Epidemiology and classification for canine and feline mammary gland tumors: a histopathological survey of 437 mammary gland tumor biopsies performed in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019

Background

Metastatic disease resulting from mammary gland tumors (MGTs) is a known cause of death among dogs and cats. Keys to successful prevention and management strategies involve the accurate recording of diagnostic data.

Methods

This retrospective study reviewed the epidemiology and classification of canine mammary gland tumors (CMTs) and feline mammary gland tumors (FMTs), as well as the factors including sex, age, and breed related to the occurrence of these tumors. Accordingly, 1,736 tumor biopsy cases were reported from 2012 to 2019 at Chiang Mai University Small Animal Hospital, Thailand, with 1,639 canine tumor biopsy cases and 97 feline tumor biopsy cases.

Results

The proportion of CMTs was reported at 24.5% (401/1,639) for all canine tumor biopsy cases. Benign and malignant tumors were reported at 14.5% (58/401) and 85.5% (343/401) for all CMT cases, respectively. The mean age of dogs affected by benign CMTs was 9.0 ± 3.0 years, which was significantly lower than for malignant CMTs at 9.9 ± 2.8 years (P = 0.0239). According to histopathological classification, benign mixed tumors and simple carcinoma types were highest among benign and malignant CMT cases, respectively. Moreover, female dogs were at significantly higher risk of developing mammary gland tumors (OR = 45.8, 95% CI [3.9-86.0], P < 0.0001) than male dogs, as well as older dogs (>8 years) (OR = 1.7, 95% CI [1.2-2.2], P = 0.0001) compared to young ones (≤8 years). The proportion of FMTs was 37.1% (36/97) for all feline tumor biopsy cases. Benign and malignant tumors for all FMTs were reported at 16.7% (6/36) and 83.3% (30/36), respectively. According to histopathological classifications, adenoma and simple carcinoma were present in the highest proportion among benign and malignant FMTs, respectively. Female cats were at a significantly higher risk of developing mammary gland tumors than male cats (OR = 25.7, 95% CI [3.9-272.8], P < 0.0001).

Conclusions and clinical importance

There was a high proportion of MGT cases compared with other tumor cases reported in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019, and malignant tumor biopsies have been more frequently observed than benign tumor biopsies in both CMT and FMT cases. The resulting data originating from this study can be an aid for veterinary oncologists in better educating clients and planning treatment and prevention strategies and it can be used as a basis for further experimental studies in the oncology section.

Evaluation of an in-house indirect enzyme-linked immunosorbent assay of feline panleukopenia VP2 subunit antigen in comparison to hemagglutination inhibition assay to monitor tiger antibody levels by Bayesian approach

Background

Feline panleukopenia virus (FPV) is an etiologic pathogen of feline panleukopenia that infects all members of Felidae including tigers (Panthera tigris). Vaccinations against FPV among wild felid species have long been practiced in zoos worldwide. However, few studies have assessed the tiger immune response post-vaccination due to the absence of a serological diagnostic tool. To address these limitations, this study aimed to develop an in-house indirect enzyme-linked immunosorbent assay (ELISA) for the monitoring of tiger antibody levels against the feline panleukopenia vaccine by employing the synthesized subunit capsid protein VP2. An in-house horseradish peroxidase (HRP) conjugated rabbit anti-tiger immunoglobulin G (IgG) polyclonal antibody (HRP-anti-tiger IgG) was produced in this study and employed in the assay. It was then compared to a commercial HRP-conjugated goat anti-cat IgG (HRP-anti-cat IgG). Sensitivity and specificity were evaluated using the Bayesian model with preferential conditional dependence between HRP-conjugated antibody-based ELISAs and hemagglutination-inhibition (HI) tests.

Results

The posterior estimates for sensitivity and specificity of two indirect ELISA HRP-conjugated antibodies were higher than those of the HI test. The sensitivity and specificity of the indirect ELISA for HRP-anti-tiger IgG and HRP-anti-cat IgG were 86.5, 57.2 and 86.7%, 64.6%, respectively, while the results of the HI test were 79.1 and 54.1%. In applications, 89.6% (198/221) and 89.1% (197/221) of the tiger serum samples were determined to be seropositive by indirect ELISA testing against HRP-anti-tiger and HRP-anti-cat, respectively.

Conclusion

To the best of our knowledge, the specific serology assays for the detection of the tiger IgG antibody have not yet been established. The HRP-anti-tiger IgG has been produced for the purpose of developing the specific immunoassays for tigers. Remarkably, an in-house indirect ELISA based on VP2 subunit antigen has been successfully developed in this study, providing a potentially valuable serological tool for the effective detection of tiger antibodies.

