肿瘤转移微环境和细胞侵袭力在结肠癌肝转移过程中起重要作用，作为结肠癌患者常伴有的内毒素血症，LPS可以促进结肠癌肝转移，我们前期研究结果也证实这个现象，但LPS对体内散播的"种子（转移肿瘤细胞）"和它生存的"土壤（适宜肿瘤细胞生存的局部微环境）"的影响以及其中内在联系目前仍未明确。本课题拟在前期研究基础上，采用结肠癌转移动物模型观察LPS是否促进结肠癌细胞肝转移；其次，一方面研究LPS对结肠癌细胞EMT表型的影响，观察对细胞本身侵袭潜力的作用，并筛选关键作用分子，另一方面，研究LPS对肝脏微环境的影响，观察对结肠癌细胞的趋化作用，并探讨其具体的分子机制；最后结合临床结肠癌肝转移组织标本，检测外周血中LPS与组织标本中相关分子表达与结肠癌肝转移及预后的的相关性。预期研究结果有助于阐明LPS对结肠癌肝转移的影响及机制，为寻找结肠癌肝转移干预的新策略研究提供前期基础。

Tumor microenvironment and cell invasion play an important role in the process of colorectal liver metastases. Colon cancer patients often accompanied by some endotoxemia, and LPS can promote colon cancer liver metastases. Our previous findings also confirmed this phenomenon, but the influence of LPS on seeds "metastatic tumor cells" spread to body , and the soil "local microenvironment suitable for tumor cell survival", as well as intrinsic link are still not clear. On the basis of previous studies, this topic is intended to study wheather LPS promotes colorectal liver metastases by using colon cancer metastasis animal models; Secondly, on the one hand, we detect the effect of LPS on colon cancer cell EMT phenotype, and observe the invasive potential of the cells, screen the key molecular, on the other hand, we investigate the influence of LPS on liver injury, and observe the function of chemotaxis to colon cancer cells, as well as exploring the specific molecular mechanisms; Finally, combination with the clinical tissue specimen of colorectal liver metastasis, we detect the correlation of LPS in peripheral blood and related molecules expression in tissue , which provides a new method for colorectal liver metastases recurrence and prognosis. This subject demonstrates the effects of LPS on colorectal liver metastases from a new perspective, and deepens the understanding of the "seed and soil" theory of tumor metastasis.