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Breast Cancer Research : BCR Nov 2023As in most solid cancers, the emergence of cells with oncogenic mutations in the mammary epithelium alters the tissue homeostasis. Some soluble factors, such as TGFβ,...
BACKGROUND
As in most solid cancers, the emergence of cells with oncogenic mutations in the mammary epithelium alters the tissue homeostasis. Some soluble factors, such as TGFβ, potently modify the behavior of healthy stromal cells. A subpopulation of cancer-associated fibroblasts expressing a TGFβ target, the SNAIL1 transcription factor, display myofibroblastic abilities that rearrange the stromal architecture. Breast tumors with the presence of SNAIL1 in the stromal compartment, and with aligned extracellular fiber, are associated with poor survival prognoses.
METHODS
We used deep RNA sequencing and biochemical techniques to study alternative splicing and human tumor databases to test for associations (correlation t-test) between SNAIL1 and fibronectin isoforms. Three-dimensional extracellular matrices generated from fibroblasts were used to study the mechanical properties and actions of the extracellular matrices on tumor cell and fibroblast behaviors. A metastatic mouse model of breast cancer was used to test the action of fibronectin isoforms on lung metastasis.
RESULTS
In silico studies showed that SNAIL1 correlates with the expression of the extra domain A (EDA)-containing (EDA+) fibronectin in advanced human breast cancer and other types of epithelial cancers. In TGFβ-activated fibroblasts, alternative splicing of fibronectin as well as of 500 other genes was modified by eliminating SNAIL1. Biochemical analyses demonstrated that SNAIL1 favors the inclusion of the EDA exon by modulating the activity of the SRSF1 splicing factor. Similar to Snai1 knockout fibroblasts, EDA- fibronectin fibroblasts produce an extracellular matrix that does not sustain TGFβ-induced fiber organization, rigidity, fibroblast activation, or tumor cell invasion. The presence of EDA+ fibronectin changes the action of metalloproteinases on fibronectin fibers. Critically, in an mouse orthotopic breast cancer model, the absence of the fibronectin EDA domain completely prevents lung metastasis.
CONCLUSIONS
Our results support the requirement of EDA+ fibronectin in the generation of a metastasis permissive stromal architecture in breast cancers and its molecular control by SNAIL1. From a pharmacological point of view, specifically blocking EDA+ fibronectin deposition could be included in studies to reduce the formation of a pro-metastatic environment.
Topics: Animals; Female; Humans; Mice; Alternative Splicing; Breast Neoplasms; Fibronectins; Lung Neoplasms; Protein Isoforms; Serine-Arginine Splicing Factors; Transforming Growth Factor beta
PubMed: 37964360
DOI: 10.1186/s13058-023-01736-y -
Endocrine-related Cancer Dec 2023Development of the mammary gland requires both proper hormone signaling and cross talk between the stroma and epithelium. While estrogen receptor (ERα) expression in...
Development of the mammary gland requires both proper hormone signaling and cross talk between the stroma and epithelium. While estrogen receptor (ERα) expression in the epithelium is essential for normal gland development, the role of this receptor in the stroma is less clear. Moreover, several lines of evidence suggest that mouse phenotypes of in utero exposure to endocrine disruption act through mesenchymal ERα in the developing fetus. We utilized a Twist2-cre mouse line to knock out mesenchymal ERα. Herein, we assessed mammary gland development in the context of mesenchymal ERα deletion. We also tested the effect of in utero bisphenol A (BPA) exposure to alter the tumor susceptibility in the mouse mammary tumor virus-neu (MMTV-neu) breast cancer mouse model. Mesenchymal ERα deletion resulted in altered reproductive tract development and atypical cytology associated with estrous cycling. The mammary gland demonstrated mature epithelial extension unlike complete ERα-knockout mice, but ductal extension was delayed and reduced compared to ERα-competent mice. Using the MMTV-Neu cancer susceptibility model, ERα-intact mice exposed to BPA had reduced tumor-free survival and overall survival compared to BPA-exposed mice having mesenchymal ERα deletion. This difference is specific for BPA exposure as vehicle-treated animals had no difference in tumor development between mice expressing and not expressing mesenchymal ERα. These data demonstrate that mesenchymal ERα expression is not required for ductal extension, nor does it influence cancer risk in this mouse model but does influence the cancer incidence associated with in utero BPA exposure.
Topics: Mice; Animals; Receptors, Estrogen; Estrogen Receptor alpha; Mice, Knockout; Epithelium; Neoplasms; Mammary Glands, Animal
PubMed: 37855322
DOI: 10.1530/ERC-23-0062 -
Scientific Reports Mar 2024Biophysical cues from the cell microenvironment are detected by mechanosensitive components at the cell surface. Such machineries convert physical information into...
