Search Results (418)

Background/Objectives: Carvedilol is an adrenergic blocker FDA-approved to improve outcomes in heart failure with reduced ejection fraction. Clinical trials examining whether carvedilol may be cardioprotective in the setting of cancer therapy-induced heart failure have generated mixed results that may depend on the cancer regimen, tumor, or comorbidities. Methods: To investigate the therapeutic potential of carvedilol to mitigate doxorubicin cardiotoxicity in cardiomyocytes, myocardial tissue, and in vivo, independent of confounding factors in clinical studies, we utilized disease-free cardiac slices and cardiomyocytes from mice, dogs, and human in vitro, and in wildtype mice injected with doxorubicin in vivo. We further evaluated the impact of carvedilol in dogs with cancer receiving doxorubicin. Results: In primary canine and murine cardiac slices, carvedilol treatment restored autophagy and prevented apoptosis from doxorubicin. Carvedilol restored mitochondrial energetics in human, canine, and murine models. In wildtype mice challenged with doxorubicin, carvedilol prevented declines in cardiac function and alterations in cardiac structure. In pet dogs with cancer and undergoing doxorubicin treatment, carvedilol was beneficial in preserving cardiac function and structure. Conclusions: Carvedilol activates cardioprotective autophagy, arrests doxorubicin-induced cell death, and improves energetics and cardiac structure and function across species. Full article

Cancer is a leading cause of death in dogs, and incidence rates in dogs exceed those in humans. Current therapeutic options for canine cancer patients remain limited, with most treatments focused on palliative care. Immune checkpoint inhibitors such as anti-PD-1, anti-PD-L1, and anti-CTLA-4 antibodies that have transformed cancer therapy and expanded the therapeutic options in humans could offer the same clinical benefit in canine cancer patients. This study details the engineering and functional characterization of mouse and chimeric mouse–canine anti-canine PD-1 (cPD-1) monoclonal antibodies. We demonstrate that anti-cPD-1 antibodies block the interaction between cPD-1 and its ligand cPD-L1, thereby inhibiting this immune signaling pathway. In a proof-of-concept study in seven companion canine cancer patients, intratumoral therapy with the lead anti-cPD-1 antibody (HugPetmab) was safe, well-tolerated, had no observed adverse events, and showed evidence of tumor control in a subset of injected tumors. These findings support the potential of HugPetmab antibody as an immunotherapeutic option for treating canine cancer patients. Full article

Cryptorchidism is one of the most frequently diagnosed developmental disorders of the male canine reproductive system, defined as the failure of one or both testes to descend into the scrotum. Physiologically, testicular descent is typically completed by six to eight weeks of age, although some authors extend this period to sixteen weeks. Failure of testicular descent beyond this timeframe is considered pathological. The condition has multiple causes and affects between 1% and 10% of the canine population. Genetics is the most significant factor, indicating the hereditary basis of cryptorchidism. In addition, increasing attention has been directed toward the potential impact of environmental and epigenetic factors on the incidence of cryptorchidism, suggesting that the condition may result from complex interactions between genetic predisposition and external influences. The effect of hormones (such as INSL3 and testosterone), mechanical factors (including narrowing of the inguinal canal, abnormalities of the gubernaculum, and shortening of the spermatic cord), and environmental factors (for example, exposure to external estrogens and maternal stress during pregnancy) all contribute to the development of this disorder. Recent results have emphasized the role of the orexin system, particularly the OX2R receptor, in regulating endocrine and reproductive functions in cryptorchid testes. Computed tomography is increasingly utilized in complex cases due to its high precision in localizing retained testes. Clinically, cryptorchidism may present unilaterally or bilaterally. Unilateral cryptorchidism may preserve partial fertility, whereas bilateral cryptorchidism results in complete infertility. Undescended testes may be located in the abdominal cavity or inguinal canal. Major complications include an increased risk of testicular cancer (Sertoli cell tumors and seminomas) and endocrine disorders leading to feminization. Diagnosis is based on clinical examination and imaging modalities such as ultrasound. Orchiectomy, involving the removal of both the retained and normally descended testicles, is thought to be the gold standard for treatment. This method helps avoid complications and the transmission of the defect to offspring. According to Fédération Cynologique Internationale (FCI) standards, affected individuals should not be used for breeding or shows. Early detection, surgical intervention, and consistent exclusion from breeding programs are the primary strategies for reducing the incidence of this disorder in the canine population. Full article

