shRNA down-regulation of Notch signaling inhibits growth of ZNF112 cells and diminishes/reduces leukemogenesis in mice grafted with ZNF112 cells. (A) Schematic view of the Notch1 signaling pathway identifying the target points of the shRNAs. (B) ZNF112 cells infected with retroviral shNotch1 or shMAML1 resulted in down-regulation of Ptera and Dtx3l transcription levels (top left panel). The activated form of Notch3 was also down-regulated (bottom left panel), as was cell-surface expression of CD25 (right panel). (C) Stable knock-down of either Notch1 or its coactivator, MAML1, led to reduced in vitro proliferation in ZNF112 cells. (D) Syngeneic female Balb/c mice were transplanted with ZNF112 cells (n = 10) carrying shNotch1, shMAML1, or shLuc (control). Survival time in the mice receiving the Notch-inhibited cells was markedly prolonged.