Search Results (127)

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

Background/Objectives: Mammary carcinoma is a common disease in female dogs. Cannabidiol (CBD) can inhibit cell proliferation and induce apoptosis in human cancer cells. However, its low solubility in aqueous media requires solvents such as ethanol or dimethylsulfoxide that limit their dosage. Incorporating CBD into oil-in-water nanoemulsions (Nem) can improve its aqueous dispersibility. This study aimed to develop a CBD-Nem formulation and evaluate its effects on canine mammary cancer cell lines (CF41.Mg and IPC366) and non-cancer cells (MDCK). Methods: CBD-Nem was prepared with Miglyol 812 oil and Epikuron 145 V as the surfactant, and was characterized by analyzing size, morphology, zeta potential, release profile, and uptake/internalization. Moreover, the antitumor effects of CBD-Nem were evaluated in cancer cells through viability, proliferation, cell cycle, and migration–invasion assays. Results: CBD-Nem exhibited a monodisperse nanometric population (~150 nm), spherical shape, and negative zeta potential (~−50 mV). The in vitro release kinetics showed slow and sustained delivery at both pH 5.5 and pH 7.4. Rhodamine-Nem, as a fluorescent model of CBD-Nem, was taken up and homogenously internalized in CF41.Mg cells. CBD-Nem decreased the viability of cancer cells with a maximum effect at 50 µM and showed a lower toxicity in MDCK cells. Long-term efficacy (20 days) was evidenced by CBD-Nem at inhibiting colony formation in cancer cells. Furthermore, CBD-Nem reduced the proportion of cells in the G2-M phase, induced apoptosis, and inhibited the migration and invasion of CF41.Mg cells. Conclusions: CBD-Nem exhibited an in vitro antitumor effect, which supports its study in dogs with mammary carcinoma. 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

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

Mammary tumors occur in female and male guinea pigs. However, published data on their histology and sex predispositions are limited. Histologically, we examined proliferative mammary lesions of 69 female and 48 male pet guinea pigs. Lobular hyperplasia was observed only in females (n = 50). Benign tumors included simple adenomas (n = 20), adenolipomas (n = 3) and intraductal papillary adenomas (n = 5). All except two intraductal papillary adenomas occurred in females. Most malignancies were tubulopapillary and solid carcinomas (n = 54), and intraductal papillary carcinomas (n = 13). These were diagnosed more frequently in male (n = 41) than in female (n = 26) guinea pigs. The carcinomas of males had higher mitotic counts than those of females (p = 0.05). Three carcinosarcomas developed in adenolipoma, and one arose in adenoma. Results show that the mammary tumor classification of dogs and cats can be applied to guinea pigs. However, some tumors (adenolipoma, metaplastic carcinoma) are unique to guinea pigs and shared with laboratory rodents and humans, respectively. Benign tumors may undergo malignant progression. Male guinea pigs appear predisposed to ductal-associated and malignant tumors. Data suggest that male guinea pigs represent an animal model for human male breast cancer. Full article

Mammary gland tumors in dogs are very common in clinical practice. Betulinic acid is currently a compound considered to have anticancer properties in human mammary tumors via nanoemulsions. In this study, betulinic acid nanoemulsions with a particle size of less than 300 nm were prepared. Biopsies were obtained from five female dogs with mammary tumors for histopathological analysis, confirming that two were tubular mammary carcinomas (MMTs, malignant) and three were complex mammary adenomas (BMTs, benign). The five female dogs were administered with a daily oral dose of nanoemulsion containing 5 mg/kg of betulinic acid for 30 days. Tumor size was measured every 7 days, and the response to treatment was assessed according to RECIST (Response Evaluation Criteria In Solid Tumors) standards. In one of the females with MMTs treated with the nanoemulsion, the tumor size was reduced by approximately 38%, while in the BMT female dogs, the nanoemulsion reduced the tumor size by 25.3%. It was concluded that oral administration of betulinic acid nanoemulsions reduced the size of canine mammary tumors. Experimental studies are still needed to further evaluate this preparation. Full article

