Joanne Emerman | University of British Columbia (original) (raw)

Papers by Joanne Emerman

Bone Marrow Transplantation

A number of recombinant cytokines believed to regulate normal hematopoiesis are now being used in... more A number of recombinant cytokines believed to regulate normal hematopoiesis are now being used in cancer treatment protocols to reduce the myelosuppressive toxicity of intensive chemoradiotherapy regimens. It is widely assumed that such cytokines are relatively specific for hematopoietic cells, although some cell lines derived from a variety of non-hematopoietic human tumors can respond to some of these factors. However, relatively little is known about their ability to stimulate (or inhibit) the proliferation of freshly isolated normal or malignant non-hematopoietic cells. We have used a serum-free culture medium that selectively supports the growth of human breast epithelial cells (HBEC) obtained directly from normal or malignant tissue samples to evaluate potential stimulatory or inhibitory effects of eight cytokines: granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, Steel factor, interleukin-2, interleukin-3, interleukin-6, transforming gro...

Cancer Research

In the present study, we demonstrate that social housing conditions significantly alter the respo... more In the present study, we demonstrate that social housing conditions significantly alter the response of the transplantable androgen-responsive Shionogi mouse mammary tumor (SC115) to chemotherapy. Mice were reared either in groups (G) or as individuals (I). Immediately following tumor cell or vehicle injection, mice were rehoused from group to individual (GI) or from individual to group (IG) conditions. A combination of Adriamycin (4 mg/kg) and cyclophosphamide (61.5 mg/kg), in a series of three i.p. injections 7 days apart, was initiated when mean tumor weights of mice within a housing condition (GI or IG) reached 1 g. Survival probability was significantly greater in mice in the IG housing condition compared to those in the GI housing condition (47% versus 19%, respectively). Additionally, the median survival time following the initiation of chemotherapy was greater for mice in the IG than for mice in the GI condition (24.5 days versus 15.0 days, respectively). These findings sugg...

Cancer Research

We have shown that social housing conditions affect the growth rate of the androgen-responsive Sh... more We have shown that social housing conditions affect the growth rate of the androgen-responsive Shionogi mouse mammary tumor (SC115) and differentially stimulate splenic natural killer (NK) cell activity. Mice reared in a social group and then singly housed (GI) following tumor cell injection have increased tumor growth rates and increased NK cell activity, whereas mice reared individually and then group housed following tumor cell injection have decreased tumor growth rates and decreased NK cell activity compared to that in mice remaining in their rearing group. The present study was undertaken to determine whether NK cells are involved in mediating the effects of social housing conditions on SC115 tumor growth rates. We demonstrate that the presence of the SC115 tumor significantly stimulates the activity of NK cells at the tumor site in the first 7 days after tumor cell injection, and that, consistent with the data on splenic NK cells, mice of the GI group (largest tumors) have si...

Physiology & behavior

We have demonstrated marked effects of social housing condition on the growth rate of the androge... more We have demonstrated marked effects of social housing condition on the growth rate of the androgen-responsive Shionogi mouse mammary carcinoma. The present study investigated the possible role of psychosocial variables in modulating the differential tumor growth rates observed. Male DD/S mice were reared individually housed (I) or in groups (G) of three or five siblings or nonsiblings. Following tumor cell injection, mice either remained in their rearing conditions (II, GG) or were rehoused (IG, GI). Effects of group size, sibling relationship, dominance status, change vs. no change in housing condition, and direction of change (individual to group or group to individual) were examined. Home cage behaviors were monitored both prior to and following tumor cell injection and rehousing. Overall, mice in the GI conditions showed faster tumor growth rates than mice in the IG conditions. Mice in the II and GG conditions showed intermediate tumor growth rates. Differences in group size and...

