scholarly journals Retroviral expression of Wnt-1 and Wnt-7b produces different effects in mouse mammary epithelium

2000 ◽  
Vol 113 (12) ◽  
pp. 2129-2138 ◽  
Author(s):  
S. Naylor ◽  
M.J. Smalley ◽  
D. Robertson ◽  
B.A. Gusterson ◽  
P.A. Edwards ◽  
...  
Keyword(s):  
Cell Culture ◽  
Mammary Gland ◽  
Mammary Gland Development ◽  
Ectopic Expression ◽  
Mammary Epithelium ◽  
Mouse Mammary Gland ◽  
Normal Mammary Gland ◽  
Gland Development

Several Wnt genes are expressed in the postnatal mouse mammary gland and are thought to be involved in mammary gland development. Ectopic expression of Wnt-1, which is not normally expressed in the mammary gland, drives the formation of a pre-neoplastic hyperplasia. Cell culture-based assays have shown that Wnt-1 and some mammary-expressed Wnts transform C57MG cells. This has led to the suggestion that Wnt-1 functions as an oncogene through the inappropriate activation of developmental events that are normally controlled by the ‘transforming’ class of Wnts. In this study, Wnt-7b was expressed in vivo using recombinant retroviruses. Wnt-7b did not alter normal mammary gland development despite having similar effects to Wnt-1 in cell culture. We conclude that the in vitro classification of Wnts as ‘transforming’ does not correlate with the transformation in vivo. To facilitate the analysis of Wnt-expression, a lacZ-containing, bicistronic recombinant retrovirus was developed. Immunohistochemistry and electron microscopy identified retrovirally transduced myoepithelial and luminal epithelial cells in normal and hyperplastic tissues. The distribution of transduced cells in mammary outgrowths was consistent with current models of mammary stem cell identity.

scholarly journals Normal mammary gland development after MMTV-Cre mediated conditional PAK4 gene depletion

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Parisa Rabieifar ◽  
Ting Zhuang ◽  
Tânia D. F. Costa ◽  
Miao Zhao ◽  
Staffan Strömblad
Keyword(s):  
Breast Cancer ◽  
Mammary Gland ◽  
Mammary Gland Development ◽  
Mammary Epithelium ◽  
Small Gtpases ◽  
Normal Mammary Gland ◽  
Knock Out ◽  
Adult Mice ◽  
Gland Development

Abstract p21-activated kinases (PAKs) are serine/threonine kinases functioning as downstream effectors of the small GTPases Rac1 and Cdc42. Members of the PAK family are overexpressed in human breast cancer, but their role in mammary gland development is not fully explored. Here we examined the functional role of PAK4 in mammary gland development by creating a mouse model of MMTV-Cre driven conditional PAK4 gene depletion in the mammary gland. The PAK4 conditional knock-out mice were born healthy, with no observed developmental deficits. Mammary gland whole-mounts revealed no defects in ductal formation or elongation of the mammary tree through the fat pad. PAK4 gene depletion also did not alter proliferation and invasion of the mammary epithelium in young virgin mice. Moreover, adult mice gave birth to healthy pups with normal body weight upon weaning. This implies that MMTV-Cre induced gene depletion of PAK4 in mice does not impair normal mammary gland development and thereby provides an in vivo model that can be explored for examination of the potential function of PAK4 in breast cancer.

scholarly journals Prep1 (pKnox1) transcription factor contributes to pubertal mammary gland branching morphogenesis

2018 ◽  
Vol 62 (11-12) ◽  
pp. 827-836 ◽  
Author(s):  
Lara Sicouri ◽  
Federica Pisati ◽  
Salvatore Pece ◽  
Francesco Blasi ◽  
Elena Longobardi
Keyword(s):  
Transcription Factor ◽  
Mammary Gland ◽  
Progenitor Cells ◽  
Mammary Gland Development ◽  
Branching Morphogenesis ◽  
Mouse Mammary Gland ◽  
Mammary Stem ◽  
Gland Development

