Papers by Christine Watson
Development, 1986
The mouse t-complex is a region of chromosome 17, found in wild mouse populations, which is gross... more The mouse t-complex is a region of chromosome 17, found in wild mouse populations, which is grossly rearranged when compared to those of normal laboratory strains. So far, two large, independent inversions have been demonstrated. The distal inversion includes the entire Major Histocompatibility Complex (MHC) (Artzt, Shin & Bennett, 1982; Shin et al. 1983; Pla & Condamine, 1984) and the recently discovered proximal inversion (Herrmann et al. 1986) also contains many genes, including the t-complex polypeptide-1 gene (Tcp-1) discussed in this article. Using in situ hybridization, the MHC (Lader et al. 1985) and Tcp-1 (Lyon et al. 1986) genes have been positioned on chromosome 17 and the t-complex would appear to occupy Giemsa bands 17B and 17A3, representing roughly 15 % of the chromosome. Presumably, in addition to those already mapped, many hundreds of genes are located in this region.
Journal of mammary gland biology and neoplasia, May 18, 2024
The transcription factor STAT3 is activated by multiple cytokines and other extrinsic factors. It... more The transcription factor STAT3 is activated by multiple cytokines and other extrinsic factors. It plays a key role in immune and inflammatory responses and, when dysregulated, in tumourigenesis. STAT3 is also an indispensable mediator of the cell death process that occurs during post-lactational regression of the mammary gland, one of the most dramatic examples of physiological cell death in adult mammals. During this involution of the gland, STAT3 powerfully enhances the lysosomal system to efficiently remove superfluous milk-producing mammary epithelial cells via a lysosomal-mediated programmed cell death pathway. The lysosome is a membrane-enclosed cytoplasmic organelle that digests and recycles cellular waste, with an important role as a signalling centre that monitors cellular metabolism. Here, we describe key strategies for investigating the role of STAT3 in regulating lysosomal function using a mammary epithelial cell culture model system. These include protocols for lysosome enrichment and enzyme activity assays, in addition to microscopic analyses of the vesicular compartment in cell lines. Collectively, these approaches provide the tools to investigate multiple aspects of lysosome biogenesis and function, and to define both direct and indirect roles for STAT3.
FEBS Journal, Sep 24, 2014
Mammary gland involution involves a process that includes one of the most dramatic examples of ce... more Mammary gland involution involves a process that includes one of the most dramatic examples of cell death in an adult mammalian organism. We have previously shown that Stat3 regulates a lysosomal pathway of cell death in the first 48 hours of involution and induces lysosome leakiness in mammary epithelial cells. Interestingly, Stat3 is associated also with the striking induction of autophagy which occurs concomitantly with cell death, presumably as a transient survival mechanism. The PI3 Kinase regulatory subunits p55α and p50α are dramatically and specifically upregulated at the transcriptional level by Stat3 at the onset of involution. We show here that ablation of either Stat3 or p55α/p50α in vivo affects autophagy during involution. We used two different cell culture models, normal mammary epithelial cells and mouse embryonic fibroblasts, to further investigate the role of p55α/p50α in autophagy regulation. Our results demonstrate a direct role for p55α/p50α as inhibitors of autophagy mediated by p85α. Thus Stat3 and its downstream targets p55α/p50α are key regulators of the balance between autophagy and cell death in vivo.
Cell Death and Disease, May 6, 2010
Biochemical Journal
The mammary gland provides a spectacular example of physiological cell death whereby the cells th... more The mammary gland provides a spectacular example of physiological cell death whereby the cells that produce milk during lactation are removed swiftly, efficiently, and without inducing inflammation upon the cessation of lactation. The milk-producing cells arise primarily during pregnancy and comprise the alveolar lineage that is specified by signalling pathways and factors that are activated in response to pregnancy hormones. There are at least two alveolar sub-lineages, one of which is marked by the presence of binucleate cells that are especially susceptible to programmed cell death during involution. This process of post-lactational regression, or involution, is carefully orchestrated and occurs in two phases, the first results in a rapid switch in cell fate with the secretory epithelial cells becoming phagocytes whereupon they destroy dead and dying cells from milk. This reversible phase is followed by the second phase that is marked by an influx of immune cells and a remodellin...
