PTEN acts upstream to determine the p42/p30 C/EBPα ratio and CTNNA1 expression. (A) Western blot analysis of PTEN protein levels in HL-60, NB4, and KG-1 cells. (B) Effects of lentivirally mediated overexpression of PTEN on α-catenin protein levels in HL-60 and NB4 cells as determined by Western blot analysis. (C) Effects of lentivirus-mediated overexpression of PTEN on H3K27me3 modification at the P1E1 site. (D-E) Western blot and quantitative real-time RT-PCR analyses of murine C/ebpα protein and Ctnna1 transcripts in MNCs and FACS-sorted Lin⁻c-Kit⁺ myeloid progenitors from Pten^−/− knockout mice,¹⁵  respectively. The Arabic numerals at the bottom of panel D denote the p42/p30 ratio. (F) FACS-sorted c-Kit⁺ myeloid progenitors from Pten^−/− knockout mice were infected with MSCV-IRES-GFP or MSCV-p42 C/ebpα-IRES-GFP. FACS-GFP positive cells were serially plated on methylcellulose and colonies were counted (n = 3). (G) FACS-sorted c-Kit⁺ myeloid progenitors from wild-type mice were infected with MSCV-IRES-GFP or MSCV-p30 C/ebpα-IRES-GFP. FACS-sorted GFP⁺ cells were serially plated on methylcellulose and colonies were counted (n = 3).