Collagen-anchored interleukin-2 and interleukin-12 safely reprogram the tumor microenvironment in canine soft tissue sarcomas

Canine soft tissue sarcomas were analyzed for gene expression changes following intratumoral treatment with collagen-anchored IL-2 and IL-12 therapy. Tumors were surgically resected at different intervals following treatment to assess persistence of any therapy-driven gene expression changes. Ten client-owned dogs with soft tissue sarcomas were recruited to three treatment cohorts to receive intratumoral doses of interleukin-2 and interleukin-12 collagen-binding fusion proteins. The first cohort (n=3) had tumors surgically excised 2 days after treatment; the second cohort (n=3) had tumors excised 8 days after treatment; and the third cohort (n=4) received a second cytokine dose 6 days after the first dose, with tumors excised two days later (day 8 post-first dose). Tumor tissue was formalin-fixed and paraffin-embedded prior to RNA extraction (Qiagen FFPE RNEasy) and QC on Bioanalyzer (Agilent). Gene expression was analyzed through hybridization to the Nanostring Canine IO nCounter panel set probes, with quantification by Nanostring Digital Analyzer. Expression data was analyzed using Nanostring nSolver software.