Veterinary and comparative oncology最新文献

Canine oral melanoma (OM) exhibits poor prognosis and limited treatment options. The success of immune checkpoint inhibitors (ICIs) in human melanoma has driven interest in similar therapeutic approaches in the dog, although the immunosuppressive mechanisms adopted by canine OM remain unclear. This study aimed to evaluate the expression of the immune checkpoints PD-1/PD-L1 and CTLA-4 by RNAscope in situ hybridization (ISH) in canine OM, to investigate their expression pattern and explore their potential role in melanoma progression. Twenty-four formalin-fixed, paraffin-embedded canine OM were included in the study. PD-L1 expression by tumour cells was detected in 100% melanomas (score 1-3), especially at the host-tumour interface. PD-1 and CTLA-4 expression by tumour cells was detected in 13/24 (54%, score 1-2) and 18/24 (75%, score 1) melanomas, respectively. Dual ISH-immunohistochemistry with Melanoma Triple Cocktail, CD3, CD20 and Iba1 demonstrated the expression of tested immune checkpoints in neoplastic and immune cells. Notably, PD-1 and CTLA-4 were predominantly expressed by tumour-infiltrating T lymphocytes, while PD-L1 was primarily expressed by tumour-associated macrophages. PD-1 expression in neoplastic cells was significantly correlated with mitotic count (p < 0.05), while no associations were found between immune checkpoint expression and disease-free interval or overall survival. Whole tumour PD-L1 and PD-1 expression, assessed by image analysis, correlated to PD-L1 scores in neoplastic cells and the grade of tumour-infiltrating lymphocytes, respectively. Collectively, PD-L1, PD-1 and CTLA-4 likely contribute to immunosuppression in canine OM. Further studies are warranted to investigate whether ISH can serve as a biomarker for selecting patients suitable for ICI treatment.

In cancer cells, folate is metabolised in the cytoplasm and mitochondria. Folate metabolism mediates nucleic acid synthesis and, thereby, the growth of cancer cells. One of the enzymes within this folate metabolic pathway, methylenetetrahydrofolate dehydrogenase/cyclohydrolase 2 (MTHFD2), is rarely expressed in normal adult cells but is abundantly expressed in the mitochondria and nuclei of foetal and cancer cells in humans and mice. In this study, we examined the localisation and function of MTHFD2 in canine mammary cancer cells. MTHFD2 was expressed in the nuclei and mitochondria of canine mammary carcinoma cell lines. Short-term inhibition of MTHFD2 with an inhibitor reduced the growth of each cell line. Furthermore, long-term decreased expression, mimicked by the knockdown of MTHFD2 by RNA interference, resulted in epithelial-like cell morphology and reduced migratory ability without inducing apoptosis. Increased expression of the epithelial marker E-cadherin in MTHFD2-knock down cells suggested an enhanced epithelial-like phenotype through the inhibition of MTHFD2. To our knowledge, this is the first study to analyse the function of MTHFD2 in canine mammary carcinomas.

In human medicine, the choice of medical terminology influences patients' choice of management options and associated anxiety levels in relation to their diagnoses. The objective of this study was to determine the association between canine caregiver's treatment choices and anxiety levels when papillary thyroid cancer is described with or without the term cancer. This randomised cross-sectional study surveyed 683 people over 18 years old over 8.5 months. Respondents ranked their treatment preference (total thyroidectomy, active surveillance, medical therapy, or radiation therapy) following a scenario-based diagnosis of papillary thyroid cancer (PTC), thyroid papillary lesion (TPL) or abnormal cells (AC) in their canine pet. Respondents stated their level of anxiety associated with the diagnosis and treatment choice. Of 683 respondents, 622 (91.7%) were female. When presented with a diagnosis of PTC, TPL or AC, 78.1%, 34.2% and 59.3% of participants, respectively, reported being anxious or very anxious about this diagnosis (p < 0.01). Surgery was chosen as a first-choice treatment for PTC, TPL and AC by 71.8%, 39.8% and 53.8% of respondents, respectively, whereas active surveillance was chosen as a first-choice treatment by 24.5%, 57.5% and 43.9% of respondents, respectively. There was a statistically significant difference in first-choice treatment selection (p < 0.01) and anxiety levels related to treatment (p < 0.01) between the three different terms. The terminology used when presenting caregivers with a diagnosis of PTC influences treatment choices and levels of anxiety.

