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Figure 1 | Breast Cancer Research

Figure 1

From: Amphiregulin mediates progesterone-induced mammary ductal development during puberty

Figure 1

Both 17-β-estradiol and progesterone induce similar morphologic and proliferative responses in the pubertal mammary gland. Pubertal 4-week-old BALB/c mice were OVX, allowed to recover for 3 weeks, and then treated for 5 days with vehicle control (C), E2, P, or E2+P, as described in the Materials and Methods section. (A) Morphologic response to 5d C, E2, P, or E2+P. Note lack of EBs in controls and similar presence of EBs in E2-, P-, and E2+P-treated glands. Scale bar, 1 mm. (B) End bud (EB) quantitation. Values represent the mean ± SEM number of EBs in a number 4 mammary gland (n = 3 mice). (C) Morphologic response to 5d P in the adult 17-week-old BALB/c OVX mammary gland; note presence of extensive side branching. Scale bar, 1 mm. (D) Immunofluorescent detection of PR expression in luminal cells. The values represent the mean ± SEM percentage PR-positive cells (n = 3 animals per treatment). The percentage PR-positive cells in 5-day P-treated BALB/c mice was less than control (*P < 0.05). (E) Inhibition of EB formation by E2+ ICI 182,780 and P+RU486. Scale bar, 1 mm. (F) Proliferation analysis by dual immunofluorescent detection of BrdU and PR. The total percentages BrdU-positive cells and BrdU-positive cells co-expressing PR in ducts and EBs are presented. The values represent the mean ± SEM (n = 3 animals per treatment). The percentage of BrdU-positive luminal epithelial cells in ducts after E2, P, or E2+P treatment was greater than control (*P < 0.05). The percentage of BrdU-positive cells was greater in EBs than in ducts after E2, P, or E2+P treatment (#P < 0.05).

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