Development of a Biobank for In Vitro Models in Comparative Oncology

Canine melanoma and lymphoma are spontaneous neoplastic models that share numerous biological and histological similarities with human cancers. Features such as invasiveness, poor prognosis, limited response to chemotherapy, and significant side effects highlight the clinical need to develop new experimental models to better understand the mechanisms underlying tumor initiation and progression. These models are essential for improving existing therapies and developing new translational therapeutic approaches. This study aims to validate collection and pre-processing protocols for samples obtained through lymph node fine needle aspiration (FNA) and tissue biopsies of canine melanoma and lymphoma, which are essential for the establishment of biobanks, as well as for conducting histopathological analyses. Therefore, part of the melanoma tissue samples was formalin-fixed and paraffin-embedded for immunohistochemical (IHC) analyses aimed at the protein characterization of the neoplasm and the evaluation of predictive markers of intrinsic drug resistance, such as PNL-2, SOX-2, GFAP, in untreated dogs. In parallel, the project involves the development of biologically relevant in vitro models through the establishment of primary cell cultures derived from tissue biopsies and FNA samples from both neoplasms. Validation of collection and pre-processing procedures includes enzymatic digestion of the samples, red blood cells lysis treatment, seeding into flasks and monitoring to assess cell culture quality. Protocol validation includes monitoring cell adhesion, morphology, viability, proliferative capacity and immunohistochemical characterization with specific lymphoma and melanocytic markers. The results obtained support the importance of creating biobanks, which are fundamental for the development of complex in vitro models applied to translational studies aimed at improving therapeutic strategies.