Inhibition of programmed death 1 (PD-1), expressed on activated T cells, can break through immune resistance and elicit durable responses in human melanoma as well as other types of cancers. Canine ...oral malignant melanoma is one of the most aggressive tumors bearing poor prognosis due to its high metastatic potency. However, there are few effective treatments for the advanced stages of melanoma in veterinary medicine. Only one previous study indicated the potential of the immune checkpoint inhibitor, anti-canine PD-L1 therapeutic antibody in dogs, and no anti-canine PD-1 therapeutic antibodies are currently available. Here, we developed two therapeutic antibodies, rat-dog chimeric and caninized anti-canine PD-1 monoclonal antibodies and evaluated in vitro functionality for these antibodies. Moreover, we conducted a pilot study to determine their safety profiles and clinical efficacy in spontaneously occurring canine cancers. In conclusion, the anti-canine PD-1 monoclonal antibody was relatively safe and effective in dogs with advanced oral malignant melanoma and other cancers. Thus, our study suggests that PD-1 blockade may be an attractive treatment option in canine cancers.
Lymphoma is the most common hematological cancer in dogs. Canine diffuse large B cell lymphoma shows a relatively good response to treatment with multi-agent cyclophosphamide, doxorubicin, ...vincristine, and prednisone (CHOP) chemotherapy; however, the 2-year survival rate is as low as 20%. For human B cell type lymphoma, the anti-CD20 chimeric antibody, rituximab, was developed two decades ago. The combination of rituximab and CHOP chemotherapy was highly successful in improving patient prognosis. However, no anti-canine CD20 antibody is available for the treatment of canine lymphoma. During this study, a rat anti-canine CD20 monoclonal antibody was established. We also generated a rat-canine chimeric antibody against canine CD20 designed for clinical application. This chimeric antibody (4E1-7-B) showed in vitro antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against the canine B cell lymphoma cell line CLBL-1. Moreover, to obtain stronger ADCC activity, a defucosylated 4E1-7-B antibody (4E1-7-B_f) was also generated, and it showed tenfold stronger ADCC activity compared with 4E1-7-B. 4E1-7-B_f as well as 4E1-7-B suppressed the growth of CLBL-1 tumors in an immunodeficient xenotransplant mouse model. Finally, a single administration of 4E1-7-B_f induced considerable peripheral B cell depletion in healthy beagles. Thus, 4E1-7-B_f is a good antibody drug candidate for canine B cell type lymphoma.
Recent research has focused on immunotherapy, particularly with regard to cancer treatment. Programmed death-1 and programmed death ligand 1 (PD-1/PD-L1) pathway blockade is a central topic of the ...promising immunotherapy field. In veterinary medicine, observations of the PD-1/PD-L1 pathway, including the relationship between immune cells and diseases, have increased. In this study, monoclonal antibodies specific to canine PD-1 and PD-L1 were developed, and the antibodies against PD-1 and PD-L1 bind to PD-1 and PD-L1 overexpressing cells, respectively. Additionally, each antibody interfered with the interaction between PD-1 and PD-L1. The expression of PD-1 and PD-L1 was detected on activated T cells from canine peripheral blood mononuclear cells (PBMC), and, remarkably, was the first recorded instance of PD-L1 expression on canine immature dendritic cells. Production of IFN-γ by activated T cells increased significantly when incubated with anti-PD-1 antibody alone and with both anti-PD-1 and anti-PD-L1 antibodies, revealing the functional effects of the antibodies. The antibodies will be useful for research on immune systems and may be the first passive immunotherapy approach in canine cancer patients.
Atlanto-axial instability is a common disease that affects toy-breed dogs. Most cases of atlanto-axial instability are congenital. Furthermore, patients with atlanto-axial instability are predisposed ...to other concurrent diseases. Therefore, this study aimed to retrospectively determine the presence of concurrent diseases in cases with atlanto-axial instability using imaging data and analyze the relationship between clinical parameters and the incidence of complex malformations. The clinical data and imaging findings of 41 toy-breed dogs diagnosed with atlanto-axial instability were analyzed using their medical records and imaging data. Occipital dysplasia (17/27), atlanto-occipital overlapping (22/34), dens dysplasia (27/41), Chiari-like malformation (8/34), syringomyelia (5/34), lateral ventricular enlargement (20/36), and intracranial arachnoid cyst (5/35) were observed in patients with atlanto-axial instability. The body weight of the patients in the groups with atlanto-occipital overlapping and lateral ventricular enlargement was lower than that of those in the groups without these diseases (1.78 ± 0.71 vs 2.71 ± 1.15 kg, P = 0.0269, 1.60 ± 0.40 vs 2.75 ± 1.08 kg, P = 0.001, respectively). Furthermore, when the correlation between the total number of concurrent diseases and the age at onset and body weight was examined, it became clear that lower body weight was associated with the incidence of a greater number of concurrent diseases. Thus, the findings of this study suggest that toy-breed dogs are more likely to present with complex malformations and should be evaluated carefully with additional examinations and treatment methods.
