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 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 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 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.

Apoptosis in mammary gland and cancer.

2000 ◽  
pp. 257-269 ◽  
Author(s):  
R Kumar ◽  
R K Vadlamudi ◽  
L Adam
Keyword(s):  
Breast Cancer ◽  
Mammary Gland ◽  
Mammary Gland Development ◽  
Expression Profiles ◽  
Critical Role ◽  
Physiological Mechanism ◽  
Cell Loss ◽  
Normal Mammary Gland ◽  
Organ Systems ◽  
Gland Development

Homeostasis in normal tissue is regulated by a balance between proliferative activity and cell loss by apoptosis. Apoptosis is a physiological mechanism of cell loss that depends on both pre-existing proteins and de novo protein synthesis, and the process of apoptosis is integral to normal mammary gland development and in many diseases, including breast cancer. The mammary gland is one of the few organ systems in mammals that completes its morphologic development postnatally during two discrete physiologic states, puberty and pregnancy. The susceptibility of the mammary gland to tumorigenesis is influenced by its normal development, particularly during stages of puberty and pregnancy that are characterized by marked alterations in breast cell proliferation and differentiation. Numerous epidemiologic studies have suggested that specific details in the development of the mammary gland play a critical role in breast cancer risk. Mammary gland development is characterized by dynamic changes in the expression profiles of Bcl-2 family members. The expression of Bcl-2 family proteins in breast cancer is also influenced by estradiol and by progestin. Since the ratio of proapoptotic to antiapoptotic proteins determines apoptosis or cell survival, hormone levels may have important implications in the therapeutic prevention of breast cancer.

scholarly journals Progesterone and Overlooked Endocrine Pathways in Breast Cancer Pathogenesis

Endocrinology ◽  
2015 ◽  
Vol 156 (10) ◽  
pp. 3442-3450 ◽  
Author(s):  
Cathrin Brisken ◽  
Kathryn Hess ◽  
Rachel Jeitziner
Keyword(s):  
Breast Cancer ◽  
Mammary Gland ◽  
Hormone Receptor ◽  
Cell Activation ◽  
Mammary Gland Development ◽  
Breast Cancer Incidence ◽  
Menstrual Cycles ◽  
Hormone Receptor Positive ◽  
Gland Development

Worldwide, breast cancer incidence has been increasing for decades. Exposure to reproductive hormones, as occurs with recurrent menstrual cycles, affects breast cancer risk, and can promote disease progression. Exogenous hormones and endocrine disruptors have also been implicated in increasing breast cancer incidence. Numerous in vitro studies with hormone-receptor-positive cell lines have provided insights into the complexities of hormone receptor signaling at the molecular level; in vivo additional layers of complexity add on to this. The combined use of mouse genetics and tissue recombination techniques has made it possible to disentangle hormone action in vivo and revealed that estrogens, progesterone, and prolactin orchestrate distinct developmental stages of mammary gland development. The 2 ovarian steroids that fluctuate during menstrual cycles act on a subset of mammary epithelial cells, the hormone-receptor-positive sensor cells, which translate and amplify the incoming systemic signals into local, paracrine stimuli. Progesterone has emerged as a major regulator of cell proliferation and stem cell activation in the adult mammary gland. Two progesterone receptor targets, receptor activator of NfκB ligand and Wnt4, serve as downstream paracrine mediators of progesterone receptor-induced cell proliferation and stem cell activation, respectively. Some of the findings in the mouse have been validated in human ex vivo models and by next-generation whole-transcriptome sequencing on healthy donors staged for their menstrual cycles. The implications of these insights into the basic control mechanisms of mammary gland development for breast carcinogenesis and the possible role of endocrine disruptors, in particular bisphenol A in this context, will be discussed below.

scholarly journals Early Steps of Mammary Stem Cell Transformation by Exogenous Signals; Effects of Bisphenol Endocrine Disrupting Chemicals and Bone Morphogenetic Proteins

