Deciphering breast cancer: from biology to the clinic.

Breast cancer remains a leading cause of cancer-related mortality in women, reflecting profound disease heterogeneity, metastasis, and therapeutic resistance. Over the last decade, genomic and transcriptomic data have been integrated on an unprecedented scale and revealed distinct cancer subtypes, critical molecular drivers, clonal evolutionary trajectories, and prognostic signatures. Furthermore, multi-dimensional integration of high-resolution single-cell and spatial technologies has highlighted the importance of the entire breast cancer ecosystem and the presence of distinct cellular "neighborhoods." Clinically, a plethora of new targeted therapies has emerged, now being rapidly incorporated into routine care. Resistance to therapy, however, remains a crucial challenge for the field.

Stem Cells and the Differentiation Hierarchy in Mammary Gland Development.

The mammary gland is a highly dynamic organ that undergoes profound changes within its epithelium during puberty and the reproductive cycle. These changes are fueled by dedicated stem and progenitor cells. Both short- and long-lived lineage-restricted progenitors have been identified in adult tissue as well as a small pool of multipotent mammary stem cells (MaSCs), reflecting intrinsic complexity within the epithelial hierarchy. While unipotent progenitor cells predominantly execute day-to-day homeostasis and postnatal morphogenesis during puberty and pregnancy, multipotent MaSCs have been implicated in coordinating alveologenesis and long-term ductal maintenance. Nonetheless, the multipotency of stem cells in the adult remains controversial. The advent of large-scale single-cell molecular profiling has revealed striking changes in the gene expression landscape through ontogeny and the presence of transient intermediate populations. An increasing number of lineage cell-fate determination factors and potential niche regulators have now been mapped along the hierarchy, with many implicated in breast carcinogenesis. The emerging diversity among stem and progenitor populations of the mammary epithelium is likely to underpin the heterogeneity that characterizes breast cancer.

Metastatic-niche labelling reveals parenchymal cells with stem features.

Direct investigation of the early cellular changes induced by metastatic cells within the surrounding tissue remains a challenge. Here we present a system in which metastatic cancer cells release a cell-penetrating fluorescent protein, which is taken up by neighbouring cells and enables spatial identification of the local metastatic cellular environment. Using this system, tissue cells with low representation in the metastatic niche can be identified and characterized within the bulk tissue. To highlight its potential, we applied this strategy to study the cellular environment of metastatic breast cancer cells in the lung. We report the presence of cancer-associated parenchymal cells, which exhibit stem-cell-like features, expression of lung progenitor markers, multi-lineage differentiation potential and self-renewal activity. In ex vivo assays, lung epithelial cells acquire a cancer-associated parenchymal-cell-like phenotype when co-cultured with cancer cells and support their growth. These results highlight the potential of this method as a platform for new discoveries.

Author Correction: Metastatic-niche labelling reveals parenchymal cells with stem features.

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

Connecting the dots: Neutrophils at the interface of tissue regeneration and cancer.

Knowledge about neutrophil biology has exponentially grown over the past decades. A high volume of investigations focusing on the characterization of their initially unappreciated multifaceted functions have grown in parallel with the immunity and the cancer fields. This has led to a significant gain in knowledge about their functions not only in tissue defence against pathogens and the collateral damage their overactivation can cause, but also their role in tissue repair and regeneration especially in the context of sterile injuries. On the other hand, the cancer field has also intensively focused its attention on neutrophil engagement in the many steps of the tumorigenic process. This review aims to draw the readers' attention to the similar functions described for neutrophils in tissue repair and in cancer. By bridging the two fields, we provide support for the hypothesis that the underlying program driving cancer-dependent exploitation of neutrophils is rooted in their physiologic tissue protection functions. In this view, cross-fertilization between the two fields will expedite the discovery of therapeutic interventions based on neutrophil targeting or their manipulation.

Liposome-enabled bufalin and doxorubicin combination therapy for trastuzumab-resistant breast cancer with a focus on cancer stem cells.

