Journal of Mammary Gland Biology and Neoplasia最新文献

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.

As both perimenopausal and menopausal periods are recognized critical windows of susceptibility for breast carcinogenesis, development of a physiologically relevant model has been warranted. The traditional ovariectomy model causes instant removal of the entire hormonal repertoire produced by the ovary, which does not accurately approximate human natural menopause with gradual transition. Here, we characterized the mammary glands of 4-vinylcyclohexene diepoxide (VCD)-treated animals at different time points, revealing that the model can provide the mammary glands with both perimenopausal and menopausal states. The perimenopausal gland showed moderate regression in ductal structure with no responsiveness to external hormones, while the menopausal gland showed severe regression with hypersensitivity to hormones. Leveraging the findings on the VCD model, effects of a major endocrine disruptor (polybrominated diphenyl ethers, PBDEs) on the mammary gland were examined during and after menopausal transition, with the two exposure modes; low-dose, chronic (environmental) and high-dose, subacute (experimental). All conditions of PBDE exposure did not augment or compromise the macroscopic ductal reorganization resulting from menopausal transition and/or hormonal treatments. Single-cell RNA sequencing revealed that the experimental PBDE exposure during the post-menopausal period caused specific transcriptomic changes in the non-epithelial compartment such as Errfi1 upregulation in fibroblasts. The environmental PBDE exposure resulted in similar transcriptomic changes to a lesser extent. In summary, the VCD mouse model provides both perimenopausal and menopausal windows of susceptibility for the breast cancer research community. PBDEs, including all tested models, may affect the post-menopausal gland including impacts on the non-epithelial compartments.

Metastatic spread of tumour cells to tissues and organs around the body is the most frequent cause of death from breast cancer. This has been modelled mainly using mouse models such as syngeneic mammary cancer or human in mouse xenograft models. These have limitations for modelling human disease progression and cannot easily be used for investigation of drug resistance and novel therapy screening. To complement these approaches, advances are being made in ex vivo and 3D in vitro models, which are becoming progressively better at reliably replicating the tumour microenvironment and will in the future facilitate drug development and screening. These approaches include microfluidics, organ-on-a-chip and use of advanced biomaterials. The relevant tissues to be modelled include those that are frequent and clinically important sites of metastasis such as bone, lung, brain, liver for invasive ductal carcinomas and a distinct set of common metastatic sites for lobular breast cancer. These sites all have challenges to model due to their unique cellular compositions, structure and complexity. The models, particularly in vivo, provide key information on the intricate interactions between cancer cells and the native tissue, and will guide us in producing specific therapies that are helpful in different context of metastasis.

Conflicting data exist as to how mammary epithelial cell proliferation changes during the reproductive cycle. To study the effect of endogenous hormone fluctuations on gene expression in the mouse mammary gland, we performed bulk RNAseq analyses of epithelial and stromal cell populations that were isolated either during puberty or at different stages of the adult virgin estrous cycle. Our data confirm prior findings that proliferative changes do not occur in every mouse in every cycle. We also show that during the estrous cycle the main gene expression changes occur in adipocytes and fibroblasts. Finally, we present a comprehensive overview of the Wnt gene expression landscape in different mammary gland cell types in pubertal and adult mice. This work contributes to understanding the effects of physiological hormone fluctuations and locally produced signaling molecules on gene expression changes in the mammary gland during the reproductive cycle and should be a useful resource for future studies investigating gene expression patterns in different cell types across different developmental timepoints.