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Purpose: This study aimed to identify novel biological markers for the prediction of colorectal cancer liver metastasis. Experimental Design: We established two models that mimicked the interactions between colorectal tumor cells and the liver microenvironment. From these models we established subcell lines that had an enhanced ability to metastasize to the liver. Genes that related to hepatic metastasis were screened by microarray. The candidate markers were tested by immunohistochemistry, and their predictive accuracy was assessed by the cross-validation method and an independent test set. Results: Highly metastatic colon cancer cell sublines SW1116p21 and SW1116v3 were established from the tumor cell-microenvironment interaction models. Seven of the upregulated genes in the sublines were selected as candidate markers for predicting metastatic potential. A total of 245 colorectal cancer samples were divided into a training set containing 117 cases and a test set containing 128 cases. In the training set, immunohistochemical analysis showed CCL2 and SNCG expression was higher in the hepatic metastasis group than in the nonmetastasis group, and was correlated with poor survival. Logistic regression analysis revealed that CCL2 and SNCG levels in primary tumors, serum carcinoembryonic antigen level, and lymph node metastasis status were the only significant (P < 0.05) parameters for detecting liver metastasis. In leave-one-out-cross-validation, the two markers, when combined with clinicopathologic features, resulted in 90.5% sensitivity and 90.7% specificity for hepatic metastasis detection. In an independent test set, the combination achieved 87.5% sensitivity and 82% specificity for predicting the future hepatic metastasis of colorectal cancer. Conclusion: Our results suggest that these models are able to mimic the interactions between colorectal cancer cells and the liver microenvironment, and may represent a promising strategy to identify metastasis-related genes. CCL2 and SNCG, combined with clinicopathologic features, may be used as accurate predictors of liver metastasis in colorectal cancer. (Clin Cancer Res 2009;15(17):5485-93) Colorectal carcinoma is one of the major causes of cancer death worldwide (1). Liver is the most common target for metastasis in patients with this disease. It is estimated that approximately 50% of colorectal cancer patients develop liver metastases, with 15% to 25% of synchronous and 20% of heterochronous cases (2). Liver metastasis is the most critical prognostic factor for colorectal cancer. The 5-year overall survival rate of patients with hepatic metastasis is only 25% to 40%

There is a microcirculation system within the islets of Langerhans. However, little is known about the phenotypic and functional characterization of islet microvascular endothelial cells (MVEC). In this study, we purified MVEC from human pancreatic islets by using Ulex europaeus (Sigma, St. Louis, MO) agglutinin-1 (UEA-1)-coated dynabeads (Dynal A.S., Oslo, Norway). These purified human islet MVEC (HI-MVEC) express von Willebrand factor, take up high levels of acetylated LDL, and upregulate endothelial cell leukocyte adhesion molecule 1 in response to tumor necrosis factor-alpha. Ultrastructure examination shows the presence of microvilli and fenestrations on the cell surface, Weibel-Palade bodies in the cytoplasm, and tight junctions between cells. Furthermore, we show that vascular endothelial cell growth factor contributes to the formation of surface fenestrations on cultured HI-MVEC. After purification, HI-MVEC exhibit a very low proliferation capacity and are strongly resistant to trypsin, compared with other original MVEC. We also demonstrate that alpha-1 proteinase inhibitor (Api) is expressed on HI-MVEC and specifically located at the area of cell-cell junctions. By reverse transcription-polymerase chain reaction, a significant messenger RNA band of Api was found only in HI-MVEC, but not in other organ-derived MVEC, indicating that expression of Api is islet MVEC specific. Antibodies to Api significantly reversed the resistance to trypsin and promoted proliferation of HI-MVEC, suggesting that these specific functional characteristics of HI-MVEC are related to the expression of Api. These results indicate that HI-MVEC exhibit some specific morphological and functional characteristics that differ from MVEC derived from other organs.