A MOUSE MODEL OF MAMMARY HYPERPLASIA INDUCED BY ORAL HORMONE ADMINISTRATION

Modified Estrogen-Progesterone Induction Method of Mammary Gland Hyperplasia in Rats

In female Wistar rats, mammary gland hyperplasia (MGH) was modeled according to a modified protocol involving estrogen-progesterone induction and taking into account the duration of the estrous cycle of this animal species. MGH was induced over four 7-day cycles; each cycle included subcutaneous administration of 17β-estradiol (0.5 mg/kg) for 4 days, injection of progesterone (5 mg/kg) on day 5, then 2 days without injections. In females with MGH, a significant increase in the height and diameter of the nipples of the mammary glands was recorded, two types of changes were observed in the gland tissue: tubuloalveolar and lobuloalveolar hyperplasia. The study confirmed the development of MGH in rats by a modified method.

Artesunate attenuates proliferation of epithelial cells by downregulating the NF-κB and AKT signaling pathways in benign mammary gland hyperplasia rats

Background

The aim of this study was to investigate the effects of artesunate (ART) on breast epithelial cell proliferation in vitro and in vivo.

Methods

Immortalized human non-cancer mammary epithelial (MCF-10A) cells were used to determine the effect of ART on estrogen-induced mammary hyperplasia cells. We investigated the effect of ART on the synthesis of cyclooxygenase-2 (COX-2) and proliferating cell nuclear antigen (PCNA) in MCF-10A by treating MCF-10A 36 h with different concentrations of ART (0, 100, 200, 400 µm, n=12/group). We then investigated the effect of ART on estrogen induced COX-2, PCNA, nuclear factor-kappa B (NF-κB), and pNF-κB synthesis by treating MCF-10A with both estrogen and ART (0, 50, 100, 200 µm, n=12/group). A mammary hyperplasia model (MGH) was established in rats. All rats (n=12) were divided into 4 groups [group A: negative control (NC) + Art −; group B: NC + Art +; group C: MGH + Art −; group D: MGH + Art +] by the random number table method and the effects of ART on estradiol-induced mammary hyperplasia, fibrosis, and phosphorylation of AKT and NF-κB were studied by histopathological staining, Masson trichrome staining, immunohistochemistry (IHC), and western blotting.

Results

The proliferation and inflammation of mammary epithelial cells were blocked by ART (P<0.05). The phosphorylation of NF-κB induced by estradiol in MCF-10A was attenuated by ART (P<0.05). In the rat MGH, ART reduced cell proliferation and fibrosis (P<0.05) and inhibited the phosphorylation of AKT and NF-κB (P<0.05).

Conclusions

The drug ART inhibits estrogen-induced breast hyperplasia by blocking AKT and NFkB phosphorylation.