Reduced treatment efficacy, SC effects, and molecular insights into smoking induced proliferative signaling in vivo. (A) Leukemic burden as measured via IVIS on days 3, 7, 15, and 17 after engraftment in NS mice bearing MOLM13-luc cells treated with vehicle (dimethyl sulfoxide [DMSO]) or daunorubicin, 2 mg/kg delivered 3 times weekly IV using 8 mice per group. Days 14 and 17 show a significant difference in leukemia burden in daunorubicin-treated mice compared with that in diluent-treated mice (P < .05). (B) Leukemia burden as measured by IVIS on days 3, 7, 15, and 17 after engraftment in SE mice bearing MOLM13-luc cells treated with vehicle (DMSO) or daunorubicin 2 mg/kg delivered 3 times weekly IV using 8 mice per group. No significant difference (n.s.) was seen in daunorubicin-treated mice at any of the time points. (C) Representative mice from day 14 of experiments depicted in panels A-B. (D) SC upon engraftment significantly slows leukemia progression in MV411-luc bearing mouse models (4 mice per group) and MOLM13-luc bearing mouse models (10 mice per group) compared with mice that continue smoking. P < .01 or .05, respectively. (E) HO-1 protein expression in MOLM13 bearing spleen lysates from NS, SC, and CSE mice. Ratio to tubulin is shown between westerns. (F) Densitometry of western blots from spleens of MOLM13 bearing NS, CSE, or SC mice for HO-1, BCL-2, and AHRR. (G) Immunohistochemistry for HO-1 in spleens and livers from MOLM13-luc bearing NS and SE mice (n = 6 mice per group with 5 slides per mouse depicted graphically and representative sections). (H) Mass cytometry of HO-1 of spleens from MOLM13-bearing mice. (I) Percent frequency of hematopoietic populations of whole bone marrow of NS or SE MOLM14-bearing mice. (J) Tsne plots of CD45⁺ or CD45⁻ cells from spleens of NS or SE MOLM13-bearing mice. Two mouse samples were combined for each group in the analysis. (K) Heat maps of percentages of CD45⁻ (left) or CD45⁺ (right) cells present in clusters depicted in panel J. (L) Tsne plots with expression of p21, p-FLT3, MCL-1, and RUNX1 in CD45⁺ samples from NS or SE mice, as depicted in panel J. (M) Overall median expression of RUNX1, MCL1, DNMT3B, P21, and P-FLT3 in CD45⁺ cells NS or SE samples. IVIS, in vivo imaging system; MCL1, myeloid cell leukemia 1.