Background/Objectives: Machine learning approaches are widely used in modern medical diagnostics, including cancer detection. The results can be significantly improved by aggregating individual measurements, and appropriate aggregation methods should be established. Methods: We applied various measurement aggregation strategies both before and after machine learning modeling to two datasets of X-ray diffraction images: human breast biopsy samples and canine claw samples. Two classifiers, Random Forest and Logistic Regression, were used to determine classification metrics: the area under the receiver operating characteristic curve (ROC-AUC) and balanced accuracy. Results: We found that all aggregation types improve classification metrics, with aggregation after modeling yielding better performance. Depending on the dataset and approach, either classifier can produce better results. For human breast samples, Random Forest with the logit aggregation strategy provides an ROC-AUC exceeding 0.9. For the canine dataset, both Random Forest with the logit aggregation strategy and Logistic Regression with the median of cancer probabilities achieve an ROC-AUC of about 0.85. Conclusions: We examined several simple, straightforward aggregation methods for patient diagnosis based on multiple measurements per patient and achieved significant improvements in classification metrics. Full article

Cancer is a leading cause of death in humans and dogs. Several erythrocyte and platelet characteristics (indices and morphology) have shown promise as indicators of metastasis in humans. Similar studies have not been performed in dogs. This study evaluated erythrocyte and platelet characteristics measured on the Advia 2120i in 59 tumor-bearing dogs with carcinoma or sarcoma. Tumor-bearing dogs with and without intracavitary hemorrhage that underwent complete post-mortem and histopathology examinations were compared to healthy age-controlled dogs. Carcinoma- and sarcoma-bearing dogs without hemorrhage were compared. All tumor-bearing dogs without hemorrhage or metastasis were compared to those with metastasis, and characteristics were evaluated as indicators of metastasis. Tumor-bearing dogs without intracavitary hemorrhage (n = 49) had decreased hematocrit (p = 0.002) and reticulocyte hemoglobin content (p = 0.022), and increase in anisocytosis (p = 0.002), polychromasia (p = 0.002), macrocytosis (p = 0.032), codocytes (p = 0.022), absolute reticulocyte count (p = 0.035), platelet concentration (p = 0.002), plateletcrit (p = 0.022), and platelet volume distribution width (p = 0.022) compared to healthy dogs (n = 20). In tumor-bearing dogs with intracavitary hemorrhage (n = 10), additional significant differences were reflective of acute hemorrhage. No difference in characteristics between carcinoma- and sarcoma-bearing dogs without hemorrhage was identified. After correction for multiple comparisons, no differences in erythrocyte or platelet characteristics were identified between tumor-bearing dogs without intracavitary hemorrhage and metastasis and those without metastasis. Significant differences in characteristics exist between tumor-bearing dogs and healthy dogs. Based on the limited number of dogs in this preliminary study, no red blood cell or platelet characteristics were associated with metastatic disease in tumor-bearing dogs without hemorrhage. Full article

Cancer remains the leading cause of death in domestic dogs. Conventional therapeutic approaches, including surgery, chemotherapy, and radiotherapy, frequently fail to achieve sustained remission or stabilization. Oncolytic virotherapy, a rapidly advancing therapeutic modality in human oncology, is emerging as a novel strategy in veterinary medicine. This systematic review summarizes current knowledge on the application of oncolytic viruses (OVs) in canine cancer treatment, focusing on their mechanisms of action, safety profiles, and clinical efficacy. We evaluate diverse OV platforms, including myxoma virus, reovirus, vesicular stomatitis virus, canine adenoviruses, vaccinia virus, Sendai virus, and Newcastle disease virus, across preclinical and clinical studies in dogs with various malignancies. While several OVs have demonstrated favorable tolerability and modest antitumor activity, key challenges such as pre-existing immunity, optimization of dosing regimens, and rational combination strategies remain to be addressed. This review emphasizes the translational significance of canine studies for both veterinary and human oncology, underscoring the critical need for rigorously designed clinical trials to refine virotherapy protocols and expand therapeutic options for canine cancer patients. Full article

