Search Results (342)

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

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 (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

CBL-B is an intracellular E3 ubiquitin ligase that acts as a T cell checkpoint by raising activation thresholds and limiting effector function. Here, genetic targeting of CBL-B enhances the performance of adoptively transferred T cells and CAR T cells under tumor microenvironment-like stress. In fully immunocompetent mouse models, Cblb deficiency or transient Cblb silencing improves control of MC-38 colon carcinoma and autochthonous mammary tumors, demonstrating that CBL-B restrains anti-tumor immunity. Cblb-deficient T cells show enhanced expansion and effector/effector-memory differentiation during an in vivo mixed lymphocyte reaction, confirming a cell-intrinsic brake function of CBL-B during sustained antigenic challenge. In a syngeneic Panc02-EpCAM model, Cblb-deficient anti-EpCAM CAR T cells show superior tumor control, enhanced infiltration, prolonged survival, and preserved effector function despite chronic antigen exposure and TGF-β. Mechanistically, Cblb targeting maintains granzyme B and IFN-γ production and is associated in vitro with increased GSDME-linked pyroptotic tumor cell death, consistent with features of immunogenic cell death. These findings extend previous CBL-B CAR T work from lymphocyte-deficient to immunocompetent settings and support CBL-B inhibition as a strategy to engineer CAR T cells that resist suppressive tumor microenvironments while promoting a more inflammatory mode of tumor killing. 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

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

Background: Routine use of the chorioallantoic membrane (CAM) tumor model in nuclear imaging studies is hampered by small tumors, embryonic movements and laborious volume-restricted intravenous tracer/drug administration. We sought a workaround by using fast-growing tumors, high-resolution autoradiography and non-intravenous tracer administration. Methods: Dekalb White chicken eggs were grafted with C3H mammary carcinoma fragments or MOC2 oral squamous cell carcinoma fragments from donor mice. The tumor uptake of ¹⁸F-fluorodeoxyglucose (FDG) following in-yolk-sac injection, dripping after CAM scoring or allantoic cavity injection was evaluated using positron emission tomography (PET) and autoradiography. Using in-yolk-sac injection, eggs were administered different tracer mixtures, namely (1) pimonidazole (hypoxia-marker), FDG and ¹⁴C-2-deoxyglucose (¹⁴C-2DG), (2) pimonidazole, FDG and ¹⁴C-acetate or (3) pimonidazole, the hypoxia-selective tracer ¹⁸F-fluoroazomycin-arabinoside (FAZA) and ¹⁴C-2DG. For comparison, tumor-bearing mice were administered FDG/¹⁴C-acetate/pimonidazole. Gross tumor uptake was evaluated using PET. Tumor cryosections were analyzed using dual-tracer autoradiography. Complementary autoradiograms were co-registered, covered by a square grid (0.5 × 0.5 mm). Pearson correlation coefficients (PCC) were calculated from scatterplots. Results: C3H tumors reached a mean weight (with 95% confidence interval) of 0.32 g (0.28–0.37 g), while for MOC2, it was 0.19 g (0.09–0.29 g). In-yolk-sac tracer injection was simple and effective, producing high tracer uptake and contrast 3 h post-administration. Spatial tracer overlap (PCC) was: FDG vs. ¹⁴C-2DG, 0.95–0.97; FAZA vs. ¹⁴C-2DG, 0.71–0.79 and FDG vs. ¹⁴C-acetate, 0.26–0.84 (0.15–0.76 in mice). Pimonidazole revealed tumor hypoxia. Conclusions: Direct-grafting from donor mice generated larger tumors than previously reported. In-yolk-sac tracer administration was practical and allowed larger injected volumes. Autoradiography revealed that: (1) FDG and ¹⁴C-2DG can be used interchangeably, (2) ¹⁴C-2DG was elevated in FAZA-positive areas, suggesting that in some tumors FDG-PET may provide information on the intratumoral distribution of hypoxic areas, and (3) FDG and ¹⁴C-acetate showed variable overlap. We conclude that in-yolk-sac tracer injection and autoradiography simplify and optimize CAM-based nuclear imaging research. Full article

