约15％的结直肠癌患者初诊时已发生肝转移，其确切机制不明。我们前期发现血清miR141在结直肠癌肝转移患者中高表达，转移灶组织中miR141靶蛋白ZEB1、SIP1的表达与EMT标志物E-cadherin表达有明显相关性。我们推测miR141通过对靶基因ZEB1、SIP1调控介导结直肠癌肝转移。为证实这一假说，首先，我们在结直肠癌组织中分析miR141、靶基因及EMT标志物与结直肠癌肝转移患者临床病理学特征的关系；其次，在细胞学水平通过miRNA干扰及靶基因过表达、敲减等技术，分析miR141、靶基因与EMT标志物的表达，揭示该通路调控结直肠癌肝转移的机制；第三，通过前期建立的肝转移裸鼠模型，探讨miR141通过靶基因参与结直肠癌肝转移的动物试验在体研究，为结直肠癌肝转移治疗提供新的靶点。

Colorectal cancer is a common gastrointestinal malignancy in china, about 15% of newly diagnosed patients have occurred liver metastases. However, the exact mechanism of liver metastases has not been elucidated. The research group found that serum miR141 was high expression in patients of colorectal cancer with liver metastases. It was also found that there was significant correlation between the expression ZEB1,SIP1 target proteins of miR141 and E-cadherin the expression biomarkers of EMT in metastatic tumor tissue. we hypothesized that miR141/ZEB1,SIP1 pathway is involved in colorectal cancer liver metastases. In order to confirm this hypothesis, we would analyze the miR141/ZEB1,SIP1/EMT pathway relationship with liver metastases of colorectal cancer clinicopathological features in colorectal cancer tumor. We have established an animal model of colorectal cancer with liver metastases and colorectal cancer cell lines, to further observe the correlation of miR141 and its target genes expression with biomarkers of EMT by using techniques such as molecular biology. This study revealed miR141/ZEB1,SIP1/EMT regulation pathway participated in colorectal cancer liver metastases. It preliminarily evaluated for exploring pathophysiologic mechanism and the treatment interventions of colorectal cancer with liver metastases. 

在结直肠癌转移机制研究中，相关基因和通路主要包括：RAS-MAPK，TGF-β，PTEN/ PI3K/Akt，Notch，Wnt，Smad等，目前对结直肠癌肝转移的机制研究尚未完全阐明，本研究内容主要目的是探讨miR141如何通过对靶基因ZEB1、SIP1的调控介导结直肠癌肝转移的机制。我们首先通过细胞学水平研究，构建重组慢病毒LV3-miR-141进行MicRNA过表达研究，构建重组慢病毒LV3-miR-141 inhibitor进行MicRNA表达干扰研究；其次我们进行了动物实验在体研究，以转染重组慢病毒LV3-miR-141（过表达）的结直肠癌细胞，进行裸鼠皮下成瘤及结直肠肝转移瘤实验，以重组慢病毒LV3-miR-141 inhibitor 进行MicRNA表达干扰进行反向验证。重要结果：⑴建立miR141高表达和低表达的细胞系模型；⑵证实了过表达miR141会明显抑制结肠癌细胞的转移侵袭；⑶过表达miR141抑制结肠癌细胞在裸鼠体内皮下的增殖，同时抑制裸鼠肝脏转移瘤的成瘤。关键数据：⑴选择人结肠癌HCT116和SW480细胞系作为研究对象，建立miR141高表达和低表达细胞系模型，同时我们测定不同miR141表达情况下ZEB1/2的表达情况，发现抑制miR141表达情况下会明显导致ZEB2（SIP1）的高表达；⑵通过transwell迁移实验、裸鼠脾脏注射肝转移成瘤实验，检测miR 141高表达及低表达细胞的侵袭、转移能力，结果说明了miR141低表达后，促进了结肠癌细胞的转移侵袭；⑶我们首先应用裸鼠皮下成瘤实验以确定miR141对结肠癌细胞体内增殖能力的影响。miR 141低表达细胞在裸鼠体内的成瘤能力更强，生长速度更快，即miR141低表达后，促进了结肠癌细胞在体内的增殖。科学意义：通过细胞学及动物实验研究，初步证实了miR-141可能通过miR141/SIP1 /EMT通路介导结直肠癌肝转移的机制，为结直肠癌肝转移提供新的精准治疗靶点。