Lipocalin-2 suppresses normal hematopoietic cell growth through activation of the p53 pathway. (A) Average percent increase of apoptosis in parental 32D cells treated with each CM (n = 3 each). (B) Quantitative real-time PCR analysis of a subset p53 target genes in 32D cells treated with 32D-JAK2V617F CM relative to those with EV-32D CM (n = 3). (C) Immunoblotting of p53 and phospho-p53 in 32D cells incubated with CM of EV-32D, JAK2WT-32D, or JAK2V617F-32D with or without shRNA against Lcn2. (D-E) Immunoblotting of p53 and phospho-p53 in (D) 32D cells and (E) murine bone marrow c-Kit⁺ cells with or without exposure to 100 ng/mL lipocalin-2. (F) Average percent increase of apoptosis in murine bone marrow c-Kit⁺ cells when treated with 100 ng/mL lipocalin-2. (G) Relative cell numbers of wild-type or Trp53-deficient murine bone marrow c-Kit⁺ cells after 36 hours incubation with or without 100 ng/mL lipocalin-2 (n = 3 each). Error bars indicate SD. n.s., not significant.