Journal of Mammary Gland Biology and Neoplasia最新文献

The second edition of the Buenos Aires Breast Cancer Symposium (BA-BCS), the first held in person, took place from September 3rd to 6th in Buenos Aires, Argentina. This report provides an overview of the talks delivered as individual lectures or as part of the mini-symposia illustrating the diversity and complexity of the topics discussed throughout the meeting. The event brought together leading scientists and clinical experts dedicated to advancing breast cancer research and improving therapeutic strategies and patient care. The contributions from both speakers and attendees fostered an extraordinary atmosphere at the gathering in Buenos Aires. We hope these interactions will lead to more translational approaches and promote future collaborations.

The collection on Methods and Models in Mammary Gland Biology and Breast Cancer Research showcases recent advances in tools and models that enhance our understanding of mammary gland development and breast cancer. This collection includes sixteen articles, collectively addressing approaches to investigate key aspects of mammary gland biology and tumorigenesis, including hormonal signaling, tissue architecture, tumor microenvironment, and species-specific mammary development. The issue highlights innovations such as optimized progesterone receptor reporters, improved menopause models, and 3D-printed mammary epithelial structures. It also features advancements in organoid-based studies, in situ labeling of epithelial proliferation in large animals, preclinical models for breast cancer prevention, and high-resolution imaging techniques. Methodologies for studying macrophage-cancer cell interactions and lysosomal function are provided as step-by-step protocols. Additionally, review articles provide insights into diverse mammalian organoid systems, rat mammary tumor models, and strategies for modeling breast cancer metastasis. Together, these contributions advance mammary gland research by refining experimental approaches, expanding model diversity, and fostering translational applications in breast cancer.

Tumorigenesis in mammals is driven by inherited genetic variants, environmental factors and random errors during normal DNA replication that lead to cancer-causing mutations. These factors initiate uncontrolled cellular proliferation and disrupt the regulation of critical checkpoints. A few mammalian species possess unique protective mechanisms that enable them to resist widespread cancer development and achieve longevity. Tissue-specific tumor protection adds another layer of complexity to this diversity. Breast cancer is a leading cause of human mortality, particularly among females. Driven by the need for new strategies in treatment and prevention, this opinion article explores and supports the idea that herbivores are more resistant to mammary cancer than carnivores and omnivores. This diversity has occurred despite the remarkably similar basic mammary biology. Herbivores' meatless diet cannot explain the differences in cancer resistance, which have accompanied species segregation since the Jurassic era. To investigate the causes of this diversity, the characteristics of tumorigenesis in the human breast-and to a lesser extent in other carnivores-have been compared with data from retrospective analyses of bovine mammary tumor development across various locations over the past century. Well-established genomic, cellular, and systemic triggers of breast cancer exhibit different, or less pronounced tissue-specific activity in the bovine mammary gland, accompanied by novel bovine-specific protective mechanisms. Together, these factors contribute to the near absence of breast cancer in bovines and offer a basis for developing future anticancer strategies.

Nipple pain is a common reason for premature breastfeeding cessation. There exists anecdotal evidence that one cause of lactational nipple pain is a ductal obstruction, but there is no published literature describing this phenomenon. Herein we present two case reports for two patients who experienced breast and nipple pain concurrent with milk flow reduction. Both patients removed a small stone-like obstructing object from their nipple; this action was painful for one of the patients, resulting in immediate release of milk and relief from breast pain. Both patients experienced recurrence of stone formation in their nipple ducts. We analyzed the mineral composition of the obstructing objects and breast milk using inductively coupled mass spectroscopy. We use literature on teat obstructions in dairy cows and dacryolith and sialolith formation to propose hypotheses as to how the formation of obstructing objects in milk ducts might occur. Future research directions for determining the pathophysiology, clinical presentation, and management of human nipple duct obstructions are discussed.

