Inhibition of SHP2 expression in human CB CD34⁺ cells using lentiviral vectors expressing SHP2-specific shRNA. (A) Constructs consisting of U6 promoter driving expression of control and SHP2 specific shRNA were polymerase chain reaction amplified and cloned into an HIV-7 lentiviral vector backbone. Expression of the DsRED selection marker was driven by a spleen focus-forming virus (SF) promoter. (B) Human CB CD34⁺ cells were transduced with lentiviral vectors carrying control (sh-Ctrla) and SHP2-specific shRNAs (sh-Shp2-1 and sh-Shp2-2), respectively. Representative results for CD34⁺ cell transduction are shown. (C) The purity of flow cytometry–selected CD34⁺DsRED⁺ cells was checked by reanalysis using flow cytometry. Representative results are shown. (D) Inhibition of SHP2 expression was examined using Western blotting. Representative results are shown. (E) Combined data for SHP2 inhibition are shown. Data are mean ± SEM of 3 experiments.