Prep1 (pKnox1) is a homeodomain transcription factor essential for in utero and post-natal development and an oncosuppressor gene in human and adult mice. We have analyzed its role in the development of the mouse mammary gland. We used Prep1i/i hypomorphic and Prep1F/F-Ker5CRE crosses to analyze the role of Prep1 in vivo in adult mouse mammary gland development. We also cultured mammary gland stem/progenitor cells in mammospheres to perform biochemical studies. Prep1 was expressed in mammary gland progenitors and fully differentiated mammary gland cells. Using different Prep1-deficient mouse models we show that in vivo Prep1 contributes to mammary gland branching since the branching efficiency of the mammary gland in Prep1-deleted or Prep1 hypomorphic mice was largely reduced. In-vitro, Prep1 sustained functions of the mammary stem/progenitor compartment. Prep1-deficient mammary stem/progenitor cells showed reduced ability to form mammospheres; they were not able to branch in a 3D assay, and exhibited reduced expression of Snail1, Snail2 and vimentin. The branching phenotype associated with increased Tp53-dependent apoptosis and inability to properly activate signals involved in branching morphogenesis. Finally, Prep1 formed complexes with Snail2, a transcription factor essential in branching morphogenesis, and its absence destabilizes and promotes Snail2 proteasome-mediated degradation. We conclude that Prep1 is required for normal adult mammary gland development, in particular at its branching morphogenesis step. By binding Snail2, Prep1 protects it from the proteasomal degradation.

scholarly journals Normal mammary gland development after MMTV-Cre mediated conditional PAK4 gene depletion

2019 ◽  
Author(s):  
Parisa Rabieifar ◽  
Ting Zhuang ◽  
Tânia D. F. Costa ◽  
Miao Zhao ◽  
Staffan Strömblad
Keyword(s):  
Breast Cancer ◽  
Mammary Gland ◽  
Mammary Gland Development ◽  
Mammary Epithelium ◽  
Small Gtpases ◽  
Normal Mammary Gland ◽  
Knock Out ◽  
Adult Mice ◽  
Gland Development

Abstractp21-activated protein kinases (PAKs) are serine/threonine kinases functioning as downstream effectors of the small GTPases Rac1 and Cdc42. Members of the PAK family are overexpressed in human breast cancer, but their role in mammary gland development is not fully explored. Here we examined the functional role of PAK4 in mammary gland development by creating a mouse model of MMTV-Cre driven conditional PAK4 gene depletion in the mammary gland. The PAK4 conditional knock-out mice were born healthy with no observed developmental deficits. Mammary gland whole-mounts revealed no defects in ductal formation or elongation of the mammary tree through the fat pad. PAK4 gene depletion also did not alter proliferation and invasion of the mammary epithelium in young virgin mice. Moreover, adult mice gave birth to healthy pups with normal body weight upon weaning. This implies that MMTV-Cre induced gene depletion of PAK4 in mice does not impair normal mammary gland development and thereby provides an in vivo model for examination of the potential function of PAK4 in breast cancer.

scholarly journals Progesterone Receptor Isoforms A and B: Temporal and Spatial Differences in Expression during Murine Mammary Gland Development

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3577-3588 ◽  
Author(s):  
Mark D. Aupperlee ◽  
Kyle T. Smith ◽  
Anastasia Kariagina ◽  
Sandra Z. Haslam
Keyword(s):  
Mammary Gland ◽  
Progesterone Receptor ◽  
Cyclin D1 ◽  
Mammary Gland Development ◽  
Minor Role ◽  
Normal Mammary Gland ◽  
Temporal Separation ◽  
Stage Of Development ◽  
Gland Development