Cancer research, 1995

Breast cancer research : BCR, 2005

Phosphorylated Akt (P-Akt) is an attractive molecular target because it contributes to the develo... more Phosphorylated Akt (P-Akt) is an attractive molecular target because it contributes to the development of breast cancer and confers resistance to conventional therapies. Akt also serves as a signalling intermediate for receptors such as human epidermal growth factor receptor (HER)-2, which is overexpressed in 30% of breast cancers; therefore, inhibitors to this pathway are being sought. New celecoxib analogues reportedly inhibit P-Akt in prostate cancer cells. We therefore examined the potential of these compounds in the treatment of breast cancer. The analogues were characterized in MDA-MB-453 cells because they overexpress HER-2 and have very high levels of P-Akt. To evaluate the effect of the celecoxib analogues, immunoblotting was used to identify changes in the phosphorylation of Akt and its downstream substrates glycogen synthase kinase (GSK) and 4E binding protein (4EBP-1). In vitro kinase assays were then used to assess the effect of the drugs on Akt activity. Cell death was...

Stem Cell Reports, 2013

Telomeres are essential for genomic integrity, but little is known about their regulation in the ... more Telomeres are essential for genomic integrity, but little is known about their regulation in the normal human mammary gland. We now demonstrate that a phenotypically defined cell population enriched in luminal progenitors (LPs) is characterized by unusually short telomeres independently of donor age. Furthermore, we find that multiple DNA damage response proteins colocalize with telomeres in >95% of LPs but in <5% of basal cells. Paradoxically, 25% of LPs are still capable of exhibiting robust clonogenic activity in vitro. This may be partially explained by the elevated telomerase activity that was also seen only in LPs. Interestingly, this potential telomere salvage mechanism declines with age. Our findings thus reveal marked differences in the telomere biology of different subsets of primitive normal human mammary cells. The chronically dysfunctional telomeres unique to LPs have potentially important implications for normal mammary tissue homeostasis as well as the development of certain breast cancers.

Psychosomatic Medicine, 2001

The objective of this study was to investigate 1) whether social housing condition, tumor size, a... more The objective of this study was to investigate 1) whether social housing condition, tumor size, and tumor growth rate alter responses to chemotherapy and 2) whether the timing of tumor cell injection or chemotherapy initiation (relative to housing condition formation) influences tumor growth rate or the efficacy of chemotherapy. Mice were reared individually (I) or in groups (G). In experiment 1, mice were rehoused (IG or GI) or left in group housing (GG) immediately after tumor cell injection. In experiment 2, housing conditions (II, IG, GG, or GI) were formed when tumors weighed 1 g. Chemotherapy (adriamycin 4 mg/kg and cyclophosphamide 61.5 mg/kg IP) and exposure to acute novelty stress (15 min/d, 5 d/wk) were initiated 1 day after housing condition formation. If chemotherapy was initiated when the tumor burden was undetectable (experiment 1), housing condition did not alter tumor response to chemotherapy, although IG mice lost the most weight and overall had the lowest probability of survival. If chemotherapy was initiated when tumors weighed 1 g (experiment 2), both tumor and host responses to chemotherapy were poorest for IG mice. Timing of tumor cell injection relative to housing condition formation also differentially influenced the rate of tumor growth in mice treated with the drug vehicle; in experiment 1, tumor growth rate was faster in GI and GG mice than in IG mice, whereas in experiment 2, the rate of tumor growth was faster in II mice than in GG and IG mice. Altering the temporal relationships among social housing condition formation, tumor cell injection, and chemotherapy initiation differentially influences the rate of tumor growth and the efficacy of chemotherapy. Effects of housing condition are independent of tumor growth rate at chemotherapy initiation and, in terms of host responses, independent of tumor burden.

Proceedings of the National Academy of Sciences, 2014

Mechanisms that control the levels and activities of reactive oxygen species (ROS) in normal huma... more Mechanisms that control the levels and activities of reactive oxygen species (ROS) in normal human mammary cells are poorly understood. We show that purified normal human basal mammary epithelial cells maintain low levels of ROS primarily by a glutathione-dependent but inefficient antioxidant mechanism that uses mitochondrial glutathione peroxidase 2. In contrast, the matching purified luminal progenitor cells contain higher levels of ROS, multiple glutathione-independent antioxidants and oxidative nucleotide damage-controlling proteins and consume O 2 at a higher rate. The luminal progenitor cells are more resistant to glutathione depletion than the basal cells, including those with in vivo and in vitro proliferation and differentiation activity. The luminal progenitors also are more resistant to H 2 O 2 or ionizing radiation. Importantly, even freshly isolated "steady-state" normal luminal progenitors show elevated levels of unrepaired oxidative DNA damage. Distinct ROS control mechanisms operating in different subsets of normal human mammary cells could have differentiation state-specific functions and long-term consequences.

