ShRNA targeting Notch1 sensitizes breast cancer stem cell to paclitaxel
ShRNA targeting Notch1 sensitizes breast cancer stem cell to paclitaxel
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靶向Notch1的ShRNA使乳腺癌干细胞对紫杉醇敏感
DOI：
10.1016/j.biocel.2013.02.022
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发表时间：
2013-06-01
影响因子：
4
通讯作者：
Li, Lianhong
中科院分区：
文献类型：
--
作者：
Mao, Jun;Song, Bo;Li, Lianhong
乳腺癌是目前许多国家最致命的妇科恶性肿瘤，紫杉醇是治疗这种恶性肿瘤的基石。不幸的是，由于耐药性的发展，紫杉醇的疗效有限。有证据表明，癌症干细胞（CSCs）参与了对包括化疗在内的各种形式治疗的耐药性。然而，紫杉醇耐药与CSCs之间的相互作用及其潜在机制尚未被探索。在这项研究中，我们证实了紫杉醇在MCF-7人乳腺癌细胞系中以剂量依赖的方式富集乳腺CSCs （CD44+/CD24-）。我们随后证明，与非CSCs相比，Notch1在从紫杉醇处理的MCF-7细胞分离的乳腺CSCs中过表达。短发夹RNA （short hairpin RNA, shRNA）介导的Notch1敲低抑制MCF-7细胞增殖，诱导细胞凋亡。shRNA-Notch1可显著降低细胞抗凋亡蛋白NF-kappa B的表达，而与紫杉醇联合使用可显著改善这一作用。紫杉醇下调Notch1后，可降低MCF-7细胞中的CD44+/CD24-细胞群，减少原代乳腺球的大小和数量。shRNA-Notch1对裸鼠移植瘤生长有明显抑制作用。RT-PCR和Western blotting分析显示，体外和体内ALDH1、NICD、Hes-1和药物转运体ABCG2的表达均降低。这些结果提示Notch1可能在紫杉醇耐药中起关键作用，靶向Notch1可能在癌症治疗中具有重要的临床应用价值。(C) 2013 Elsevier Ltd.版权所有。
Breast cancer is currently the most lethal gynecologic malignancy in many countries, and paclitaxel is a cornerstone in the treatment of this malignancy. Unfortunately, the efficacy of paclitaxel is limited due to the development of drug resistance. Evidence has suggested that cancer stem cells (CSCs) are involved in resistance to various forms of therapies, including chemotherapy. However, the interaction between paclitaxel resistance and CSCs and its underlying mechanisms have not been previously explored. In this study, we confirmed that paclitaxel enriched breast CSCs (CD44+/CD24-) in a dose-dependent manner in MCF-7 human breast cancer cell line. We then demonstrated that Notch1 was overexpressed in breast CSCs isolated from paclitaxel-treated MCF-7 cells compared to non-CSCs. The short hairpin RNA (shRNA) mediated knock-down of Notch1 inhibited MCF-7 cell proliferation and induced cell apoptosis. The antiapoptosis protein NF-kappa B was decreased significantly when treated with shRNA-Notch1, and this effect was sharply improved by combination with paclitaxel. Paclitaxel decreased CD44+/CD24- cell population in MCF-7 cells and reduced the size and number of primary mammospheres after down-regulating the Notch1. Furthermore, shRNA-Notch1 inhibited the growth of tumor xenografts in nude mice noticeably. RT-PCR and Western blotting analysis showed that the expressions of ALDH1, NICD, Hes-1 and the drug transporter ABCG2 were decreased both in vitro and in vivo. These results suggest that Notch1 might play a critical role in the resistance to paclitaxel, and targeting Notch1 may have important clinical applications in cancer therapy. (C) 2013 Elsevier Ltd. All rights reserved.