Proton beam therapy (PBT) is a rapidly advancing modality of hadron therapy. The primary advantage of proton therapy lies in a unique depth-dose distribution characterized by the Bragg peak, which enables a highly targeted irradiation of the area limited to the tumor, while minimizing the impact on healthy tissues. However, a broader clinical adoption of the ion beam therapy is limited by both economic and radiobiological constraints. One of the possible ways to increase the relative biological effectiveness (RBE) of proton therapy involves the use of radiosensitizers. Background/Objectives: In this work, we investigated the efficacy of using colloidal solutions of lanthanum hexaboride (LaB₆) nanoparticles (NPs) coated with polyacrylic acid (PAA) as sensitizers to increase the antitumor biological effectiveness of proton irradiation. This material has not yet been studied extensively so far, despite its promising physical and chemical properties and several reports on its biocompatibility. Methods: LaB₆ NPs were synthesized by femtosecond pulsed laser ablation, functionalized with PAA and characterized. The safety of NPs was evaluated in vitro using a Live/Dead assay on cell cultures: EMT6/P, BT-474, and in vivo in Balb/c mice after intravenous (i.v.) administration. The efficacy of binary proton therapy was evaluated in vitro on cell cultures: EMT6/P, BT-474, and in vivo in the model of human ductal carcinoma of the mammary gland BT-474 in female Nu/j mice after intratumoral (i.t.) administration at a dose of 2.0 mg/mouse and local proton irradiation (fractional exposure of 31 Gy + 15 Gy). The biodistribution of LaB₆-PAA NPs in the animal body was also evaluated. Results: Significant enhancement in cancer cell death following proton beam irradiation was demonstrated in vitro on EMT6/P, BT-474 cell lines. Although the antitumor efficacy observed in vivo was comparatively lower—likely due to the high sensitivity of the BT-474 xenografts—both proton monotherapy and binary treatment were well tolerated. Conclusions: LaB₆-PAA NPs show promise as efficient sensitizers capable of enhancing the biological efficacy of proton therapy, offering a potential path forward for improving therapeutic outcomes. Full article

Feline mammary carcinoma (FMC) is an aggressive neoplasm with a poor prognosis. Clinical staging is crucial for risk assessment, yet the current WHO system lacks granularity, particularly in Stage III. Aligning this system with human breast cancer staging has the potential to improve prognostic accuracy. Additionally, prognostic factors such as tumor size, ulceration, lymph node metastasis, and lymphovascular invasion require further evaluation. This study retrospectively analyzed 75 female cats with FMC to assess the prognostic impact of clinicopathological factors and evaluate a novel staging system (new staging) adapted from the AJCC Cancer Staging Manual. Survival analyses included disease-free interval (DFI), and overall survival (OS). Tumor size >3 cm (p < 0.001), ulceration (p = 0.010), lymphovascular invasion (p < 0.001), lymph node metastasis (p < 0.001), WHO and new staging (p < 0.001) were significantly associated with shorter survival. The new staging refined Stage III into III_A (T₃N₀M₀), III_B (T₄N₀M₀), and III_C (AnyTN₁M₀), improved prognostic differentiation. Stage III_C cases had the worst survival (p < 0.001). Multivariate survival analysis identified lymphovascular invasion (HR = 2.834, 95% CI: 1.546–5.195, p = 0.001), histological Grade II (HR = 5.013, 95% CI: 1.122–22.397, p = 0.035) and III (HR = 9.894, 95% CI: 2.195–44.594, p = 0.003) and skin ulceration (HR = 2.462, 95% CI: 1.256–4.825, p = 0.009). These findings support the prognostic relevance of key clinicopathological factors in FMC and highlight the advantages of a refined TNM-based staging system, which may enhance risk stratification and therapeutic decision-making in veterinary oncology. Full article

High-throughput omics approaches have long been used to uncover potential vulnerabilities in human personalized oncology but are often limited by the lack of functional validation. Therefore, we placed our emphasis on functional drug testing using patient-derived organoids (PDOs). However, PDOs generated from tumors mostly lack comparison with matching normal tissue, and the number of testable drugs is limited. Here, we demonstrate how matching the neoplastic and non-neoplastic mammary PDOs derived from the same dog can utilize targeted CRISPR/Cas9 screens to unveil cancer cell specific vulnerabilities. We performed two independent CRISPR/Cas9 dropout screens using sub-libraries targeting the epigenome (n = 1269) or druggable genes (n = 834) in paired PDOs derived from both carcinoma and normal mammary tissues from the same dog. A comparison of essential genes for tumor cells survival identified CDK2 as a functional vulnerability in canine mammary tumors (CMTs) that can be targeted with the PF3600 inhibitor. Additional potential targets were also uncovered, providing insights for personalized cancer treatments in dogs. Full article