Abstract Progesterone is a potent mitogen in the mammary gland. Based on studies using cells and animals engineered to express progesterone receptor (PR) isoforms A or B, PRA and PRB are believed to have different functions. Using an immunohistochemical approach with antibodies specific for PRA only or PRB only, we show that PRA and PRB expression in mammary epithelial cells is temporally and spatially separated during normal mammary gland development in the BALB/c mouse. In the virgin mammary gland when ductal development is active, the only PR protein isoform expressed was PRA. PRA levels were significantly lower during pregnancy, suggesting a minor role at this stage of development. PRB was abundantly expressed only during pregnancy, during alveologenesis. PRA and PRB colocalization occurred in only a small percentage of cells. During pregnancy there was extensive colocalization of PRB with 5-bromo-2′-deoxyuridine (BrdU) and cyclin D1; 95% of BrdU-positive cells and 83% of cyclin D1-positive cells expressed PRB. No colocalization of PRA with either BrdU or cyclin D1 was observed at pregnancy. In the virgin gland, PRA colocalization with BrdU or cyclin D1 was low; only 27% of BrdU-positive cells and 4% of cyclin D1-positive cells expressed PRA. The implication of these findings is that different actions of progesterone are mediated in PRB positive vs. PRA-positive cells in vivo. The spatial and temporal separation of PR isoform expression in mouse mammary gland provides a unique opportunity to determine the specific functions of PRA vs. PRB in vivo.

Progesterone and EGF inhibit mouse mammary gland prolactin receptor and beta-casein gene expression

1994 ◽  
Vol 267 (5) ◽  
pp. C1467-C1472 ◽  
Author(s):  
S. Nishikawa ◽  
R. C. Moore ◽  
N. Nonomura ◽  
T. Oka
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Prolactin Receptor ◽  
Mammary Epithelium ◽  
Mouse Mammary Gland ◽  
Mrna Levels ◽  
Casein Gene ◽  
Beta Casein

Regulation of mouse mammary gland long-form prolactin receptor (PRL-RL) mRNA levels by progesterone and epidermal growth factor (EGF) and the relationship between PRL-RL and beta-casein gene expression were examined in vivo and in vitro. PRL-RL and beta-casein mRNA levels increased approximately 6- and 15-fold from the pregnant to the lactating period, respectively, when normalized to the level of beta-actin mRNA. Ovariectomy of pregnant mice rapidly reduced the serum concentration of progesterone and increased the level of PRL-RL and beta-casein mRNAs approximately three- and fourfold compared with sham-operated animals 24 h after the operation. Injection of progesterone, but not estrogen, inhibited the increase in both mRNA levels. PRL-RL and beta-casein mRNA levels in cultured mammary epithelium increased in response to insulin, hydrocortisone, and prolactin, whereas progesterone or EGF caused inhibition. The combination of EGF and progesterone produced a greater inhibition than either hormone alone. These results indicate that both progesterone and EGF serve as negative regulators of lactogenesis.

scholarly journals The Role of Csmd1 during Mammary Gland Development

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 162
Author(s):  
Samuel J. Burgess ◽  
Hannah Gibbs ◽  
Carmel Toomes ◽  
Patricia L. Coletta ◽  
Sandra M. Bell
Keyword(s):  
Mammary Gland ◽  
Mammary Gland Development ◽  
Expression Patterns ◽  
Development In Vitro ◽  
Duct Development ◽  
Gland Development ◽  
Ductal Development

The Cub Sushi Multiple Domains-1 (CSMD1) protein is a tumour suppressor which has been shown to play a role in regulating human mammary duct development in vitro. CSMD1 knockdown in vitro demonstrated increased cell proliferation, invasion and motility. However, the role of Csmd1 in vivo is poorly characterised when it comes to ductal development and is therefore an area which warrants further exploration. In this study a Csmd1 knockout (KO) mouse model was used to identify the role of Csmd1 in regulating mammary gland development during puberty. Changes in duct development and protein expression patterns were analysed by immunohistochemistry. This study identified increased ductal development during the early stages of puberty in the KO mice, characterised by increased ductal area and terminal end bud number at 6 weeks. Furthermore, increased expression of various proteins (Stat1, Fak, Akt, Slug/Snail and Progesterone receptor) was shown at 4 weeks in the KO mice, followed by lower expression levels from 6 weeks in the KO mice compared to the wild type mice. This study identifies a novel role for Csmd1 in mammary gland development, with Csmd1 KO causing significantly more rapid mammary gland development, suggesting an earlier adult mammary gland formation.