Physiology & Behavior, 1999

Interactive effects of psychosocial stressors and gender on mouse mammary tumor growth. PHYSIOL B... more Interactive effects of psychosocial stressors and gender on mouse mammary tumor growth. PHYSIOL BEHAV 66 (2) 277-284, 1999.-We have previously demonstrated that social housing condition significantly affects the growth rate of the androgen-responsive Shionogi mouse mammary carcinoma (AR SC115) in male mice. The present study examined the effects of social housing condition and acute daily exposure to a novel environment on the growth rate of an androgen-independent variant of the AR SC115 carcinoma, designated SC115V, in male and female mice. Immediately following tumor cell injection, male and female mice that were reared as individuals (I) or in groups (G) of the same sex were rehoused either from individual to same-sex groups (IG) or from group to individual (GI), or remained in their group housing condition (GG). Approximately half the mice in each housing condition were subjected to acute daily exposure to novel environments (novelty stress), a treatment shown previously to increase the significant difference in tumor growth rates between male mice in the IG and GI housing conditions. The remaining mice were left undisturbed (no novelty stress). In the presence of acute daily novelty stress, the growth rate of the SC115V tumor was significantly increased in GI compared to IG males. However, no significant differences in SC115V tumor growth rates among nonstressed GI, IG, or GG males were observed. For females, in contrast to males, acute daily novelty stress significantly decreased tumor growth in GI compared to IG mice, whereas under nonstressed conditions, tumor growth rate was significantly increased in GI compared to IG females. Neither housing condition nor novelty stress altered estrous cyclicity, nor did the stage of the estrous cycle at the time of tumor cell injection influence tumor growth rates. These findings suggest that social housing condition and novelty stress may interact to produce differential effects on the growth rate of the SC115V tumor in male and female mice.

Neurotoxicology and Teratology, 2000

Stressful life events and the ability to cope with stress may play a role in the progression of b... more Stressful life events and the ability to cope with stress may play a role in the progression of breast cancer; however, the complex relationship between stressors and tumor growth is difficult to investigate in humans. Our studies have utilized the androgen-responsive Shionogi mouse mammary carcinoma (AR SC115) in male mice to investigate the effects of social housing condition on tumor growth rates and responses to chemotherapy. We demonstrate that, depending on social housing condition, mammary tumor growth and response to chemotherapy can both increase and decrease. We have examined the possible role(s) of 1) psychosocial variables, 2) testosterone and corticosterone, hormones altered by stress and known to stimulate SC115 cells in vivo and in vitro, 3) NK cells, one of the body's first lines of defense against tumor cells, 4) stress proteins, in mediating the differential tumor growth rates observed in our model. This review discusses the investigations we have undertaken to elucidate the mechanisms through which a psychosocial stressor, social housing condition, can alter tumor growth rate.

Nature Medicine, 2008

Previous studies have demonstrated that normal mouse mammary tissue contains a rare subset of mam... more Previous studies have demonstrated that normal mouse mammary tissue contains a rare subset of mammary stem cells. We now describe a method for detecting an analogous subpopulation in normal human mammary tissue. Dissociated cells are suspended with fibroblasts in collagen gels, which are then implanted under the kidney capsule of hormone-treated immunodeficient mice. After 2-8 weeks, the gels contain bilayered mammary epithelial structures, including luminal and myoepithelial cells, their in vitro clonogenic progenitors and cells that produce similar structures in secondary transplants. The regenerated clonogenic progenitors provide an objective indicator of input mammary stem cell activity and allow the frequency and phenotype of these human mammary stem cells to be determined by limiting-dilution analysis. This new assay procedure sets the stage for investigations of mechanisms regulating normal human mammary stem cells (and possibly stem cells in other tissues) and their relationship to human cancer stem cell populations.

