三维微环境调控肿瘤干细胞EMT表型及其在乳腺癌侵袭转移中的分子机制研究

Invasion and metastasis are the primary causes of deaths in breast cancer patients while their mechanisms are still not clear. Epithelial-mesenchymal transition (EMT) might play an important role in these processes. Whether EMT is intimately correlated with the acquirement and maintenance of characteristics of breast cancer stem cells? Our research has revealed that three-dimensional (3D) collagen scaffold culture could promote the EMT of breast cancer cells and enhance the invasion ability in vitro and tumorigenesis ability in vivo. We summarized the research results of correlation between EMT and cancer stem cells and propose a hypothesis that 3D collagen scaffold can be used as a new model in vitro to study the correlations between cancer stem cells and EMT, the maintenance of characteristics of cancer stem cells and then the regulation of the invasion and metastasis of breast cancer. Our project focuses on the EMT phenotype of breast cancer stem cells, clarifies the important role of CD54 by studies in vivo and in vitro and detecting of circulating cancer stem cells in breast cancer patients' blood. Furthermore, we investigate whether the blockage of NF-kappa B pathway could inhibit the EMT process and change the properties of breast cancer stem cells and the lung metastasis effects in nude mice, in order to reveal the role of NF-kappa B pathway on the EMT process and breast cancer stem cells. Our research will provide theoretical and practical basis for blockage of the EMT and then the inhibition of invasion and metastasis of breast cancer.

侵袭转移是乳腺癌患者死亡的主要原因，但乳腺癌侵袭转移机制仍不清楚。EMT（上皮-间质转化）可能是重要机制，EMT是否和乳腺癌干细胞特性的获得和维持密切相关？我们的前期研究结果揭示三维胶原基质可提高乳腺癌细胞的EMT并增强体外侵袭及体内成瘤能力。我们总结了EMT和肿瘤干细胞理论之间的研究成果，提出"三维胶原微环境可用作新的体外培养模型研究乳腺癌肿瘤干细胞与EMT的相关性，肿瘤干细胞特性的维持以及乳腺癌的侵袭转移"，本课题以EMT表型的乳腺癌肿瘤干细胞为切入点，通过三维胶原培养模型、裸鼠体内模型，及临床患者循环血干细胞检测，阐明CD54的标记意义，探讨封闭NF-kappa B通路是否可抑制EMT，乳腺癌干细胞特性是否发生改变，及其对裸鼠肺转移模型的影响，从而揭示NF-κB通路在乳腺癌EMT和肿瘤干细胞理论中的作用，为阻断EMT进而遏制乳腺癌侵袭转移奠定理论基础和实验依据。

侵袭转移是导致乳腺癌患者死亡的主要原因，但乳腺癌侵袭转移机制仍不清楚。上皮-间质转化（EMT）可能是重要机制，EMT与乳腺癌干细胞（CSCs）特性的获得和维持密切相关。我们的研究结果揭示三维胶原基质可提高乳腺癌细胞的EMT并增强体外侵袭及体内成瘤能力。通过总结EMT和肿瘤干细胞理论之间的研究成果，本课题提出"三维胶原微环境可用作新的体外培养模型研究乳腺癌肿瘤干细胞与EMT的相关性、肿瘤干细胞特性的维持以及乳腺癌的侵袭转移"，研究以EMT表型的乳腺癌肿瘤干细胞为切入点，通过三维胶原培养模型、流式细胞分析、周期分析、蛋白及分子定量分析、裸鼠体内模型以及侵袭迁移能力检测，揭示了乳腺癌CSCs与EMT的相关性，阐明了EMT表型的CSCs在乳腺癌侵袭转移中的作用，研究了阻断乳腺癌EMT的途径，进而为遏制乳腺癌侵袭转移奠定理论和实验依据。同时，提出CD54在CSCs侵袭转移中的重要性，将其应用于干性检验中，对EMT表型的CSCs进行检测，揭示了CD54与EMT及CSCs的直接联系，阐明了CD54的标记意义。通过封闭NF-κB通路以抑制乳腺癌细胞的EMT，使乳腺癌干细胞特性发生改变，从而揭示NF-κB通路在乳腺癌EMT和侵袭转移中的作用，为阻断EMT进而遏制乳腺癌侵袭转移奠定理论基础和实验依据。