Breast cancer stem cells (BCSCs) play a key role in therapeutic resistance in breast cancer treatments and disease recurrence. This study aimed to develop a combination therapy loaded with pH-sensitive liposomes to kill both BCSCs and the okbulk cancer cells using trastuzumab-sensitive and resistant human epidermal growth factor receptor 2 positive (HER2+) breast cancer cell models. The anti-BCSCs effect and cytotoxicity of all-trans retinoic acid, salinomycin, and bufalin alone or in combination with doxorubicin were compared in HER2+ cell line BT-474 and a validated trastuzumab-resistant cell line, BT-474R. The most potent anti-BCSC agent was selected and loaded into a pH-sensitive liposome system. The effects of the liposomal combination on BCSCs and bulk cancer cells were assessed. Compared with BT-474, the aldehyde dehydrogenase positive BCSC population was elevated in BT-474R (3.9 vs. 23.1%). Bufalin was the most potent agent and suppressed tumorigenesis of BCSCs by ∼50%, and showed strong synergism with doxorubicin in both BT-474 and BT-474R cell lines. The liposomal combination of bufalin and doxorubicin significantly reduced the BCSC population size by 85%, and inhibited both tumorigenesis and self-renewal, although it had little effect on the migration and invasiveness. The cytotoxicity against the bulk cancer cells was also enhanced by the liposomal combination than either formulation alone in both cell lines (p < 0.001). The liposomal bufalin and doxorubicin combination therapy may effectively target both BCSCs and bulk cancer cells for a better outcome in trastuzumab-resistant HER2+ breast cancer.

Prevalence of probable eating disorders and associated risk factors: An analysis of the Northern Ireland Youth Wellbeing Survey using the SCOFF.

OBJECTIVES: Eating disorders (ED) are associated with significant morbidity and mortality rates and are most common in young people aged between 15 and 19 years. Large representative surveys on disordered eating in youth are lacking. The main aims were to estimate the prevalence of disordered eating in a representative sample of 11-19 year olds in Northern Ireland and investigate the associations between probable eating disorder and a range of risk factors. DESIGNS AND METHODS: A large nationally representative household survey was conducted, and the bivariate and multivariate associations between demographic, familial, economic and psychological risk factors and probable eating disorder were assessed. RESULTS: A total of 16.2% (n = 211) of the sample met the SCOFF screening criteria for disordered eating. Probable eating disorder was associated with being female (OR = 2.44), having a parent with mental health problems (OR = 1.68), suffering from certain psychological problems, such as mood or anxiety disorder (OR = 2.55), social media disorder (OR = 2.95), being the victim of physical bullying (OR = 1.71) and having smoked (OR = 2.46). CONCLUSIONS: This study provides the first prevalence estimates of probable eating disorder among youth in Northern Ireland. Furthermore, the study identifies unique risk factors for probable eating disorder among this representative sample.

CD38 knockout natural killer cells expressing an affinity optimized CD38 chimeric antigen receptor successfully target acute myeloid leukemia with reduced effector cell fratricide.

There is a strong biological rationale for the augmentation of allogeneic natural killer (NK) cell therapies with a chimeric antigen receptor (CAR) to enhance acute myeloid leukemia (AML) targeting. CD38 is an established immunotherapeutic target in multiple myeloma and under investigation as a target antigen in AML. CD38 expression on NK cells and its further induction during ex vivo NK cell expansion represents a barrier to the development of a CD38 CAR-NK cell therapy. We set out to develop a CD38 CAR-NK cell therapy for AML, first by using an NK cell line which has low baseline CD38 expression and subsequently healthy donor expanded NK cells. To overcome anticipated fratricide due to NK cell CD38 expression when using primary expanded NK cells, we applied CRISPR/Cas9 genome editing to disrupt the CD38 gene during expansion achieving a mean knockdown efficiency of 84%. The resulting CD38 KD expanded NK cells, after expression of an affinity optimized CD38 CAR, showed reduced NK cell fratricide and an enhanced ability to target primary AML blasts. Furthermore, the cytotoxic potential of CD38 CAR-NK cells was augmented by pre-treatment of the AML cells with all-trans retinoic acid which drove enhanced CD38 expression offering a rational combination therapy. These findings support the further investigation of CD38 KD - CD38 CAR-NK cells as a viable immunotherapeutic approach to the treatment of AML.

