姜黄素协同Glu-GNPs对乳腺癌干细胞放射增敏作用及其机制研究

Breast cancer has been the most dangerous malignant tumor for women. The recurrence , metastasis and irradiation resistance after radiation treatment of breast cancer are some hard problems in clinic. It was reported that breast cancer stem cells（BCSCs）had stronger irradiation resistance than the ordinary cancer cells in which DNA was not damaged easily. Therefore, we presume that BCSCs are the key points of irradiation resistance of breast cancer. Scientific studies have found irradiation resistance of breast cancer is related to the blood circulation blocked and radiation aggravating the disturbance of microcirculation. For the past few years，we prepared Glucose-gold nanoparticles (Glu-GNPs) assisted with radiation and found that they can enhance the irradiation of cytotoxicity targeting on cancer cells. Curcumin is a kind of compound extracted from the herb of Jianghuang which belongs to the herbs of promoting blood circulation and dissipating stasis. It is proved that Curcumin can promote the microcirculation, improve the oxygen content and the irradiation sensitivity in malignant cells. Recently, studies found Curcumin can resist the proliferation of BCSCs. Based on that, we are ready to observe the effect of decreasing irradiation resistance on BCSCs by using Curcumin and Glu-GNPs and explore the mechanism of irradiation sensitivity of them. The research will be the proof of improving the effect of radiation treatment and developing the drug of increasing irradiation sensitivity from traditional Chinese herbs.

乳腺癌高居女性恶性肿瘤发病率之首，其放疗后复发、转移及癌肿部位照射后的放疗抵抗是乳腺癌放射治疗的重要难题。已有报道乳腺癌肿瘤干细胞（BCSCs）较普通乳腺癌细胞抵抗电离辐射力增强，不易发生DNA损伤，因此推测BCSCs是乳腺癌对辐射产生放疗抵抗的关键所在。研究还发现乳腺癌对放疗的抵抗与肿瘤组织血液流通受阻、放射线加重微循环障碍等相关。前期我们构建偶联葡萄糖纳米金颗粒（Glu-GNPs）介导放疗，发现其能增强放射线对肿瘤的电离辐射能力，提高靶向治疗作用。姜黄素是传统活血化瘀类中药化合物，在改善微循环、增加癌细胞含氧量及对辐射敏感性等方面有独特的优势。新近研究发现姜黄素对BCSCs具有抑制作用。基于上，本项目拟以BCSCs为靶点，将姜黄素与Glu-GNPs联用，观察其对BCSCs放疗抵抗的综合作用，初步探讨其放射增敏作用机制。研究可为提高乳腺癌的放疗效果及活血化瘀中药放射增敏剂的开发提供依据。

项目背景：乳腺癌高居女性恶性肿瘤发病率之首，其放疗后复发、转移及癌肿部位多次照射后的放射抵抗是乳腺癌放射治疗的重要难题。有报道乳腺癌肿瘤干细胞（BCSCs）较普通乳腺癌细胞抵抗电离辐射力增强，推测BCSCs是乳腺癌产生放疗抵抗的关键所在。研究发现乳腺癌对放疗抵抗与肿瘤组织血液流通受阻、放射线加重微循环障碍等相关。前期我们构建偶联葡萄糖纳米金颗粒（Glu-GNPs）介导放疗，发现其能增强放射线对肿瘤电离辐射能力。姜黄素是传统活血化瘀类中药化合物，在改善微循环、增加癌细胞含氧量及辐射敏感性等方面有独特优势。.主要研究内容：本项目以顺铂为阳性对照，首先观察姜黄素对乳腺癌贴壁细胞MCF-7、MDA-MB-231增殖活性和克隆形成的影响及其对高转移乳腺癌细胞MDA-MB-231侵袭和迁移能力的作用，研究其干预作用是否与EMT转化进程相关。进而分离培养和鉴定乳腺癌悬浮球细胞，观察姜黄素对MCF-7，MDA-MB-231悬浮球干细胞表面标志物CD44+CD24-/low细胞亚群含量及球形成、分化能力的影响。在此基础上，研究姜黄素、Glu-GNPs及协同用药是否能够靶向提高放射线对BCSCs辐射敏感性，探讨其调控机制是否与克服乏氧，调节细胞周期变化与诱导肿瘤细胞凋亡有关。并建立裸小鼠MDA-MB-231-Luc移植瘤模型，小动物活体成像技术动态观察姜黄素协同Glu-GNPs辅助X-ray对荷瘤小鼠肿瘤生长的干预作用。.重要结果、关键数据及科学意义：研究发现姜黄素能够抑制MCF-7、MDA-MB-231细胞增殖活性、克隆形成及MDA-MB-231细胞侵袭和迁移能力，降低乳腺癌干细胞球形成和诱导分化能力及乳腺癌干细胞表面标志物CD44+ CD24-/low细胞亚群，抑制BCSCs干细胞相关基因，调节EMT标记物表达；姜黄素、Glu-GNPs协同用药能够靶向提高放射线对乳腺癌细胞辐射敏感性，降低HIF-1α、HSP90表达，促进MDA-MB-231细胞ROS活性，与克服乏氧、调节细胞周期与诱导肿瘤细胞凋亡有关。进一步在体动物实验研究表明，姜黄素协同Glu-GNPs辅助X-ray对荷瘤裸小鼠肿瘤生长具有抑制作用，降低移植瘤细胞HSP90表达。提示姜黄素有望成为防止乳腺癌侵袭、转移的有效药物，为探索应用中药化合物协同纳米金颗粒提高乳腺癌放疗效果提供新的视角。