Search Results (746)

Macrophage-mediated inflammation is known to be involved in the epithelial–mesenchymal transition (EMT) of various types of cancer. This makes macrophage-derived inflammatory factors prime targets for the development of new treatments. This study uncovers the therapeutic potential and action mechanism of DAB-2-28, a small-molecule derived from para-aminobenzoic acid, in the treatment of breast cancer. The luminal MCF-7 and the triple-negative MDA-MB-231 cancer cell lines used in this study represent, respectively, breast cancers in which the differentiation states are related to the epithelial phenotype of the mammary gland and breast cancers expressing a highly aggressive mesenchymal phenotype. In MCF-7 cells, soluble factors from macrophage-conditioned media (CM-MØ) induce a characteristic morphology of mesenchymal cells with an upregulated expression of Snail1, a mesenchymal marker, as opposed to a decrease in the expression of E-cadherin, an epithelial marker. DAB-2-28 does not affect the differential expression of Snail1 and E-cadherin in response to CM-MØ, but negatively impacts other hallmarks of EMT by decreasing invasion and migration capacities, in addition to MMP9 expression and gelatinase activity, in both MCF-7 and MDA-MB-231 cells. Moreover, DAB-2-28 inhibits the phosphorylation of key pro-EMT transcriptional factors, such as NFκB, STAT3, SMAD2, CREB, and/or AKT proteins, in breast cancer cells exposed to different EMT inducers. Overall, our study provides evidence suggesting that inhibition of EMT initiation or maintenance is a key mechanism by which DAB-2-28 can exert anti-tumoral effects in breast cancer cells. Full article

Nuclear receptors are involved in multiple biological processes, among which RORγ can regulate the expression of inflammation-related genes and is thus frequently used as a therapeutic target for cancer. Canine mammary cancer is one of the most common tumor diseases in dogs, with a relative incidence rate of 46.71% for CMT in China over the past five years, severely threatening the life and health of dogs. Therefore, the search for novel drugs targeting canine mammary cancer is of great significance. This study aims to investigate how the RORγ inhibitors W6134 and XY018 affect the expression of inflammatory genes through histone modifications in CMT-N7 cells. These results show that W6134 and XY018 can upregulate signaling pathways related to inflammation and apoptosis and influence the expression of associated genes. The close link between RORγ and inflammation-related genes further confirms that RORγ may serve as a therapeutic target for canine cancer. Additionally, ChIP-qPCR was used to detect the enrichment of histone markers such as P300, H3K27ac, H3K4me1, H3K9la, and H3K9bhb at the target loci of CXCL10 and MECOM genes. Collectively, our findings provide molecular evidence for the protective role of RORγ in canine mammary cancer, potentially by regulating inflammatory pathways via histone modifications, offering new insights for improving the cure rate and survival of affected dogs. Full article

Feline mammary carcinoma (FMC) exhibits aggressive behavior, with limited treatment options. Given the relevance of the PD-1/PD-L1/PD-L2 axis in human breast cancer immunotherapy, this study assessed PD-1 and its ligands in rare FMC histotypes (n = 48) using immunohistochemistry on tumor cells (TCs), intratumoral lymphocytes (iTILs), and stromal tumor-infiltrating lymphocytes (sTILs). PD-1 was expressed in 13% of TCs, 85% of iTILs, and 94% of sTILs, while PD-L1 was observed in 46% of TCs, 96% of iTILs, and 100% of sTILs. PD-L2 was expressed in 79% of TCs and 100% of both iTILs and sTILs, with PD-L1/PD-L2 co-expression in 42% of TCs. Higher PD-1 IHC scores in TCs were associated with a less aggressive biological behavior; PD-L1 in iTILs was linked to skin ulceration, whereas PD-L2 in TCs was associated with its absence. Our findings highlight the relevance of the PD-1/PD-L1/PD-L2 immune checkpoint in rare FMC subtypes and support further investigation into checkpoint-blockade therapies. Full article

