Advances in diagnosis of splenic tumors in dogs using analysis of miRNA from veterinary biobank samples

Challenges in diagnosing spleen tumors

Splenic masses, which can arise from benign or malignant lesions, are common in dogs and vary dramatically in their clinical behavior. Benign tumors, such as splenic hematomas and nodular hyperplasia, are non-cancerous masses of clotted blood. They can be surgically removed with curative intent. In contrast, malignant lesions, including hemangiosarcoma, a common and aggressive tumor, pose significant challenges. This is due to their poor prognosis and the difficulty in differentiating them from benign tumors both clinically and histologically.

These masses are often discovered incidentally or during emergencies induced by hemoabdomen, leading to urgent surgical intervention. However, severe blood loss complicates surgery risks.

A need for diagnostic point-of-care tests

A diagnostic point-of-care test could greatly assist in identifying the type of mass, thereby influencing treatment decisions between surgery and euthanasia. Early detection of splenic masses through routine blood screening could not only prevent emergencies but also enable timely treatment for malignant cases, potentially improving survival rates. In veterinary medical research, the availability of high-quality samples with detailed information on sample handling and medical history, remains a limiting factor for conducting research projects. To overcome this challenge, samples from the veterinary biobanks of two universities have been combined to provide sufficient sample material for statistically significant analysis.

Using miRNA to differentiate tumor types

This study demonstrated the potential of microRNAs (miRNAs) obtained from tissue and serum samples to effectively distinguish splenic hemangiosarcomas from other splenic tumors and from controls without splenic tumors in dogs.

The researchers developed multiple miRNA models for both serum and tissue samples:

• The model using miR-135a-5p, miR-10a, miR-450b, miR-152-3p, and miR-126-5p from serum to distinguish between controls, benign splenic masses, and hemangiosarcoma achieved an overall accuracy of 0.86.
• For the model distinguishing only between splenic masses (benign splenic masses or hemangiosarcomas) using miR-135a-5p, miR-10a, miR-152-3p, and miR-19a-3p the accuracy was 0.93.
• The tissue model using miR-126-5p, miR-502-3p, and miR-452-5p produced an accuracy of 0.96 in identification benign splenic masses versus hemangiosarcoma, outperforming the corresponding serum model.

Implications for veterinary medicine

The results suggest that measuring the levels of these miRNAs could assist veterinarians in the diagnosis of splenic masses, ultimately aiding in treatment decisions and improving outcomes for affected dogs. Further validation is required, but this study provides a basic profile of miRNA expression in hemangiosarcoma compared to normal dogs and dogs with other splenic masses, thereby evaluating the early diagnostic potential of miRNAs.

Possible contribution to human health research

Veterinary samples are becoming increasingly important because the canine model is recognized as a valuable tool for translational cancer research. Sarcomas in dogs share many similarities with human sarcomas, including tumor genetics, molecular targets, histological appearance, and response to conventional therapies. The role of microRNAs in carcinogenesis, proliferation, invasion, and metastasis is well documented in both human and canine cancers. The homology of miRNAs between dogs and humans emphasizes the significance of domestic dogs as a model organism and provides an opportunity to share research findings.

Overall, the article highlights the promise of miRNAs as diagnostic tools in veterinary oncology for better management of splenic tumors in dogs. Moreover, it highlights the pivotal role of veterinary samples and data for research.

About VetBiobank Vienna

Founded in 2007, the VetBiobank at the University of Veterinary Medicine Vienna is dedicated to preserving residual biospecimens obtained from the university campus and making them available for both local and external researchers from academia and industry. The primary objectives of the VetBiobank are to achieve comprehensive collections of high-quality animal samples and associated medical and pre-analytical data. The collections mainly consist of tumor tissue and healthy reference tissue from cats and dogs, as well as a limited number of biospecimens from other species and diseases, including macaques, horses, pigs, and small companion animals, covering various diseases.

In 2014, VetBiobank joined the BBMRI.at consortium, which prioritizes the sample quality by controlling the pre-analytical sample management process. Since 2015, all tissue samples have been collected in compliance with the CEN pre-analytical standards 16826: 1-2 and 16827: 1-3, which have recently transitioned into ISO standards. The VetBiobank also collects specific samples for research projects, including both tissue samples and body fluids (plasma, serum, urine, feces). Occasionally samples from animal experiments are archived to support the principles of the 3Rs. The operational procedures of the VetBiobank are described in the article DOI: https://doi.org/10.5334/ojb.60.