A Neutral Glimpse At Natural Product Library

Compared with mammary tissues from wild-type (WT) EP-treated mice, minimal CXCR4 staining was seen in glands from EP-treated PRKO mice, confirming the requirement of a functional PR for CXCR4 expression in the adult mammary gland (Figure?3A). Figure?3 Effects of CXCR4 Inhibition Aldosterone on Total, Luminal, and Basal Clonogenic Capacity CXCR4 Inhibition Abrogates Luminal Progenitor Expansion and Mammopoiesis We next determined whether CXCR4 is important for mammary stem and progenitor cell function in the adult gland, using two CXCR4 inhibitors with distinct modes of action: AMD3100 and AMD3465. Previous studies found that only specific cell types in the mammary gland, termed progenitor cells, can contribute to colony formation in?vitro (Shehata et?al., 2012). Both CXCR4 inhibitors decreased mammary clonogenic selleck kinase inhibitor capacity (total, luminal, and basal) by ?20% following EP treatment, whereas the clonogenic capacity of E-treated mammary epithelial populations remained unchanged (Figures 3C, 3D, and S3). These data indicate that a proportion of progenitor cells in the luminal and basal populations that expand in response to progesterone are functionally dependent on CXCR4, which is consistent with the elevated CXCR4 expression observed in the progesterone-stimulated state (see above, Figure?2D). Application of CXCR4 inhibitors to cells derived from EP-treated PRKO mice (total, luminal, and basal) did not result in significant differences in colony-forming capacity, attesting to the importance of intact PR signaling for CXCR4-mediated effects on mammary progenitors (Figure?3C). We then investigated whether CXCR4 signaling is essential Small molecule library for progesterone effects in the mammary gland in?vivo. Mice were treated concurrently with EP and AMD3100 (18?mg/kg/day and 6?mg/kg/day) for 2?weeks, followed by mammary cell dissociation and phenotypic analyses of mammary epithelial subsets (Figure 4A). The effects of AMD3100 on peripheral white blood cell counts were measured as a control (Figure?S4). CXCR4 inhibition resulted in a significant attenuation in the number of CD24+CD49flo luminal cells and CD24?CD49fhi basal cells (at the higher concentration) compared with PBS-treated controls (p?