Table 6

VEGF concentration and receptor densities for the tumor (breast cancer)


Measured parameter
Tissue model

Value
Unit
Value
Unit

Free VEGF concentration
Breast cancer
0.5–1.5
pM
2.6–7.83 10-4
pmol/cm3 tissue

Total tumor VEGF
Breast cancer
13
pg/mg tumor
0.3
pmol/cm3 tissue

VEGFR1 tissue concentration

102–105
#/EC
1.7 10-3–1.7 100
pmol/cm3 tissue

VEGFR2 tissue concentration

104
#/EC
1.7 10-1
pmol/cm3 tissue

NRP1 tissue concentration

103–106
#/EC
1.7 10-2-1.7 101
pmol/cm3 tissue

ECM binding site density
ECM
0.75
μM
389
pmol/cm3 tissue
Vessel BM
13
μM
4
pmol/cm3 tissue
Tumor cell BM
13
μM
32
pmol/cm3 tissue

The conversion of receptor densities to tissue concentrations is based on the relationship mentioned in table 5, and the surface area of an endothelial cell, 1000 μm2. VEGF concentration is normalized based on the entire interstitial space, since it diffuses throughout: 5.2 108 (pmol/cm3 tissue)/M (here, M = moles/liter interstitial space). VEGF binding sites in the ECM and BMs are based on those volumes: 5.2 108 (pmol/cm3 tissue)/M(ECM), 2.7 105 (pmol/cm3 tissue)/M(EBM), 2.5 106 (pmol/cm3 tissue)/M(PBM) [4].

Stefanini et al. BMC Systems Biology 2008 2:77   doi:10.1186/1752-0509-2-77