Obesity and metabolic dysfunction are established risk factors for luminal breast cancer, yet current preclinical models inadequately recapitulate the complex metabolic and immune interactions driving tumorigenesis. To develop and characterize an immunocompetent rat model of luminal breast cancer induced by chronic exposure to a cafeteria diet mimicking Western obesogenic nutrition, female rats were fed a cafeteria diet or standard chow from weaning. Metabolic parameters, plasma biomarkers (including leptin, insulin, IGF-1, adiponectin, and estrone), mammary gland histology, tumor incidence, and gene expression profiles were longitudinally evaluated. Gene expression was assessed by PCR arrays and qPCR. A subgroup underwent dietary reversal to assess the reversibility of molecular alterations. Cafeteria diet induced significant obesity (mean weight 426.76 g vs. 263.09 g controls, p < 0.001) and increased leptin levels without altering insulin, IGF-1, or inflammatory markers. Histological analysis showed increased ductal ectasia and benign lesions, with earlier fibroadenoma and luminal carcinoma development in diet-fed rats. Tumors exhibited luminal phenotype, low Ki67, and elevated PAI-1 expression. Gene expression alterations were time point specific and revealed early downregulation of ID1 and COX2, followed by upregulation of MMP2, THBS1, TWIST1, and PAI-1. Short-term dietary reversal normalized several gene expression changes. Overall tumor incidence was modest (~12%), reflecting early tumor-promoting microenvironmental changes rather than aggressive carcinogenesis. This immunocompetent cafeteria diet rat model recapitulates key metabolic, histological, and molecular features of obesity-associated luminal breast cancer and offers a valuable platform for studying early tumorigenic mechanisms and prevention strategies without carcinogen-induced confounders. Full article

This study aimed to investigate the underlying mechanisms by which dandelion extract inhibits the proliferation of breast cancer MDA-MB-231 cells. Dandelion root and leaf extracts were prepared using a heat reflux method and subjected to solvent gradient extraction to obtain fractions with different polarities. MTT assays revealed that the ethyl acetate fraction exhibited the strongest inhibitory effect on cell proliferation. LC-MS analysis identified 12 potential active compounds, including sesquiterpenes such as Isoalantolactone and Artemisinin, which showed significantly lower toxicity toward normal mammary epithelial MCF-10A cells compared to tumor cells (p < 0.01). Mechanistic studies demonstrated that the extract induced apoptosis in a dose-dependent manner, with an apoptosis rate as high as 85.04%, and significantly arrested the cell cycle at the S and G2/M phases. Label-free quantitative proteomics identified 137 differentially expressed proteins (|FC| > 2, p < 0.05). GO enrichment analysis indicated that these proteins were mainly involved in cell cycle regulation and apoptosis. KEGG pathway analysis revealed that the antitumor effects were primarily mediated through the regulation of PI3K-Akt (hsa04151), JAK-STAT (hsa04630), and PPAR (hsa03320) signaling pathways. Moreover, differential proteins such as PI3K, AKT1S1, SIRT6, JAK1, SCD, STAT3, CASP8, STAT2, STAT6, and PAK1 showed strong correlation with the core components of the EA-2 fraction of dandelion. Molecular docking results demonstrated that these active compounds exhibited strong binding affinities with key target proteins such as PI3K and JAK1 (binding energy < −5.0 kcal/mol). This study elucidates the multi-target, multi-pathway synergistic mechanisms by which dandelion extract inhibits breast cancer, providing a theoretical basis for the development of novel antitumor agents. Full article

The tumor microenvironment (TME) plays a central role in cancer progression, with tumor-associated macrophages (TAMs) and extracellular matrix (ECM) components such as collagen being key modulators of invasiveness and immune regulation. Although macrophage infiltration and ECM remodeling are well-documented individually, their coordinated contribution to mammary carcinoma aggressiveness remains underexplored, particularly in comparative oncology models. This study analyzed 117 mammary carcinoma samples—59 from dogs and 58 from women—using immunohistochemistry, immunofluorescence, and second-harmonic-generation (SHG) microscopy. We quantified TAM density and phenotype (CD206, iNOS, and S100A8/A9), assessed collagen fiber organization, and examined correlations with clinical–pathological variables and overall survival. Increased TAM infiltration was associated with a higher histological grade, aggressive molecular subtypes, enhanced cell proliferation, and shortened survival in dogs. High TAM density also correlated with decreased collagen fiber length and increased alignment, suggesting active immune–matrix remodeling in aggressive tumors. Macrophage phenotyping revealed heterogeneous populations, with CD206⁺ cells predominating in high-grade tumors, while S100A8/A9⁺/iNOS⁺ phenotypes were enriched in less aggressive subtypes. The findings were consistent across species, reinforcing the relevance of canine models. Our results identify macrophage–collagen interactions as critical determinants of tumor aggressiveness in mammary carcinomas. This study bridges comparative oncology and translational research by proposing immune–ECM signatures as potential prognostic biomarkers and therapeutic targets. These insights contribute to the advancement of molecular oncology in Brazil by supporting innovative strategies that integrate immune modulation and matrix-targeted interventions in breast cancer. Full article

