Fig. 3
MSI2 is overexpressed in AML and facilitates leukemogenesis (A) Relative expression of MSI2 mRNA was determined in BM aspirates from healthy donors (N = 14) and newly diagnosed AML patients (N = 58). (B) Relative expression of MSI2 mRNA was exhibited in different FAB subtypes. (C) AML patients were divided into the MSI2 high expression group (≥ 11.861, N = 21) and low expression group (< 11.861, N = 37) according to the optimal cutoff value (11.861) for risk score and the OS of the patients was observed (P = 0.05). (D) Effect of MSI2 knockdown using siRNAs on the cell growth was detected in HEL cells by CCK-8 assay. (E) The clonogenic capacity of KG-1α, HL-60, HEL cells and patient AML blasts was weakened after siR-MSI2 transfection. (F) Agarose gel electrophoresis (left panel) and RIP-PCR (right panel) were used to test the interaction between MSI2 protein and DLL1 mRNA. *P < 0.05 vs. IgG. (G) Half-life (t1/2) of DLL1 transcripts in MSI2-OE. HEL and NC. HEL cells were shown in exponential regression curves (left panel) and statistical analysis diagram (right panel). (H) Relative expression of MSI2 and HES1 mRNA was determined in BM aspirates from healthy donors (N = 14) and newly diagnosed AML patients (N = 58). Correlation between MSI2 mRNA expression and HES1 mRNA expression was assessed (P < 0.001, R = 0.47, N = 72). (I) AML patients were divided into the HES1 high expression group (≥ 0.062, N = 22) and low expression group (< 0.062, N = 36) according to the optimal cutoff value (0.062) for risk score and the OS of the patients was observed (P = 0.14). (J) Core components of Notch1 signaling including NOTCH1 ligand (DLL1), cleaved NOTCH1 (c-NOTCH1) and HES1, and cancer stemness-related proteins including NANOG, OCT4 and SOX2 were determined in HEL and HL-60 cells transfected with siR-MSI2 or siR-NC by western blot. (K) Key factors of Notch1 signaling pathway and cancer stemness-related proteins were determined in Lenti- DLL1 vector- or Lenti- Control vector-transfecting KG-1α cells after the transfection with siR-MSI2 or siR-NC. (L) Colony formation was performed in Lenti- DLL1 vector- or Lenti- Control vector-transfecting KG-1α cells after the transfection with siR-MSI2 or siR-NC. Representative plots (above) and statistical analysis diagram (below) were illustrated. Data are expressed as mean ± SD (error bars). * P < 0.05, ** P < 0.01 and ***P < 0.001, t-test