Abstract 46: High-plex spatial transcriptomic characterization of canine tumor tissue

Abstract

Abstract Background: Combination therapy to treat hematological and solid malignancies including chemotherapy, radiation, targeted and immunotherapy all hold huge potential for eliciting clinical responses. Informative pre-clinical testing of these approaches can be greatly facilitated using immune competent animals with spontaneous tumors. Pet dogs are immunologically outbred, immune competent and develop spontaneous tumors such as non Hodgkin’s lymphoma, glioblastoma, osteosarcoma, urothelial carcinoma and melanoma that share remarkable clinical, biological and genetic features with their human counterparts. As such, pre clinical testing of therapeutic approaches in dogs with cancer promises to accurately inform human clinical trial design. For this comparative approach to provide maximum information to accelerate human clinical translation of novel combination therapies and identify correlative biomarkers of therapeutic response, it is necessary to develop research tools for deep interrogation of the canine tumor microenvironment (TME). Here we present spatial transcriptomic analysis of multiple canine tumor and tissue types using GeoMx® digital spatial profiler (DSP) Canine Cancer Atlas (CCA) panel. Methods: FFPE slides or tissue microarrays were used to profile tumor and normal tissue from canines. Each slide was stained with tissue specific immunofluorescent antibodies, including Pan-cytokeratin, CD45, Vimentin, IBA1, CD3, and/or CD68. Regions of interest were selected to assess the TME and normal tissue as possible. Slides were then run on the DSP using the CCA panel that contains 1900-canine specific genes using standard DSP methods. Results: We were able to spatially detect over 1700 genes across multiple tissue types from canines, including osteosarcoma, glioblastoma, melanoma and normal tissues. Genes were detected in spatial compartments including malignant tumor, tumor stroma and normal tissue. Conclusions: Together the GeoMx CCA allow for interrogation of the TME of multiple tumor types and has the potential to inform spatial biomarkers for response to therapy, as well as translate the effectiveness of these therapies to humans. Citation Format: Sarah E. Church, Cheryl London, Christine M. Toedebusch, Ben Sutton, Sarah Weigel, Erin Piazza. High-plex spatial transcriptomic characterization of canine tumor tissue [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 46.