Figure 5.
IGF2BP2 binds to mRNAs and regulates multiple oncogenic genes, including NRAS. A, IGF2BP2 binds to mRNAs of Igf2, Ccnd2, NRas, Ran, RhoA, and Sp1, but not GAPDH, MYOD, and HMGA2. **, P < 0.01, Student t test, IGF2BP2 antibody versus IgG control. B, IGF2BP2 binds to the 3′UTR of NRAS mRNA. C, IGF2BP2 regulates the stability of NRAS mRNA. After IGF2BP2 shRNA treatment, NRAS mRNA half-life (T1/2) is reduced from 6.3 to 3.9 hours. HMGA2 shRNA reduces half-life to 3.5 hours. D, knockdown of IGF2BP2 reduces NRAS protein levels. Five different shRNAs were used to knock down IGF2BP2; NRAS protein levels correlate well with IGF2BP2 knockdown efficacy. E, knockdown of HMGA2 reduces the NRAS protein level in ERMS cells. F, IGF2BP2 stabilizes NRAS-3′UTR-luciferase protein. Luciferase assays show a dose-dependent increase of luciferase activity with IGF2BP2 overexpression. *, P < 0.01, Student t test.