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1351 ◽  
Author(s):  
Nora Jung ◽  
Veronique Maguer-Satta ◽  
Boris Guyot
Keyword(s):  
Breast Cancer ◽  
Stem Cell ◽  
Mammary Gland ◽  
Bone Morphogenetic Proteins ◽  
Mammary Gland Development ◽  
Cell Transformation ◽  
Current Knowledge ◽  
Endocrine Disrupting Chemicals ◽  
Normal Mammary Gland ◽  
Gland Development

Estrogens are major regulators of the mammary gland development, notably during puberty, via estrogen receptor (ER) activation, leading to the proliferation and differentiation of mammary cells. In addition to estrogens, the bone morphogenetic proteins (BMPs) family is involved in breast stem cell/progenitor commitment. However, these two pathways that synergistically contribute to the biology of the normal mammary gland have also been described to initiate and/or promote breast cancer development. In addition to intrinsic events, lifestyle habits and exposure to environmental cues are key risk factors for cancer in general, and especially for breast cancer. In the latter case, bisphenol A (BPA), an estrogen-mimetic compound, is a critical pollutant both in terms of the quantities released in our environment and of its known and speculated effects on mammary gland biology. In this review, we summarize the current knowledge on the actions of BMPs and estrogens in both normal mammary gland development and breast cancer initiation, dissemination, and resistance to treatment, focusing on the dysregulations of these processes by BPA but also by other bisphenols, including BPS and BPF, initially considered as safer alternatives to BPA.

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 Minireview: Mouse Models of Rho GTPase Function in Mammary Gland Development, Tumorigenesis, and Metastasis

2016 ◽  
Vol 30 (3) ◽  
pp. 278-289 ◽  
Author(s):  
Yan Zuo ◽  
Wonkyung Oh ◽  
Arzu Ulu ◽  
Jeffrey A. Frost
Keyword(s):  
Mammary Gland ◽  
Mammary Gland Development ◽  
Rho Gtpase ◽  
Cultured Cells ◽  
Current Knowledge ◽  
Small Gtpases ◽  
Normal Mammary Gland ◽  
Rho Proteins ◽  
And Function ◽  
Gland Development

Abstract Ras homolog (Rho) family small GTPases are critical regulators of actin cytoskeletal organization, cell motility, proliferation, and survival. Surprisingly, the large majority of the studies underlying our knowledge of Rho protein function have been carried out in cultured cells, and it is only recently that researchers have begun to assess Rho GTPase regulation and function in vivo. The purpose of this review is to evaluate our current knowledge of Rho GTPase function in mouse mammary gland development, tumorigenesis and metastasis. Although our knowledge is still incomplete, these studies are already uncovering important themes as to the physiological roles of Rho GTPase signaling in normal mammary gland development and function. Essential contributions of Rho proteins to breast cancer initiation, tumor progression, and metastatic dissemination have also been identified.

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.

scholarly journals Macrophages: Regulators of the Inflammatory Microenvironment during Mammary Gland Development and Breast Cancer

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Nicholas J. Brady ◽  
Pavlina Chuntova ◽  
Kathryn L. Schwertfeger
Keyword(s):  
Breast Cancer ◽  
Mammary Gland ◽  
Immune System ◽  
Mammary Gland Development ◽  
Adaptive Immune System ◽  
Innate Immune ◽  
Normal Mammary Gland ◽  
Inflammatory Microenvironment ◽  
Mediators Of Inflammation ◽  
Gland Development

Macrophages are critical mediators of inflammation and important regulators of developmental processes. As a key phagocytic cell type, macrophages evolved as part of the innate immune system to engulf and process cell debris and pathogens. Macrophages produce factors that act directly on their microenvironment and also bridge innate immune responses to the adaptive immune system. Resident macrophages are important for acting as sensors for tissue damage and maintaining tissue homeostasis. It is now well-established that macrophages are an integral component of the breast tumor microenvironment, where they contribute to tumor growth and progression, likely through many of the mechanisms that are utilized during normal wound healing responses. Because macrophages contribute to normal mammary gland development and breast cancer growth and progression, this review will discuss both resident mammary gland macrophages and tumor-associated macrophages with an emphasis on describing how macrophages interact with their surrounding environment during normal development and in the context of cancer.

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