Canine oral melanoma (COM) is an aggressive oral tumor with poor prognosis. MicroRNAs (miRNAs) have emerged as potential diagnostic and therapeutic targets, but the role of individual miRNAs remains underexplored. This study investigated miR-708 expression and function in KMeC and LMeC COM cell lines. MiR-708 expression was significantly higher in both cell lines than in controls. Inhibition of miR-708 using a mirVANA inhibitor did not affect cell morphology or proliferation but significantly enhanced migration in both cell lines (P < 0.01). Invasion showed a non-significant increase. These results suggest that miR-708 is upregulated in COM and may regulate cell motility. Further studies are needed to clarify its functions and potential as a diagnostic or therapeutic biomarker.
Canine prostate cancer (cPC) is a highly invasive and metastatic malignancy in male dogs, often associated with a poor prognosis despite conventional treatments such as surgery, radiotherapy, and chemotherapy. Notably, the BRAF V595E mutation, orthologous to the human BRAF V600E mutation, is present in 61-80 % of cPC cases and may contribute to tumor progression via activation of the MAPK pathway. While BRAF/MEK dual inhibition has shown clinical efficacy in various human cancers with BRAF mutations, its utility in cPC remains unexplored. In this study, we established a novel cPC cell line (EPC) derived from a canine patient with BRAF V595E-mutant cPC. EPC demonstrated strong proliferative activity in vitro and tumorigenicity in immunodeficient nude mice. Molecular analysis confirmed the presence of the BRAF V595E mutation. In vitro, EPC exhibited resistance to the BRAF inhibitor dabrafenib, characterized by reactivation of pERK, but this resistance was overcome by the MEK inhibitor trametinib or by combination therapy. The IC50 values for dabrafenib and trametinib in the combination treatment were approximately 28.1 nM and 2.81 nM, respectively, comparable to clinically achievable concentrations. EPC is the first BRAF V595E-mutant cPC cell line to demonstrate resistance to BRAF inhibition and sensitivity to MEK inhibition. These findings highlight EPC as a valuable model for studying MAPK pathway-mediated drug resistance and support the potential of dabrafenib/trametinib combination therapy as a novel treatment strategy for cPC.
This study evaluated the incidence of acute eyelid and/or corneal complications (AC) in 172 eyes of 86 dogs with head tumors treated by 3D-conformal radiation therapy (3D-CRT). AC occurred in 24 eyes (13.9%), presenting as blepharoconjunctivitis, non-ulcerative keratitis, ulcerative keratitis, or corneal perforation. Median shortest distance from the ocular center to the tumor margin (DOCT), ocular cumulative exposure dose (OCED), and ocular radiation exposure rate (ORER) in AC cases (12.8 mm, 24.5 Gy, 72.5%) were significantly higher or shorter than in non-AC cases (26.4 mm, 12.6 Gy, 35.0%) (P < 0.01). All AC occurred during or within 21 days after 3D-CRT. Receiver operating characteristic curve analysis identified cut-off values for AC prediction: DOCT 17.6 mm, OCED 17.5 Gy, and ORER 55.0%. These parameters may aid in AC risk assessment in canine head tumor radiotherapy.
Infectious bursal disease (IBD), caused by infectious bursal disease virus (IBDV), remains a major threat to poultry production due to its immunosuppressive effects and economic losses. Rapid and reliable detection of IBDV is essential for disease surveillance and outbreak management, particularly in field and resource-limited laboratory settings. In this study, an isothermal reverse transcription-thermophilic helicase-dependent amplification (RT-tHDA) assay targeting a conserved region of VP1 gene of IBDV was developed and evaluated, amplifying a 99-bp fragment at 65 degrees C within 90 min without the need for a thermocycler. Analytical sensitivity testing using ten-fold serial dilutions of viral RNA demonstrated a detection limit of 440 fg, representing a 100-fold improvement over conventional RT-PCR and sensitivity comparable to real-time RT-PCR. The assay showed high analytical specificity, with no cross-reactivity against other avian viral or bacterial pathogens. Diagnostic evaluation of 180 suspected field bursal samples showed IBDV detection rates of 35.0% by RT-tHDA, 35.6-36.1% by RT-PCR (VP1/VP2), 31.7% by virus isolation, and 45.0% by real-time RT-PCR. Comparing with World Organization for Animal Health (WOAH) reference methods, RT-tHDA demonstrated excellent performance, with 100% sensitivity to virus isolation, >= 96.9% sensitivity to RT-PCR, high specificity (>= 95%), and almost perfect agreement (kappa > 0.93). Although real-time RT-PCR detected more positive samples due to its ability to identify very low viral loads, RT-tHDA consistently detected all clinically relevant infections confirmed by reference methods. Overall, RT-tHDA offers high sensitivity, specificity, and strong agreement with WOAH methods, supporting its use as a rapid screening tool for IBDV in field and resource-limited laboratories.
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease characterized by excessive collagen deposition and irreversible scarring. Reliable animal models are essential for elucidating IPF pathogenesis and evaluating antifibrotic therapies. However, conventional bleomycin (BLM) models generally induce only transient and moderate fibrosis. Considering the profibrotic role of eosinophils, we developed a novel IPF model using the spontaneous eosinophilic mutant Yama mice strain to achieve persistent and severe fibrosis. Male Yama and C57BL/6 mice (6 weeks old, n = 24) received eight intranasal administrations of BLM (2 mg/kg) at two-week intervals, while controls received saline. Peripheral eosinophil counts were monitored, and tissues were analyzed histologically and biochemically. Yama mice exhibited a sharp eosinophil peak after the first BLM exposure, followed by a gradual decline. Histological analysis revealed markedly enhanced fibrosis, greater collagen deposition, and higher Ashcroft scores in Yama mice than in C57BL/6 mice. Alcian blue-PAS-positive fibroblast foci, a characteristic feature of human IPF, were abundant in Yama mice. Immunohistochemistry demonstrated increased expression of eosinophil cationic protein (ECP). Moreover, mRNA expression of Th2 cytokines (IL-4, IL-5, IL-13) and profibrotic mediators (IL-6, Col1a1) was significantly higher in Yama mice. However, the pronounced fibrotic changes, TGF-beta expression exhibited only a modest increase in Yama mice, suggesting that fibrosis might develop via pathways not totally dependent on conventional TGF-beta signaling. This repeated BLM administration model successfully reproduces the key pathological features of severe IPF and emphasizes the pivotal contribution of eosinophils to fibrogenesis.
