温肾壮骨方对乳腺癌骨微转移骨髓血窦龛中休眠肿瘤细胞的作用及机制研究

Bone metastases are found in about 70% of advanced breast cancer patients. Dormant disseminated breast cancer cells could entry into and hide in bone marrow sinusoidal vascular regions or niche long time by interacting with E-selectin/SDF-1. The activated dormant disseminated tumor cells induce bone metastasis. Therefore, dormant tumor cells are an important risk factor for high incidence of bone metastases in advanced breast cancer. Evidence indicates that there is an important therapeutic window which by inhibiting dormant cancer cells in bone marrow sinusoidal niche for breast cancer bone metastasis. We believe that invigorating kidney could enhance bone tissue and thus reduce bone metastasis. Additionally, our previous works show that Wenshen Zhuanggu formula could inhibit breast cancer bone metastasis in clinical and experimental researches. However, the regulation of Wenshen Zhuanggu formula on dormant breast cancer cells in bone marrow sinusoidal niche is poorly understood. In order to provide a scientific basis and clinical guidance for breast cancer bone metastasis, the present project tries to investigate the effect and mechanism Wenshen Zhuanggu formula on dormant breast cancer cells in bone marrow sinusoidal niche, focus on E-selectin/SDF-1 signa pathways, using dormant breast cancer micrometastases in vitro and in vivo experiments.

约70%晚期乳腺癌患者最终会发生骨转移。乳腺癌细胞与E-selectin/SDF-1分子结合侵入骨髓血窦龛后保持休眠，形成骨微转移。休眠肿瘤细胞一旦被激活则诱发临床表现明显的骨转移。因此，休眠肿瘤细胞是晚期乳腺癌骨转移高发生率的重要潜在危险因子。提示防治骨转移存在一个重要治疗窗：可通过阻止无症状时期骨髓血窦龛中休眠乳腺癌细胞恶化扩张来抑制骨转移。课题组提出乳腺癌骨转移“肾虚骨空，癌毒旁窜”病机理论及“温肾壮骨”治法，前期临床及基础研究证实，以此理论为指导的“温肾壮骨方”具有良好抗乳腺癌骨转移效应。然而我们并不清楚温肾壮骨方对骨微转移骨髓血窦龛中休眠乳腺癌细胞是否有调控作用。本项目拟通过构建休眠性乳腺癌骨微转移细胞和小鼠模型，围绕E-selectin/SDF-1相关分子，探讨温肾壮骨方及主要成分对乳腺癌骨微转移骨髓血窦龛的影响及作用机制，最终为中医药防治乳腺癌骨转移提供科学依据和临床指导。

全球乳腺癌发病率位居第一，且女性死亡率第一。约70%晚期患者发生骨转移，遭受骨痛等困扰，严重降低患者生活质量。肿瘤细胞休眠是乳腺癌骨转移复发的重要因素之一。.我们前期临床实践与基础研究均表明温肾壮骨方可效防治乳腺癌骨转移发生与发展。然而温肾壮骨方是否会影响乳腺癌骨微转移骨髓血窦龛中休眠性肿瘤细胞的命运，从而最终抑制了休眠性乳腺癌细胞向骨转移的发生与发展。这将为中医药防治乳腺癌骨转移提供科学依据和临床指导。.本项目从体外细胞3D共培养、体内骨微转移小鼠模型以及生信分析与验证等多层面，发现温肾壮骨方激活了乳腺癌细胞中EGFR/ERK/MAPK信号通路，可通过调控骨转移微环境骨髓血窦龛中SDF-1、CXCR4和SLeX基因表达水平，将肿瘤细胞阻滞在S期，从而引发乳腺癌细胞凋亡，并抑制乳腺癌细胞休眠，最终减轻乳腺癌骨转移进展。此外，温肾壮骨方预防性给药具有更佳的乳腺癌骨转移抑制作用。