Melanoma-associated antigen (MAGE) is a promising immunotherapeutic target for cancer vaccines. Heat shock protein 110 (HSP110), expressed in various tumors, including canine mammary tumors, serves as a molecular marker. This study aimed to develop a recombinant fusion protein by linking HSP110 with MAGE-B10 to target MAGE-B10-expressed tumors and assess immune response efficacy. The recombinant MAGE-B10-HSP110 (rMAGE-B10-HSP110) fusion protein was constructed, and separate recombinant MAGE-B10 (rMAGE-B10) and recombinant HSP110 (rHSP110) proteins were also prepared for comparison. Our study on mice is distributed across five treatment groups: the rMAGE-B10-HSP110 fusion protein, rMAGE-B10, rHSP110, a protein mixture, and a PBS control. Antibody responses specific to canine MAGE-B10 were measured using ELISA, while splenocyte activation, proliferation, and cytokine production were analyzed using flow cytometry. The results showed significantly higher antibody responses in mice immunized with the rMAGE-B10-HSP110 fusion protein compared to those receiving PBS or rHSP110 on days 7, 14, and 21. The proportion of CD3+ and CD4+ lymphocytes were significantly higher in these mice (p < 0.05). rMAGE-B10-HSP110 fusion protein immunization also resulted in increased CD69+ lymphocytes and higher IFN-γ levels in stimulated lymphocytes (p < 0.05). In conclusion, the rMAGE-B10-HSP110 fusion protein effectively stimulates both innate and adaptive immune responses. Further in vivo investigation is recommended. Full article

Testicular tumors are the most common neoplasms of the canine male reproductive tract, corresponding to approximately 25% of all tumors in intact males. A large percentage of cases are characterized by one of three main tumor types: seminomas, interstitial Leydig cell tumors, or Sertoli cell tumors. Clinical importance is primarily associated with endocrine activity rather than malignant behavior; orchiectomy is the treatment of choice for most canine testicular cancers. Endocrine activity, particularly estrogen secretion, may result in feminization syndrome and, in severe cases, bone marrow suppression. The diagnostic approach combines physical examination, ultrasonography with hormonal assessment using endocrine testing (testosterone, estradiol, and T:E ratio), and/or tissue level evidence of the estrogen effect (preputial cytology). Management is centered on orchiectomy; unilateral surgery may be considered when the contralateral testis is clinically and ultrasonographically normal and when preservation of reproductive capacity or working ability is still a priority. Dogs with hormonally active tumors benefit from postoperative hematologic and endocrine monitoring. Recent advances in immunohistochemistry (IHC), such as Ki-67 and inhibin-α markers, and imaging techniques are improving tumor characterization and individualized clinical decision making. Full article

Human breast cancer (HBC) is the most common and often lethal malignancy in women. Canine mammary tumors (CMTs) share significant molecular and clinical characteristics with HBC, which makes dogs a valuable spontaneous model for the study of HBC. HBC chemotherapy treatment relies mainly on carboplatin, which is effective but, in turn, highly toxic. Here we tested enrofloxacin, a Minichromosomal Maintenance Complex Component (MCM2) inhibitor, for its ability to increase tumor cell sensitivity to platinum-based drugs, thus suggesting a potential synergistic therapeutic strategy. CMT samples were used to establish primary cell cultures. Cells were treated with carboplatin, enrofloxacin, and their combination at different concentrations. Cytotoxic and antiproliferative effects were assessed using xCELLigence and MTT assays. Single-drug treatments exert limited effects on cell proliferation, while enrofloxacin significantly enhances carboplatin efficacy, leading to a complete growth arrest within 48 h. The MTT assay confirms a strong synergistic effect of the two drugs, whereas the Dose Reduction Index analysis indicates that carboplatin could be decreased without losing effectiveness. These findings suggest that combined therapy could represent a more effective and less toxic option for HBC and CMTs. This work also strengthens the possible use of the canine model for cancer studies within a One Health framework. Full article