Biophysical cues from the cell microenvironment are detected by mechanosensitive components at the cell surface. Such machineries convert physical information into biochemical signaling cascades within cells, subsequently leading to various cellular responses in a stimulus-dependent manner. At the surface of extracellular environment and cell cytoplasm exist several ion channel families that are activated by mechanical signals to direct intracellular events. One of such channel is formed by transient receptor potential cation channel subfamily V member, TRPV4 that is known to act as a mechanosensor in wide variaty of tissues and control ion-influx in a spatio-temporal way. Here we report that TRPV4 is prominently expressed in the stem/progenitor cell populations of the mammary epithelium and seems important for the lineage-specific differentiation, consequently affecting mechanical features of the mature mammary epithelium. This was evident by the lack of several markers for mature myoepithelial and luminal epithelial cells in TRPV4-depleted cell lines. Interestingly, TRPV4 expression is controlled in a tension-dependent manner and it also impacts differentation process dependently on the stiffness of the microenvironment. Furthermore, such cells in a 3D compartment were disabled to maintain normal mammosphere structures and displayed abnormal lumen formation, size of the structures and disrupted cellular junctions. Mechanosensitive TRPV4 channel therefore act as critical player in the homeostasis of normal mammary epithelium through sensing the physical environment and guiding accordingly differentiation and structural organization of the bilayered mammary epithelium.
Topics: Humans; TRPV Cation Channels; Epithelium; Signal Transduction; Epithelial Cells; Cytoplasm
PubMed: 38514727
DOI: 10.1038/s41598-024-57346-x -
Nature Communications Sep 2023The accumulation of somatic mutations in healthy human tissues has been extensively characterized, but the mutational landscape of the healthy breast is still poorly...
The accumulation of somatic mutations in healthy human tissues has been extensively characterized, but the mutational landscape of the healthy breast is still poorly understood. Our analysis of whole-genome sequencing shows that in line with other healthy organs, the healthy breast during the reproduction years accumulates mutations with age, with the rate of accumulation in the epithelium of 15.24 ± 5 mutations/year. Both epithelial and stromal compartments contain mutations in breast-specific driver genes, indicative of subsequent positive selection. Parity- and age-associated differences are evident in the mammary epithelium, partly explaining the observed difference in breast cancer risk amongst women of different childbearing age. Parity is associated with an age-dependent increase in the clone size of mutated epithelial cells, suggesting that older first-time mothers have a higher probability of accumulating oncogenic events in the epithelium compared to younger mothers or nulliparous women. In conclusion, we describe the reference genome of the healthy female human breast during reproductive years and provide evidence of how parity affects the genomic landscape of the mammary gland.
Topics: Pregnancy; Humans; Female; Adult; Parity; Breast; Breast Neoplasms; Mutation; Epithelial Cells
PubMed: 37673861
DOI: 10.1038/s41467-023-40608-z -
BioRxiv : the Preprint Server For... Nov 2023Breast cancer is a heterogeneous disease, and treatment is guided by biomarker profiles representing distinct molecular subtypes. Breast cancer arises from the breast...
Breast cancer is a heterogeneous disease, and treatment is guided by biomarker profiles representing distinct molecular subtypes. Breast cancer arises from the breast ductal epithelium, and experimental data suggests breast cancer subtypes have different cells of origin within that lineage. The precise cells of origin for each subtype and the transcriptional networks that characterize these tumor-normal lineages are not established. In this work, we applied bulk, single-cell (sc), and single-nucleus (sn) multi-omic techniques as well as spatial transcriptomics and multiplex imaging on 61 samples from 37 breast cancer patients to show characteristic links in gene expression and chromatin accessibility between breast cancer subtypes and their putative cells of origin. We applied the PAM50 subtyping algorithm in tandem with bulk RNA-seq and snRNA-seq to reliably subtype even low-purity tumor samples and confirm promoter accessibility using snATAC. Trajectory analysis of chromatin accessibility and differentially accessible motifs clearly connected progenitor populations with breast cancer subtypes supporting the cell of origin for basal-like and luminal A and B tumors. Regulatory network analysis of transcription factors underscored the importance of BHLHE40 in luminal breast cancer and luminal mature cells, and KLF5 in basal-like tumors and luminal progenitor cells. Furthermore, we identify key genes defining the basal-like ( , , , ) and luminal A/B ( , ) lineages, with expression in both precursor and cancer cells and further upregulation in tumors. Exhausted CTLA4-expressing CD8+ T cells were enriched in basal-like breast cancer, suggesting altered means of immune dysfunction among breast cancer subtypes. We used spatial transcriptomics and multiplex imaging to provide spatial detail for key markers of benign and malignant cell types and immune cell colocation. These findings demonstrate analysis of paired transcription and chromatin accessibility at the single cell level is a powerful tool for investigating breast cancer lineage development and highlight transcriptional networks that define basal and luminal breast cancer lineages.