The enzyme poly (ADP-ribose) polymerase-1 (PARP-1) is crucial for cellular regulation and DNA repair. Its immunohistochemical overexpression is known in various human neoplasms, but it was not yet a topic of veterinary research. Formalin-fixed paraffin-embedded canine samples of 15 controls and 34 tumours were immunohistochemically tested for PARP-1 expression. Controls included five skin samples with mast cells, five oral mucosa samples and five thyroid glands. Tumours included 18 mast cell tumours (MCTs), 10 oral squamous cell carcinomas (SCCs) and six follicular thyroid carcinomas. A board-certified veterinary pathologist defined the optimal region for the blind PARP-1 evaluation, assessed by two independent veterinary PhD students. Positive nuclei were evaluated by the immunoreactivity score (IRS) and quick score (QS) and, for both scores, the averages of the two observers were used for statistical analysis. In all MCTs, 6/10 SCCs and all thyroid carcinomas as well as four thyroid controls a nuclear expression was observed. A cytoplasmic granular staining was visible in all dermal mast cells and in 11/18 MCTs due to non-specific antibody uptake. No PARP-1 was expressed in 11/15 controls.Compared to the controls, thyroid carcinomas significantly overexpressed PARP-1 when calculated by IRS and QS (p = 0.003 and p = 0.005, respectively). The latter also applied to the MCTs (p = 0.001). A significantly higher PARP-1 IRS and QS were observed in thyroid carcinomas (p = 0.003, p = 0.005) and MCTs (p = 0.003, p = 0.012) compared to oral SCCs. The immunohistochemical PARP-1 overexpression in these tumours invites further research to assess its potential as a therapeutic target.

Cross-sectional imaging may be used to characterise the location and extent of colorectal mesenchymal tumours (CRMTs). Given the anticipated variation in tumour behaviour and varying morbidity based on surgical margins, a reliable, non-invasive means of predicting malignant potential could facilitate case management. The purpose of this multi-institutional, retrospective study was to determine the diagnostic accuracy of contrast-enhanced CT for distinguishing benign and malignant CRMTs. Twenty-seven dogs with CRMTs were included. Initial diagnoses were reviewed, and slides or blocks were available for 24/27 dogs for further histologic review and immunohistochemical labelling for smooth muscle actin, KIT and vimentin. Two masked radiologists reviewed DICOM images for tumour characteristics, including a final, binary, consensus, subjective interpretation of malignancy. Eighteen tumours (66.7%) were classified as leiomyoma, one (3.7%) as a benign other non-lymphogenic intestinal mesenchymal tumour (benign), one (3.7%) as leiomyosarcoma, and seven (25.9%) as gastrointestinal stromal tumour (malignant). Agreement between radiologists ranged from none to weak for categorical variables, with no agreement (κ = 0.135) for the final assessment of a tumour as benign or malignant. Substantial overlap was noted between groups, with no single categorical variable demonstrating high accuracy as a predictor of malignancy. Consensus final assessment was a sensitive (80.0%) but not specific (29.4%) predictor of malignancy (accuracy: 48.2%). No association was identified between CT determination of malignancy and histologic determination of malignancy (p = 0.678). Non-standardised contrast-enhanced CT was ineffective at distinguishing malignant from benign CRMTs in this study.

Canine multicentric lymphoma is a common malignancy in dogs. It often responds well to initial chemotherapy but frequently relapses and has a poor response to subsequent treatment. B-cell (BCL) and T-cell (TCL) lymphomas differ in both their prognoses and chemotherapeutic treatment protocols. Currently, immunophenotyping can be costly and can only be performed on specific high-quality samples. MicroRNAs (miRNAs) are small molecules present in blood and tissues and are dysregulated in both human and canine lymphoma. We investigated 59 miRNAs by RT-qPCR to establish a serum miRNA profile in dogs with B-cell and T-cell multicentric lymphoma. Multiple miRNA pruned decision tree models were used to classify BCL and TCL cases from each other and controls, and to predict prognosis in BCL cases receiving standard CHOP chemotherapy. Six individual miRNAs were differentially expressed in serum between BCL and controls, and three were differentially expressed between BCL and TCL. A three-miRNA model (miR-155-5p, miR-1 and miR-181b) could differentiate between BCL, TCL and control samples with an accuracy of 83.02%. A three-miRNA model (miR-125b-5p, miR-350 and let-7b-5p) in BCL samples separated the cases into four groups with hazard ratios ranging from 0.44 to 3.5 for overall survival. This study established a serum miRNA profile for both BCL and TCL and demonstrated the utility of multiple serum miRNA models to assist in the diagnosis of lymphoma and BCL prognostication.

