Search Results (1,037)

Alcohol consumption is associated with increased breast cancer risk, partly due to the accumulation of toxic aldehydes like acetaldehyde, a carcinogenic byproduct of ethanol metabolism. Acetaldehyde Dehydrogenase 2 (ALDH2), a key mitochondrial enzyme, detoxifies acetaldehyde and other reactive aldehydes that drive oxidative stress, DNA damage, and hormonal dysregulation—processes central to carcinogenesis. Although alcohol consumption has been implicated in breast cancer, the role of ALDH2 deficiency itself, in the absence of exogenous alcohol exposure, in mammary gland biology and cancer susceptibility remains unclear. Genetic variants that impair ALDH2 activity are highly prevalent in East Asian populations, where carriers of inactive ALDH2 alleles exhibit impaired aldehyde detoxification. While such individuals are more susceptible to alcohol-related cancers, the effects of ALDH2 deficiency on mammary gland development and homeostasis without alcohol exposure remain unexplored. To investigate the effects of ALDH2 deficiency on mammary proliferation and development, we utilized a C57BL/6-based ALDH2 knockout (Aldh2−/−) mouse model. Our findings revealed that Aldh2−/− mice displayed hyperproliferative mammary glands with increased epithelial cell density, ductal expansion, and increased numbers of Ki67+ cells. Flow cytometry analysis revealed expansion of luminal and basal epithelial subpopulations, accompanied by enhanced mammary epithelial stemness, as indicated by increased mammosphere formation and colony-forming efficiency. At the molecular level, ALDH2 deficiency activated oxidative stress pathways, reflected by elevated 8-OHdG, p38 MAPK, NF-κB, and Nrf2 signaling, along with DNA damage responses involving p53 and H2A.X. We also identified a novel upregulation of RANK and RANKL in Aldh2−/− mammary glands, identifying the RANK/RANKL upregulation associated with NF-κB/p38 MAPK activation and enhanced mammary stemness. Furthermore, hormonal dysregulation was observed, with a significant increase in ERα and PR expression and phosphorylation. Dysregulated ER signaling correlated with enhanced erbB3 activation and downstream signaling, including the cyclin D1–pRb-E2F1 axis. These findings suggest that ALDH2 deficiency, possibly through accumulated endogenous aldehydes, profoundly alters mammary morphogenesis, epithelial repopulation, and stemness. These effects are associated with activation of oxidative stress and DNA damage pathways, together with upregulation of RANKL, estrogen receptor and receptor tyrosine kinase signaling. This study is the first to identify ALDH2 deficiency as a novel factor associated with mammary epithelial alterations that may create a tissue state that could predispose to oncogenic transformation. Full article