Deciphering the spatiotemporal distribution of bacteria during breast cancer progression may provide critical insights for developing bacterial-based therapeutic strategies. Using a murine breast cancer model, we longitudinally profiled the microbiota in breast tumor tissue, mammary gland, spleen, and cecal contents at 3-, 5-, and 7- weeks post-tumor implantation through 16S rRNA gene sequencing. Breast tumor progression was associated with lung metastasis and splenomegaly, accompanied by distinct tissue-specific microbial dynamics. While alpha diversity remained stable in tumors, mammary tissue, and cecal contents, it significantly increased in the spleen (p < 0.05). Longitudinal analysis revealed a progressive rise in Firmicutes and a decline in Proteobacteria abundance within tumors, mammary tissue, and cecum, whereas the spleen microbiota displayed unique phylum-level compositional shifts. Tissue- and time-dependent microbial signatures were identified at phylum, genus, and species levels during breast tumor progression. Strikingly, the spleen microbiota integrated nearly all genera enriched in other sites, suggesting its potential role as a microbial reservoir. Gut-associated genera (Lactobacillus, Desulfovibrio, Helicobacter) colonized both cecal contents and the spleen, with Lactobacillus consistently detected across all tissues, suggesting microbial translocation. The spleen exhibited uniquely elevated diversity and compositional shifts, potentially driving splenomegaly. These results delineated the trajectory of microbiota translocation and colonization, and demonstrated tissue-specific microbial redistribution during breast tumorigenesis, offering valuable implications for advancing microbiome-targeted cancer therapies. Full article

Background/Objectives: Breast cancer (BC) is the leading cause of cancer incidence and mortality among women and the recent identification of a resident mammary microbiota has highlighted its potential role in breast carcinogenesis. Given that environmental and socioeconomic factors influence both BC prevalence and tumor-associated bacterial composition, this study aimed to evaluate the compositional and functional features of the mammary microbiota in cancerous (oncobiome) and adjacent healthy BC tissues from patients living in urban and rural areas. Methods: Microbiota composition in both the oncobiome and adjacent healthy BC tissues was analyzed using 16S rRNA sequencing. Results: Significant variations in breast oncobiome composition were observed among BC patients from urban and rural areas. A statistically significant β dispersion among breast oncobiome of patients from urban or rural areas was highlighted. Specifically, the genera Selenomonas, Centipeda, Leptotrichia, Neisseria and Porphyromonas were found exclusively in BC tissues of patients from rural areas. Additionally, bacteria from the Neisseriaceae, Porphyromonadaceae, and Selenomonadaceae families, as well as the Selenomonas genus, were significantly enriched in the oncobiome of rural BC patients. Furthermore, the results of the PICRUSt2 (phylogenetic investigation of communities by reconstruction of unobserved states) revealed a significant increase in phospholipid biosynthesis pathways in breast oncobiome of patients from rural areas compared to those from urban areas. Conclusions: This study provides evidence of distinct compositional and functional differences in the breast oncobiome between BC patients from rural and urban areas. These findings suggest that environmental factors influence local microbiome composition, potentially contributing to BC development and/or progression. Full article

Breast cancer invasion and subsequent metastasis to distant tissues occur when cancer cells lose cell–cell contact, develop a migrating phenotype, and invade the basement membrane (BM) and the extracellular matrix (ECM) to penetrate blood and lymphatic vessels. The identification of the mechanisms which induce the development from a ductal carcinoma in situ (DCIS) to a minimally invasive breast carcinoma (MIBC) is an emerging area of research in understanding tumor invasion and metastatic potential. To investigate the progression from DCIS to MIBC, we analyzed peritumoral collagen architecture using correlative scanning electron microscopy (SEM) on histological sections from human biopsies. In DCIS, the peritumoral collagen organizes into concentric lamellae (‘circular fibers’) parallel to the ducts. Within each lamella, type I collagen fibrils align in parallel, while neighboring lamellae show orthogonal fiber orientation. The concentric lamellar arrangement of collagen may physically constrain cancer cell migration, explaining the lack of visible tumor cell invasion into the peritumoral ECM in DCIS. A lamellar dissociation or the development of small inter fiber gaps allowed isolated breast cancer cell invasion and exosomes infiltration in the DCIS microenvironment. The radially arranged fibers observed in the peri-tumoral microenvironment of MIBC biopsies develop from a bending of the circular fibers of DCIS and drive a collective cancer cell invasion associated with an intense immune cell infiltrate. Type I collagen fibrils represent the peri-tumoral nano-environment which can play a mechanical role in regulating the development from DCIS to MIBC. Collectively, it is plausible to suggest that the ECM effectors implicated in breast cancer progression released by the interplay between cancer, stromal, and/or immune cells, and degrading inter fiber/fibril hydrophilic ECM components of the peritumoral ECM, may serve as key players in promoting the dissociation of the concentric collagen lamellae. Full article