scholarly journals Loss of glutaredoxin 3 impedes mammary lobuloalveolar development during pregnancy and lactation

2017 ◽  
Vol 312 (3) ◽  
pp. E136-E149 ◽  
Author(s):  
Khanh Pham ◽  
Jie Dong ◽  
Xiqian Jiang ◽  
Ying Qu ◽  
Han Yu ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Mammary Gland Development ◽  
Redox Homeostasis ◽  
Physiological Role ◽  
Cell Types ◽  
Normal Mammary Gland ◽  
Pregnancy And Lactation ◽  
Gland Development ◽  
Lobuloalveolar Development

Mammalian glutaredoxin 3 (Grx3) has been shown to be important for regulating cellular redox homeostasis in the cell. Our previous studies indicate that Grx3 is significantly overexpressed in various human cancers including breast cancer and demonstrate that Grx3 controls cancer cell growth and invasion by regulating reactive oxygen species (ROS) and NF-κB signaling pathways. However, it remains to be determined whether Grx3 is required for normal mammary gland development and how it contributes to epithelial cell proliferation and differentiation in vivo. In the present study, we examined Grx3 expression in different cell types within the developing mouse mammary gland (MG) and found enhanced expression of Grx3 at pregnancy and lactation stages. To assess the physiological role of Grx3 in MG, we generated the mutant mice in which Grx3 was deleted specifically in mammary epithelial cells (MECs). Although the reduction of Grx3 expression had only minimal effects on mammary ductal development in virgin mice, it did reduce alveolar density during pregnancy and lactation. The impairment of lobuloalveolar development was associated with high levels of ROS accumulation and reduced expression of milk protein genes. In addition, proliferative gene expression was significantly suppressed with proliferation defects occurring in knockout MECs during alveolar development compared with wild-type controls. Therefore, our findings suggest that Grx3 is a key regulator of ROS in vivo and is involved in pregnancy-dependent mammary gland development and secretory activation through modulating cellular ROS.

scholarly journals Effect of glycogen synthase kinase-3 inactivation on mouse mammary gland development and oncogenesis

2013 ◽  
Author(s):  
Joanna Dembowy ◽  
Hibret A Adissu ◽  
Jeff C Liu ◽  
Eldad Zacksenhaus ◽  
James Robert Woodgett
Keyword(s):  
Mammary Gland ◽  
Mammary Gland Development ◽  
Glycogen Synthase ◽  
Mammary Epithelium ◽  
Intraepithelial Neoplasia ◽  
Tumor Formation ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Normal Mammary Gland ◽  
Gland Development

Many components of Wnt/β-catenin signaling pathway have critical functions in mammary gland development and tumor formation, yet the contribution of glycogen synthase kinase-3 (GSK-3α and GSK-3β) to mammopoiesis and oncogenesis is unclear. Here, we report that WAP-Cre-mediated deletion of GSK-3 in the mammary epithelium results in activation of Wnt/β-catenin signaling and induces mammary intraepithelial neoplasia that progresses to squamous transdifferentiation and development of adenosquamous carcinomas at 6 months. To uncover possible β-catenin-independent activities of GSK-3, we generated mammary-specific knock-outs of GSK-3 and β-catenin. Squamous transdifferentiation of the mammary epithelium was largely attenuated, however mammary epithelial cells lost the ability to form mammospheres suggesting perturbation of stem cell properties unrelated to loss of β-catenin alone. At 10 months, adenocarcinomas that developed in glands lacking GSK-3 and β-catenin displayed elevated levels of γ-catenin/plakoglobin as well as activation of the Hedgehog and Notch pathways. Collectively these results establish the two isoforms of GSK-3 as essential integrators of multiple developmental signals that act to maintain normal mammary gland function and suppress tumorigenesis.

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