Journal of Mammary Gland Biology and Neoplasia, 2005

The human mammary gland is organized developmentally as a hierarchy of progenitor cells that beco... more The human mammary gland is organized developmentally as a hierarchy of progenitor cells that become progressively restricted in their proliferative abilities and lineage options. Three types of human mammary epithelial cell progenitors are now identified. The first is thought to be a luminal-restricted progenitor; in vitro under conditions that support both luminal and myoepithelial cell differentiation, this cell produces clones of differentiating daughter cells that are exclusively positive for markers characteristic of luminal cells produced in vivo (i.e., keratins 8/18 and 19, epithelial cell adhesion molecule [EpCAM] and MUC1). The second type is a bipotent progenitor. It is identified by its ability to produce "mixed" colonies in single cell assays. These colonies contain a central core of cells expressing luminal markers surrounded by cells with a morphology and markers (e.g., keratin 14 + ) characteristic of myoepithelial cells. Serial passage in vitro of an enriched population of bipotent progenitors promotes the expansion of a third type of progenitor that is thought to be myoepithelialrestricted because it only produces cells with myoepithelial features. Luminal-restricted and bipotent progenitors can prospectively be isolated as distinct subpopulations from freshly dissociated suspensions of normal human mammary cells. Both are distinguished from many other cell types in mammary tissue by their expression of EpCAM and CD49f (α6 integrin). They are distinguished from each other by their differential expression of MUC1, which is expressed at much higher levels on the luminal progenitors. To relate the role of these progenitors to the generation of the three-dimensional tubuloalveolar structure of the mammary tree produced in vivo, we propose a model in which the commitment to the luminal versus the myoepithelial lineage may play a determining role in the generation of alveoli and ducts.

Experimental Cell Research, 1981

In the mammary gland of nonruminant animals, glucose is utilized in a characteristic and unique w... more In the mammary gland of nonruminant animals, glucose is utilized in a characteristic and unique way during lactation. We have measured the incorporation of glucose carbon from [U-¹C] glucose into intermediary metabolites and metabolic products in mammary epithelial cells from virgin, pregnant, and lactating mice and demonstrate that glucose metabolite patterns can be used to recognize stages of differentiated function. For these cells, the rates of synthesis of glycogen and lactose, the ratio of lactate to alanine, and the ratio of citrate to malate were important parameters in identifying the degree of expression of differentiation. We further show that these patterns can be used as markers to determine the differentiated state of cultured mammary epithelial cells. Cells maintained on plastic substrates lose their distinctive glucose metabolite patterns while those on floating collagen gels do not. Cells from pregnant mice have a pattern similar to freshly isolated cells from pregnant mice. The pattern of cells from lactating mice is different from that of the cells of origin, and resembles that of the cells from pregnant mice. Our findings suggest that the floating collagen gels under the culture conditions used in these experiments provide an environment for the functional expression of the pregnant state, while additional factors are needed for the expression of the lactating state.