Mammary tumors are the most common neoplasms diagnosed in female dogs and have been considered excellent models for studying human breast cancer. Establishing cell lines from primary cultures of canine mammary tumors provides an in vitro model to better understand the disease and develop new treatments. This study aimed to establish and characterize canine mammary tumor cell lines. Ten cell cultures were generated from tumor tissue obtained from affected dogs, including seven from primary mammary tumors and three from metastatic sites. Characterization included molecular marker expression (ER, PR, HER2, cytokeratin 5/6 (CK5/6), vimentin, and the marker of cell proliferation Ki67) and in vitro tumorigenic capacity assessment. Additionally, the susceptibility of five cell lines to DOX, 5-FU, paclitaxel, colchicine, and carboplatin was evaluated using the MTT assay. ICC analysis revealed negative expression of hormonal receptors (ER and PR) in five cell lines, while only one cell line was positive for both. Six cell lines were HER2-negative and positive for vimentin. Five cell lines exhibited in vitro tumorigenic capacity, forming colonies in soft agar. DOX showed the highest growth-inhibitory effect (DOX > Paclitaxel > Colchicine > 5-FU > Carboplatin). Two cell lines had a minimal concentration for 50% inhibition in vitro (IC₅₀) < 0.63 µM and 4.37 ± 0.40 µM for DOX, while one was sensitive to colchicine and paclitaxel (IC₅₀ 0.19 µM and 0.04 µM, respectively). All tested cell lines were resistant to carboplatin and 5-FU. These cell lines provide a valuable model for studying breast cancer in humans and dogs and evaluating new potential therapeutic strategies. Full article

Mammary tumors are the most common neoplasms in female dogs, with mastectomy being the primary treatment. The impact of mastectomy type on survival remains unclear. This study evaluated the effect of different surgical techniques on the survival of female dogs with mammary carcinomas. A total of 307 dogs with 734 mammary tumors were analyzed. Ages ranged from 1 to 17 years, with mixed breeds comprising 48.9%. Most tumors (92.9%) were malignant, predominantly carcinoma in a mixed tumor (30.2%). Unilateral mastectomy was the most common technique (65.8%). Lumpectomy showed the shortest mean survival (179 days) and was associated with a 4.9-fold increased risk of death (p = 0.009). There was no significant association between surgical technique and overall survival or recurrence of mammary carcinoma (p = 0.2). This study relied on owner-reported data for survival and tumor recurrence. Lumpectomy appears to be associated with shorter survival times in female dogs with mammary carcinoma. Therefore, it may be advisable to reconsider this technique as a primary treatment option. Full article

Here, the authors report the first case of a primary mast cell tumor originating from the inguinal lymph node in a nine-year-old intact female Maltese dog that had undergone a left ureteral stent, ureterotomy and splenectomy, and left-side mastectomy, including inguinal lymph node removal and ovariohysterectomy, in South Korea in May 2024. The splenic mass, mammary gland mass, and inguinal lymph node underwent histopathological examination, resulting in the diagnosis of nodular hyperplasia, grade 1 mammary complex carcinoma, and a mast cell tumor (MCT), respectively. To clarify the origin of the MCT from the inguinal lymph node, a computed tomography (CT) scan was performed. In addition, through a blood smear test, mast cell leukemia was ruled out. After CT scanning by veterinary radiologists and a biopsy of all possible masses, it was finally concluded that the MCT primarily originated from lymph nodes, which is extremely rare in dogs. The patient is recovering well as of February 2025, just 7 months after the first diagnosis, following surgery and 16 weeks of chemotherapy with a combination of prednisolone and vinblastine, considering the C-kit PCR results of the left inguinal lymph node after the surgical removal of the MCT. This report is significant for two reasons, firstly because of the rarity of MCTs originating from lymph nodes other than the skin and gastrointestinal organs, and secondly because the authors propose a hypothesis for the rarity of primary lymph node mast cell tumors and the correlation between mammary gland tumors and mast cell tumor growth based on a comparative literature review in humans, focusing on molecular mechanisms. Full article

