Veterinary and comparative oncology最新文献

Mitotic count (MC) is a well-established prognostic factor in many canine malignancies. While standardisation efforts have improved inter-pathologist agreement regarding the morphology of mitotic figures and the size of the counting area, the selection of the tumour region for MC assessment remains to be standardised. This study aimed to evaluate the spatial distribution of the most proliferative areas in selected canine tumour types, using Ki67 immunohistochemistry, to identify optimal candidate regions for MC assessment. Tumour types analysed included melanomas, cutaneous mast cell tumours (cMCT), canine mammary carcinomas (CMC) and soft tissue sarcomas (STS). Using image analysis, Ki67 density maps were generated from digital slides and classified according to their distribution pattern (focal/multifocal or diffuse) and location within the tumour (central, peripheral or scattered). A total of 202 cases were included: 43 melanomas, 30 cMCTs, 42 CMCs and 87 cSTSs. The vast majority of tumours (92.6%) exhibited a multifocal hotspot distribution. Peripheral hotspot localisation was predominant in 55% of cases, particularly in cMCTs (73.3%) and melanomas (76.7%). In contrast, cSTSs more frequently showed a scattered hotspot pattern (60.9%) (χ² = 41.9; p < 0.001). CMCs had a higher proportion of centrally located hotspots (16.7%). These findings suggest that pathologists should focus on peripheral tumour regions when assessing MC in cMCTs and melanomas. Both central and peripheral regions should be considered in CMCs, while a more extensive, comprehensive evaluation may be required in STSs. The observed association between tumour histotype and proliferation pattern likely reflects inherent biological differences among the tumour types studied.

Human enteropathy-associated T-cell lymphoma (EATL) is a rare primary aggressive intestinal T-cell lymphoma associated with celiac disease and is considered to be a neoplasm of intraepithelial lymphocytes (IELs) with an innate lymphoid cell (ILC)-like immunophenotype. The lack of an animal model has delayed the elucidation of its pathogenesis. In dogs, the histopathological and immunophenotypic features of intestinal large T-cell lymphoma (ILTCL) are similar to EATL; however, its cell of origin remains unclear. We herein performed detailed immunophenotyping, an RNA expression analysis of selected genes, and gene mutation analysis of 54 cases of ILTCL, including 27 with fresh frozen samples available and 21 of intestinal small T-cell lymphoma (ISTCL) in dogs. Canine ILTCL was characterised by the expression of cytotoxic granules (53/54) and frequent absence of CD4/CD8 (26/27) and T-cell receptors (14/27). The mRNA expression of CD103 (25/35) and NKp46 (15/35) was detected in ILTCL by RNA in situ hybridisation. The gene mutation analysis showed mutations in NFKBIA (ILTCL, 31/54; ISTCL, 10/21), including truncating mutations (ILTCL, 11/54; ISTCL, 3/21). Mutations in STAT3 SH2 were less frequent (ILTCL, 13/54; ISTCL, 3/21) and the hotspot JAK1 mutation of human EATL was not detected. Immunohistochemistry for p-Stat3 showed STAT3 pathway activation in ILTCL cases. These results suggest that canine ILTCL is also a neoplasm of IEL with an ILC-like immunophenotype and STAT3 pathway activation, and loss-of-function mutations in NF-κB pathway inhibitors are associated with its neoplastic changes. Therefore, canine ILTCL has potential as a valuable model for investigating the pathogenesis of EATL.

Diffuse large B-cell lymphoma (DLBCL) is one of the most prevalent haematological malignancies in both humans and dogs, characterised in both species by significant clinical heterogeneity and limited prognostic predictability. With the introduction of next-generation sequencing (NGS) technologies in veterinary medicine over the past decade, researchers have begun to elucidate the molecular basis of canine DLBCL (cDLBCL); however, much of the clinical heterogeneity associated with this tumour remains unexplained. In this study, we performed whole genome sequencing on 10 cDLBCL cases, all treated with chemo-immunotherapy, which exhibited similar clinico-pathological features but markedly different outcomes. Cases were classified as "poor" or "good" responders based on whether their lymphoma-specific survival fell below or above the cohort's median. Protein-coding variants and copy number aberrations unique to poor or good responders revealed novel candidate genes not previously identified in cDLBCL studies, while splicing, untranslated regions, and intronic variants were detected in genes already known to be recurrently mutated. In conclusion, our investigation has broadened the spectrum of potentially pathogenic variants implicated in cDLBCL, though further studies with larger cohorts are necessary to validate these findings.

