得注意的是，在诱导肿瘤细胞凋亡的浓度下，冬凌草甲素未能诱导正常人成纤维细胞的细胞凋亡。蛋白质印迹分析用于测定冬凌草甲素处理后 LNCaP 细胞中抑癌基因 p53 (wt) 和 Bax 以及原癌基因 Bcl-2 的蛋白表达。冬凌草甲素以剂量依赖性方式上调p53和Bax的表达并下调Bcl-2的表达。为了进一步探索冬凌草甲素和 DNA 之间可能的相互作用，在存在和不存在双链 (ds) DNA 的情况下测量了其吸收光谱。观察到光谱变化和吸收带强度增加，表明冬凌草甲素与 DNA 碱基相互作用。目前结合的性质尚不清楚，但在用冬凌草甲素处理的 DU-145 细胞中没有明显的组蛋白 H2AX 在 Ser-139 上磷酸化的证据，这表明诱导了双链 DNA 断裂。总之，冬凌草甲素以细胞周期特异性方式抑制癌细胞生长，并改变促凋亡蛋白和抗凋亡蛋白之间的平衡，有利于细胞凋亡。目前的数据表明，需要进一步研究来评估冬凌草甲素在癌症预防和/或治疗中的潜力。
Rabdosia rubescens is a herbal medicine used to treat esophageal cancer in China. In this study, the sesquiterpene oridonin, an isoprenoid, was isolated from Rabdosia rubescens. Mass spectroscopy and carbon 13 NMR spectroscopy were used to identify the structure of the purified compound. It was then evaluated for biological activity against human cell lines derived from prostate (DU-145, LNCaP), breast (MCF-7), and ovarian (A2780 and PTX10) cancers. Oridonin exhibited anti-proliferative activity toward all cancer cell lines tested, with an IC50 estimated by the MTT cell viability assay ranging from 5.8+/-2.3 to 11.72+/-4.8 microM. Flow cytometric analysis demonstrated that oridonin induced a G1 phase arrest in androgen receptor-positive LNCaP cells containing wt p53, while it blocked the cell cycle at G2 and M phases in androgen receptor-negative DU-145 cells with mutated p53; the arrest in M was verified by examination of cell morphology and by the increased frequency of cells with Ser-10 phosphorylated histone H3. The increased incidence of apoptosis, identified by characteristic changes in cell morphology, was seen in tumor lines treated with oridonin. Notably, at concentrations that induced apoptosis among tumor cells, oridonin failed to induce apoptosis in cultures of normal human fibroblasts. Western blot analysis was used to determine the protein expression of cancer suppressor genes, p53 (wt) and Bax, and the proto-oncogene, Bcl-2 in LNCaP cells following treatment with oridonin. Oridonin up-regulated p53 and Bax and down-regulated Bcl-2 expression in a dose-dependent manner. To further explore the possible interaction between oridonin and DNA, its absorption spectrum was measured in the presence and absence of double stranded (ds) DNA. Spectral shifts and an increase in absorption band intensity were observed indicating interaction of oridonin with DNA bases. The nature of the binding is not clear at present though no evidence of histone H2AX phosphorylation on Ser-139 was apparent in DU-145 cells treated with oridonin that would indicate the induction of ds DNA breaks. In conclusion, oridonin inhibits cancer cell growth in a cell cycle specific manner and shifts the balance between pro- and anti-apoptotic proteins in favor of apoptosis. The present data suggest that further studies are warranted to assess the potential of oridonin in cancer prevention and/or treatment.