Investigating the relationship between IMP1 and APE1 in HEPG2 cells

The oncofetal IGF2-mRNA binding protein 1 (IMP1) is overexpressed in cancer and is thought to promote cancer by binding and stabilizing oncogenic mRNAs. However, the regulation of IMP1 expression remains poorly understood. This study shows for the first time that IMP1 expression is regulated by apurinic/apyrimidinic endonuclease 1 (APE1) in HepG2 liver cancer cells. The underlying mechanism whereby IMP1 is regulated by APE1 was investigated. APE1 was found to regulate IMP1 expression at the translational level without altering IMP1 mRNA expression. Evidence provided shows that the translational control of IMP1 by APE1 was at least partially attributed to the 3’UTR of IMP1. The combined studies from our laboratory suggest that APE1 is involved in the process of translation likely through regulating ribosome assembly and recruitment of IMP1 mRNA. Finally, this study shows that APE1’s role in regulating cell invasion is independent of IMP1.