Canine transmissible venereal tumour (CTVT) is a common diagnosis in many low-income countries, and managing its chemoresistant cases can be challenging within the conventional vincristine sulfate chemotherapy protocol. Also, predictive markers of chemoresistance for this tumour remain unidentified. This study aimed to evaluate CTVT cytological characteristics to develop a predictive cytological scoring system for vincristine sulfate resistance. For this purpose, 40 cases were retrospectively analysed based on their clinical aspects and response to vincristine chemotherapy. First, cytological preparations underwent a double-blind assessment to evaluate a modified cytomorphological classification. This classification, an adaptation of a previously published system, categorised tumours based on cell shape (plasmacytic versus lymphocytic), but no association with chemoresistance was found (p = 0.083). Subsequently, a novel cytology scoring system was developed and tested to identify cases potentially associated with chemoresistance. This system was based on three criteria: anisokaryosis, mitotic count, and the presence of binucleated cells. Malignancy criteria, evaluated in 5 hotspots, were inversely associated with chemoresistance (p = 0.001), predicted by low anisokaryosis, a mitotic count of ≤ 6 in a 2.37 mm² area, and no binucleated cells. This study introduces a novel cytology scoring system for CTVTs, designed to serve as a predictive tool for vincristine treatment response. This system has the potential to aid practitioners in clinical decision-making. However, further studies are required to validate its reliability and applicability.

Mammary tumours are the most common type of neoplasm in female dogs, with nearly half being malignant. Oncolytic Newcastle disease virus (NDV) therapy has emerged as a novel cancer treatment option; however, its precise oncolytic mechanism in canine mammary tumours (CMT) remain unclear. Ultrastructural analysis of NDV-infected CMT-U27 cells with locally damaged cell membranes and swollen and ruptured mitochondria revealed the occurrence of pyroptosis. Transcriptome sequencing further identified a significant upregulation of pyroptosis-related genes, including NLRP1, NOD2, caspase-1, and GSDMD. Subsequent examination of RNA and protein expression levels of pyroptosis-related molecules in vitro indicated that NDV induces pyroptosis in CMT-U27 cells via the caspase-1/GSDMD pathway. Additionally, inhibition of the TNFα/NF-κB pathway and knockdown of NOD-like receptor pyrin domain-containing protein 3 (NLRP3) using small interfering RNA demonstrated that the TNFα/NF-κB pathway can regulate NDV-induced pyroptosis through the NLRP3 inflammasome. In a xenograft model, intravenous administration of NDV significantly inhibited tumour growth, and prolonged the survival time in nude mice bearing CMT-U27 cells. NDV treatment enhances intratumoural pyrotosis in tumour bearing mice. In conclusion, these findings suggest that NDV induces pyroptosis in CMT-U27 cells through the TNFα/NF-κB/NLRP3 pathway, providing a foundation for future research into NDV's therapeutic potential in canine mammary cancer.

Feline oral squamous cell carcinoma (FOSCC) is the most common oral malignancy in cats. In general, FOSCC develops rapidly and is highly locally invasive. The existing treatments for treating FOSCC are limited. The objective of this single-centre retrospective cohort study was to report the prognosis and surgical complications in cats that underwent total glosso-mandibulectomy (TGM) for feline oral squamous cell carcinoma (FOSCC). We investigated the medical records of 20 cats diagnosed with FOSCC by histopathologic examination and treated with TGM. The locations of FOSCC were in the mandible and tongue in 12 and 8 cats, respectively. All cats underwent percutaneous endoscopic gastrostomy. Postoperative complications of TGM were observed in 18 (90.0%) cats; incisional swelling was noted in 11 cats, including three cats with airway obstruction requiring management by tracheal intubation for several days. Postoperative anaemia was observed in 10 cats; two cats required blood transfusions. No cats died during the postoperative period. Progression-free interval (PFI) and overall survival time (OST) were 914 and 533 days, respectively. The 1- and 2-year survival rates were 50.2% and 37.8%, respectively. On univariate analysis, only histopathologic margin was associated with PFI and OST. TGM was successful in achieving long-term survival for FOSCC. Conversely, lifelong nutritional support via a gastrostomy tube and routine home care, including the removal of secretions from the palate and throat, was needed. There were no perioperative deaths, but serious complications occurred in some cats. The histopathologic margin was an important prognostic factor.