Background/Objectives: Rosmarinic acid (RA) is a naturally occurring polyphenolic compound with promising anticancer activity; however, its potential to enhance the therapeutic efficacy of doxorubicin (DOX) against triple-negative breast cancer (TNBC) has not been comprehensively characterised. This study investigated the pharmacological interaction and associated cellular responses of RA combined with DOX in MDA-MB-231 breast cancer cells, while including HaCaT human keratinocytes as a non-malignant, non-mammary reference model for comparative cytotoxicity assessment. Methods: Cell viability was assessed using the MTT assay, and pharmacological interactions were evaluated using Chou–Talalay combination index (CI) and dose reduction index (DRI) analyses. Intracellular oxidative activity was evaluated using DCFH-DA fluorescence analyses together with N-acetyl-L-cysteine (NAC) modulation experiments. Apoptosis, cell-cycle distribution, mitochondrial membrane potential (JC-1), Caspase-9 immunocytochemistry, nuclear morphology (NucBlue staining), apoptosis- and proliferation-related gene expression (RT-qPCR; BAX, BCL2, CASP3, CASP9, TP53, CDKN1A, MKI67, and PCNA), and bioinformatic pathway analyses were performed to characterise cellular and molecular responses associated with the combined treatment. Results: After 48 h, RA exhibited IC₅₀ values of 188.4 ± 4.2 µM in MDA-MB-231 cells and 146.6 ± 6.8 µM in HaCaT cells, while DOX showed IC₅₀ values of 1.2 ± 0.08 µM and 2.6 ± 0.15 µM, respectively. The Chou–Talalay analysis demonstrated synergistic interactions in MDA-MB-231 cells, with CI values of 0.86, 0.72, and 0.64 at the effect levels of IC₂₅, IC₅₀, and IC₇₅, respectively; the model-derived DOX DRI value at Fa = 0.50 was 1.8. Combination treatment markedly increased intracellular DCFH-DA fluorescence, whereas NAC pretreatment attenuated this signal and partially restored cell viability, supporting a contributory role of intracellular oxidative stress in treatment-associated cytotoxicity. Increased intracellular oxidative activity coincided with mitochondrial membrane depolarisation, increased apoptotic cell death, accumulation of cells in the sub-G₁ phase, enhanced Caspase-9 immunoreactivity, and pronounced apoptotic nuclear alterations. RT-qPCR analysis demonstrated significant upregulation of BAX, CASP3, CASP9, and TP53, together with downregulation of BCL2, MKI67, and PCNA, resulting in a marked reduction in the BCL2/BAX mRNA expression ratio. A modest but non-significant increase in CDKN1A expression was also observed. Bioinformatic analyses further identified predicted associations with mitochondrial apoptosis and p53-associated signalling pathways. Conclusions: The RA + DOX combination showed synergistic cytotoxic activity in MDA-MB-231 cells, accompanied by increased intracellular oxidative activity, mitochondrial membrane depolarisation, apoptosis, cell-cycle perturbation, and changes in proliferation-related gene expression. These findings indicate associated cellular responses but do not establish a ROS-dependent mitochondrial apoptotic mechanism. The findings provide an exploratory in vitro basis for further investigation of the RA + DOX combination in additional TNBC models, non-malignant mammary epithelial cells, and appropriate in vivo systems. Full article

Feline mammary tumors are the third most common neoplasms in female cats and they are characterized by high aggressiveness and high metastatic rates. Given the pivotal role of iron in human breast cancer development, in this study, we preliminarily explore the immunohistochemical expression of proteins involved in iron uptake, storage and efflux [Transferrin Receptor 1 (TfR1), Transferrin Receptor 2 (TfR2), ferritin (FTH1), and ferroportin (SLC40A1)] in non-metastatic and metastatic feline mammary carcinomas and their tributary lymph node and the possible correlation with hypoxia-inducible factor-1 (HIF-1). Our results showed an increased expression of TfR1 and TfR2 in relation to tumor progression. FTH1 immunolabeling was mainly observed in cancer cells delimiting necrotic areas and in lymph node metastasis, indicating greater iron storage possibly associated with hypoxic environments, as suggested by increased expression of HIF-1α. Also, an increase in SLC40A1 labeling in tumoral cells suggested greater iron efflux. Although preliminary, our results underline interesting differences between feline normal and tumoral mammary tissues, which could pave the way to further in vitro studies to better understand the role of iron in the progression of feline mammary tumors. Full article

Background/Objectives: The implementation of tattoo-free radiotherapy (RT) for breast cancer reflects an effort to mitigate the psychological distress of permanent marks through surface-guided techniques, while simultaneously evaluating its utility in meeting setup precision requirements. Methods: In this prospective trial, patients were positioned for breast cancer RT including regional nodal irradiation exclusively using surface-guided RT (SGRT). Cone-beam computed tomography (CBCT) was acquired at each fraction as the ground truth to analyze translational setup deviations. Results: A total of 457 paired SGRT–CBCT data points in 30 patients were acquired. A residual translational setup deviation of ≤6 mm was achieved in 97.6% of all fractions with a median deviation of 2 mm (range: 0–12). Neither age, comorbidities, body mass index, extent of target volumes, choice of breathing technique, nor patient-reported symptoms (pain, dermatitis, anxiety) correlated significantly with setup deviations. The median in-room positioning time was 92 s (range: 20 s–6 min and 37 s) and significantly prolonged in patients with an elevated BMI and higher grades of pain and skin dermatitis, and for chest wall irradiation. Manual assessment of the accuracy of regional nodal CTVs in each CBCT relative to the planning CT showed good-to-minor deviations in 99.7% (Level 1/2), 95.0% (Supra-/infraclavicular), and 90.8% (Internal mammary), respectively, with major deviations in only 0.3% (Level 1/2), 5.0% (Supra-/infraclavicular) and 9.2% (Internal mammary). A forward dose calculation on CBCT geometries (n = 86) revealed high median CTV dose coverage of 100.0% (range: 57.1–107.7%) of the original target dose for all lymph node levels combined. Conclusions: The tattoo-free positioning setup for regional nodal irradiation in breast cancer patients exhibited pronounced robustness, maintaining its accuracy and reliability irrespective of patient-, tumor-, or treatment-specific variables with high clinical efficiency. However, larger cohorts are required to confirm whether these parameters genuinely operate independently of setup accuracy. Full article

