Supplementary Figure 1. Apoptosis detected by TUNEL in MDA-MB-231 cells expressing shSEMA4C or EV.

Supplementary Figure 2. Sema4C cDNA re-expressed in these MDA-MB-231 siSEMA4C cells could recover cell

growth and ANG and CSF secretion. (A). Western blot analysis of Sema4C in each kind of MDA-MB-231 with

different siSEMA4C RNA or sema4C cDNA. (B) Proliferation index was analyzed by CellTrace™ CSFE cell

proliferation kits in presence of siSEMA4C RNA or sema4C cDNA in MDA-MB-231cells.

Supplementary Figure 3 Expression of senescence-associated pathway proteins in MDA-MB-231 cells were

examined using western blot post-transfection at the indicated time. Representative pictures of three independent

experiments. (A) The altered expression of cell cycle regulators in MDA-MB-231 cells transfected with either

siSEMA4C or siPLEXINB2 (B) The protein expression of p53 signal pathway in the MDA-MB-231 cells

overexpressing SEMA4C *, P < 0.05; **, P < 0.01.

Supplementary Figure 4. SEMA4C regulates angiogenesis. (A) and (B) Sema4C expression in MDA-MB-435S

and MCF-7 transduced with lentiviral vectors either encoding shSEMA4C or SEMA4C or a noncoding empty

vector. (C) HUVECs (1×104) were incubated in conditioned medium for 4~6h. Tube formation of HUVECs was

significantly declined by conditioned medium from SEMA4C-knock down MDA-MB-435S cells as compared

with EV transfection. (D) Tube formation of HUVECs was significantly increased by conditioned medium from

SEMA4C-knock in MCF-7 cells as compared with EV transfection. **p < 0.01.

Supplementary Figure 5. The vascular integrity was detected in EV tumours and shSEMA4C tumours. (A) NG2

(red) and CD31 (green) double immunostaining on C13K tumor sections demonstrated pericyte coverage defects

(arrowheads) in EV and sh-SEMA4C tumours. Arrowheads indicates a rupture of the vessel wall. (**p<0.01). (B)

The in vitro BBB model showed how endothelial monolayer or EC-pericyte coculture was seeded on the Transwell

membrane. The quantification of FITC-dextran permeability showed increased permeability in EV conditioned

media than in shSEMA4C when HUVEC cocultured with the wild-type primary pericytes. (**p<0.01).

Supplementary Figure 6. Sections from tumors were immunostained with anti-cd45 (white arrowhead) or

F4/80(black arrow) antibody.

Supplementary Figure 7. SEMA4C regulates macrophage recruitment. (A) Representative photographs of

migration of monocytes purified from human peripheral blood were analyzed in a Transwell migration assay. CM

derived from MDA-MB-435S transduced with shSEMA4C or EV was included in the lower chamber. (B)

Representative photographs of migration of monocytes purified from human peripheral blood were analyzed in a

Transwell migration assay. CM derived from MCF-7 transduced with EV or SEMA4C was included in the lower

chamber. Data are the mean ± SD from three separate experiments; **p < 0.01.

Supplementary Figure 8. The vascular density and macrophage area were detected in EV tumours and shSEMA4C

tumours at the same weight. (A) Tumour weight measured after excision at the 14 days of EV tumours and at the

25 days of shSEMA4C tumours. (B) Vascular density and (C) macrophage area detected in EV tumours and

shSEMA4C tumours, which was resected respectively at the age in the Figure C (**p<0.01).

Supplementary Figure 9. Recombinant soluble Sema4C did not affect MDA-MB-231 proliferation and endothelial

cells tube formation despite could increase macrophages migration. (A) MDA-MB-231 growth curves, in presence

of various concentration of recombinant soluble Sema4C (from12.5 to 1000 ng/ml). Proliferation index was

analyzed by CellTrace™ CSFE cell proliferation kits. (B) The number of migration of monocytes purified from

human peripheral blood were analyzed in a Transwell migration assay in presence of various concentration of

recombinant soluble Sema4C (from 125 to 1000 ng/ml). (C) Tube formation of HUVECs was analyzed in presence

of recombinant soluble Sema4C (500 ng/ml). Data are the mean ± SD from three separate experiments; **p <

0.01.

Supplementary Figure 10. mRNA levels of ANG and CSF were analyzed in presence of siSEMA4C RNA or

sema4C cDNA in MDA-MB-231cells. Data are the mean ± SD from three separate experiments; **p < 0.01.

Supplementary Figure 11. Expression of mRNA(A) and secreted protein(B) level of ANG and CSF-1 were

detected in the MCF-7 cells overexpressing SEMA4C. Data are the mean ± SD from three separate experiments;

**p < 0.01.

Supplementary Figure 12. The growth curve and cell cycle were detected in presence of siANG in MDA-MB-231

cells. (A) MDA-MB-231 growth curves, in presence of transfecting with different siRNA. OD values were

detected by CCK8 kit (DoJinDo Cell Counting Kit-8). Data are the mean ± SD from three separate experiments;

**p < 0.01. (B) Cells were transfected with siNC or siANG for 96 h, and the cell cycle profile was detected using

FACS analyses following PI staining.