1. VC
KX-01
Total Src
p-Y416 Src
Supplementary Figure S1. KX-01 at low dose inhibited phosphorylation of Src in
MDA-MB-231 xenografts.

2. ER m-RNA expression in PDX tumors* *
Supplementary Figure S2. Effect of KX-01 on ERα mRNA expression in Patient
Derived Xenograft (PDX) tumors.

3. MDA-MB-231 tumor c-myc Cyclin D1 PS2 GAPDH
MCF VC TAM KX-01 TAM+KX-01
c-myc
Cyclin D1
PS2
GAPDH
Supplementary Figure S3. Effect of KX-01 and tamoxifen on ERα regulated proteins
c-myc, cyclin D1 and pS2 in MDA-MB-231 tumor lysates by Western blot analysis. 

4. Positive control for TUNEL
DAPI VC
TAM
TUNEL
DAPI
TUNEL
DAPI
TUNEL
DAPI
KX-01
KX-01 + TAM * *
Supplementary Figure S4. TUNEL immunofluorescence microscopy on MDA-MB-231
tumor sections from mice treated with VC, TAM, KX-01, KX-01 + TAM.

5. A.
ERα immunostaining
Vehicle control
KX-01 1mg/kg b.wt
PR immunostaining
Vehicle control
KX-01 1mg/kg b.wt B.
MDA-MB-157 tumor xenograft
Vehicle control
Tamoxifen 5mg pellet (60 day release)
KX-01 1mg/kg b.wt
KX-01 + Tamoxifen
Supplementary Figure S5. Effect of KX-01and tamoxifen co-treatment on growth of
MDA-MB-157 breast tumor xenografts.

6. TUNEL VC
DAPI
TUNEL
TAM
DAPI
KX-01
KX-01 + TAM * *
Supplementary Figure S6. TUNEL immunofluorescence microscopy on MDA-MB-157
tumor sections from mice treated with VC, TAM, KX-01, KX-01 + TAM.

7. B ERα expression at day 30 in MDA-MB-231 tumors
A MDA-MB-231 tumor volume
KX-01 (day 1-14);
VC (day 15-30)
KX-01 (day 1-14);
TAM (day 15-30)
B ERα expression at day 30 in MDA-MB-231 tumors
KX-01 (day 1-14); VC (day 15-30)
KX-01 (day 1-14); TAM (day 15-30)
ERα C
ERα expression MCF-7 tumor
(positive control)
ERα
Supplementary Figure S7. Effect of KX-01 withdrawal on ERα expression and
tamoxifen sensitivity in MDA-MB-231 tumors. 

8. MDA-MB-231 tumor ERα E-cad GAPDH
MCF VC TAM KX-01 TAM+KX-01
ERα
E-cad
GAPDH
Supplementary Figure S8. Effect of KX-01 on ERα and E-cadherin protein
expression in MDA-MB-231 xenografts measured by Western blot analysis of
 tumor lysates.

9. Supplementary Figure S9
Supplementary Figure S9. Effect of KX-01 on histone deacetylases (HDACs) 
activity in MDA-MB-231 tumors.

10. Supplementary Figure S10. Low dose KX-01 had no effect on microtubule
Tubulin
DAPI VC
TAM 5 mg pellet
(60 day release)
KX-01 (1mg/kg/BID)
KX-01 (1mg/kg/BID)+TAM
KX-01 (5mg/kg/BID)
Supplementary Figure S10. Low dose KX-01 had no effect on microtubule
formation in MDA-MB-231 tumors.

11. ERα
GAPDH
ERα m-RNA expression in TNBC cell lines after treatment of with KX nM for 96 h
MCF-7 MDA-MB MDA-MB MDA-MB 157 VC
KX-01
Supplementary Figure S11. ERα mRNA expression induced by KX-01 in
MDA-MB-231, MDA-MB-468 and MDA-MB-157 triple negative breast cancer cells.