Background/Objectives: This study engineered and evaluated a targeted, folate-functionalized chitosan nanoparticle (CS-FA NP) delivery system to enhance the therapeutic efficacy of standard quercetin and Coriandrum sativum seed extract against breast cancer. Methods: Phytochemical profiling confirmed a 14% crude yield for the methanolic extract, with gas chromatography–mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) identifying quercetin as the principal bioactive agent. The synthesized CS-FA NPs exhibited a core size of 7–20 nm, an average hydrodynamic diameter of 150–160 nm, a stable zeta potential of −55 mV, and high encapsulation efficiencies (87.2% for quercetin and 80.5% for coriander). Kinetic assessments confirmed a biphasic, diffusion-controlled release matching Higuchi matrix kinetics. Anticancer activity was evaluated in vitro using MTT cytotoxicity, Annexin V-FITC/PI apoptosis analysis, RT-qPCR, and ex vivo rat aortic ring assays, followed by validation in a syngeneic 4T1 mammary tumor mouse model. Results: In vitro, folate-receptor-targeted quercetin nanoparticles (T4) demonstrated superior, selective cytotoxicity, particularly against triple-negative MDA-MB-231 cells, while sparing normal fibroblasts. Annexin V-FITC/PI apoptosis profiling and ex vivo aortic ring assays revealed profound, cell-line-dependent programmed cell death and up to 90% inhibition of microvessel sprout outgrowth. Mechanistically, RT-qPCR verified that nano-formulations induced complete transcriptional silencing of NANOG, MMP-1, VEGFA, TSPAN8, TWIST, EMMPRIN, and CDK1, alongside marked upregulation of P27^KIP1 and P21^CIP1. In vivo, these nano-formulations successfully improved tumor-associated pathological features, reduced aggressive tumor spindle-cell proliferation, and suppressed elevated serum CA15-3 and arginase biomarkers. Conclusions: Folate-functionalized chitosan nano-formulations significantly enhanced the anticancer efficacy of quercetin and Coriandrum sativum seed extract through improved targeted delivery, potent antiproliferative, anti-angiogenic, and pro-apoptotic activities, together with favorable modulation of multiple molecular pathways associated with breast cancer progression. These findings support their potential as promising targeted nanotherapeutic strategies for breast cancer treatment. Full article

Breast cancer is one of the most prevalent malignancies in women worldwide and the most common malignant tumor in unspayed female dogs, highlighting the comparative relevance of this disease across these species. The release of EVs is increased in mammary tumors compared to normal tissue, with the quantity generally correlating with the tumor’s histological grade and aggressiveness. EVs carry a varied molecular load, mainly composed of proteins, RNAs, including microRNAs (miRNAs), lipids, and nucleic acids. These contents reflect the cell of origin and are related to the tumor profile (adenoma, adenocarcinoma, or carcinoma). EVs influence biological processes such as cell proliferation, migration, and invasion, as well as interfere with the immune response, potentially favoring tumor growth, disease progression, and metastasis formation, since they act as intercellular messengers, modulating the tumor microenvironment. Despite substantial advances in research related to EVs in human breast cancer, there is still a significant lack of studies focused on veterinary oncology, especially regarding the association of EVs with CMTs. In this context, this review aimed to compile the evidence available to highlight the importance of EVs in CMTs in female dogs, especially as promising tools for innovative strategies in veterinary medicine. Full article

