Fig. 5

ATRA inhibits the tumorigenesis of human leukemia cells and blocks multiple cancer-driving pathways in vitro and in vivo. a After 72 h incubation of different concentrations of ATRA, cell lysates were subjected to western blot analysis of the indicated proteins. b ATRA inhibits cell proliferation in indicated AML cell lines. After 3 days treatment of different concentrations of ATRA, cell growth was measured by CCK-8 analyses. c ATRA reduces colony formation in indicated AML cell lines. Cells were cultured in normal medium containing methylcellulose with or without ATRA (10 μM) for 1 or 2 weeks, followed by staining with p-iodonitrotetrazolium violet. d–f U937 cells were injected subcutaneously into flank of 7-week-old BALB/c nude mice, and the mice were randomly divided into placebo group and ATRA slow-releasing pellet group. Tumor volumes were measured and the tumor growth curves were plotted over time (d). Error bars represent standard deviations. Photographic illustration of tumors harvested from nude mice at the end point (e). Each scale of the ruler represents 1 mm. Weights of tumors harvested from nude mice at the end point (f). Error bar represents SEM. g Total proteins from xenograft tumor samples were subjected to western blot analysis of indicated Pin1 downstream oncoproteins. Statistically significant differences using Student’s t test are indicated by p values. (*p < 0.05, **p < 0.01, ***p < 0.001)