Differentiation, 1998

The developmental relationships between the different mammary epithelial cell lineages in the hum... more The developmental relationships between the different mammary epithelial cell lineages in the human mammary gland are not well defined. To characterize human breast epithelial cells (HBEC) with progenitor activity, we used flow cytometry and single cell sorting to analyze the distribution of cellular phenotypes in primary cultures of reduction mammoplasties and their associated ability to generate colonies in 2-dimensional (D) and 3-D (collagen gel) culture systems. This approach allowed two distinct types of HBEC progenitor populations to be distinguished on the basis of their differential expression of the MUC-1 glycoprotein, CALLA/CD10 and epithelial-specific antigen (ESA). The first type of progenitor, which is enriched in the MUC-1 + /CAL-LA -/ESA + subpopulation, generated colonies of tightly arranged cells in 2-D cultures and small alveolar-like colonies with a central lumen when cultured in a collagen matrix. The cells produced in the colonies and derived from these MUC-1 + /CALLA -/ESA + progenitors were found to express typical luminal epitopes (keratin 8/18, keratin 19, MUC-1, ESA) and showed low levels of expression of myoepithelial epitopes (keratin 14 and CD44v6). The second type of progenitor, which is present in the MUC-1 -to ± /CALLA ± to + /ESA + subpopulation, generated mixed colonies of both luminal and myoepithelial cells when seeded in 2-D and 3-D cultures. In 2-D cultures, the centrally located cells exhibited a luminal morphology and expressed ESA, but were heterogeneous in their expression of MUC-1. Radiating from the periphery of these ESA + HBEC were highly refractile ESAteardrop-shaped myoepithelial-like cells. When cultured in a collagen matrix, these bipotent progenitors generated large branched colonies composed of a heterogeneous population of cells, with some of the progeny cells expressing luminal epitopes (keratin 8/18, keratin 19 and MUC-1) and others expressing myoepithelial epitopes (keratin 14 and CD44v6). A third type of progenitor, which became apparent in passaged HBEC cultures and was enriched in the MUC-1 -/CALLA + /ESAsubpopulation, was found to generate colonies of cells with an exclusively myoepithelial phenotype. These results provide definitive evidence for the existence of multilineage HBEC progenitors in normal adult human mammary tissue. The phenotypic profile of these cells suggest that these multilineage progenitors are a relatively undifferentiated cell since they express low levels of MUC-1 and that they have a luminal location within the mammary epithelium since they are ESA + . Furthermore, we suggest that the MUC-1 + /CALLA -/ESA + and the MUC-1 -to ± /CALLA ± to + /ESA + progenitors we have identified and characterized are candidate in vivo alveolar and ductal progenitors, respectively. & k w d : Abbreviations HBEC Human breast epithelial cells · CALLA Common acute lymphoblastic leukemia antigen · MUC-1, MUC-1 glycoprotein · ESA Epithelial specific antigen · F12/DME/H Hams F12/Dulbecco's modified Eagle's medium/Hepes · BSA Bovine serum albumin · INS Insulin · HC Hydrocortisone · CT Cholera toxin · FBS Fetal bovine serum · EDTA Ethylenediaminetetraacetic acid · STV Saline-trypsin-versene · FACS Fluorescence activated cell sorting · EGF Epidermal growth factor · SF Serum-free · HFN Hanks balanced salt solution supplemented with 0.02% sodium azide and 2% FBS · PE Phycoerythrin · Ig Immunoglobulin · FITC Fluorescein isothiocyanate · PI Propidium iodide · PBS Phosphate buffered saline · APAAP Alkaline phosphatase anti-alkaline phosphatase ·

Journal of Tissue Culture Methods, 1983

Summary A survey conducted to determine methods of choice for providing procarcinogen activation ... more Summary A survey conducted to determine methods of choice for providing procarcinogen activation and treatment protocols for mammalian cell tests in various genetic toxicology testing laboratories showed that one-third of respondents were performing assays without exogenous activation systems, one-third used liver homogenate preparations with short exposure to the test compound, and one-third used cocultivation with metabolically competent cells with longer

Clinical & Experimental Metastasis, 2005

MUC1 is a transmembrane glycoprotein expressed by normal breast epithelium and virtually all brea... more MUC1 is a transmembrane glycoprotein expressed by normal breast epithelium and virtually all breast cancers. MUC1 is normally restricted to the apical surface of epithelia and loss of this polarized distribution in breast carcinomas is associated with lymph node metastasis. Our previous work found that MUC1 can bind intercellular adhesion molecule-1 (ICAM-1), mediating adhesion of breast cancer cells to a simulated blood vessel wall, and also triggering a calcium-based signal in the MUC1-bearing cells. It is possible that the depolarized membrane distribution of MUC1 in breast carcinomas may facilitate interactions with stromal/endothelial ICAM-1 leading to adhesion and subsequent migration through the vessel wall. In the current study, we provide evidence that ICAM-1 can influence the migration of cells that express endogenous or transfected MUC1. Migration across a gelatin-coated Transwell membrane could be increased in a step-wise manner by the sequential addition of ICAM-1-expressing cells (endothelial cells and fibroblasts), and ICAM-1-inducing inflammatory cytokines (tumour necrosis factor-alpha and interleukin-1 beta). Antibodies against MUC1 or ICAM-1, but not a control antibody, could abrogate migratory increases. Cells that did not express MUC1 were unresponsive to ICAM-1. Our current findings build on our earlier work, by suggesting that the end result of the MUC1/ICAM-1-mediated cell-cell adhesion and calcium-based signal is migration. This has implications for the exit of circulating tumour cells from the vasculature, as well as tumour cell migration through fibroblast-containing stroma underlying the endothelial wall.

