A phosphatase associated with metastasis of colorectal cancer

To gain insights into the molecular basis for metastasis, we compared the g lobal gene expression profile of metastatic colorectal cancer with that of primary cancers, benign colorectal tumors, and normal colorectal epithelium . Among the genes identified, the PRL-3 protein tyrosine phosphatase gene w as of particular interest. It was expressed at high levels in each of 18 ca ncer metastases studied but at lower levels in nonmetastatic tumors and nor mal colorectal epithelium. In 3 of 12 metastases examined, multiple copies of the PRL-3 gene were found within a small amplicon located at chromosome 8q24.3. These data suggest that the PRL-3 gene is important for colorectal cancer metastasis and provide a new therapeutic target for these intractabl e lesions.