Mammary intraductal macrophages (foam cells) in humans are the most commonly encountered cells in spontaneous breast nipple discharge, nipple aspirate fluid, and ductal lavage, yet their origin remains unproven. These cells, in both humans and murine model systems, increase in pregnancy, pseudopregnancy, and other conditions like proliferative fibrocystic disease and intraductal neoplasia, ductal carcinoma in situ (DCIS), where there is intraductal ectasia and obstruction. Previous immunocytochemical studies with macrophage (CD68, lysozyme), epithelial (cytokeratin, estrogen receptor), and myoepithelial (smooth muscle actin, CALLA, maspin) markers have indicated that intraductal foam cells are of macrophage lineage. These foam cells engage in phagocytosis of both endogenous and exogenous substances present within the ducts and are not proliferative. Although it has been suggested that foam cells could derive from tissue-specific and niche-specific precursors or circulating monocytes, to date no experimental nor clinical studies have provided direct proof of their origin. In this study, we provide evidence in both human and murine bone marrow transplant studies that intraductal foam cells are bone marrow-derived. We first studied a registry of sex-mismatched bone marrow transplant recipients who later in life had undergone breast biopsies for either proliferative fibrocystic disease, DCIS, or gynecomastia, and studied these biopsies by XY chromosome fluorescence in situ hybridization (FISH) and informative microsatellite polymorphic markers. The intraductal foam cells were of bone marrow donor-origin. Then, in the experimental bone marrow transplant murine studies, donor marrow from female ROSA26 containing the lacZ reporter were transplanted into either irradiated female recipient transgenic mice carrying the highly penetrant MMTV-pymT or FVB/N background mice, where induced pluripotent stem (iPS) cells derived from tail vein fibroblasts of FVB/N-Tg(MMTV-PyVT)634Mul/J mice were subsequently injected into their mammary fat pads. In all of the transplanted recipient mice, the intraductal foam cells expressed the β-galactosidase (lacZ) reporter and also co-expressed markers of myeloid–macrophage lineage. The number of donor-derived intraductal foam cells increased in pseudopregnancy 5-fold and in intraductal neoplasia 10-fold. Although macrophages of different origins and lineages are undoubtedly present within both the murine and human breasts, those macrophages that qualify as phagocytic intraductal foam cells are bone marrow-derived. Full article

Breast cancer (BC) remains a significant global health challenge, highlighting the need for continued research into novel risk factors, diagnostic approaches, and personalized treatments. Among emerging risk factors, viral infections have been implicated as potential contributors to breast carcinogenesis and BC progression. Recent evidence suggests that specific oncogenic strains of human cytomegalovirus (HCMV) may have the capacity to transform human mammary epithelial cells. This review assesses clinical data regarding HCMV presence in both tumor and non-tumor breast tissues, examining the role of HCMV oncoproteins in BC development and progression. Current findings indicate a higher prevalence of HCMV infection in breast carcinomas compared to non-tumor tissues, associated with an elevated risk of BC. Additionally, the HCMV-driven breast carcinogenesis model proposed here suggests that HCMV oncoproteins may activate multiple oncogenic pathways, fostering cell proliferation, survival, and tumor development. A deeper understanding of the role of HCMV in BC could enhance risk stratification and support the creation of targeted therapeutic strategies. Full article

Mammary neoplasms in dogs are a common clinical concern, especially in middle-aged and older intact females. These tumors share similarities with human breast cancer in terms of histology, disease progression, and risk factors, making dogs a relevant model for breast cancer research. The search for biomarkers in canine mammary tumors is essential to understand tumor progression and identify potential therapeutic targets. This study investigated the expression of two potential biomarkers—Inter-Alpha-Trypsin Inhibitor Heavy Chain 2 (ITIH2) and Enolase 1 (ENO1)—in the mammary glands of healthy and tumor-bearing dogs using immunohistochemistry. Both proteins were identified in previous proteomic analyses of extracellular vesicles derived from the plasma of healthy and tumor-bearing dogs. A total of fifty-one canine mammary tissue samples were analyzed and categorized into three groups: (i) the control group, composed of five samples of normal mammary tissue without neoplasia; (ii) benign tumors, composed of nineteen samples of benign mixed tumors; and (iii) malignant tumors, which included six carcinomas in grade 1 mixed tumors, five carcinomas in grade 2 mixed tumors, thirteen solid carcinomas of grade 3, one papillary carcinoma, and two tubular carcinomas. Regarding the intensity of staining, quantified by histoscore, there were no significant differences in the comparison between the groups; for ITIH2, the p-value was 0.33, and for ENO1, the p-value was 0.57. Regarding the predictive potential of their respective ROC curves, the proteins demonstrated low predictive power in canine mammary tumors. These findings indicate that neither ITIH2 nor ENO1 demonstrated strong prognostic value in this setting, as demonstrated by their moderate AUC values, wide confidence intervals, and lack of statistical significance. However, this study found distinct tissue localization patterns for ITIH2 and subcellular localization for ENO1. As an additional way to examine possible associations of these proteins with epithelial–mesenchymal transition, the ZEB1 antibody was tested by both single and double immunohistochemistry, demonstrating a tendency to be more intensely expressed in the malignant group and tending to be associated with ENO1 in canine mammary tumors. Full article