Background: Comparative oncology uses naturally occurring cancers in companion animals to study tumor biology and therapeutic responses relevant to human cancer. Spontaneous feline tumors are increasingly recognized as useful comparative models because they arise in immunocompetent hosts, develop under shared environmental exposures, and can reproduce selected clinical, histopathologic, molecular, and therapeutic features of human malignancies. Methods: This review compares feline oral squamous cell carcinoma (FOSCC) with human head and neck squamous cell carcinoma (HNSCC), and feline mammary carcinoma (FMC) with human breast cancer, emphasizing shared pathologic, molecular, tumor microenvironment, and therapeutic features. Results: Recent immunohistochemical, genomic, transcriptomic, and biomarker studies have identified shared features between feline and human cancers. FOSCC resembles human HNSCC through aggressive local invasion, histologic features, therapeutic resistance, and recurrent alterations of TP53, MYC, and PTEN. FMC shows strong overlap with aggressive human triple-negative breast cancer, including reduced hormone receptor expression, recurrent TP53, PIK3CA, and CXCL12/CXCR4 signaling alterations, and tumor microenvironment features involving immune-checkpoint, inflammatory, and angiogenic pathways. FOSCC clinical trials and emerging clinical investigations into FMC treatments further support the use of cats for translational therapy evaluation. Conclusions: FOSCC and FMC are promising comparative oncology models for human HNSCC and aggressive breast cancer, respectively. Future multicenter studies incorporating standardized tumor classification and grading, predefined stratification criteria, and clinically meaningful endpoints will be essential to strengthen their translational value. Full article

The glycosidic composition of Psolus phantapus was studied for the first time. Two new glycosides, phantapusosides A (1) and B (2), and the known psolusoside P (3) were isolated and their structures were established by analysis of ¹H, ¹³C NMR, 1D TOCSY, and 2D NMR (¹H,¹H COSY, HMBC, HSQC, ROESY), and HR-ESI mass spectra. These compounds are structurally close to those isolated from other representatives of the genus Psolus: P. fabricii, P. peronii and P. chitonoides. These data confirm the chemotaxonomic significance of triterpene glycosides of sea cucumbers, demonstrating that closely related species biosynthesize structurally similar metabolites. The cytotoxic activity of compounds 1 and 2 was studied against four human breast cancer cell lines (MCF-7, T-47D, MDA-MB-231, 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 glycosides were selectively active against the TNBC cell lines MDA-MB-231 and MDA-MB-468. Notably, both glycosides inhibited the clonogenic potential of TNBC cell lines more significantly than their metabolic activity (MTT assay) and demonstrated a more pronounced colony-inhibiting effect toward the basal-like cell line MDA-MB-468, making this cell line a promising model for future investigation of the antitumor effects of glycosides. Full article

Salvia aethiopis L. is a medicinal and aromatic species of growing scientific interest due to its biological potential. The study aimed to develop an efficient in vitro micropropagation protocol and to evaluate the antioxidant and anticancer activity of aqueous extracts derived from the three different aerial plant parts—flowers, leaves and stems—of the in vitro-cultivated plants and compare them with those of the wild-growing plants. Optimal parameters for the micropropagation of the species were established, yielding 80% field survival and flowering in the second year. The highest total polyphenol and flavonoid content and antioxidant activity were recorded in the flower extract from wild plants—14,681 ± 211 mg GAE/100 g, 2317 ± 77 mg RE/100 g and 4563 ± 280 µmol TE/g, respectively. HPLC analysis confirmed the presence of key bioactive compounds, including rosmarinic acid, caffeic acid, and apigenin. The anticancer potential of the different extracts was assessed against human cervical, mammary and colorectal cell lines. The extracts exhibited significant antiproliferative activity, with HT-29 colorectal carcinoma cells being the most sensitive. Flower extracts of wild plants showed the strongest cytotoxic effects with IC₅₀ values at 72 h being lower than 100 μg/mL for all cancer cell lines. Fluorescence microscopy and flow cytometry analyses indicated that the observed extract-induced anticancer effects were associated with mitochondrial dysfunction, cell cycle alterations, modulation of autophagy, and induction of apoptotic and necrotic cancer cell death. These findings highlight the potential of extracts of S. aethiopis for anticancer therapy. Full article