Fluorescent biosensors offer a powerful tool for tracking and quantifying protein activity in living systems with high temporospatial resolution. However, the expression of genetically encoded fluorescent proteins can interfere with endogenous signaling pathways, potentially leading to developmental and physiological abnormalities. The EKAREV-NLS mouse model, which carries a FRET-based biosensor for monitoring extracellular signal-regulated kinase (ERK) activity, has been widely utilized both in vivo and in vitro across various cell types and organs. In this study, we report a significant defect in mammary epithelial development in EKAREV-NLS C57BL/6J female mice. Our findings reveal that these mice exhibit severely impaired mammary epithelial outgrowth, linked to systemic defects including disrupted estrous cycling, impaired ovarian follicle maturation, anovulation, and reduced reproductive fitness. Notably, estrogen supplementation was sufficient to enhance mammary epithelial growth in the EKAREV-NLS C57BL/6J females. Furthermore, outcrossing to the ICR genetic background fully restored normal mammary epithelial outgrowth, indicating that the observed phenotype is dependent on genetic background. We also confirmed the functional performance of the biosensor in hormone-supplemented and outcrossed tissues through time-lapse imaging of primary mammary epithelial cells. Our results underscore the critical need for thorough characterization of biosensor-carrying models before their application in specific research contexts. Additionally, this work highlights the influence of hormonal and genetic factors on mammary gland development and emphasizes the importance of careful consideration when selecting biosensor strains for mammary studies.

Zinc finger and BTB domain-containing protein (ZBTB) proteins have been implicated in different cellular processes, including DNA damage responses and cell cycle progression. However, the mechanism by which ZBTB14 modulates radiotherapy (RT) radioresistance (RT-R) remains to be elucidated. We aimed to elucidate the regulation mechanism of ZBTB14 in breast cancer (BC) RT-R. Using integrated bioinformatics prediction, ZBTB14 was identified as a hub transcription factor related to RT-R in BC. ZBTB14 was significantly under-expressed in non-responders and RT-R/BC cells, whereas its target transmembrane protein 208 (TMEM208) was significantly overexpressed in non-responders and RT-R/BC cells. Chromatin immunoprecipitation-qPCR and luciferase reporter assays revealed that ZBTB14 downregulated TMEM208 expression through transcriptional repression. Overexpression of ZBTB14 significantly inhibited the malignant biological behavior of BC cells and tumor growth in vivo, and further upregulation of TMEM208 reversed the biological activity and radiotherapy resistance of RT-R/BC cells inhibited by overexpression of ZBTB14.

Following previous editions, the fifteenth annual workshop of the European Network for Breast Development and Cancer (ENBDC) on Methods in Mammary Gland Biology and Breast Cancer was held from the 2nd to the 4th of May in Weggis, Switzerland. Over the course of this meeting, participants followed and discussed presentations from a roster of internationally renowned invited speakers and selected abstracts, complemented with two poster sessions covering exciting unpublished results. The sessions covered projects on normal mammary gland development, breast cancer evolution and metastasis, as well as epigenetic and metabolic regulation of breast cancer. As last year, early career researchers (ECR) hosted a pre-workshop day, when a stage was provided to allow PhD students and postdocs to showcase their projects and results, and when they had ample time for discussions on experimental settings and career planning, while interacting with several invited guests.

