Breast cancer metastasis is responsible for most breast cancer-related deaths and is influenced by many factors within the tumor ecosystem, including tumor cells and microenvironment. Breast cancer stem cells (BCSCs) constitute a small population of cancer cells with unique characteristics, including their capacity for self-renewal and differentiation. Studies have shown that BCSCs not only drive tumorigenesis but also play a crucial role in promoting metastasis in breast cancer. The tumor microenvironment (TME), composed of stromal cells, immune cells, blood vessel cells, fibroblasts, and microbes in proximity to cancer cells, is increasingly recognized for its crosstalk with BCSCs and role in BCSC survival, growth, and dissemination, thereby influencing metastatic ability. Hence, a thorough understanding of BCSCs and the TME is critical for unraveling the mechanisms underlying breast cancer metastasis. In this review, we summarize current knowledge on the roles of BCSCs and the TME in breast cancer metastasis, as well as the underlying regulatory mechanisms. Furthermore, we provide an overview of relevant mouse models used to study breast cancer metastasis, as well as treatment strategies and clinical trials addressing BCSC-TME interactions during metastasis. Overall, this study provides valuable insights for the development of effective therapeutic strategies to reduce breast cancer metastasis.
肿瘤转移是导致乳腺癌患者死亡的重要原因，这一过程受到肿瘤微生态系统中多种因素的影响，后者主要由肿瘤细胞本身和肿瘤微环境组成。乳腺肿瘤干细胞是一小群拥有自我更新和分化能力的特殊肿瘤细胞。过去的研究表明，乳腺肿瘤干细胞不仅驱动肿瘤的发生，而且在乳腺癌转移中也发挥十分重要的作用。肿瘤微环境由基质细胞、各种免疫细胞、血管细胞、成纤维细胞和微生物等构成，它们可以与乳腺肿瘤干细胞相互作用并促进其在肿瘤组织中的存活、生长以及转移。因此，了解乳腺肿瘤干细胞和肿瘤微环境的相互作用有助于理解乳腺癌转移的潜在机制。本文中，我们就目前关于乳腺肿瘤干细胞与肿瘤微环境相互作用进而调控乳腺癌转移的功能和分子机制进行了综述。另外，我们还总结了目前应用于研究乳腺癌转移过程的小鼠模型，以及现有乳腺癌转移治疗策略和相关临床试验，旨在为开发更有效的乳腺癌转移治疗策略提供帮助。.
Keywords: Breast cancer; Cancer stem cell; Ecosystem; Metastasis; Mouse model; Tumor microenvironment.