Extended Data Fig. 2: MAF overexpression provides a competitive advantage for bone colonization in ER+ BCa.
From: MAF amplification licenses ERα through epigenetic remodelling to drive breast cancer metastasis
a, Schematic representation of the experimental design to obtain mouse BCa cell lines (mTB1-TB4). b, Cell proliferation assay of mTB BCa cells cultured with HD medium and treated with vehicle or 10 nM E2, n = 3 biological replicates. Data is shown as mean ± sd. Statistical significance, two-sided Wilcoxon rank-sum test. c, 4-OHT dose-response curve (mean ± sd) and IC50 measurement in mTB BCa cells. n = 3 biological replicates. d, Representative H&E and ER staining in a tumor generated by mTB BCa cells. Scale bar, 50 μm. e, Immunoblot showing MAF overexpression in different BCa cell lines. f, Schematic representation of the bone-colonization experiment (left). Normalized ex vivo leg photon flux of mice injected in the mammary fat pad (MFP) with control (n = 4 limbs) or Maf-overexpressing (n = 14 limbs) mTB cells (right). The median (centre line), first and third quartiles (box limits) and the minimum to maximum values (whiskers) are shown. Statistical significance, two-tailed Mann–Whitney test. g, Schematic representation of the bone-colonization experiment (left). Quantification of bone colonization by control (n = 24 limbs) and Maf-overexpressing (n = 24 limbs) mTB cells at day 25 (right). Statistical significance, two-tailed Fisher’s exact test. h, Schematic representation of the bone-colonization experiment (left). Normalized ex vivo leg photon flux of mice injected intratibially with a mixture of Ad-ctrl-mCherry and Ad-cre MAF-GFP cells at different ratios (10:0 n = 16 limbs; 9:1 n = 16 limbs; 5:5 n = 15 limbs; 1:9 n 16 limbs; 0:10 n = 13 limbs)(right). The median (centre line), first and third quartiles (box limits) and the minimum to maximum values (whiskers) are shown. i, Representative staining images of mCherry and GFP (left) and quantification of mock (mCherry) and GFP-positive metastatic cells (right) in sized-matched bone metastasis from mice injected intratibially with a mixture of different proportions of control and MAF-GFP MCF7 cells. Scale bar, 50 μm (left); n = 3 limbs in each group (right).
