Biomarker End Point Cell Culture Model
184-B5 MCF-7 184-B5/HER MDA-MB-231
Population Doubling (hr.)a 34 15.2 15 15
Saturation Density (x105)b 22.3 ±1.2 26.6 ±1.7 32.8 ±1.5 32.9 ±2.3
2-OHE1: 16α-OHE1Ratioc E2
GC-MS
4.2 ±0.3 0.8 ±0.2 0.5 ±0.1 0.4 ±0.2
AI Colony Formationd        
Incidence 0/18 18/18 18/18 18/18
Mean Colony Number ---- 30.9 ±2.4 23.0 ±2.6 38.9 ±1.6
Tumor Formatione        
Incidence 0/10 10/10 10/10 10/10
Latency 24 weeks 3-5 weeks 3-5 weeks 3-5 weeks
Table 1: Homeostatic Growth Control and Cancer Risk in Cell Culture Models for Molecular Subtypes of Clinical Breast Cancer. aDetermined from the exponential growth phase. bDetermined at day 7 post-seeding of 1.0x105 cells. cDetermined at day 3 post-seeding of 3.0x106 cells. E2 at a concentration of 20 nm was used as the substrate for the stable isotope dilution and gc-ms analysis. dAnchorage Independent (AI) colonies counted at day 21 post-seeding of 1,000 cells. ePalpable tumors after sub-cutaneous transplantation.