The FEBS Journal, 2019
The adult mammary gland undergoes dynamic changes during puberty and the postnatal developmental ... more The adult mammary gland undergoes dynamic changes during puberty and the postnatal developmental cycle. The mammary epithelium is composed of a bilayer of outer basal, or myoepithelial, cells and inner luminal cells, the latter lineage giving rise to the milk‐producing alveolar cells during pregnancy. These luminal alveolar cells undergo Stat3‐mediated programmed cell death following the cessation of lactation. It is established that immune cells in the microenvironment of the gland have a role to play both in the ductal outgrowth during puberty and in the removal of dead cells and remodelling of the stroma during the process of postlactational regression. However, most studies have focussed on the role of the stromal immune cell compartment or have quantified immune cell populations in tissue extracts. Our recent development of protocols for deep imaging of the mammary gland in three dimensions (3D) has enabled the architectural relationship between immune cells and the epithelium ...
Development, 2020
The mammary gland is a unique tissue and the defining feature of the class Mammalia. It is a late... more The mammary gland is a unique tissue and the defining feature of the class Mammalia. It is a late-evolving epidermal appendage that has the primary function of providing nutrition for the young, although recent studies have highlighted additional benefits of milk including the provision of passive immunity and a microbiome and, in humans, the psychosocial benefits of breastfeeding. In this Review, we outline the various stages of mammary gland development in the mouse, with a particular focus on lineage specification and the new insights that have been gained by the application of recent technological advances in imaging in both real-time and three-dimensions, and in single cell RNA sequencing. These studies have revealed the complexity of subpopulations of cells that contribute to the mammary stem and progenitor cell hierarchy and we suggest a new terminology to distinguish these cells.
Development
Post-lactational mammary gland regression encompasses extensive programmed cell death and removal... more Post-lactational mammary gland regression encompasses extensive programmed cell death and removal of milk-producing epithelial cells, breakdown of extracellular matrix components and redifferentiation of stromal adipocytes. This highly regulated involution process is associated with a transient increased risk of breast cancer in women. Using a syngeneic tumour model, we show that tumour growth is significantly altered depending on the stage of involution at which tumour cells are implanted. Tumour cells injected at day3 involution grew faster than those in nulliparous mice, while tumours initiated at day6 involution grew significantly slower. These differences in tumour progression correlate with distinct changes in innate immune cells, in particular among F4/80-expressing macrophages and among TCRδ+ unconventional T cells. Breast cancer post-pregnancy risk is exacerbated in older first-time mothers and in our model, initial tumour growth is moderately faster in aged mice compared t...
Trends in cell biology, Aug 6, 2017
Adult mammary stem cells (MaSCs) drive postnatal organogenesis and remodeling in the mammary glan... more Adult mammary stem cells (MaSCs) drive postnatal organogenesis and remodeling in the mammary gland, and their longevity and potential have important implications for breast cancer. However, despite intense investigation the identity, location, and differentiation potential of MaSCs remain subject to deliberation. The application of genetic lineage-tracing models, combined with quantitative 3D imaging and biophysical methods, has provided new insights into the mammary epithelial hierarchy that challenge classical definitions of MaSC potency and behaviors. We review here recent advances - discussing fundamental unresolved properties of MaSC potency, dynamics, and plasticity - and point to evolving technologies that promise to shed new light on this intractable debate. Elucidation of the physiological mammary differentiation hierarchy is paramount to understanding the complex heterogeneous breast cancer landscape.