ICD-11 'mixed depressive and anxiety disorder' is clinical rather than sub-clinical and more common than anxiety and depression in the general population.

BACKGROUND: The new International Classification of Diseases was published in 2018 (ICD-11; World Health Organization, 2018) and now includes 'Mixed depressive and anxiety disorder' (6A73: MDAD) designated as a mood disorder. This disorder is defined by symptoms of both anxiety and depression occurring more days than not, for a period of two weeks, and neither set of symptoms considered separately reaches a diagnostic threshold for either disorder. However, to date no study has examined the validity of these guidelines in a general population sample. METHODS: Using Goldberg et al.'s (2017) guidelines regarding measurement of depression and anxiety, this study used factor mixture modelling (FMM) to examine the validity of the ICD-11 criteria of MDAD. Symptom endorsement rates are provided as well as demographic predictors and somatization outcomes. RESULTS: Fit indices suggested the two-factor four-class solution was the best balance between model complexity and model fit. The results did not support a class that is subsyndromal to both anxiety and depression. On the contrary, we suggest that there exists a 'Comorbid' class that represents endorsement of both anxiety and depression symptoms at a higher level when compared to both 'anxiety' and 'depression' groups. Demographic predictors, as well as somatization and functional impairment outcomes, provided support for this FMM solution. CONCLUSIONS: The 'Comorbid' group was the largest symptomatic group and had the highest levels of both anxiety and depression symptoms. Importantly, this group was larger than either the 'anxiety' or 'depression' group and was associated with high levels of functional impairment and somatization.

How is loneliness related to anxiety and depression: A population-based network analysis in the early lockdown period.

High risk of mental health problems is associated with loneliness resulting from social distancing measures and "lockdowns" that have been imposed globally due to the COVID-19 pandemic. This study explores the interconnectedness of loneliness, anxiety and depression on a symptom level using network analysis. A representative sample of participants (N = 1041), who were of at least 18 years of age, was recruited from the Republic of Ireland (ROI). Loneliness, anxiety and depression were assessed using validated instruments. Network analysis was used to identify the network structure of loneliness, anxiety and depression. Loneliness was found to be largely isolated from anxiety and depression nodes in the network. Anxiety and depression were largely interconnected. "Trouble relaxing," "feeling bad about oneself" and "not being able to stop or control worrying" were suggested as the most influential nodes of the network. Despite the expectation that loneliness would be implicated more robustly in the anxiety and depression network of symptoms, the results suggest loneliness as a distinct construct that is not interwoven with anxiety and depression.

The CD38low natural killer cell line KHYG1 transiently expressing CD16F158V in combination with daratumumab targets multiple myeloma cells with minimal effector NK cell fratricide.

Multiple myeloma (MM) is a clonal plasma cell malignancy typically associated with the high and uniform expression of the CD38 transmembrane glycoprotein. Daratumumab is a humanized IgG1κ CD38 monoclonal antibody (MoAb) which has demonstrated impressive single agent activity even in relapsed refractory MM patients as well as strong synergy with other anti-MM drugs. Natural Killer (NK) cells are cytotoxic immune effector cells that mediate in vivo tumour immunosurveillance. NK cells also play an important role during MoAb therapy by inducing antibody dependent cellular cytotoxicity (ADCC) via their FcγRIII (CD16) receptor. Furthermore, 15% of the population express a naturally occurring variant of CD16 harbouring a single-point polymorphism (F158V). However, the contribution of NK cells to the efficacy of daratumumab remains debatable as clinical data clearly indicate the rapid depletion of CD38high peripheral blood NK cells in patients upon daratumumab administration. In contrast, CD38low peripheral blood NK cells have been shown to survive daratumumab mediated fratricide in vivo, while still retaining their potent anti-MM cytolytic effector functions ex vivo. Therefore, we hypothesize that transiently expressing the CD16F158V receptor using a "safe" mRNA electroporation-based approach on CD38low NK cells in combination with daratumumab could represent a novel therapeutic option for treatment of MM. In the present study, we investigate a NK cell line (KHYG-1), derived from a patient with aggressive NK cell leukemia, as a platform for generating CD38low NK cells expressing CD16F158V which can be administered as an "off-the-shelf" therapy to target both CD38high and CD38low tumour clones in patients receiving daratumumab.

