Upregulation of p21WAF1/CIP1 in human breast cancer cell lines MCF-7 and MDA-MB-468 undergoing apoptosis induced by natural product anticancer drugs 10-hydroxycamptothecin and camptothecin through p53-dependent and independent pathways.
Upregulation of p21WAF1/CIP1 in human breast cancer cell lines MCF-7 and MDA-MB-468 undergoing apoptosis induced by natural product anticancer drugs 10-hydroxycamptothecin and camptothecin through p53-dependent and independent pathways.
复制标题
天然产物抗癌药物 10-羟基喜树碱和喜树碱通过 p53 依赖性和独立途径诱导细胞凋亡的人乳腺癌细胞系 MCF-7 和 MDA-MB-468 中 p21WAF1/CIP1 的上调。
DOI：
--
复制
发表时间：
1998
影响因子：
5.2
通讯作者：
R. Zhang
中科院分区：
文献类型：
--
作者：
W. Liu;R. Zhang
近年来，天然产物DNA拓扑异构酶I抑制剂10-羟基喜树碱（HCPT）和喜树碱（CPT）已被证明在体外和体内人类乳腺癌模型中具有治疗作用。在本研究中，我们研究了HCPT和CPT在人乳腺癌细胞系MCF-7和MDA-MB-468中诱导的体外和体内凋亡途径。通过各种DNA片段分析和末端脱氧核苷酸转移酶介导的缺口末端标记（TUNEL）实验，HCPT和CPT诱导的细胞凋亡显示出剂量和时间依赖性。MDA-MB-468细胞对HCPT和CPT的敏感性均高于MCF-7细胞。HCPT诱导MDA-MB-468细胞凋亡的效果优于CPT；然而，在MCF-7细胞中，CPT比HCPT更有效。在HCPT或CPT处理的MCF-7细胞中，p53和p21WAF1/CIP1蛋白水平呈剂量和时间依赖性增加。在HCPT或CPT处理的MDA-MB-468细胞中，p21WAF1/CIP1蛋白水平也以剂量和时间依赖的方式增加，而突变的p53蛋白水平没有显著变化。DNA断裂抑制剂aphidicolin预孵卵可显著抑制CPT处理MCF-7细胞中p53蛋白水平的升高，而p21WAF1/CIP1蛋白水平的升高不受抑制。aphidicolin不抑制CPT处理MDA-MB-468细胞中p21WAF1/CIP1的升高。通过Northern blot分析，p21WAF1/CIP1的转录在HCPT或CPT处理的MCF-7和MDA-MB-468细胞中呈剂量依赖性增加。这些结果表明，HCPT和CPT治疗可导致p21WAF1/CIP1蛋白和mRNA水平升高，并通过p53依赖性和非依赖性途径诱导人乳腺癌细胞凋亡。这些发现可能对进一步了解喜树碱治疗人类癌症的作用机制具有重要意义。
Recently, natural product DNA topoisomerase I inhibitors 10-hydroxycamptothecin (HCPT) and camptothecin (CPT) have been shown to have therapeutic effects in both in vitro and in vivo models of human breast cancer. In the present study, we characterized the in vitro and in vivo apoptotic pathways induced by HCPT and CPT in the human breast cancer cell lines MCF-7 and MDA-MB-468. Using various DNA fragmentation analyses and the terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, the apoptosis induced by HCPT and CPT was shown to be dose- and time-dependent. The MDA-MB-468 cells were more sensitive to both HCPT and CPT than MCF-7 cells. HCPT induced apoptosis in MDA-MB-468 cells more effectively than CPT; however, in MCF-7 cells, CPT was more effective than HCPT. The levels of p53 and p21WAF1/CIP1 protein increased in MCF-7 cells treated with HCPT or CPT in a dose- and time-dependent manner. The levels of p21WAF1/CIP1 protein also increased in a dose- and time-dependent manner in MDA-MB-468 cells treated with HCPT or CPT, whereas the mutated p53 protein levels had no significant change. The elevation of p53 protein levels in MCF-7 cells treated with CPT was significantly inhibited by preincubation with DNA breaks inhibitor aphidicolin, while the elevation of p21WAF1/CIP1 protein levels was not inhibited. The elevation of p21WAF1/CIP1 in MDA-MB-468 cells treated with CPT was not inhibited by aphidicolin. Using Northern blot analysis, the transcription of p21WAF1/CIP1 was shown to increase in a dose-dependent manner in MCF-7 and MDA-MB-468 cells treated with HCPT or CPT. These results suggest that treatment with HCPT and CPT results in increased levels of p21WAF1/CIP1 protein and mRNA, and that they induce apoptosis in human breast cancer cells through both p53-dependent and -independent pathways. These findings may be significant in further understanding the mechanisms of actions of camptothecins in the treatment of human cancers.