Table 1.

Relative mitochondrial activity, glucose uptake and ROS production in single cell cultures vs. co-cultures

	Single cell cultures (Fibro/MCF7)	Co-cultures (Fibro/MCF7)	Ratio (Co-culture/Single)
5 Days
Mitochondrial Activity	2.35	0.62	0.26
Glucose Uptake	0.99	2.83	2.86
ROS Production	1.28	2.17	1.70
2 Days
ROS Production	1.20	0.51	0.43
	Single cell cultures (Fibro/MDA)	Co-cultures (Fibro/MDA)	Ratio (Co-culture/Single)
5 Days
Mitochondrial Activity	2.06	0.26	0.13

Mitochondrial activity, glucose uptake and ROS production were measured with fluorescent probes (MitoTracker, NBD-2-deoxy-glucose, and DCF-DA). The fluorescence intensity of a given probe in fibroblasts was compared to that of MCF7 cells. Fold-change was calculated as Fibroblast (intensity) divided by MCF7 cell (intensity). Results were separately calculated for individual cell cultures (Fibroblasts or MCF7 cells cultured alone) or co-cultures (See first and second columns, respectively). Finally, to get a more quantitative view of co-cultures vs. single cell type (homotypic) cultures, a ratio between the two was calculated (See the third column). For example, in single cell cultures, fibroblasts have >two-fold more mitochondrial activity than MCF7 cells (first row). In contrast, in co-cultures, fibroblasts have roughly half the mitochondrial activity of MCF7 cells. In terms of relative change, this represents a near four-fold reduction in relative mitochondrial activity in fibroblasts (first row). Conversely, under the same conditions, fibroblasts show a near three-fold increase in glucose uptake, to compensate for the loss of mitochondrial activity (second row). Similarly, fibroblasts show a near two-fold increase in ROS production (third row). See text for further details and analysis.