Predicting the ecological impacts of an alien invader: Experimental approaches reveal the trophic consequences of competition.

Ecological theory on the trophic impacts of invasive fauna on native competitors is equivocal. Whilst increased interspecific competition can result in coexisting species having constricted and diverged trophic niches, the competing species might instead increase their niche sizes to maintain energy intakes. Empirical experiments can test invasion theory on competitive interactions and niche sizes across different spatial scales and complexity. The consequences of increased interspecific competition from a model alien fish Leuciscus idus were tested on two taxonomically and trophically similar native fishes, Squalius cephalus and Barbus barbus. Competitive interactions were tested in tank aquaria using comparative functional responses (CFRs) and cohabitation trials. The consequences of these competitive interactions for the trophic niche sizes and positions of the fishes were tested in pond mesocosms. Comparative functional responses revealed that compared to B. barbus, L. idus had significantly higher attack and consumption rates; cohabitation trials revealed B. barbus growth rates were depressed in sympatry with L. idus. For L. idus and S. cephalus, differences in their functional response parameters and growth rates were not significant. Pond mesocosms used stable isotope metrics to quantify shifts in the trophic niche sizes of the fishes between allopatry and sympatry using a substitutive experimental design. Isotopic niches were smaller and more divergent in sympatric paired species than predicted by their allopatric treatments, suggesting trophic impacts from interspecific competition. However, an all-species sympatric treatment revealed similar niche sizes with allopatry. This maintenance of niche sizes in the presence of all species potentially resulted from the buffering of direct competitive effects of the species pairs by indirect effects. Experimental predictions from tank aquaria assisted the interpretation of the constricted and diverged trophic niches detected in the paired-species sympatric treatments of the pond mesocosms. However, the all-species sympatric treatment of this experiment revealed greater complexity in the outcomes of the competitive interactions within and between the species. These results have important implications for understanding how alien species integrate into food webs and influence the trophic relationships between native species.

Investigation of a fluorescent reporter microenvironment niche labeling strategy in experimental brain metastasis.

Brain metastases are the most common brain tumors in patients and are associated with poor prognosis. Investigating the colonization and outgrowth of brain metastases is challenging given the complexity of the organ, tissue sampling difficulty, and limited experimental models. To address this challenge, we employed a strategy to analyze the metastatic niche in established lesions, based on the release of a cell-penetrating mCherry tag from labeled tumor cells to neighboring niche cells, using different brain metastasis mouse models. We found that CD206+ macrophages were the most abundant cells taking up the mCherry label in established metastases. In vitro and in vivo experiments demonstrated that macrophages uptake and retain the canonical form of mCherry, even without the cell-penetrating portion of the tag. These results identify a specific macrophage subset in the brain that retains tumor-supplied fluorescent molecules, thereby complicating the long-term use of niche labeling strategies in established experimental brain metastasis.

Parental physical activity, parental mental health, children's physical activity, and children's mental health.

Introduction: The benefits of physical activity for mental health and well-being and the associations between parental mental health and children's mental health have been well established. These important issues tend to be examined separately however, and there is limited research on the associations between parent and child physical activity and mental health when all considered together. While family focused practice is recommended to provide support for parents who have mental health problems and their families and includes various components (such as psychoeducation, support for mental health and parenting), promoting physical activity for parents and children is not usually a core component of these interventions. Methods: The Northern Ireland Youth Wellbeing Survey aimed to provide estimates of the prevalence of mental health problems among children and young people. The survey also included questions about parental physical activity, parental mental health, and children's physical activity (for those aged 11-19 years). The main aim of the analysis reported in this article was to explore possible bivariate associations between parent and child physical activity and mental health and also explore these associations when all considered together. Participants were included in the analysis where there were completed interviews for the young person and one of their parents, and both young person and parent provided responses in relation to questions on weekly physical activity (n = 882). Results: The findings highlight the positive associations between parental physical activity and parental mental health, and between children's physical activity and children's mental health. They also explore some of the more complex interactions between these four variables, which suggest that gender may also be an important consideration. There were significant associations between father's physical activity and son's mental health, and son's physical activity and father's mental health. Discussions: These findings suggest that including support for parental physical activity and children's physical activity should be a routine component of family focused mental health interventions. It is important to acknowledge that there may be additional barriers to engaging in physical activity for families where a parent is experiencing mental health problems, and these should also be explored and addressed.

