Fig. 3

DNMT1 facilitates breast cancer cells tumorigenesis and metastasis in vivo. A, B MDA-MB-231-shCtrl/shDNMT1#1 cells were subcutaneously injected into the female nude mice, respectively. n = 5 for each group. After 4 weeks the xenograft tumours were detached (A). Effect of knockdown DNMT1 on the xenograft model was assessed by evaluating tumour weight (B). C IHC staining detected Ki67 and DNMT1 expression in xenograft tumours. D, E Representative bioluminescence images of lung metastasis (D) in mice injected with MDA-MB-231-shCtrl or MDA-MB-231-shDNMT1 cells via tail veins, and the metastasis were quantified by measuring the photo flux (E). F–H After 8 weeks, nude mice were sacrificed and lung metastatic nodules (F) were examined macroscopically (G) or detected by H&E staining (H). The white arrows denote the metastatic nodules. I Representative images of the IHC staining of DNMT1 in nude mice lung metastasis sections. Scale bars: 100 μm. Data are represented as mean ± SD of three or four independent experiments, and *p < 0.05, **p < 0.01, ***p < 0.001 (Student’s t test)