Figure 4

Donor’s obesity status and depot site of ASCs differentiates its influence on tumorigenicity in vivo . MCF7 cells alone (10⁶) or MCF7 cells and adipose stem cells (ASCs) (n = 6 donors per group) were co-mixed in a 1:1 ratio (10⁶ of each cell type) in a total volume of 50 μl of sterile PBS and mixed with 100 μl of reduced growth factor Matrigel™. Cells were injected into the fifth mammary fat pad of six-week old female ovariectomized SCID/beige mice (n = 5 mice per group). Estrogen was delivered subcutaneously in the neck as a 0.72 mg 60-day time-release estrogen pellet. Tumor volume was measured every 3 days for a total of 36 days. (A) Tumor volume of tumors formed with MCF7 cells alone or co-mixed cells (MCF7 and ASCs) injected into the mammary fat pad with or without estrogen pellet (E₂). (B) Representative images of H&E, Ki-67, TUNEL and PGR staining of tumor sections from tumor sections taken at 10x and 40x. Scale bars both represent 50 μm. (C) Quantification of Ki-67, TUNEL and PGR staining with ImageScope represented as the percentage of positive pixels over total number of pixels per tumor section. Values reported are means of 10 tumor sections. Bars, ± SD. *, P <0.05 between MCF7 and other groups. ^#, P <0.01 between MCF7 with estrogen and other groups, **, P <0.001 between MCF7 and other groups.