Breast cancer remains a leading cause of cancer-related mortality worldwide, highlighting the need for novel therapeutic strategies that selectively target tumor cells while minimizing systemic toxicity. Dietary ammonium hydroxide enhancement (AHE) has previously been shown to modulate metabolic pathways in animal studies. However, its potential as a localized anticancer therapy has not been investigated. In the present study, we evaluated the antitumor efficacy and systemic safety of NH₄OH using complementary in vitro and orthotopic breast cancer xenograft models. MDA-MB-231 breast cancer cells and non-tumorigenic MCF10A mammary epithelial cells were treated with increasing concentrations of NH₄OH (2.5–225 µM) to assess dose-dependent effects on cell proliferation, viability, and apoptosis. Following this, MDA-MB-231 cells were orthotopically xenografted into female athymic nude mice and treated by intratumoral injection with NH₄OH using a stepwise dose-escalation regimen (0.01%, 0.1%, and 0.5%; total volume of 20 μL per tumor divided between two injection sites) or phosphate-buffered saline (PBS). Differences between treatment groups of mammary tumors and kidney tissues were analyzed molecularly and histologically. NH₄OH significantly suppressed MDA-MB-231 cell growth and metabolic activity, with minimal effects on MCF10A cells, and induced apoptosis in MDA-MB-231 cells without detectable apoptotic induction in MCF10A cells. In vivo, although tumor volume only showed a non-significant downward trend, histological and molecular analyses demonstrated substantial alterations in tumor biology. NH₄OH treatment induced molecular changes consistent with an antitumor response, including increased Caspase-3 and p53 expression, reduced BCL2 and Ki-67 expression, and attenuation of TNFα, IL-6, and TLR4 inflammatory signaling. Furthermore, the tumor architecture in T-NH tumors displayed increased pale eosinophilic regions and reduced cellular density, suggestive of treatment-associated tumor tissue disruption. Histological analysis of kidney tissue showed no evidence of overt renal toxicity. Indeed, localized NH₄OH administration was associated with reduced renal inflammatory and apoptotic signaling, preserved renal morphology, and increased expression of the ammonia transporters RHBG and RHCG. Cross-sectional morphometric measurements showed decreased area for the distal convoluted tubules in NH₄OH-treated samples. Although this initial preclinical study was limited by a relatively small sample size, further studies are warranted to validate these findings and define the molecular mechanisms underlying NH₄OH-mediated antitumor activity. Collectively, these findings suggest that intratumoral NH₄OH modulates tumor metabolic, inflammatory, and apoptotic pathways associated with a less aggressive tumor phenotype while showing no overt molecular or histological evidence of renal injury, supporting further investigation as a localized metabolic intervention targeting molecular and histological drivers of breast cancer progression. Full article