Prevalence and risk factors of parental mental health problems: A cross-sectional study.

An understanding of the prevalence and risk factors of parental mental health problems is important for early intervention and prevention measures and shaping services for parents and their children. However, large representative surveys of parental mental health problems and associated risk factors are lacking. The aim of this study was to estimate prevalence rates of parental mental health problems using a standardised measure of psychiatric morbidity (General Health Questionnaire; GHQ-12), in a representative sample of parents and caregivers of children and young people (2-19 years) in Northern Ireland. Further, this study explored associated risk factors of parental mental health problems. A random household survey of parents and children was conducted between June 2019 and March 2020. Parental responses on demographic, economic, familial and psychological measures were collected (N = 2815) and 22% of parents and caregivers screened positive for mental health problems. The STROBE checklist for observational research was adhered to. Multivariate logistic regression indicated that being in receipt of benefits, having poor family support, a history of adverse childhood experiences, a history of exposure to politically motivated violence (the Troubles), and a child with conduct problems and poor health were all independent risk factors of increased parental mental health problems. Findings will help to inform future commissioning and development of services and broaden understanding of the correlates of parental mental health problems.

Variants in the MS4A cluster interact with soluble TREM2 expression on biomarkers of neuropathology.

Recent evidence suggests that Alzheimer's disease (AD) genetic risk variants (rs1582763 and rs6591561) of the MS4A locus are genome-wide significant regulators of soluble TREM2 levels such that the minor allele of the protective variant (rs1582763) is associated with higher sTREM2 and lower AD risk while the minor allele of (rs6591561) relates to lower sTREM2 and higher AD risk. Our group previously found that higher sTREM2 relates to higher Aß40, worse blood-brain barrier (BBB) integrity (measured with the CSF/plasma albumin ratio), and higher CSF tau, suggesting strong associations with amyloid abundance and both BBB and neurodegeneration complicate interpretation. We expand on this work by leveraging these common variants as genetic tools to tune the interpretation of high CSF sTREM2, and by exploring the potential modifying role of these variants on the well-established associations between CSF sTREM2 as well as TREM2 transcript levels in the brain with AD neuropathology. Biomarker analyses leveraged data from the Vanderbilt Memory & Aging Project (n = 127, age = 72 ± 6.43) and were replicated in the Alzheimer's Disease Neuroimaging Initiative (n = 399, age = 73 ± 7.39). Autopsy analyses were performed leveraging data from the Religious Orders Study and Rush Memory and Aging Project (n = 577, age = 89 ± 6.46). We found that the protective variant rs1582763 attenuated the association between CSF sTREM2 and Aß40 (ß = -0.44, p-value = 0.017) and replicated this interaction in ADNI (ß = -0.27, p = 0.017). We did not observe this same interaction effect between TREM2 mRNA levels and Aß peptides in brain (Aß total ß = -0.14, p = 0.629; Aß1-38, ß = 0.11, p = 0.200). In contrast to the effects on Aß, the minor allele of this same variant seemed to enhance the association with blood-brain barrier dysfunction (ß = 7.0e-4, p = 0.009), suggesting that elevated sTREM2 may carry a much different interpretation in carriers vs. non-carriers of this allele. When evaluating the risk variant (rs6591561) across datasets, we did not observe a statistically significant interaction against any outcome in VMAP and observed opposing directions of associations in ADNI and ROS/MAP on Aß levels. Together, our results suggest that the protective effect of rs1582763 may act by decoupling the associations between sTREM2 and amyloid abundance, providing important mechanistic insight into sTREM2 changes and highlighting the need to incorporate genetic context into the analysis of sTREM2 levels, particularly if leveraged as a clinical biomarker of disease in the future.