Nature Communications, 2016
The mammary gland undergoes cycles of growth and regeneration throughout reproductive life, a pro... more The mammary gland undergoes cycles of growth and regeneration throughout reproductive life, a process that requires mammary stem cells (MaSCs). Whilst recent genetic fate-mapping studies using lineage-specific promoters have provided valuable insights into the mammary epithelial hierarchy, the true differentiation potential of adult MaSCs remains unclear. To address this, herein we utilize a stochastic genetic-labelling strategy to indelibly mark a single cell and its progeny in situ, combined with tissue clearing and 3D imaging. Using this approach, clones arising from a single parent cell could be visualized in their entirety. We reveal that clonal progeny contribute exclusively to either luminal or basal lineages and are distributed sporadically to branching ducts or alveoli. Quantitative analyses suggest that pools of unipotent stem/progenitor cells contribute to adult mammary gland development. Our results highlight the utility of tracing a single cell and reveal that progeny of a single proliferative MaSC/progenitor are dispersed throughout the epithelium.
Journal of mammary gland biology and neoplasia, 2009
International Journal of Surgery, 2014
assessors (1 surgery, 1 pathology). Survival was analyzed using KaplaneMeier curves and the Log-r... more assessors (1 surgery, 1 pathology). Survival was analyzed using KaplaneMeier curves and the Log-rank test. Results: There is increased tumour epithelial cytoplasmic staining for NR4A2, and an altered nuclear-cytoplasmic ratio with more cytoplasmic NR4A2 in tumour compared to matched normal tissue (p ¼ 0.001). High tumour cytoplasmic NR4A2 is associated with a significantly worse overall and disease specific survival in colorectal cancer. (5-year DSS 64% high cytoplasmic NR4A2 versus 80% low cytoplasmic NR4A2, log-rank test p¼0.049, 5-year OS p¼0.003) Conclusions: There is marked cytoplasmic mislocalisation of NR4A2 in colon cancer. High tumour cytoplasmic NR4A2 is associated with an adverse prognosis.
Development
Post-lactational mammary gland regression encompasses extensive programmed cell death and removal... more Post-lactational mammary gland regression encompasses extensive programmed cell death and removal of milk-producing epithelial cells, breakdown of extracellular matrix components and redifferentiation of stromal adipocytes. This highly regulated involution process is associated with a transient increased risk of breast cancer in women. Using a syngeneic tumour model, we show that tumour growth is significantly altered depending on the stage of involution at which tumour cells are implanted. Tumour cells injected at day3 involution grew faster than those in nulliparous mice, while tumours initiated at day6 involution grew significantly slower. These differences in tumour progression correlate with distinct changes in innate immune cells, in particular among F4/80-expressing macrophages and among TCRδ+ unconventional T cells. Breast cancer post-pregnancy risk is exacerbated in older first-time mothers and in our model, initial tumour growth is moderately faster in aged mice compared t...
Aging, 2010
The pro-oncogenic transcription factor STAT3 is constitutively activated in a wide variety of tum... more The pro-oncogenic transcription factor STAT3 is constitutively activated in a wide variety of tumours that often become addicted to its activity, but no unifying view of a core function determining this widespread STAT3-dependence has yet emerged. We show here that constitutively active STAT3 acts as a master regulator of cell metabolism, inducing aerobic glycolysis and down-regulating mitochondrial activity both in primary fibroblasts and in STAT3-dependent tumour cell lines. As a result, cells are protected from apoptosis and senescence while becoming highly sensitive to glucose deprivation. We show that enhanced glycolysis is dependent on HIF-1α up-regulation, while reduced mitochondrial activity is HIF-1α-independent and likely caused by STAT3-mediated down-regulation of mitochondrial proteins. The induction of aerobic glycolysis is an important component of STAT3 pro-oncogenic activities, since inhibition of STAT3 tyrosine phosphorylation in the tumour cell lines down-regulates...