Breast cancer (BC) is a heterogeneous disease influenced by genetic and regulatory mechanisms. Despite this, X-linked non-coding variants remain underexplored, particularly in admixed Latin American populations. Therefore, this study aimed to characterize the non-coding variant rs5945619 at Xp11.22 in Ecuadorian mestizo women with BC and to assess its potential regulatory effects on nearby genes through in silico cis-eQTL analysis. A prospective observational case series was conducted in 21 Ecuadorian mestizo women with histologically confirmed BC. Tumor DNA was extracted and analyzed using the Illumina TruSight Cancer Sequencing Panel. The rs5945619 variant was identified from sequencing data and compared with reference allele frequencies from dbSNP, ALFA, and the 1000 Genomes Project. Regulatory potential was assessed using RegulomeDB v2.2, and tissue-specific cis-eQTL associations were explored using GTEx. All 21 patients carried the genetic variant rs5945619 in a heterozygous state. The mean age at diagnosis was 54.5 ± 12.2 years, and invasive breast carcinoma of no special type was the predominant histological subtype. The T-allele frequency in the study cohort was 0.50, whereas Latin American reference populations showed higher frequencies ranging from 0.69 to 0.83. RegulomeDB assigned rs5945619 a rank of 1f and a functional score of 0.22, supporting its regulatory potential. GTEx analysis identified tissue-specific cis-eQTL signals, including LINC01496 upregulation in testis, NUDT11 and LINC01496 downregulation in prostate, and modest GSPT2 downregulation in mammary tissue. This study provides the first characterization of rs5945619 in Ecuadorian mestizo women with BC and suggests its role as a potential X-linked regulatory variant, requiring further validation. Although universal heterozygosity was observed, the small sample size, tumor-only design, and absence of a healthy control cohort prevent any causal, risk-factor, or tumor-driven selection inference. The in silico evidence supports a tissue-dependent regulatory model involving LINC01496 and NUDT11, mainly in prostate/testis, and a modest GSPT2 signal in mammary tissue. Therefore, breast cancer-specific eQTL analyses, functional validation, and larger ancestry-informed case–control studies are required to determine the biological and clinical relevance of this locus. Full article

As a result of investigation of glycosidic composition of the sea cucumber Ocnus glacialis (Cucumariidae, Dendrochirotida) two new glycosides, glacialisosides A (1) and B (2), were isolated. Their structures were established by in-depth analysis of ¹H, ¹³C NMR, 1D TOCSY, and 2D NMR (¹H,¹H COSY, HMBC, HSQC, ROESY), in addition to HR-ESI mass spectra. The structures of the obtained desulfated derivatives 3, 4 were elucidated by HR-ESI-MS and ESI-MS/MS. The aglycone moieties of these glycosides are known from other glycosides of four species belonging to the order Dendrochirotida. However, despite sharing common sugar compositions and architectures, the carbohydrate chains of 1, 2 are novel due to the distinct positioning of sulfate groups. Glacialisosides A (1) and B (2) exhibit structural features shared with compounds from sea cucumbers of the orders Holothuriida, Elasipodida, and Dendrochirotida. The hemolytic and cytotoxic activities of compounds 1–4 were studied against human erythrocytes and four breast cancer cell lines (MCF-7, T-47D, MDA-MB-231, and MDA-MB-468), as well as the non-tumorigenic mammary epithelial cell line MCF-10A and the pancreatic epithelioid carcinoma cell line PANC-1. The sulfated native compounds 1 and 2 were significantly more potent than desulfated derivatives 3 and 4 across all tested cell lines, indicating a positive contribution of sulfate groups to bioactivity. Notably, the normal epithelial MCF-10A cells exhibited resistance to the membranolytic action of the glycosides, an important and favorable feature, particularly given the pronounced cytotoxicity observed against the triple-negative MDA-MB-231 cell line. Furthermore, glacialisoside A (1) demonstrated potent inhibitory activity against the formation and growth of MDA-MB-468 cell colonies, effectively blocking cell division even at concentrations below 0.2 μM and completely halting it at a dosage of 1 μM. Thus, the colony formation assay reveals a latent sensitivity of cancer cells—not only to the membranolytic action of triterpene glycosides, but also to the effects of these compounds relevant to other aspects of cell survival, division, and spread. Full article

