DOI: 10.1038/ncb2607 Figure S1 Elf5 loss promotes EMT in mammary epithelium while Elf5 overexpression inhibits TGFβ induced EMT. (a, c) Different confocal slices through the Z stack image. (b, d) 3D rendering of the Z stack image. Size bar = 40μm. (e) Quantification of Vimentin-positive epithelial cells in Elf5-KO mammary epithelium compared to wide type (WT). Data represented are shown as mean ± SD collected from 10 fields of 3 independent animals per genotype. *p < 0.05 by Student s t-tests. (f) Western blot expression of E-cadherin and Vimentin in mouse mammary epithelial cells from wild type or Elf5-KO mice at lactation day 1. Uncropped images of blots are shown in Supplementary Fig. S9. (g) Quantitative RT-PCR analysis of EMTrelated transcription factors from whole mammary gland tissue samples at lactation day 1. Real time PCR values were normalized to the housekeeping gene Gapdh. Experiments were performed three times, each with qrt-pcr performed in technical duplicate, and presented as the mean ± SD. *p < 0.05 by Student t-test. (h) Heat map showing the expression of EMT-related genes in mammary epithelial cells isolated from Elf5-KO mammary glands in lactation day 1 as compared to wild type glands. (i) Phase contrast and E-cadherin immunofluorescence images of NMuMG (control) or NMuMG-HA- Elf5 cells undergoing TGFb-induced EMT at high cellular density. Size bar = 100μm for bright field and 40μm for E-cadherin. (j) Apoptosis assay by FACS analysis for cleaved caspase-3 with NMuMG (control) or NMuMG-Elf5 cells undergoing TGFb-induced EMT. WWW.NATURE.COM/NATURECELLBIOLOGY 1
Figure S2 Elf5 expression in breast cancer cell lines and during AG490- induced EMT in T47D cells. (a) Heat map showing the expression of ELF5 and other EMT-related genes in various breast cancer cell lines with high or low metastatic abilities. Microarray data of human cell lines were obtained from the previously published Hoeflich et al. dataset 42. (b) Western blot analysis of T47D cells treated with DMSO or AG-490 (50 μm) in starvation media for 24 hours before stimulation with hprl (100 ng/ml) for 10 minutes. Uncropped images of blots are shown in Supplementary Fig. S9. (c) Phase contrast and immunofluorescence images (stained for E-CADHERIN) of T47D cells treated with DMSO or AG490. Size bar = 20 μm in the phase contrast images and 37.5 μm in immunofluorescence images. 2 WWW.NATURE.COM/NATURECELLBIOLOGY
Figure S3 Elf5 enforces epithelial features in various cell lines. (a) Phase contrast images of T47D cells (mock transfected) at low and high density. There is no difference in cell morphology as compared to the control, untransfected cells or scramble sirna treated cells (see Figure 3d). Size bar = 100 μm. (b) Elf5 and HA immunostaining in HA-Elf5 overexpressing MDA-231-Elf5 cells. TOPRO was used as a nuclear stain. Size bar = 75 μm. (c) Phase contrast images of HEK293 cells transduced with vector control or Elf5 expressing lentiviruses. Size bar = 20 μm. (d) Western blot analysis of Elf5, E-CADHERIN and VIMENTIN expression in control or Elf5-overexpressing HEK293 cells. Uncropped images of blots are shown in Supplementary Fig. S9. WWW.NATURE.COM/NATURECELLBIOLOGY 3
Figure S4 Elf5-induced MET of MDA-231 cells is reversible and dependent upon the DNA-binding activity of Elf5. (a) Western blot analysis of Elf5 expression in MDA-231-Elf5 cells after 72 hours of treatment with control or Elf5 targeting sirna. Uncropped images of blots are shown in Supplementary Fig. S9. (b) Phase contrast images of MDA-231-Elf5 cells after 72 hours of treatment with control or Elf5 targeting sirna. Size bar = 40 μm. (c) Western blot analysis of MDA-231 cells expressing wild type (WT) Elf5 or mutant (MT) Elf5. Uncropped images of blots are shown in Supplementary Fig. S9. (d) Phase contrast images of MDA-231 cells expressing wild type (WT) Elf5 or mutant (MT) Elf5. Size bar = 40 μm. (e) GSEA data showing the negative enrichment of published EMT gene signatures in MDA-231 cells expressing wild type (WT) Elf5 compared to) mutant (MT) Elf5. (f) Quantitative PCR was performed with primers spanning 2 regions of the TWIST1 promoter. P1 primer: -332 to -252 bp; P2 primer: -104 to +57 bp (proximal promoter). (g) Quantitative PCR was performed with primers spanning 2 regions of the SNAI1 promoter. P1 primer: -1037 to -940 bp; P2 primer: -25 to +62 bp (proximal promoter). Data shown are presented after normalization to a control genomic locus (GAPDH). Experiments were performed three times, each with qrt-pcr in technical duplicate, and data presented as the mean ± SD for (f) and (g). 4 WWW.NATURE.COM/NATURECELLBIOLOGY