Gestational breast cancer (GBC), defined as breast cancer (BC) diagnosed during pregnancy or the first-year post-partum, accounts for 6-15% of BC cases in women aged 20-44 years. GBC has worse prognosis than non-GBC, but reasons behind are not clear. The GEICAM/2012-03 Study (Molecular Characterization of Gestational Breast Cancer) is a multicenter prospective/retrospective observational registry of patients diagnosed with GBC. From November 2014 to June 2015 seventy patients diagnosed with GBC were included in the study, 30 diagnosed during pregnancy and 40 after delivery. Our current study was aimed to explore differences in epidemiological, clinico-pathological and gene expression features of GBC tumors, from the GEICAM/2012-03 Study, compared to non-GBC tumors from patients of similar age (< 43 years) from six different GEICAM studies, used as non- GBC control population. As per the main objective, the study found multiple differences showing GBC tumors as a different biological entity. GBC showed a more aggressive biology, with higher Ki67 levels, higher incidence of breast and/or ovarian cancer family history, and germline deleterious BRCA1/2 mutations, and are enriched in basal-like intrinsic subtype. GBC patients showed a lower number of tumor infiltrating lymphocytes, while specific genetic signatures highlight differences in GBC´s distinctive transcriptome. Our study shows that GBC is potentially a clinically and molecularly different entity, with specific epidemiological, clinical, and histological features, as well as a distinctive altered immune state and genetic signature. Nevertheless, further studies are needed to better understand the biology of GBC and to identify new targets against which develop new, more effective, targeted therapies.

Thymidine analogs such as ethynyl deoxyuridine (EdU) or bromodeoxyuridine (BrdU) can be used to label mitosis of mammary epithelial cells (MEC) and to quantify their proliferation. However, labeling cells in larger animals requires considerable amounts of chemical that can be costly and hazardous. We developed a strategy to infuse EdU into the mammary glands of ewes to directly label mitotic MEC. First, each udder half of nulliparous ewes (n = 2) received an intramammary infusion of one of four different concentrations of EdU (0, 0.1, 1.0 or 10 mM) which was compared to BrdU IV (5 mg/kg) 24 h later. Tissues were analyzed by immunofluorescent histochemistry to detect EdU, BrdU, and total MEC. Of the EdU doses tested, 10 mM EdU yielded the greatest labeling index, while a proportion of MEC were labeled by both EdU and BrdU. We next sought to establish whether intramammary labeling could detect the induction of mitosis after exposure to exogenous estrogen and progesterone (E + P). We first infused EdU (10 mM) into the right udder half of ewes (n = 6) at t 0, followed by thymidine (100 mM) 24 h later to prevent further labeling. Three ewes were then administered E + P for 5 d, while n = 3 ewes served as controls. On d 5, EdU was infused into the left udder half of all mammary glands alongside BrdU IV (5 mg/kg). By the time of necropsy 24 h later an average MEC labeling index of 2.9% resulted from EdU delivered at t 0. In the left half of the udder on d 5, CON glands had a final EdU labeling index of 3.4% while glands exposed to E + P had a labeling index of 4.6% (p = 0.05). The corresponding degree of labeling with BrdU was 5.6% in CON glands, and 12% following E + P (p < 0.001). Our findings reveal that intramammary labeling is an efficient and cost-effective method for single- and dual-labeling of cell division in the mammary glands.

Postpartum breast cancer (PPBC) is a unique subset of breast cancer, accounting for nearly half of the women diagnosed during their postpartum years. Mammary gland involution is widely regarded as being a key orchestrator in the initiation and progression of PPBC due to its unique wound-healing inflammatory signature. Here, we provide dialogue suggestive that lactation may also facilitate neoplastic development as a result of sterile inflammation. Immune cells are involved in all stages of postnatal mammary development. It has been proposed that the functions of these immune cells are partially directed by mammary epithelial cells (MECs) and the cytokines they produce. This suggests that a more niche area of exploration aimed at assessing activation of innate immune pathways within MECs could provide insight into immune cell contributions to the developing mammary gland. Immune cell contribution to pubertal development and mammary gland involution has been extensively studied; however, investigations into pregnancy and lactation remain limited. During pregnancy, the mammary gland undergoes dramatic expansion to prepare for lactation. As a result, MECs are susceptible to replicative stress. During lactation, mitochondria are pushed to capacity to fulfill the high energetic demands of producing milk. This replicative and metabolic stress, if unresolved, can elicit activation of innate immune pathways within differentiating MECs. In this review, we broadly discuss postnatal mammary development and current knowledge of immune cell contribution to each developmental stage, while also emphasizing a more unique area of study that will be beneficial in the discovery of novel therapeutic biomarkers of PPBC.