Trends in cell biology, Aug 6, 2017
Adult mammary stem cells (MaSCs) drive postnatal organogenesis and remodeling in the mammary glan... more Adult mammary stem cells (MaSCs) drive postnatal organogenesis and remodeling in the mammary gland, and their longevity and potential have important implications for breast cancer. However, despite intense investigation the identity, location, and differentiation potential of MaSCs remain subject to deliberation. The application of genetic lineage-tracing models, combined with quantitative 3D imaging and biophysical methods, has provided new insights into the mammary epithelial hierarchy that challenge classical definitions of MaSC potency and behaviors. We review here recent advances - discussing fundamental unresolved properties of MaSC potency, dynamics, and plasticity - and point to evolving technologies that promise to shed new light on this intractable debate. Elucidation of the physiological mammary differentiation hierarchy is paramount to understanding the complex heterogeneous breast cancer landscape.
Nucleic Acids Research, 1990
Sequences encoding adenovirus type 2 DNA polymerase were placed under control of the polyhedrin p... more Sequences encoding adenovirus type 2 DNA polymerase were placed under control of the polyhedrin promoter and inserted into the baculovirus Autographa californica nuclear polyhedrosis virus by homologous recombination. Insect cells infected with the recombinant virus produced substantial amounts of the adenovirus type 2 DNA polymerase protein which was functional in both DNA polymerase and replication initiation reactions. Thus, the baculovirus expression system can provide active adenovirus type 2 DNA polymerase that is produced in quantities suitable for biochemical and structural analysis.
Nature Communications, 2016
The mammary gland undergoes cycles of growth and regeneration throughout reproductive life, a pro... more The mammary gland undergoes cycles of growth and regeneration throughout reproductive life, a process that requires mammary stem cells (MaSCs). Whilst recent genetic fate-mapping studies using lineage-specific promoters have provided valuable insights into the mammary epithelial hierarchy, the true differentiation potential of adult MaSCs remains unclear. To address this, herein we utilize a stochastic genetic-labelling strategy to indelibly mark a single cell and its progeny in situ, combined with tissue clearing and 3D imaging. Using this approach, clones arising from a single parent cell could be visualized in their entirety. We reveal that clonal progeny contribute exclusively to either luminal or basal lineages and are distributed sporadically to branching ducts or alveoli. Quantitative analyses suggest that pools of unipotent stem/progenitor cells contribute to adult mammary gland development. Our results highlight the utility of tracing a single cell and reveal that progeny of a single proliferative MaSC/progenitor are dispersed throughout the epithelium.
FEBS Letters, 1986
A representative cDNA library has been constructed from the small quantities of poly(A)+ RNA pres... more A representative cDNA library has been constructed from the small quantities of poly(A)+ RNA present in unfertilised mouse oocytes. The construction of this library has been achieved by use of cow pea mosaic virus RNA as a carrier during isolation of polyadenylated message and during subsequent cloning procedures. This approach may be applicable to any system in which amounts of mRNA are limiting. cDNA cloning (Mouse oocyte) Cow pea mosaic virus RNA maternal RNA
Breast Cancer Research, 2013
Acta Biomaterialia, 2012
Sponge-like matrices with a specific three-dimensional structural design resembling the actual ex... more Sponge-like matrices with a specific three-dimensional structural design resembling the actual extracellular matrix of a particular tissue show significant potential for the regeneration and repair of a broad range of damaged anisotropic tissues. The manipulation of the structure of collagen scaffolds using a freeze-drying technique was explored in this work as an intrinsically biocompatible way of tailoring the inner architecture of the scaffold. The research focused on the influence of temperature gradients, imposed during the phase of crystallisation of collagen suspensions, upon the degree of anisotropy in the microstructures of the scaffolds produced. Moulding technology was employed to achieve differences in heat transfer rates during the freezing processes. For this purpose various moulds with different configurations were developed with a view to producing uniaxial and multi-directional temperature gradients across the sample during this process. Scanning electron microscopy analysis of different cross-sections (longitudinal and horizontal) of scaffolds revealed that highly aligned matrices with axially directed pore architectures were obtained where single unidirectional temperature gradients were induced. Altering the freezing conditions by the introduction of multiple temperature gradients allowed collagen scaffolds to be produced with complex pore orientations, and anisotropy in pore size and alignment.
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Papers by Christine Watson