A, Schematic depicting experimental strategy for intraductal
injection experiments. Control CAFs were injected into one mammary fat pad (n
= 5), while STAT1-depleted CAFs (shSTAT1) were injected into the
contralateral fat pad (n = 5). After 24 hours, DCIS.COM cells were
injected into the nipple of each mammary gland. B, Representative
H&E images of tumor progress in glands injected with control CAFs (left) and
shSTAT1 CAFs (right) at both 10× (top) and 40× (bottom).
C, Mean percent of DCIS/IDC-like lesion per field of view in
glands injected with control CAFs (n = 5) compared to glands injected
with shSTAT1 CAFs (n = 5). D, Representative 40×
images showing tumor lesions in glands injected with control CAFs (left) and
shSTAT1 CAFs (right) stained with either human K8 (top row) or α-SMA
(bottom row). DCIS: ductal carcinoma in situ, IDC: invasive
ductal carcinoma, ADH: advanced ductal hyperplasia. E,
Quantification of percent α-SMA+ cells per
40× field of view in 5 μm sections from mammary glands injected
with sh.Control CAFs (left) or sh.STAT1 CAFs (right).