Background/Objectives: Mammary adipose tissue functions as an active endocrine organ, potentially influencing breast carcinogenesis through metabolic and inflammatory mechanisms. This systematic review synthesized evidence on associations between mammary adipocyte size, obesity-related adipose tissue dysfunction, and breast cancer. Methods: A comprehensive literature search was conducted across MEDLINE, EMBASE, CENTRAL, CINAHL and Web of Science (January 2010–September 2025) for observational studies measuring mammary adipocyte size in human breast tissue. Two reviewers independently conducted screening following the Cochrane Review’s rigorous methodology, and bias assessment using the ROBINS-E (Risk Of Bias In Non-randomized Studies of Exposure) tool. Random-effects meta-analyses were performed for quantifiable outcomes, with heterogeneity assessed using the I² statistic. Results: Twenty-one studies were included in the systematic review. Meta-analyses indicated that mammary adipocyte diameter was positively correlated with body mass index (8 studies; n = 720; correlation coefficient (r) = 0.44, 95% CI: 0.29–0.56), crown-like structure (CLS) density (5 studies; n = 383; r = 0.45, 95% confidence interval (CI): 0.36–0.54), aromatase expression (3 studies; n = 333; r = 0.36, 95% CI: 0.05–0.61), and three studies compared adipocyte diameter between CLS-positive and CLS-negative tissue (n = 297; mean difference = 9.69 μm, 95% CI: 4.94–14.44). Conclusions: This review summarizes moderate positive correlations of mammary adipocyte size with systemic adiposity, local breast inflammation, and aromatase expression, supporting a potential role for mammary adipose tissue in obesity-related metabolic dysfunction. Future prospective studies with standardized measurement protocols and improved control for confounding variables are needed to strengthen causal inference and clinical applications. Full article

Estrogen receptor-positive breast cancer remains difficult to treat, driving the search for new therapeutic agents. Juncus effusus L., a medicinal plant rich in bioactive constituents, has shown preliminary anticancer activity, yet its efficacy in hormone-responsive tumor models in vivo has not been established. We evaluated the antitumor effects of the ethyl acetate sub-extract of J. effusus L. subsp. effusus in an N-methyl-N-nitrosourea (NMU)-induced rat mammary tumor model, assessing tumor burden, histopathology, and molecular markers. Thirty-six Sprague–Dawley rats were divided into six groups (n = 6): sham, control, reference, and three groups receiving the sub-extract at 100, 200, or 400 mg/kg. After NMU induction (50 mg/kg), treatment began once tumor volumes reached approximately 2000 mm³ and continued for eight weeks. The 200 mg/kg dose markedly reduced tumor volume relative to control (p < 0.0001) and lowered both ERα and PCNA expression (p < 0.001 and p < 0.0001). The 100 and 200 mg/kg groups also showed lower p53 and ERα mRNA levels than the other treatment groups. HIF-1α, though elevated in control tumors, declined only modestly and without statistical significance after treatment. These results indicate that J. effusus subsp. effusus, particularly at 200 mg/kg, suppresses proliferation and modulates ERα- and p53 expression, supporting its potential for further preclinical investigation. Full article

The extracellular matrix (ECM) is increasingly recognized as an active regulator of breast cancer progression rather than a passive structural scaffold. This narrative review examines how ECM remodeling contributes to tumor aggressiveness through changes in matrix composition, collagen architecture, tissue stiffness, mechanotransduction, stromal permissiveness, immune and metabolic programs, invasion, metastasis and therapeutic response. A structured narrative search of literature published from 1981 to June 2026 was used to support this synthesis. Evidence from breast cancer studies indicates that collagens, fibronectin, laminins, proteoglycans, matricellular proteins, ECM-remodeling enzymes, and matrix-crosslinking pathways regulate integrin–FAK/Src, RhoA–ROCK, PI3K–AKT, MAPK, TGF-β/SMAD, Wnt/β-catenin, and YAP/TAZ signaling. Spontaneous canine mammary tumors are discussed as complementary comparative models that may preserve selected tumor–stroma–ECM interactions under naturally occurring disease conditions while requiring cautious interpretation due to species-specific biological and clinical differences. Proteomics, lipidomics, metabolomics, spatial omics, digital pathology, and artificial intelligence may support ECM-informed biomarker discovery and response prediction. However, translational application requires standardized pathology, reproducible assays, harmonized metadata, external validation, model interpretability, and clinically meaningful endpoints. Overall, ECM-informed comparative oncology is best viewed as a framework grounded in rigorous validation for identifying matrix-defined tumor phenotypes and prioritizing future biomarker and therapeutic strategies. Full article