PubMed: 37961519
DOI: 10.1101/2023.10.31.565031 -
BioRxiv : the Preprint Server For... Sep 2023Malignant forms of breast cancer refractory to existing therapies remain a major unmet health issue, primarily due to metastatic spread. A better understanding of the...
Malignant forms of breast cancer refractory to existing therapies remain a major unmet health issue, primarily due to metastatic spread. A better understanding of the mechanisms at play will provide better insights for alternative treatments to prevent breast cancer cells dispersion. Here, we identify the lysine methyltransferase SMYD2 as a clinically actionable master regulator of breast cancer metastasis. While SMYD2 is overexpressed in aggressive breast cancers, we notice that it is not required for primary tumor growth. However, mammary-epithelium specific SMYD2 ablation increases mouse overall survival by blocking the primary tumor cells ability to metastasize. Mechanistically, we identify BCAR3 as a genuine physiological substrate of SMYD2 in breast cancer cells. BCAR3 monomethylated at lysine K334 (K334me1) is recognized by a novel methyl-binding domain present in FMNLs proteins. These actin cytoskeleton regulators are recruited at the cell edges by the SMYD2 methylation signaling and modulates lamellipodia properties. Breast cancer cells with impaired BCAR3 methylation loose migration and invasiveness capacity and are ineffective in promoting metastases . Remarkably, SMYD2 pharmacologic inhibition efficiently impairs the metastatic spread of breast cancer cells, PDX and aggressive mammary tumors from genetically engineered mice. This study provides a rationale for innovative therapeutic prevention of malignant breast cancer metastatic progression by targeting the SMYD2-BCAR3-FMNL axis.
PubMed: 37790557
DOI: 10.1101/2023.09.18.558201 -
Annals of Plastic Surgery Feb 2024The number of cancer survivors continues to increase because of advances in therapeutic modalities. Along with surgery and chemotherapy, radiotherapy is a commonly used... (Review)
Review
The number of cancer survivors continues to increase because of advances in therapeutic modalities. Along with surgery and chemotherapy, radiotherapy is a commonly used treatment modality in roughly half of all cancer patients. It is particularly helpful in the oncologic treatment of patients with breast, head and neck, and prostate malignancies. Unfortunately, among patients receiving radiation therapy, long-term sequalae are often unavoidable, and there is accumulating clinical evidence suggesting significant radiation-related damage to the vascular endothelium. Ionizing radiation has been known to cause obliterative fibrosis and increased wall thickness in irradiated blood vessels. Clinically, these vascular changes induced by ionizing radiation can pose unique surgical challenges when operating in radiated fields. Here, we review the relevant literature on radiation-induced vascular damage focusing on mechanisms and signaling pathways involved and highlight microsurgical anastomotic outcomes after radiotherapy. In addition, we briefly comment on potential therapeutic strategies, which may have the ability to mitigate radiation injury to the vascular endothelium.
Topics: Male; Humans; Vascular System Injuries; Radiation Injuries; Neoplasms; Endothelium, Vascular; Breast; Radiotherapy
PubMed: 37962260
DOI: 10.1097/SAP.0000000000003723 -
Journal of Thermal Biology Aug 2023Heat stress leads to milk production losses and mammary gland inflammation, which may be associated with mammary epithelium damage. Taurine is one of the most abundant...
Heat stress leads to milk production losses and mammary gland inflammation, which may be associated with mammary epithelium damage. Taurine is one of the most abundant free amino acids in mammals which has anti-inflammatory properties. This study aimed to explore the effect of taurine pretreatment on heat stress-induced mammary epithelial integrity disruption and inflammatory damage. In our first experiment on dairy cows our results showed that compared with animals under autumn thermoneutral condition (THI = 62.99 ± 0.71), summer heat stress (THI = 78.01 ± 0.39) significantly reduced milk yield and disrupted mammary epithelial integrity as revealed by increased concentrations of serotonin and lactose in plasma, and increased levels of SA and Na/K in milk. In our second study, 36 lactating mice were randomly divided into three groups (n = 12) for a 9d experiment using a climate chamber to establish a heat stress model. Our findings suggest taurine pretreatment could attenuate heat stress-induced mammary histopathological impairment, inflammation response, and enhance mammary epithelium integrity, which was mainly achieved by promoting the secretion of ZO-1, Occludin, and Claudin-3 through inhibiting activation of the ERK1/2-MLCK signaling pathway in the mammary gland. Overall, our findings indicated that heat stress induced mammary epithelium dysfunction in dairy cows, and emphasized the protective effect of taurine on mammary health under heat stress conditions using a mouse model, which may be achieved by alleviating the mammary epithelium integrity damage and inflammation response.