The purpose of this study was to compare the retinal gene expression profiles in canines with Sudden Acquired Retinal Degeneration Syndrome (SARDS) and Cancer-Associated Retinopathy (CAR) and identify shared and distinct molecular pathways. Previously published SARDS and CAR canine retinal microarray data were used for the purposes of retinal transcriptomic pathway analysis, followed by KEGG and GO pathway enrichment analysis using DAVID and MetaCore tools. Gene expression patterns were analyzed to detect the most important signaling pathways. ProteinBERT deep-learning language model, and large language models (LLM-Grok 4, ChatGPT4o) were used for analytical prediction of possible drug targets. Both diseases showed significant upregulation in T-cell co-stimulation and complement activation pathways, including CD86, DLA-79, and C5AR1. Downregulated genes were enriched in pathways associated with visual perception and cardiomyocyte signaling. CAR exhibited upregulation of tumor-related chemokine signaling (e.g., CCR5, CXCR4), while SARDS showed pronounced enrichment in vascular inflammation pathways. Analysis of drug targets identified different classes of drugs, which could be potentially utilized for SARDS and CAR treatment. SARDS and CAR share immune-related molecular signatures but potentially differ in secondary mechanisms—vascular inflammation and endothelial activation in SARDS versus paraneoplastic mimicry in CAR. These data provide potential insight into the pathogenesis of SARDS as well as CAR, and identify potential diagnostic and therapeutic targets. Full article

Research based on the similarities between canine and human mammary tumors should extend beyond clinical, pathophysiological, epidemiological, and histopathological characteristics to include applicable molecular markers with prognostic significance. However, despite shared similarities, important differences must also be considered in comparative and translational studies. The nuclear erythroid 2-related factor (NRF2), a nuclear transcription factor that regulates the expression of antioxidant proteins, is pathologically activated during carcinogenesis. The role of NRF2 in human breast cancer is well established, making it a potential prognostic marker. Objectives: This study aimed to evaluate NRF2 tissue expression in mammary neoplasms of female dogs and its association with tumor progression, other prognostic factors, and survival. Methods: A group of 57 female dogs was studied. Tissue samples of mammary glands from 10 healthy dogs and 47 dogs with mammary neoplasms (39 malignant tumors and 8 benign tumors) were examined for NRF2 immunoexpression. Clinicopathological data and immunohistochemical expression, assessed by histochemical score (H-score), were correlated. Results: NRF2 tissue expression showed a predominantly cytoplasmic distribution and a lower H-score in tumors with higher malignancy grading. Dogs with higher NRF2 H-scores had improved survival rates (p = 0.0036). Univariate analysis revealed significant associations between H-scores < 135 and behavior (p = 0.007), tumor size (p = 0.001), and Ki-67 index (p = 0.018). Conclusions: These results suggest that NRF2 also holds prognostic value in the evaluation of canine mammary tumors. Full article

Canine mammary cancers (CMCs) are one of the most prevalent types of neoplasm in dogs, are frequently malignant, and display high tumour heterogeneity, making evaluating prognosis and predicting successful treatment outcomes difficult. In a previous pilot study, overexpression of the Wnt pathway-associated protein SFRP1 was found to correlate with negative metastasis status in CMCs at both mRNA and protein levels. To establish SFRP1 as a potential biomarker for CMC progression, additional verification of these results in an independent dataset is required, as well as an investigation as to whether SFRP1 expression in CMCs is associated with altered Wnt- or RANKL signalling pathways. In an independent verification cohort of 122 cases of archival CMC FFPE material, expression of SFRP1 was assessed by RT-qPCR and immunohistochemistry. The same tumours were further assessed for RANKL, phosphoROCK2, and NFkB-p65 protein expression. Our data verified that SFRP1 mRNA (p = 0.025) was negatively associated with metastasis status; however, differences in protein expression did not reach statistical significance (p = 0.139). Neither did SFRP1 significantly correlate with expression of any of the other proteins tested. Instead, a strong association was found for RANKL positivity with increased metastasis status (p < 0.001). Co-expression of SFRP1 significantly lowered the higher risk of metastatic spread when compared to RANKL_pos/SFRP1_neg CMCs (p = 0.033). Noticeably, all vascular-invasive cell clusters observed in tissue section vessels stained positive for RANKL. Our study identified RANKL expression as a strong marker for cancer progression with a strong link to vascular-invasive cells. However, SFRP1 expression may potentially suppress the pro-metastatic nature of RANKL_pos CMCs. Full article

