IMP-3 (insulin-like growth factor-IImRNA-binding protein 3, IGF2BP3), known as L523S and KOC, is a member of the insulin-like growth factor (IGF) messenger RNA (mRNA)-binding protein (IMP) family. It binds to and regulates IGF-II transcripts and is involved in the post-transcriptional regulation of cell proliferation during embryogenesis. Our microarray analysis of 50 paired gastric cancer and non-cancerous samples revealed that IMP-3 is overexpressed in gastric cancer. The abundant expression of IMP-3 mRNA was detected in various types of cancer cell lines (including gastric, pancreas, colon, lung, mesothelioma, breast, ovary, leukemia and HUVEC) using real-time RT-PCR. IMP-3 expression in clinical cancer tissues was also confirmed. To clarify the biological function of IMP-3 expression, full-length IMP-3 was cloned into a retroviral vector and introduced into HEK293 and NIH3T3 cells. Overexpression of IMP-3 enhanced the cellular proliferation compared with the control cells in these cell lines. In addition, IMP-3 increased cellular mobility and ability of adhesion detected by adhesion assay. These data suggest that IMP-3 plays key roles in oncogenic activity in gastric cancer.
99th AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA