乳腺导管内癌发生浸润过程中腺上皮细胞与肌上皮细胞相互作用的研究

Ductal carcinoma in situ (DCIS) is the precursor lesion of invasive breast cancer， by timely treatment can survive for 10 years or longer ; however, if progress to invasive cancer , the prognosis was significantly worse. With respect to invasive breast cancer, DCIS in clinical and basic research has been an ignored area, and the causes and biological mechanisms of DCIS progress to invasive breast cancer are not very clear, so it is urgent to need study the key issue in-depth. Our team proposed the hypothesis : With the progress of DCIS , EMT gives DCIS epithelial cell infiltration characteristics ; DCIS associated myoepithelial cells exhibit abnormal behavior , loss of inhibition of infiltration of the previous function ; in addition, microenvironment changes , they promote and facilitate the progress from DCIS to invasive cancer together. Our project intends to use co-culture system, Westeron-blot, Transwell, wound scratch assay, TUNEL and other technologies to study the molecular mechanism of the interactions between epithelial cells and myoepithelial cell from in situ to invasive stage, at the the level of cellular, animal and human. The results may identify suitable molecular targets blocking infiltration occurred, and find early intervention and treatment for DCIS.

导管内癌（DCIS）是浸润性乳腺癌的前趋病变，经及时治疗可生存10年或更长；若进展为浸润性癌，预后明显变差。相对于浸润性乳腺癌，DCIS在临床和基础研究中一直是被忽视的领域，DCIS进展到浸润性乳腺癌的原因和生物学机制并不是十分清楚，迫切需要作为一个关键的科学问题进行深入研究。本课题组提出假说：随着导管内癌进展，EMT赋予导管内癌腺上皮细胞浸润的特征；导管内癌相关的肌上皮细胞表现出异常行为，失去了以往的抑制浸润的功能；同时组织微环境发生改变，共同推动和促进乳腺导管内癌进展为浸润性癌。本项目拟通过细胞共培养体系、Western-blot、Transwell、划痕实验和TUNEL等技术,在细胞水平和人体水平研究乳腺导管内癌发生浸润过程中腺上皮细胞与肌上皮细胞相互作用的分子机制，研究结果将找出适用于乳腺导管内癌阻断浸润发生的分子靶标，针对具有浸润潜能的导管内癌进行适宜的早期干预和治疗。

本课题针对“乳腺导管内癌发生浸润过程中腺上皮细胞与肌上皮细胞相互作用的研究”进行探讨。主要观察腺上皮EMT的发生和肌上皮的表型改变在导管内癌浸润发生中的作用；首先检测了导管内癌和微浸润性癌之间肌上皮表达差异和腺上皮中EMT相关指标的表达差异；之后选取腺上皮表型细胞系MCF-7，肌上皮表型细胞系MD-MBA-231和Hs 578Bst；诱导MCF-7细胞系发生EMT后与肌上皮表型细胞MD-MBA-231进行共培养72小时，检测MD-MBA-231的变化；继而采用另一种更精确的肌上皮细胞系Hs 578Bst和腺上皮细胞MCF-7进行共培养，观察腺上皮细胞MCF-7的变化。结果显示：1、部分导管内癌肌上皮发生缺失，微浸润性癌中EMT表达则高于导管内癌；2、发生EMT改变的腺上皮细胞和肌上皮细胞共培养后，肌上皮表型和功能均发生了变化，分泌功能也发生了变化，如MMP9和IL-6的分泌均明显增加，结果提示：肌上皮固有的保护作用可能被削弱，甚至肌上皮已经具有了促进导管内癌浸润发生的功能；3、在肌上皮和腺上皮共培养后，检测腺上皮的结果中发现：腺上皮细胞均发生了明显EMT改变，侵袭和迁移能力明显提高，结果提示：肌上皮细胞的改变诱导了腺上皮细胞发生EMT，肌上皮细胞和腺上皮细胞二者相互影响形成恶性循环，进而促进导管内癌浸润的发生。更精确的机制有待进一步探讨。