Figure S5 SNAIL2 overexpression restores the mesenchymal characteristics in MDA-231-Elf5 cells. (a) Western blot analysis of Elf5 and EMT markers expression. Uncropped images of blots are shown in Supplementary Fig. S9. (b) Quantitative RT-PCR analysis of EMT-related genes for control, HA-Elf5- overexpressing and FLAG-SNAIL2-overexpressing MDA-231 cells. Real time PCR values were normalized to the housekeeping gene GAPDH. Experiments were performed three times, each with qrt-pcr performed in technical duplicate, and data presented as the mean ± SD. * p <0.05 by Student s t test. (c) Immunofluorescence images of control, HA-Elf5 and FLAG-SNAIL2- overexpressing MDA-231 cells stained for indicated proteins. White arrows indicate membrane-localized ZO-1. Size bar = 40 μm for E-CADHERIN, ZO-1, SNAIL2 and Size bar = 75 μm for VIMENTIN. WWW.NATURE.COM/NATURECELLBIOLOGY 5
Figure S6 ELF5 expression is inversely correlated with SNAIL2 expression in breast tumors and induces MET in LM2 breast cancer cells. (a) Scatter plot showing anti-correlation between SNAI2 and ELF5 expression in patients from the NKI295 clinical dataset 48. Pearson s coefficient test was performed to assess statistical significance. (b) Table showing anti-correlation between ELF5 and SNAI2 in breast cancer subtypes. Pearson coefficients (r) and corresponding p-values (p) for correlations between ELF5 expression and SNAI2 expression in clinical subtypes of the NKI295 dataset. n = number of patients in given subtype. (c) Positive ELF5 nuclear staining in human normal thyroid (positive control) and breast tissue. Size bar = 40 μm. (d) Kaplan-Meier plots of distant metastasis-free survival of ER- patients stratified by Elf5 and SNAIL2 expression in the NKI295 clinical dataset. p value calculated by log rank test. (e) Western blot analysis of control and Elf5 overexpressing LM2 cells. Uncropped images of blots are shown in Supplementary Fig. S9. (f) Phase contrast of parental, vector control and Elf5 overexpressing LM2 cells. Size bar = 40 μm. 6 WWW.NATURE.COM/NATURECELLBIOLOGY
Figure S7 Elf5 overexpression in 4T1 cells inhibits metastasis. (a) Western blot analysis of Elf5 and Snail2 expression in 4T1 cells overexpressing HA-Elf5. Uncropped images of blots are shown in Supplementary Fig. S9. (b) Box plot showing the number of lung metastasis nodules from experimental metastasis of control or Elf5 overexpressing 4T1 cells after tail vein injection (n=10). *** p < 0.001 calculated by Student s t-test. (c) Volume estimates of primary mammary fat pad tumors as determined by weekly caliper measurement. The data represented are shown as mean ± SD collected from 2 independent experiments, each time with n=6 mice per group. (d) qrt-pcr analysis of expression of EMT-related genes in control and Elf5 overexpressing 4T1 cells. Real time PCR values were normalized to the housekeeping gene Gapdh. Experiments were performed three times, each with qrt-pcr in technical duplicate, and data presented as the mean ± SD. p < 0.05 calculated by Student s t-test. (e) Western blot analysis of Elf5 and SNAIL2 expression in 4T1 cells overexpressing control, HA-Elf5, FLAG-SNAIL2, or HA-Elf5 and FLAG-SNAIL2. Uncropped images of blots are shown in Supplementary Fig. S9. (f, g) phase contrast (f) and immunofluorescence (g) images of control, Elf5, or Elf5 and SNAIL2 overexpressing 4T1 cells. Size bar = 40μm. (h) Representative bioluminescence (BLI) images of organs (as indicated in figure) from control, HA-Elf5, FLAG-SNAIL2, or HA-Elf5 and FLAG-SNAIL2 overexpressing 4T1 cells after mammary fat pad injection (n = 6 per experimental group). While Elf5 overexpression suppresses lung metastasis, the influence on metastasis to other organ cannot be quantified due to low incidence rate. WWW.NATURE.COM/NATURECELLBIOLOGY 7
Figure S8 Overexpression of Elf5 in MMTV-PyMT tumor cells inhibits lung metastasis. (a) Quantitative RT-PCR analysis of Elf5 and Snai2 expression in control or HA-Elf5 overexpressing MMTV-PyMT primary tumor cells. Experiments were performed three times, each with qrt-pcr in technical duplicate, and data presented as the mean ± SD. (b) Tumor volume of primary mammary fat pad tumors. n = 6 per experimental group. p value computed by Mann- Whitney U-test. (c, d) Spontaneous lung metastasis incidence and number of lung metastasis lesions from control and HA-Elf5 overexpressing primary tumors. n = 6 per experimental group, p value computed by Fisher s exact t-test (p= 0.182) (c) and Mann-Whitney U-test (d). (e) Representative lung nodules from mice injected with control and ELF5 overexpressing MMTV-PyMT tumor cells. Red arrowheads indicate lung metastasis nodules. Size bar = 2 mm. 8 WWW.NATURE.COM/NATURECELLBIOLOGY
Figure S9 Western blot scanned films. Boxes highlight lanes used in figures. WWW.NATURE.COM/NATURECELLBIOLOGY 9
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