Catching Canine Cancer: Searching for conserved gene expression in domestic dogs across a pan-cancer dataset

Abstract

Cancer is the leading cause of death in domestic dogs and the second leading cause of death in humans. Early detection is essential for successful treatment, however the most routine tests are specific to particular types of cancer, and multi-cancer detection tests are not yet widely implemented and reliable. Cancer screening via blood biopsy and transcriptome analysis offers a possible new avenue towards pan-cancer detection. Our study seeks to understand whether there are significant correlations between patterns of differential gene expression in the white blood cells of dogs with cancer versus dogs without, and whether these signatures are conserved between dogs with blood cancer and dogs with solid tumors. Using RNA-seq data from 26 dogs with Lymphoma, 21 dogs with Solid Tumors, and 42 Controls we found multiple modules of gene expression significantly correlated with Cancer status. There was also much greater differential gene expression between Cancer and Control samples than within our Cancer groups. The biological patterns most associated with Cancer included porphyrin metabolism, cellular development, and regulation of the adaptive immune system. This study offers new insights into the effects of Cancer on the immune system beyond the tumor microenvironment and provides further evidence for the potential of the transcriptome as a tool for multi-cancer detection.