Canine mammary tumors (CMTs) are the common tumors in female dogs, and approximately 50% of CMTs are malignant tumors, with abnormal regulation of non-coding RNAs being a critical factor in disease progression. Currently, research on long non-coding RNAs (lncRNAs) regulating CMT development remains limited. This study identified a novel lncRNA, aiming to explore the role of lncRNA LOC610012 in CMTs. In this study, immunofluorescence and Western blot analyses were employed to detect protein expression. LncRNA LOC610012 is downregulated in CMT tissues and cells. Stable cells of LOC610012 were constructed by the lentivirus technique. Through a variety of experimental methods, LOC610012 inhibited the proliferation, invasion, and metastasis of CMT cells in in vitro and in vivo experiments conducted using cell culture and mouse models. Mechanistically, LOC610012 regulated the expression of EP3 and GSK-3β by targeting PTGS2, resulting in excessive production of reactive oxygen species (ROS), which inhibited cell viability. Similarly, through transmission electron microscopy, mitochondrial damage caused by LOC610012 was observed in CMT cells, which was manifested as mitochondrial swelling, membrane rupture, and mitochondrial ridge disappearance. PTGS2 could partially restore the inhibition of LOC610012 on cell activity. LOC610012 acts as a tumor suppressor gene in CMTs and as a potential biomarker for the disease. Full article

Breast cancer is among the most prevalent and deadly types of cancer worldwide. Viral infections have been investigated as contributing factors in breast carcinogenesis, including infections by high-risk genotypes of human papillomavirus (HPV). Although viral DNA has been detected in breast tumors, the role of HPV activity in this type of cancer remains poorly understood. HPV oncogenes interact with various host genes, including those involved in the JAK/STAT signaling pathway. This pathway is associated with the regulation of gene expression related to the tumor microenvironment, and understanding how HPV oncogenes interact with JAK/STAT components may provide insights into the relationship between the virus and breast cancer development. In this study, we assessed the differential expression of the JAK/STAT pathway in MDA-MB-231 cells individually transfected with the E5, E6, and E7 oncogenes of HPV16. The results revealed downregulation of STAT4 in the presence of the E5, E6, and E7 oncogenes. Notably, cells transfected with E5 alone exhibited upregulation of JAK2, STAT3, and STAT6, whereas transfection with E6 and E7 resulted in their downregulation. These findings highlight the underexplored role of the E5 oncogene in contrast to the more extensively studied E6 and E7. Our results support the hypothesis that HPV oncogenes actively modulate the expression of genes involved in the tumor microenvironment in breast cancer. Full article

Background: The principal function of mammary glands is to produce milk to nourish the newborn. Optimal lactation is controlled by various hormones, growth factors, and cytokines. Objectives: Using 3D cultures of primary mouse mammary epithelial cells, we explored the effects of T helper (Th)1 cytokines, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α on the structure and function of mammary cells as well as the underlying mechanism. Methods: Three-dimensional cultures of mammary cells were treated with IFN-γ/TNF-α, and milk protein expression and acinar structures were analyzed by immunoblotting and immunofluorescence microscopy. Results: Our results revealed that combined treatment with IFN-γ and TNF-α inhibits prolactin-induced STAT5 tyrosine phosphorylation and β-casein expression. These cytokines also disrupted the structure of mammary acini, resulting in smaller or no lumens, disordered cell arrangements, and multilayered cells in certain regions. Additionally, some cells became elongated rather than maintaining their usual cube-like shape. Since cell proliferation and death can modulate the structural organization of acini, we examined the influences of IFN-γ and TNF-α on these events. Combined cytokine treatment moderately increased cell proliferation and cell death. Notably, stimulation with IFN-γ and TNF-α induced the expression of inducible nitric oxide synthase (iNOS), and the inhibition of iNOS partially restored acinar morphology and β-casein expression, revealing a novel mechanism for cytokine-induced acinar disruption. Conclusions: When a Th1 cytokine milieu is dominant, such as during inflammation and infection, IFN-γ and TNF-α might cause mammary gland ductal occlusion and lactation insufficiency. Full article