Background: Somatostatin receptors (SSTRs) are expressed in most neuroendocrine neoplasms, particularly in gastroenteropancreatic neuroendocrine tumours, and have been utilised as diagnostic markers and therapeutic targets. The radioiodinated somatostatin analogue 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid- Tyr3-octreotate (DOTATATE) has been employed for SSTR targeting for either diagnostic or therapeutic purposes depending on the labelling with ⁶⁸Gallium or ¹⁷⁷Lutetium, respectively. SSTR expression is reported in a subset of breast adenocarcinoma and breast neuroendocrine carcinomas; however, minimal knowledge exists regarding their expression in fibroepithelial (biphasic) breast lesions such as fibroadenoma and phyllodes tumours. Aggressive ends of the spectrum, i.e., “cystosarcoma phyllodes”, may present a management challenge with recurrences and metastases, and SSTRs could be a promising therapeutic target for these types of tumours. Methods: Gene and protein expressions of SSTRs in primary human fibroepithelial lesions of the breast are investigated using RT-PCR and immunoblotting. Localisation of the SSTR-positive cells was determined with immunohistochemistry and immunofluorescence. Results and Conclusions: Both fibroadenoma and phyllodes tumours express SSTRs. Immunohistochemical analyses suggested that this expression is in the stromal, not epithelial, component by demonstrating that SSTR stained in the areas overlapping with α-smooth muscle actin-positive myoepithelial cells around blood vessels and capillary structures. This study is the first in the literature to demonstrate SSTR positivity in mammary fibroepithelial neoplasms. Once validated, these findings may also have significant implications for managing the treatment of these tumours. Full article

Background: The present study investigates VKINE, a bioactive proteolytic fragment of the proteoglycan VCAN, as a novel and significant element in the tumor extracellular matrix (ECM). Although VKINE has been recognized for its immunomodulatory potential in certain tumor types, its impact on ECM degradation and prognostic implications remains poorly understood. Objectives: This study aimed to evaluate VCAN proteolysis and its association with ADAMTS enzymes involved in extracellular matrix remodeling in spontaneous canine mammary gland cancer. Methods: The expression levels of VKINE, ADAMTS enzymes, and collagen fibers were comparatively analyzed in situ and in invasive areas of carcinoma in mixed tumor (CMT) and carcinosarcoma (CSS) with different prognoses. Results: VKINE was notably expressed in the stroma adjacent to the invasion areas in CMT, whereas ADAMTS-15 was identified as the enzyme associated with VCAN proteolysis. Inverse correlations were observed between type III collagen and VCAN expression in in situ areas. Conclusions: Our findings suggest that VKINE and ADAMTS-15 play crucial roles in the tumor microenvironment, influencing invasiveness and type III collagen deposition. This study contributes to a better understanding of the dynamics within the ECM, paving the way for potential new tools in diagnosing and treating human and canine mammary tumors. Full article

Alterations of the BRAF gene and the resulting changes in the BRAF protein are one example of molecular cancer profiling in humans and dogs. We tested 227 samples of canine carcinomas from different anatomical sites (anal sac (n = 23), intestine (n = 21), liver (n = 21), lungs (n = 19), mammary gland (n = 20), nasal cavity (n = 21), oral epithelium (n = 18), ovary (n = 20), prostate (n = 21), thyroid gland (n = 21), urinary bladder (n = 22)) with two commercially available primary anti-BRAF^V600E antibodies (VE1 Ventana, VE1 Abcam). The immunohistochemical results were confirmed with droplet digital PCR (ddPCR). BRAF^V595E-mutated cases were found in canine prostatic (16/21), urothelial (17/22), and oral squamous cell carcinomas (4/18), while other carcinoma types tested negative. Both antibodies showed consistent results, with intracytoplasmic immunolabeling of tumour cells, making them reliable tools for detecting the BRAF^V595E mutation in canine carcinomas. In conclusion, identifying BRAF mutations from biopsy material offers a valuable opportunity to enhance cancer treatment strategies (BRAF inhibitors) in canine urothelial carcinomas, prostatic carcinomas, and oral squamous cell carcinomas. Full article