Glioblastoma is a diffusely growing malignant brain tumor and among the most aggressive of all tumors. Wilms' tumor 1-associating protein (WTAP) is a nuclear protein that has been associated with regulation of proliferation and apoptosis. Although its dynamic expression and physiological functions in vascular cells have been reported, those in other cells are largely unknown. Here, we show for the first time that WTAP is overexpressed in glioblastoma. Moreover we found that WTAP regulates migration and invasion of glioblatoma cells. Specific knockdown by siRNA or overexpression by cDNA regulated migration and invasion of cancer cells. In xenograft study, WTAP overexpression made cancer cells more tumorigenic. In the investigation for its underlying mechanism, we found that the activity of epidermal growth factor receptor can be regulated by WTAP. These results reveal a novel function of WTAP and suggest its clinical application. (Cancer Sci 2012; 103: 2102-2109

Nuclear protein-1 (NUPR1) is a small nuclear protein that is responsive to various stress stimuli. Although NUPR1 has been associated with cancer development, its expression and roles in cholangiocarcinoma have not yet been described. In the present study, we found that NUPR1 was over-expressed in human cholangiocarcinoma tissues, using immunohistochemistry. The role of NUPR1 in cholangiocarcinoma was examined by its specific siRNA. NUPR1 siRNA decreased proliferation, migration and invasion of human cholangiocarcinoma cell lines (HuCCT1 and SNU1196 cells). From these results, we conclude that NUPR1 is over-expressed in cholangiocarcinoma and regulates the proliferation and motility of cancer cells.