Radioactive iodine therapy (I-131) is widely used in both human and veterinary medicine for treating thyroid cancer, utilising the common biological behaviour of thyroid tissues. Recognising the need to better understand the prognostic factors affecting heterogeneous treatment outcomes, this retrospective study analysed 32 dogs with thyroid carcinoma treated at the University of Missouri Veterinary Health Center. The study examined variables such as patient demographics, tumour characteristics, and first-order radiomic features. Purposeful feature selection was employed to identify both significant and confounding factors, with a focus on treatment response and survival time. Specific administered activity (SAA) emerged as a significant predictor of treatment response, with higher SAA levels improving odds of response (p value = 0.02, OR = 10.28), while clinical signs and nodal stage (N-stage) were identified as significant confounders. Moreover, metastasis stage (M-stage) (p < 0.01, OR = 0.35) and tumour-to-salivary gland dose uptake ratio (TSGR) significantly affected survival time (p = 0.02, OR = 1.57), with TSGR displaying a notable nonlinear effect. These results underline the importance of refined patient stratification and highlight the potential for personalised dose adjustments to enhance outcomes in canine thyroid cancer.

Canine mammary tumours (CMT) are common in female dogs, often associated with malignancy and limited responses to conventional therapies. This study explores the potential of Auranofin (AF) in malignant CMT, focusing on its ability to induce distinct cell deaths. AF inhibited thioredoxin reductase (TrxR) activity, cell proliferation, and colony formation across malignant CMT cell lines, demonstrating significant anticancer effects. In AF-sensitive cell lines (CMT-U27, CHMm, and CHMp), 0.5-2 μM AF induced endoplasmic reticulum (ER) stress-mediated apoptosis, while concentrations above 3 μM caused near-complete cell death via additional proteasome inhibition. However, in AF-resistant cell lines (CIPp and CIPm), AF concentrations required for near-complete cell death were higher, expected to be challenging to achieve clinically. Therefore, we combined sublethal doses of AF (~2 μM) with the proteasome inhibitor Bortezomib (Bz) in these cells. The combination exhibited synergistic cytotoxicity and induced extensive cytoplasmic vacuolation. Live-cell staining revealed the ER origin of vacuoles, and cycloheximide pretreatment inhibited both vacuolation and AF + Bz-induced cell death, indicating features of paraptosis. While apoptosis could not be excluded, it was classified as paraptosis-like cell death occurring concurrently with apoptosis. Further analysis supported that this cell death is related to enhanced ER stress from AF-induced TrxR inhibition and Bz-induced proteasome inhibition. Based on these findings, we propose AF alone or combined with Bz as a promising therapeutic strategy for malignant CMT. Our findings highlight AF's potential to induce ER stress-mediated apoptosis and paraptosis-like cell death in canine cancer cells, expanding therapeutic options for targeting cancers in dogs.

The molecular abnormalities of canine histiocytic sarcoma (CHS) remain to be elucidated. We previously revealed that the sensitivities to dasatinib and trametinib were significantly various among CHS cell lines, indicating the differences in underlying molecular abnormalities. In the present study, we performed RNA sequencing analysis using 11 CHS cell lines to investigate molecular classifications based on the gene expression profiles (GEPs). The clustering analysis showed that CHS cell lines were divided into two distinct clusters. The comparisons of GEPs between the clusters extracted 675 differentially expressed genes (DEGs), and these DEGs were enriched with those related to the regulations of inflammatory responses. Among these DEGs, differences in the expressions of CCL3, CCL4, CCL7, CLEC7A, and TLR4 genes between the two groups were confirmed by RT-qPCR. Since no significant difference in the activation status of Akt and ERK pathways was observed between the two groups, the NF-κB pathway was focused on and its activation status was examined in the cell lines. As a result, cell lines belonging to one cluster showed nuclear translocation of the p65 protein together with increased release of CCL5 protein, which is a target molecule of the NF-κB pathway, in a cell culture supernatant. These results suggested that the molecular pathology of CHS cells might be divided into two categories depending on the activation status of the NF-κB pathway, and it is necessary to establish precision medicine for each molecular subtype of CHS.

