Fig. 6

IGF-1 is elevated in African American women and induces DNA breaks in breast acini. A Comparison of 53BP1 foci in the breast epithelium of non-Hispanic White (NHW) and African American/Black (AA) donors. ** P = 0.009 (unpaired t-test). B Correlation between 53BP1 foci and the percentage of African ancestry of the donors. Donors with > 5% African ancestry were included in the analysis. r, Spearman’s correlation coefficient. C Differences in cytokine/adipokine in serum from NHW (N = 24) vs. AA (N = 9) women. * P < 0.05 (t-test). D IGF-1 and IGFBP-1 levels in serum from NHW and AA women. * P < 0.05, ** P < 0.01 (t-test). E 53BP1 repair foci in acini treated with IGF-1 (100 ng/ml, 72 h) or untreated (control). ** P < 0.01 (t-test). F Comet assay with S1 acini treated with IGF1, in the absence or presence of an IGF1R inhibitor (PPP; 0.01 μM). * P < 0.05, ns not significant (one-sample t-test). Symbols on the graphs represent individual donors (A-D) and independent experiments (E-F)