Professor of Comparative Medicine University of Georgia Athens, Georgia, United States
Abstract: Canine bladder cancer (BC) is a malignant tumor that affects the urinary tract of dogs. Canine BC is a spontaneous animal disease model of human bladder cancer since it closely mimics human invasive bladder cancer in terms of molecular characteristics, drug response, and histopathologic appearance. The use of spontaneously occurring canine tumors as a model for research in human cancers is facilitated by the fact that canine cells can be cultured in the same way as human cells, and in the form of advanced in vitro models. Such models, in relation to oncological research, are organoids – 3D cultures reflecting the heterogeneity and spatial orientation of tumor cells. Organoids replicate the functions and genetic mutations of their in vivo counterparts, providing an effective platform for testing novel therapeutics. Canine BC organoids can be cultured from either urine or tissue biopsies from tumors, offering the development of a non-invasive in vitro model (urine). However, there is limited research on the similarities between urine-derived organoids, tissue-derived organoids, and tumor tissue biopsies, which reduces the importance of the dog model. Therefore, the aim of this study was to develop canine patient-derived BC organoids and compare their molecular characteristic with corresponding tissue biopsies from the same tumor. Urine-derived organoids and tissue samples of five patients were used to compare bulk RNAseq-derived transcriptomic data. Cancer cells found in urine were used to establish organoid cultures and were preserved in RNALater. RNA extractions used a Qiagen RNeasy kit, samples were sequenced at Genewiz, quality of reads were checked using FastQC, and Kallisto was used for alignment. Transcriptomic analysis revealed variability of RNA expression patterns in different patients, visible in both tissues and organoids. Furthermore, the organoids were characterized with upregulation of proliferation pathways (G2M Checkpoint, MTORC1_Signaling) while inflammatory pathways (IL2 STAT5_Signaling, Allograft_Rejection) were upregulated in tissues. Principal component analysis revealed strong patient-specific clustering in both organoids and tissues, highlighting their potential as a personalized medicine tool that accurately reflects patient heterogeneity in canine bladder cancer.
Funding Source: 5 R21 CA267372-02; NIH ID 10539328