The patellar tendon (PT) is crucial for maintaining stability and facilitating movement in the stifle joint. Elastography has been recognized as a prominent method for evaluating PT properties in ...humans and dogs. The utilization of oscillation methods in canine studies remains limited despite their extensive documentation in human studies. Our study represents the first effort to quantitatively assess and compare the effects of muscle relaxant on the biomechanical and viscoelastic characteristics of the PT at varying stifle angles in living dogs. Five healthy female beagles were used in this study. Biomechanical (tone, stiffness, and decrement) and viscoelastic (relaxation time and creep) properties of the PT were measured using MyotonPRO (Myoton Ltd, Estonia) prior to and following administration of rocuronium (0.5 mg/kg/body weight) at normal, extended, and flexed positions. Rocuronium was selected for its safety, controllability, and widespread clinical use in veterinary anesthesia. Two-way analysis of variance showed that tone, stiffness, and decrement were significantly higher (P < 0.001) in the control group than in the muscle relaxation group. At the same time, relaxation time and creep were significantly lower (P < 0.001) in the control group than in the muscle relaxation group. The findings indicate that stifle angle position and muscle rexalant administration fundamentally alter the biomechanical loading conditions of the PT, leading to changes in its viscoelastic properties. Therefore, this novel quantitative data could benefit clinical settings that necessitate accurate and objective methods for risk identification and monitoring PT biomechanics in dogs.
Dog spontaneously develop prostate cancer (PC) like humans. Because most dogs with PC have a poor prognosis, they could be used as a translational model for advanced PC in humans. Stem cell‐derived ...3‐D organoid culture could recapitulate organ structures and physiology. Using patient tissues, a human PC organoid culture system was established. Recent study has shown that urine cells also possess the characteristic of stem cells. However, urine cell‐derived PC organoids have never been produced. Therefore, we generated PC organoids using the dog urine samples. Urine organoids were successfully generated from each dog with PC. Each organoid showed cystic structures and resembled the epithelial structures of original tissues. Expression of an epithelial cell marker, E‐cadherin, and a myofibloblast marker, α‐SMA, was observed in the urine organoids. The organoids also expressed a basal cell marker, CK5, and a luminal cell marker, CK8. CD49f‐sorted basal cell organoids rapidly grew compared with CD24‐sorted luminal cell organoids. The population of CD44‐positive cells was the highest in both organoids and the original urine cells. Tumors were successfully formed with the injection of the organoids into immunodeficient mice. Treatment with a microtubule inhibitor, docetaxel, but not a cyclooxygenase inhibitor, piroxicam, and an mTOR inhibitor, rapamycin, decreased the cell viability of organoids. Treatment with a Hedgehog signal inhibitor, GANT61, increased the radiosensitivity in the organoids. These findings revealed that PC organoids using urine might become a useful tool for investigating the mechanisms of the pathogenesis and treatment of PC in dogs.
In the present study, we for the first time generated the dog prostate cancer organoids using the urine samples. Our results suggest urine sample‐derived organoid culture system contributes to the treatment of not only dog prostate cancer but also human advanced prostate cancer.
We investigated the prognostic nutritional index (PNI), comprised of lymphocytes and albumin, as a potential prognosticator of metastatic urothelial carcinoma (mUC) patients receiving pembrolizumab.
...Sixty-five patients were retrospectively enrolled and classified as low (<40) and high (≥40) based on pretreatment PNI. Progression-free survival (PFS), overall survival (OS) and response rates were evaluated.
In the low PNI group, significantly shorter PFS and OS were observed. PNI was shown to be an independent predictor of PFS and OS in the multivariate analysis. C-index for both PFS and OS improved with the addition of PNI to the model described in the KEYNOTE-045 study. Significantly more patients experienced initial disease progression in the low PNI group.
PNI is a useful predictor of prognosis and disease progression in mUC patients receiving pembrolizumab.
