Utilization of a canine cancer cell line (FACC) panel in comparative and translational studies of gene expression and drug sensitivity

Abstract

Canine cancer is the leading cause of death in adult dogs. The use of the canine cancer model in translational research is growing in popularity due to the many biologic and genetic similarities it shares with human cancers. Cancer cell tissue culture has long been an established tool for expanding our understanding of cancer processes and for development of novel cancer treatments. With the high rate of genomic advancements in cancer research over the last decade human cancer cell line panels that combine pharmacologic and genomic information have proven very helpful in elucidating the complex relationships between gene expression and drug response in cancer. We have assembled a panel of canine cancer cell lines at the Flint Animal Cancer Center (FACC) at Colorado State University to be utilized in a similar fashion as a tool to advance canine cancer research. The purpose of these studies is to describe the characteristics of the FACC panel with the available genomic and drug sensitivity data we have generated, and to show its utility in comparative and translational oncology by focusing specifically on canine melanoma and osteosarcoma. We were able to confirm our panel of cell lines as being of canine origin and determined their genetic fingerprint through PCR and microsatellite analyses, creating a point of reference for validation in future studies and collaborations. Gene expression microarray analysis allowed for further molecular characterization of the panel, showing that similar tumor types tended to cluster together based on general as well as cancer specific gene expression patterns. In vitro studies that measure phenotypic differences in the panel can be coupled with genomic data, resulting in the identification of potential gene targets worthy of further exploration. We also showed that human and canine cancer cells are similarly sensitive to common chemotherapy. Next we utilized the FACC panel in a comparative analysis to determine if signaling pathways important in human melanoma were also activated and sensitive to targeted inhibition in canine melanoma. We were able to show that despite apparent differences in the mechanism of pathway activation, human and canine melanoma tumors and cell lines shared constitutive signaling of the MAPK and PI3K/AKT pathways, and responded similarly to targeted inhibition. These data suggest that studies involving pathway-targeted inhibition in either canine or human melanoma could potentially be directly translatable to each other. Evidence of genetic similarities between human and canine cancers led us to ask whether or not non-pathway focused gene expression models for predicting drug sensitivity could be developed in an interspecies manner. We were able to show that models built on canine datasets using human derived gene signatures successfully predicted response to chemotherapy in canine osteosarcoma patients. When compared to a large historical cohort, dogs that received the treatment our models predicted them to be sensitive to lived significantly longer disease-free. Taken together, these studies show that human and canine cancers share strong molecular similarities that can be used advantageously to develop better treatment strategies in both species.