Chemotherapy can have adverse gastrointestinal effects in dogs and people. The objective of this study was to assess the impact of vincristine and prednisolone/prednisone, as part of a CHOP chemotherapy [cyclophosphamide, hydroxydaunorubicin, oncovin (vincristine) and prednisolone/prednisone] protocol, on gastrointestinal dysbiosis in dogs with lymphoma. We hypothesised the first week of chemotherapy (administration of vincristine and prednisolone/prednisone, VCR/Pred) produces compositional and functional shifts in the canine faecal microbiota that are associated with increased dysbiosis. Faecal samples from canine lymphoma patients (n = 25) were compared for microbiota and metabolites before (pre-chemotherapy) and after the first week of VCR/Pred (post-chemotherapy). A dysbiosis index (DI) was calculated for each dog via quantitative PCR of seven bacterial taxa established for altered ratios in canine gastrointestinal dysbiosis: Faecalibacterium, Turicibacter, Escherichia coli, Streptococcus, Blautia, Fusobacterium and Peptacetobacter hiranonis (formerly Clostridium hiranonis ). There was a significant increase in the DI post-chemotherapy compared to pre-chemotherapy (p = 0.021) concurrent with a significant decrease in faecal P. hiranonis concentrations post-chemotherapy (p = 0.0003). 16S rRNA amplicon sequencing analysis revealed a significant decrease in Enterococcaceae post-chemotherapy (p = 0.013). Targeted faecal lipid profiling identified markers of host and bacterial metabolic dysfunction that were altered following chemotherapy, including significant decreases in arachidonate (p = 0.0015), nervonate (p = 0.027), cholestanol (p = 0.011) and campesterol (p = 0.0035). These findings support that shifts in gut microbiota structure and function may contribute to gastroenteritis in dogs following the first week of VCR/Pred. Gut dysbiosis measures are important for improved treatment options that alleviate gastrointestinal complications associated with chemotherapy in animals and people.

One of the primary objectives of the Oncology Pathology Working Group (OPWG) is for oncologists and pathologists to collaboratively generate consensus documents to standardise aspects of and provide guidelines for oncologic pathology in veterinary species. Consensus is established through critical review of the peer-reviewed literature relevant to a subgroup's particular focus. In this article, the authors provide a critical review of the current literature regarding methods for the diagnosis and classification of primary nodal lymphomas of dogs, including histopathology, cytopathology, immunophenotyping and assessment of molecular clonality. Knowledge gaps in the current literature and recommendations for future study are also reported. Major conclusions of this consensus include: (1) Histopathology with immunohistochemistry is required for complete diagnosis and classification of nodal lymphomas; (2) Immunohistochemistry and flow cytometry are the most reliable methods of immunophenotyping lymphomas, though neither is clearly superior to the other; (3) Molecular clonality testing should not be used in favour of immunophenotyping assays for classifying lymphomas; and (4) The use of emerging molecular tests for diagnosing lymphomas in the absence of histopathologic, cytopathologic, or immunophenotypic disease characterisation should be restricted to investigational settings until their diagnostic validity and the clinical benefit they confer to patients are more thoroughly characterised. This document represents the opinions of the OPWG and the authors; it does not constitute a formal endorsement by the American College of Veterinary Pathologists or the Veterinary Cancer Society.

The purpose of this study was to evaluate the rate and timing of neurological recovery in cats with epidural lymphoma who were treated with chemotherapy. The study included cats with various degrees of neurological impairment, confirmed diagnosis of lymphoma and spinal cord involvement. At the start of treatment, of the 14 cats diagnosed with lymphoma, 14.3% (n = 2) had ambulatory paraparesis, 14.3% (n = 2) had non-ambulatory paraparesis, 7.1% (n = 1) paraplegia with deep nociception, 50% (n = 7) were paraplegic with absent deep nociception and 14.3% (n = 2) had non-ambulatory tetraparesis. The chemotherapy treatment given was COP in 10 cats, COP and CHOP in 2 cats and CHOP in 2 cats. The number of chemotherapy sessions needed for neurological recovery varied from 1 to 4, with a total of 1-13 sessions per cat. The rate of neurological recovery was satisfactory in 83.3% (10/12) of the cats. This study indicates that cats with epidural lymphoma treated with chemotherapy have an 83.3% likelihood of partial neurological recovery and a 50% chance of full neurological recovery within a period of 7-28 days, regardless of the level of neurological impairment.