Figure 3.

MAF mediation of bone metastasis in breast cancer (BC) cells. A) MAF protein log2 score (immunohistochemistry [IHC], optical density values) on the vertical axis and various BC patient samples (n = 20) and BC cell lines (n = 10–20 sections) on the horizontal axis were plotted. Amplified (red) and not-amplified (green) categories are highlighted. B) Bone metastasis was scored from MAF-overexpressing and control parental cells implanted in the mammary fat pad. Mice bearing size-matched tumors (>300 or >100mm³ for MCF7 or T47D, respectively) at day 42 were considered when evaluating bone metastasis. Individual tumors are represented as box plots with median, interquartile range, and min and max values. Bone colonization incidence is plotted. P value scored by two-sided Wilcoxon signed-rank test. C) Schematic representation of injection via left ventricle. Kaplan-Meier curve of bone metastasis–free survival for BoM2 shControl, shMAF, and rescue cells. P value was obtained using two-sided log-rank test. Representative bioluminescent images and hematoxylin and eosin (H&E) staining at days 0 and 54 (endpoint) of bone metastasis for each group are shown. T = tumor area. 500 and 50 μm scale bars were used for middle and right panels, respectively. Histomorphometric analysis of bone metastasis lesions is depicted (BV = bone area; TV = tumor area). P values scored by two-sided Wilcoxon signed-rank test, *<.05, **<.01, ***<.001. D) Kaplan-Meier curves of bone metastasis–free survival for MCF7 parental and MAF-overexpressing cells injected via left ventricle of mice. P value was obtained using two-sided log-rank test. E) Kaplan-Meier curve of bone metastasis–free survival for T47D parental and MAF-expressing cells injected via left ventricle of mice. P value was obtained using two-sided log-rank test. F) Bone colonization incidence 14 days postintratibiae inoculation of cells in mice. (E) Two-sided Fisher test was used to score significance. G) Bone colonization incidence 28 days postintratibiae inoculation of ZR-75 control and MAF short hairpin carrying cells. Two-sided Fisher test was used to score significance. BC = breast cancer; CI = confidence interval; ER = estrogen receptor; H&E = hematoxylin and eosin; HER2 = human epidermal growth factor receptor 2; HR = hazard ratio; OD = optical density.