Identification of potential canine mammary tumour cell biomarkers using proteomic approach: Differences in protein profiles among tumour and normal mammary epithelial cells by two-dimensional electrophoresis-based mass spectrometry

Canine mammary tumours (CMTs) are regarded as invasive with a high rate of recurrent and metastasis in intact female dogs. Tumour diagnosis, therefore, is an important step in predicting and monitoring tumour progression. This study was designed to identify protein expression on CMTs by employing a proteomic approach. The primary cell culture from benign mixed tumour, simple carcinoma, complex carcinoma and normal mammary gland were established, and two-dimensional electrophoresis (2DE) was subsequently performed. The different spots on each sample type were collected for identification using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results indicated that cytokeratin 5 (CK5) and transketolase (TKT) were identified in benign mixed tumour cells and complex carcinoma cells. In contrast, cytokeratin 18 (CK18) and pyruvate kinase PKM were identified in simple carcinoma cells. Moreover, alpha-2-HS-glycoprotein tumour antigen was identified specifically in complex carcinoma cells. In addition, ATP-dependent 6-phosphofructokinase platelet type and elongation factor 2 proteins were observed in benign cells. In conclusion, all expressed proteins in this study have been recognized for acting as their expression that differs from healthy mammary epithelial cells. Expectantly, this study identified the expressed proteins that might be useful in further diagnostic biomarker studies on CMTs.

First report of canine cutaneous myiasis caused by Chrysomya bezziana Villeneuve (Diptera: Calliphoridae) in Thailand

Although myiasis caused by the blow fly, Chrysomya bezziana Villeneuve (Diptera: Calliphoridae), has been reported in Thailand, all of the cases were human. This study described three cutaneous myiasis cases caused by C. bezziana in dogs in Chiang Mai province, northern Thailand. The removal of fly larvae together with specific treatment to cure all cases in this study was represented.

The protective effect of radicicol against renal ischemia--reperfusion injury in mice

Overexpression of heat shock protein 70 kDa (HSP70) is known to confer cellular protection against ischemia-reperfusion (I/R) injury. Radicicol, a HSP90 inhibitor, has been reported to induce the expression of HSP70 protein. Here we studied whether radicicol attenuated renal I/R injury in vivo. Treatment of mice with radicicol ameliorated renal I/R injury and increased renal HSP70 mRNA and protein. Administration of radicicol with quercetin, an inhibitor of HSP70 induction, eliminated the renoprotective effect of radicicol. Our results suggest that the up-regulation of renal HSP70 protein by radicicol leads to a novel drug therapy against renal I/R injury.

The protective effect of a newly developed molecular chaperone-inducer against mouse ischemic acute kidney injury

Activation of the unfolded protein response (UPR) has been suggested to attenuate renal ischemia-reperfusion (I/R) injury. We recently found a compound, namely BIX, that activated the UPR selectively through the activating transcription factor 6 pathway. This study examined the effect of BIX on renal I/R injury in mice. BIX selectively up-regulated renal BiP mRNA and protein. Pretreatment with BIX significantly ameliorated renal I/R injury. Co-administration of BIX and tunicamycin, a non-selective UPR inducer, provided no additional protection. Our results suggest that the UPR activation by BIX leads to a novel drug therapy against renal I/R injury.

A protective role of unfolded protein response in mouse ischemic acute kidney injury

Although renal ischemia-reperfusion is known to activate the unfolded protein response, the renal site and role of activation of this response following the insult in vivo remains largely unknown. Here we studied the renal spatio-temporal expression pattern of glucose-regulated protein (GRP) 78, a central regulator of the unfolded protein response network, following renal ischemia-reperfusion and the effects of the specific chemical unfolded protein response inducers, tunicamycin and thapsigargin, on renal ischemia-reperfusion injury in mice. Renal ischemia-reperfusion resulted in expression of the spliced form of the X-box binding protein-1 (XBP-1s) transcript, an unfolded protein response target, at 1 and 2 h after the insult. This response was followed by an increase in the GRP78 transcript and protein. The increased amount of GRP78 protein after ischemia-reperfusion was largely localized in proximal tubule cells. Pretreatment with tunicamycin or thapsigargin significantly ameliorated renal dysfunction and injury after ischemia-reperfusion. Taken together with these results, the unfolded protein response was activated following renal ischemia-reperfusion at sites that are susceptible to ischemia-reperfusion injury, and this activation had a protective effect against renal ischemia-reperfusion injury in vivo. Molecules involved in the unfolded protein response may offer new opportunities for pharmacological intervention against renal ischemia-reperfusion injury, which is an important cause of acute kidney injury.

Ischemic acute tubular necrosis models and drug discovery: a focus on cellular inflammation

Acute renal failure (ARF) is a common cause of mortality and morbidity in hospitalized patients. Ischemia is an important cause of ARF, and ARF caused by ischemic injury is referred to as ischemic acute tubular necrosis (ATN). There is growing evidence from models that ischemic ATN is associated with intrarenal inflammation. Consequently, intrarenal inflammation is an attractive target for the development of novel drug therapies for ARF. This review outlines ischemic ATN models, the pathophysiological roles of inflammatory cells such as T and B cells in ischemic ATN models, and effective T and B cell therapeutic reagents.