Topics: Animals; Cattle; Female; Heat-Shock Response; Inflammation; Lactation; Mammals; Mammary Glands, Animal; MAP Kinase Signaling System; Milk; Signal Transduction; Mice
PubMed: 37478580
DOI: 10.1016/j.jtherbio.2023.103587 -
Kindlin-2 in myoepithelium controls luminal progenitor commitment to alveoli in mouse mammary gland.Cell Death & Disease Oct 2023Myoepithelium plays an important role in mammary gland development, but less is known about the molecular mechanism underlying how myoepithelium controls acinus...
Myoepithelium plays an important role in mammary gland development, but less is known about the molecular mechanism underlying how myoepithelium controls acinus differentiation during gestation. Herein, we found that loss of Kindlin-2 in myoepithelial cells impaired mammary morphogenesis, alveologenesis, and lactation. Using five genetically modified mouse lines combined with single-cell RNA sequencing, we found a Kindlin-2-Stat3-Dll1 signaling cascade in myoepithelial cells that inactivates Notch signaling in luminal cells and consequently drives luminal progenitor commitment to alveolar cells identity. Single-cell profiling revealed that Kindlin-2 loss significantly reduces the proportion of matured alveolar cells. Mechanistically, Kindlin-2 depletion in myoepithelial cells promotes Stat3 activation and upregulates Dll1, which activates the Notch pathway in luminal cells and inhibits luminal progenitor differentiation and maturation during gestation. Inhibition of Notch1 with tangeretin allowed luminal progenitors to regain commitment ability in the pregnant mice with Kindlin-2 depletion in myoepithelium. Taken together, we demonstrated that Kindlin-2 is essential to myoepithelium-controlled luminal progenitors to alveoli transition during gestation.
Topics: Animals; Female; Mice; Pregnancy; Cell Differentiation; Epithelial Cells; Epithelium; Lactation; Mammary Glands, Animal
PubMed: 37833248
DOI: 10.1038/s41419-023-06184-2 -
Cureus Jan 2024Background and objective Gynecomastia is a benign proliferation of ductal epithelium in the retroareolar region in male patients. The aim of this study was to...
Background and objective Gynecomastia is a benign proliferation of ductal epithelium in the retroareolar region in male patients. The aim of this study was to investigate the frequency of gynecomastia in male patients who underwent thoracic computed tomography (CT) imaging at our clinic, assess possible causes, highlight the imaging characteristics of gynecomastia, and compare our findings with the literature. Materials and methods Male patients over 18 years of age who underwent thoracic CT imaging in our clinic were included in the study. Patients were initially assessed based on age and the presence of gynecomastia. The patients with gynecomastia were evaluated in terms of age, gynecomastia localization (right, left, and bilateral), gynecomastia type (nodular, dentritic, and diffuse), and possible etiology. Results The study included 1500 patients with a mean age of 45.6±21.7 years, and 470 (31.3%) patients had gynecomastia. Gynecomastia was on the right side in 11.3%, on the left side in 11.1%, and bilateral in 77.7% of the patients. Gynecomastia was nodular in 52.1%, dendritic in 35.3%, and diffuse in 17.2% of the patients. The causative factor could not be identified in 44.3% of the patients with gynecomastia. Among cases where the etiology was identified (56.7%), the most common factors were cancer (23.4%), chronic kidney disease (CKD) (13.2%), and chronic hepatitis B (10.7%). Conclusion When evaluating thoracic CT, the breast area, in addition to the lungs, chest wall, and bone structures, should also be evaluated carefully. With the increased use of thoracic CT scans, incidentally detected gynecomastia in patients is also on the rise. Knowing the presence of gynecomastia is very important for the clinician to determine the etiology and treat the underlying disease. Therefore, detecting and reporting gynecomastia on thoracic CT can prevent unnecessary advanced breast imaging methods and play a very important role in treating the underlying etiology.
PubMed: 38304650
DOI: 10.7759/cureus.51509