Canine hemangiosarcoma (HSA) is a commonly occurring aggressive tumor stemming from the vascular endothelial cells and is considered to be a good model for a similar disease in humans, called ...angiosarcoma. In this study, we reviewed drug libraries to identify new signal transduction inhibitors that can suppress the cell growth of canine HSA in vitro. We observed that tenovin-6, a sirtuin (SIRT) inhibitor, inhibited cell proliferation and induced cell death in three canine HSA cell lines (JuB4, Re12, and Ud6). These effects were induced through G1 cell cycle arrest and caspase-3 activation. Although tenovin-6 is known as an inhibitor of SIRT1 and SIRT2, knockout (KO) of genes encoding SIRT1 and/or SIRT2 had no apparent impact on cell proliferation in canine HSA. In addition, tenovin-6 showed cell growth inhibition in SIRT KO cells, as well as parental cells. These results indicated the cytotoxicity of tenovin-6 was a SIRT-independent event. Instead, we found that tenovin-6 inhibited autophagy flux in canine HSA cells, as evidenced by the suppression of lysosomal proteolysis. These results suggested that tenovin-6 induces cell growth suppression in canine HSA cells by impairing the lysosomal function. Therefore, tenovin-6 could be used in a new therapeutic strategy to treat canine HSA.
•By the drug screening, we found that tenovin-6 inhibited the proliferation of canine hemangiosarcoma cell lines.•Tenovin-6 inhibited tumor cell growth with caspase-3 activation and G1 cell cycle arrest, but SIRT-independent pathway.•Tenovin-6 inhibits the autophagy flux by suppressing the lysosomal activity.
Understanding the biotransformation mechanisms of toxic sulfur-containing polycyclic aromatic hydrocarbon (PASH) pollutants such as benzothiophene (BT) is useful for predicting their environmental ...fates. In the natural environment, nondesulfurizing hydrocarbon-degrading bacteria are major active contributors to PASH biodegradation at petroleum-contaminated sites; however, BT biotransformation pathways by this group of bacteria are less explored when compared to desulfurizing organisms. When a model nondesulfurizing polycyclic aromatic hydrocarbon-degrading soil bacterium,
Sphingobium barthaii
KK22, was investigated for its ability to cometabolically biotransform BT by quantitative and qualitative methods, BT was depleted from culture media but was biotransformed into mostly high molar mass (HMM) hetero and homodimeric
ortho
-substituted diaryl disulfides (diaryl disulfanes). HMM diaryl disulfides have not been reported as biotransformation products of BT. Chemical structures were proposed for the diaryl disulfides by comprehensive mass spectrometry analyses of the chromatographically separated products and were supported by the identification of transient upstream BT biotransformation products, which included benzenethiols. Thiophenic acid products were also identified, and pathways that described BT biotransformation and novel HMM diaryl disulfide formation were constructed. This work shows that nondesulfurizing hydrocarbon-degrading organisms produce HMM diaryl disulfides from low molar mass polyaromatic sulfur heterocycles, and this may be taken into consideration when predicting the environmental fates of BT pollutants.
Objective We aimed to examine the effects of isometric handgrip (IHG) training on home blood pressure (BP) levels in hypertensive Japanese patients undergoing treatment. Methods Fifty-three ...hypertensive patients (mean age, 61.7 years; 56.6% men) with a home systolic BP ≥135 mmHg and/or a home diastolic BP ≥85 mmHg were randomly assigned to either group A or B. As per the crossover design, group A performed 8 weeks of IHG training, followed by an equivalent training-free, control period, while the reverse protocol was performed by group B. The baseline characteristics were similar between both groups. The individualized daily IHG training comprised four sets of 2-min isometric contractions at 30% of the individual's maximum voluntary contraction capacity, including 1 min of rest between sets, for ≥3 days/week. The outcome measure was morning and evening home BP readings taken over the last 2 weeks of the training and control periods. Results A combined data analysis for both groups showed that IHG training was significantly associated with the lowering of both systolic and diastolic BP in the morning (137.9±9.3 vs. 135.3±9.5 mmHg, p=0.007 and 83.0±9.5 vs. 81.2±9.3 mmHg, p<0.001, respectively) and evening (130.0±10.7 vs. 127.6±10.1 mmHg, p=0.003 and 75.8±10.4 vs. 73.8±9.2 mmHg, p<0.001, respectively), while no significant change was observed after the control period. A larger increase in the maximum grip strength due to IHG training was associated with greater BP reductions. Conclusion An 8-week period of IHG training significantly lowered both the morning and evening home BP in hypertensive Japanese patients undergoing treatment.
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