Cell Stem Cell, 2008

Mature mammary epithelial cells are generated from undifferentiated precursors through a hierarch... more Mature mammary epithelial cells are generated from undifferentiated precursors through a hierarchical process, but the molecular mechanisms involved, particularly in the human mammary gland, are poorly understood. To address this issue, we isolated highly purified subpopulations of primitive bipotent and committed luminal progenitor cells as well as mature luminal and myoepithelial cells from normal human mammary tissue and compared their transcriptomes obtained using three different methods. Elements unique to each subset of mammary cells were identified, and changes that accompany their differentiation in vivo were shown to be recapitulated in vitro. These include a stage-specific change in NOTCH pathway gene expression during the commitment of bipotent progenitors to the luminal lineage. Functional studies further showed NOTCH3 signaling to be critical for this differentiation event to occur in vitro. Taken together, these findings provide an initial foundation for future delineation of mechanisms that perturb primitive human mammary cell growth and differentiation.

Cancer Research, 2006

The emerging paradigm of ''oncogene addiction'' has been called an Achilles' heel of cancer that ... more The emerging paradigm of ''oncogene addiction'' has been called an Achilles' heel of cancer that can be exploited therapeutically. Here, we show that integrin-linked kinase (ILK), which is either activated or overexpressed in many types of cancers, is a critical regulator of breast cancer cell survival through the protein kinase B (PKB)/Akt pathway but is largely dispensable for the survival of normal breast epithelial cells and mesenchymal cells. We show that inhibition of ILK activity with a pharmacologic ILK inhibitor, QLT-0267, results in the inhibition of PKB/Akt Ser 473 phosphorylation, stimulation of apoptosis, and a decrease in mammalian target of rapamycin (mTOR) expression in human breast cancer cells. In contrast, QLT-0267 treatment has no effect on PKB/Akt Ser 473 phosphorylation or apoptosis in normal human breast epithelial, mouse fibroblast, or vascular smooth muscle cells. The inhibition of PKB/Akt Ser 473 phosphorylation by QLT-0267 in breast cancer cells was rescued by a kinase-active ILK mutant but not by a kinasedead ILK mutant. Furthermore, a dominant-negative ILK mutant increased apoptosis in the MDA-MB-231 breast cancer cell line but not in normal human breast epithelial cells. The inhibitor was active against ILK isolated from all cell types but did not have any effect on cell attachment and spreading. Our data point to an ''ILK addiction'' of breast cancer cells whereby they become dependent on ILK for cell survival through the mTOR-PKB/Akt signaling pathway and show that ILK is a promising target for the treatment of breast cancer.

Bone Marrow Transplantation

Cancer Research

Physiology & behavior

Cancer research, 1995

Breast cancer research : BCR, 2005

Stem Cell Reports, 2013

Psychosomatic Medicine, 2001

Proceedings of the National Academy of Sciences, 2014

Physiology & Behavior, 1999

Neurotoxicology and Teratology, 2000

Nature Medicine, 2008

Journal of Mammary Gland Biology and Neoplasia, 2005

Experimental Cell Research, 1981

Differentiation, 1998

Journal of Tissue Culture Methods, 1983

Clinical & Experimental Metastasis, 2005

Cell Stem Cell, 2008

Cancer Research, 2006