Cell-in-cell指一个或多个细胞主动“钻入”另一个细胞的胞质中形成细胞叠套结构并产生生物效应的过程。我们发现，胃癌、乳腺癌等多种肿瘤组织中肿瘤细胞表达巨噬细胞特异性表面标志物CD163，同时检出高表达CD163的巨噬细胞能与肿瘤细胞形成cell-in-cell，两者呈现相关性；而表达巨噬细胞特异性表面标志物的肿瘤细胞表现出更强的转移侵袭能力同时患者表现出更差的生存预后特点。肿瘤细胞通过何种机制产生巨噬细胞的特性？更新后的肿瘤细胞具有哪些新的功能？这些问题目前仍未知。本课题聚焦cell-in-cell过程参与肿瘤细胞表达巨噬细胞表面标志物的机制研究，探讨具有巨噬细胞特性的肿瘤细胞功能改变的规律，为解析单个细胞水平上巨噬细胞-肿瘤细胞相互作用提供独具特色的研究切入点，也为研究肿瘤转移侵袭提供了全新视角，具有重要的理论基础和临床研究价值。

Cell-in-cell process is characterized by one or more live cells (reffered to effector cells) internalizing into another cells (reffered to host cells) with the alteration of biological effect of both effector and host cells. Researchers reported cancer expression CD163 is related to early distant recurrence and reduced patient survival. Recently, we observed in tissue specimens many kinds of cancer expression of CD163, a macrophage scavenger receptor, which is correlated with cell-in-cell occurance between CD163+ macrophage and tumor cells. We explored in vitro a novel interaction that macrophages penetrating into tumor cells for tumor cells acquiring macrophage character led to tumor cells invasion. Unlike conventional macrophage engulfing apoptotic cells, this process was initiated by tumor cells uptaking macrophage through cell-in-cell interaction. We supposed that this process might be a manner for tumor cells acquiring cellular identity of macrophage, which is associated with migration. In the present study, we aim to clarify the mechanism of tumor cells expression macrophage marker by cell-in-cell process, which in turn leads to the tumor cells invasion and metastasis. To explore the mechanism of tumor cells acquiring new character and its significance will provide a way to elucidate the tumor cell conversion, as well as potential implication in tumor histogenesis and aggressiveness.