CMTs are biologically heterogeneous neoplasms for which reliable prognostic biomarkers remain limited. This study investigated the clinical significance of serum cancer antigen 15-3 (CA 15-3) and the immunohistochemical expression of Ki-67 and cyclooxygenase-2 (COX-2) in CMTs. Fifty-four female dogs with histologically confirmed CMTs and twelve healthy controls were prospectively evaluated. Serum CA 15-3 concentrations were measured before surgery and at 21 and 90 days post-mastectomy, while Ki-67 and COX-2 expression were assessed in tumor tissues. CA 15-3 was undetectable in controls and significantly higher in malignant than benign neoplasms (p < 0.05), with moderate correlations with clinical stage (s = 0.59), histological grade (s = 0.64), and the number of nodules (s = 0.42). Levels remained elevated in advanced stages despite surgery. ROC analysis identified a CA 15-3 cutoff of 3.01 IU/mL (AUC = 0.92) for discriminating malignant from benign tumors. Ki-67 correlated with histological grade (ρ = 0.41) but showed limited prognostic accuracy (AUC = 0.63). COX-2 expression lacked significant associations and showed poor discriminatory power (AUC = 0.44). Survival analyses did not identify significant differences among groups. Principal component analysis demonstrated clustering of aggressive CMTs according to biomarker profile. These findings suggest that serum CA 15-3 may represent a useful adjunct prognostic biomarker in canine mammary oncology, while the combination of serum and tissue biomarkers may improve prognostic stratification and may guide therapeutic decision-making in veterinary oncology. These findings support the growing role of biomarker panels in the clinical management of CMTs. Full article

Canine mixed-type mammary carcinomas (CMTs) exhibit remarkable histological and structural heterogeneity, sharing some biological similarities with human breast cancer and supporting their relevance as models in comparative oncology. These tumors frequently contain regions of malignant epithelial cells, areas of mesenchymal differentiation, and ossified tissue, reflecting their complex histological organization. In this exploratory pilot study, we performed MRM-based spatial lipidomic analysis of distinct tumor regions; namely the margin, middle (epithelial/myoepithelial-rich), and central ossified areas. Our region-resolved lipidomic analysis revealed distinct lipidomic signatures across regions, with significant alterations in phosphatidylcholines, phosphatidylethanolamines, sphingomyelins, triacylglycerides, and free fatty acids distribution. The central ossified area showed enrichment in structural lipids and ceramides, while the tumor margin demonstrated enrichment of ether lipids, which may reflect differences in tissue composition and local metabolic environments. By characterizing region-specific lipid profiles, this study provides insights into metabolic heterogeneity within a canine mixed mammary carcinoma. These findings highlight the potential of spatial lipidomics for investigating intratumoral metabolic heterogeneity and provide preliminary data to support future studies in comparative oncology involving canine and human mammary tumors. Full article

Canine mammary tumors have been investigated to determine the causes of malignancy and to promote the development of more effective therapies. The current standard of care, surgical resection where possible, often still results in recurrence of disease. Thus, there is an unmet need for better, more effective therapies that can suppress recurrence in canine patients. Because canine and human mammary cancers, particularly carcinomas and adenocarcinomas, share many similarities in genetic defects, etiology, natural history, and environment, canine mammary cancer cell lines have also been used as effective models of human disease. The genetics and immune response to canine mammary/breast cancers have been investigated to better understand this disease complex and to promote the development of more effective therapies designed to treat individual canine patients. As cancer is a heterogeneous disease, the potential to determine and possibly predict the mechanisms promoting neoplasia would allow the advancement of targeted therapeutic targets/strategies to combat cancer directly. These investigations have led to the development and evaluation of immunotherapies designed to elicit immune recognition of cancer and its suppression, thus improving survival. Hybrid dendritic-cell fusion vaccines and other autologous cancer vaccine formulations have proven effective in suppressing recurrence and extending survival in canine mammary cancer patients following surgical resection. Although current vaccines are somewhat impractical for direct application in veterinary clinics, reported success points the way toward the development of more practical vaccines designed to promote the treatment of canine mammary cancer. They also suggest a possible mechanism whereby removing a tumor from its microenvironment can promote antigenicity by removing local extracellular vesicle-mediated immunosuppression. This review provides a novel perspective on the potential of canine genetics to inform and promote more successful immunotherapies and their value as models of human disease. Full article