Fig. 2.

Stabilization of p53 in the HSPCs of mouse bone marrow by bortezomib. (A) Representative fluorescence-activated cell sorting (FACS) plots showing bone marrow cells stained for p53 or isotype controls from mice treated with Ctrl or BTZ, gated on different HSPC populations (n = 3 to 4). (A′) Quantification of p53-positive frequencies of HSPCs and mature cells from mice treated with Ctrl (in grey) or BTZ (in brown). The indicated P values were calculated by multiple unpaired t tests using Prism. *P < 0.05; **P < 0.001; ***P < 0.0001; ****P < 0.0001; ns, no significance. The error bars represent the mean (SEM) for each group. (B) Representative FACS plots showing the bone marrow cells stained for p53 or isotype control from mice treated with Ctrl or BTZ, gated on DC progenitors/precursors, matured DC and B/NK cells (n = 3 to 4). (C) Quantification of frequencies of various CD45⁺ HSPCs and mature cells from mice treated with Ctrl only. (D and E) Quantification of frequencies of p53⁺ in HSPCs and mature cells of CD45⁺ bone marrow cells from mice treated with Ctrl and BTZ. ΔCtrl and ΔBTZ were calculated to remove nonspecific staining (Δ = p53⁺ frequency − isotype⁺ frequencies). Note: 0.004% of CD45⁺ cells in Ctrl mice and 0.85% of CD45⁺ cells in BTZ-treated mice positive for p53, whereas 99.99%, and 99.15% CD45⁺ cells in Ctrl and BTZ-treated mice are p53 negative. (F) Duplex mRNA ISH analysis of Trp53/Kit in the bone marrow of p53 wild-type mice. (Scale bars, 20 μm.)