Mechanisms of Organ-Specific Metastasis of Breast Cancer.

Cancer metastasis, or the development of secondary tumors in distant tissues, accounts for the vast majority of fatalities in patients with breast cancer. Breast cancer cells show a striking proclivity to metastasize to distinct organs, specifically the lung, liver, bone, and brain, where they face unique environmental pressures and a wide variety of tissue-resident cells that together create a strong barrier for tumor survival and growth. As a consequence, successful metastatic colonization is critically dependent on reciprocal cross talk between cancer cells and host cells within the target organ, a relationship that shapes the formation of a tumor-supportive microenvironment. Here, we discuss the mechanisms governing organ-specific metastasis in breast cancer, focusing on the intricate interactions between metastatic cells and specific niche cells within a secondary organ, and the remarkable adaptations of both compartments that cooperatively support cancer growth. More broadly, we aim to provide a framework for the microenvironmental prerequisites within each distinct metastatic site for successful breast cancer metastatic seeding and outgrowth.

The structure of the Prodromal Questionnaire-16 (PQ-16) in a non-help-seeking youth population: Exploratory and confirmatory factor analyses study.

AIMS: The present study aimed to examine the structure of the Prodromal Questionnaire-16 (PQ-16) in a non-help-seeking youth population through exploratory and confirmatory factor analysis. Previous studies have not examined the structure of this self-report measure in this age group outside a clinical setting. METHODS: Participants (n = 1165) aged 11-19 years were recruited to an epidemiological study of young people in Northern Ireland, and completed the PQ-16 alongside other measures. The dataset was split randomly in two for separate factor analyses. A polychoric correlation matrix was created and exploratory factor analysis was used to identify the optimal number of factors. In addition, based on previous studies, six models were tested through confirmatory factor analysis to determine best fit. A one-factor, 3 two-factor, a three-factor and a four-factor model were all tested. RESULTS: The exploratory factor analysis indicated a two-factor structure of the PQ-16 in this population, which we have labelled 'general unusual experiences' and 'hallucinations'. Confirmatory analysis indicated that the two-factor model identified through the exploratory analysis was the best fit for the data. DISCUSSION: The present study suggests that the structure of the PQ-16 may vary across age groups in non-clinical settings, and adds further support to the validity of the PQ-16 is a cost-effective, easy to administer self-report measure that is suitable for use in non-help-seeking populations as a screening tool for prodromal symptoms.

The influence of adverse and positive childhood experiences on young people's mental health and experiences of self-harm and suicidal ideation.

BACKGROUND: Few studies have examined the interaction of adverse childhood experiences (ACEs) and positive childhood experiences (PCEs) with mental health outcomes in nationally representative European populations. OBJECTIVE: The primary objective was to test models of resilience through investigating associations between ACEs and PCEs and young people's risk of common mood and anxiety disorders, self-harm and suicidal ideation. PARTICIPANTS AND SETTING: Data were from the Northern Ireland Youth Wellbeing Survey (NIYWS), a stratified random probability household survey conducted between June 2019 and March 2020. Analysis is based on data from adolescents aged 11-19 years (n = 1299). METHOD: Logistic regression was used to test the direct effects of ACEs and PCEs on mental health outcomes and the moderating effect of PCEs at different levels of ACE exposure. RESULTS: Prevalence rates of mental health outcomes were: common mood and anxiety disorders (16 %); self-harm (10 %); suicidal ideation (12 %). ACEs and PCEs both independently predicted common mood and anxiety disorders, self-harm and suicidal ideation. Every additional ACE increased the likelihood of a common mood and anxiety disorder (81 %), self-harm (88 %) and suicidal ideation (88 %). Every additional PCE reduced common mood and anxiety disorders (14 %), self-harm (13 %) and suicidal ideation (7 %). There was no moderating effect of PCEs on ACEs and mental health outcomes. CONCLUSION: The findings suggest that PCEs act largely independently of ACEs and that initiatives to increase PCEs can assist in the prevention of mental health problems.