Background/Objectives: Histone deacetylase (HDAC) inhibitors have been shown to prime the response to immunotherapy (IMT) treatment by inducing immune activation and infiltration to target tumor cells. Many studies primarily focus on adaptive immune cells and their expression of pro-inflammatory markers, like somatostatin receptor 2 (SSTR2); however, macrophages are known to help mediate key tumor microenvironment changes. The goal of this study is to evaluate the effects of HDAC inhibitors and IMT on macrophages, their expression of SSTR2, and their impact on the treatment response in triple-negative breast cancer (TNBC). Methods: Cytotoxic effects of HDAC inhibitors on 4T1 mouse mammary carcinoma cells, including suberoylanilide hydroxamic acid (SAHA), were evaluated using flow cytometry. Bone marrow-derived macrophages (BMDMs) were stimulated to M1-like and M2-like phenotypes and treated with SAHA to explore the effects on SSTR2 expression in different macrophage phenotypes. 4T1-tumor-bearing BALB/c mice were used to evaluate the therapy response to four treatments: saline control, SAHA, anti-PD-1 + anti-CTLA-4 checkpoint blockade IMT, or a combination of SAHA + IMT. Additional cohorts of 4T1-tumor-bearing BALB/c mice and NOD SCID mice, which lack adaptive immune cells, were euthanized for early evaluation of tumor-associated macrophage (TAM) populations via flow cytometry and cytokine analysis. One-way independent ANOVAs and log-rank tests were used to compare group differences. Results: SAHA promotes SSTR2 expression on M1-like BMDMs in vitro. SAHA promotes M2-like TAMs in vivo and stimulates pro-inflammatory, anti-tumor cytokine production in combination with IMT. Conclusions: SAHA drives SSTR2 expression and anti-tumor innate immune responses with additive effects in combination with immunotherapy in preclinical TNBC. Full article

CDK4/6 inhibitors such as palbociclib, ribociclib and abemaciclib are commonly used in the clinical treatment of HR-positive, HER2-negative metastatic or locally advanced breast cancer. Patients with metastatic disease often receive palliative radiotherapy for symptom control of bone metastases and/or local lesions, typically administered in close temporal proximity to CDK4/6 inhibitor therapy, although treatment with the inhibitors may be temporarily paused during the radiotherapy period in some cases. In this study, we investigated the extent to which senescence is induced by CDK4/6 inhibitors, ionizing radiation, and the combination of the two, compared to other types of cell fate. Eight breast cancer cell lines with different molecular subtypes and two healthy cell lines (fibroblasts and keratinocytes) were treated with CDK inhibition using palbociclib, ribociclib or abemaciclib and with or without a single dose of 2 Gy ionizing radiation. Cellular senescence, cell death in form of apoptosis and necrosis, and the cell cycle were analyzed using flow cytometry. We focused mainly on understanding how CDK inhibition can trigger cellular senescence. Our data showed that in many cell lines —but not all—the use of CDK inhibitors induced senescence much more strongly than cell death. Except for one cell line, significantly more cell lines died necrotically than apoptotically. Neither apoptosis nor necrosis was responsible for a major cell fate after CDK inhibition. Combination therapy with irradiation did not show a clear additive effect. In cell lines, senescence is clearly triggered by CDK4/6 inhibitors and even more so when in combination with ionizing radiation, which, when transferred to patients, could lead to less damage caused by cell loss, such as necrotic areas. However, it could also lead to more senescence-specific side effects, such as inflammation-induced tumors and fibrosis. Full article

Maternal nutrition during critical windows of development plays a pivotal role in shaping long-term disease susceptibility, including cancer risk. This study investigated whether maternal exposure to lipotropes (methyl donor nutrients) during pregnancy and lactation modulates gene expression in 7,12-dimethylbenzanthracene (DMBA)-induced mammary tumors in adult female offspring. Timed-pregnant Sprague-Dawley rats were fed with either a control or lipotrope-supplemented diet, with or without vitamin B6. Female offspring were exposed to DMBA at puberty, and mammary tumors were evaluated histologically and molecularly. DMBA-induced tumors displayed ductal carcinoma in situ-like morphology and significant upregulation of fetal mammary developmental genes (Tbx2 and Tbx3), the tumorigenesis-associated gene Tp53, and key epigenetic regulators (Hdac1, Dnmt1, and Mthfr). Estrogen receptor 1 (Esr1) mRNA expression also showed a significant increase. Maternal lipotropes supplementation significantly attenuated the expression of these genes in offspring tumors. Collectively, these findings demonstrate that maternal methyl donor nutrition modulates tumor-associated gene expression patterns, potentially by limiting the reactivation of developmental and epigenetic pathways in adulthood. This study highlights maternal nutrition as a modifiable early-life factor with important implications for long-term health programming. Full article