Indomethacin enhances p53 levels in bone marrow cells from xenograft mice. Bone marrow cells were harvested from xenograft REH mice, xenograft ALL#18 mice, or xenograft ALL#32 mice treated with indomethacin or vehicle for 4, 16, or 23 weeks, respectively. Cells were subjected to western immunoblot analysis with antibodies specific for human p53 as described in “Materials and methods." Calnexin was used as loading control. (A, left) Western immunoblot of p53 and calnexin expression from xenograft REH mice. Regular REH cells treated with and without irradiation (IR) were used as controls for human p53. (Right) Quantification from the immunoblot in the left panel of p53 band intensities relative to calnexin. Quantifications from immunoblots of p53 band intensities relative to calnexin from xenograft ALL#18 (B) and ALL#32 (C) mice. (A-C) Each circle represents the intensity of p53 relative to calnexin in 1 mouse. Horizontal lines represent the mean of each treatment group, *P < .01 (unpaired Student t test).