Increasing evidence suggests that intratumoral microorganisms and their metabolites can modulate cancer initiation and progression. However, the composition and functional role of intratumoral bacteria in canine mammary tumors (CMTs) remain unclear. In this study, we investigated the functional significance of tumor-derived Staphylococcus in CMTs, focusing on its effects on the proliferation and migration of CMT-U27 cells. 16S rRNA sequencing revealed reduced alpha diversity in CMT tissues, with Staphylococcus pseudintermedius identified as the most frequently isolated species. Functional assays, including CCK-8, wound healing, RT-qPCR, and Western blot analyses, demonstrated that intratumoral Staphylococcus pseudintermedius significantly enhanced cellular proliferation and migration. Mechanistically, Staphylococcus pseudintermedius significantly upregulated the expression of TLR2, as well as the phosphorylation levels of PI3K, Akt and P70S6K. The inhibition of TLR2 using C29 suppressed the mRNA expression of VEGF, MMP9, MMP2, and EGFR. Collectively, these findings indicate that intratumoral Staphylococcus pseudintermedius promotes the proliferation and migration of CMT-U27 cells through activation of the TLR2/PI3K/Akt pathway, highlighting a functional link between tumor-associated bacteria and cancer progression. Full article

Cancer is a major health concern, with its incidence rate continuing to increase. There is growing interest in the microbiota and its role in carcinogenesis, as it significantly influences physiological and pathological processes. Various aspects of the microbiome have been shown to have both anti-tumor and pro-tumor effects. Advances in techniques such as high-throughput DNA sequencing have greatly improved our understanding of microbial populations in the human and canine gut. We aimed to (1) characterize the intestinal microbiota of healthy dogs and dogs with cutaneous mast cell tumors (MCTs), (2) assess changes in the intestinal microbiota of dogs undergoing electrochemotherapy (ECT) combined with gene electrotransfer (GET) of the IL-12 plasmid (IL-12), and (3) explore possible associations with the expression of immune markers Programmed cell death protein 1 (PD-1), Programmed death-ligand 1 (PD-L1), and Granzyme B (GZMB) in MCT tissue. Stool samples were collected from healthy dogs (n = 24) and dogs with MCTs (n = 24) before and after ECT and IL-12 GET. DNA was extracted from the samples, and shallow shotgun sequencing was performed. Immunohistochemistry was performed on the tumors to assess the expression of PD-1, PD-L1, and GZMB. The dysbiosis index, alpha diversity, and beta diversity did not differ between groups. Regarding microbial composition, Bifidobacterium animalis, Corynebacterium variabile, Lactobacillus johnsonii, Pediococcus pentosaceus, Streptococcus anginosus, Streptococcus equinus, Streptococcus intermedius, Clostridium thermobutyricum, Megasphaera elsdenii, and Anaerobiospirillum sp. were found in lower relative abundance in feces of dogs with MCTs, while Bacteroides togonis, Lactobacillus amylolyticus, Prevotella sp. CAG:279, and Megamonas hypermegale were more abundant compared to healthy dogs. Our study provides further insight into the composition of the gut microbiota in dogs with MCTs, where ECT and IL-12 GET did not lead to major shifts. We were unable to establish any association between the expression of immune markers and the microbiota. Full article

Canine prostatic adenocarcinoma is a rare but highly aggressive cancer that is typically diagnosed at an advanced stage, due to the lack of effective screening methods and poor recognition of early lesions. Cancer stem cells are known to drive tumour progression and treatment resistance in human prostate cancer, but their role in naturally occurring canine disease remains poorly defined. A deeper understanding of the biology of canine prostatic adenocarcinoma is therefore essential to improve prognosis and to develop relevant comparative models. We established and comprehensively characterised two novel canine prostatic adenocarcinoma cell lines, Kodiak and Bobby, with detailed comparison to their tumours of origin and, for Kodiak, xenografts generated in immunodeficient mice. Both lines displayed variable epithelial morphology influenced by culture conditions, and Kodiak xenografts recapitulated key histopathological patterns of the primary tumour. Expression of the luminal epithelial marker CK8/18 and the basal marker CK14 was largely retained across tumour, cell line, and xenograft, whereas the basal markers CK5 and p63, and the urothelial marker UPIII, were diminished or lost during in vitro culture. Evaluation of cancer stem cell-associated markers showed consistent expression of CD44, Nanog, Oct3/4, and Sox2 in the original tumours and cell lines, while CD133, Nestin, and Trop2 were present in the tumours but absent in vitro, indicating selective loss of specific stem-like populations. Media-dependent plasticity was evident in the Bobby line. These models retain key epithelial and stemness features and provide robust platforms for translational prostate cancer research in dogs and humans. Full article