Characterization of D-17 Canine Osteosarcoma Cell Line and Evaluation of Its Ability to Response to Infective Stressor Used as Alternative Anticancer Therapy

SIMPLE SUMMARY: Osteosarcoma (OSA) is the most common primary bone tumor both in dogs and in humans. Canine and human OSA share common characteristics making dogs a good model in comparative oncology. In the last years, in order to reduce animal testing, researchers shifted their attention to in vitro studies using cell lines. Aim of this work is to understand if cells obtained from canine metastatic pulmonary OSA can be a good model for cancer studies, both in humans and dogs. Results of this study were obtained by: the characterization of the expression of genes involved in the innate immune response, the sequencing of a single gene with a key role in immune response and the evaluation of the capacity of these cells to interact with microorganisms that can be used as alternative anticancer therapies. Obtained data were in agreement with those reported in literature regarding the expression of genes both in spontaneous tumors and in vitro cell lines. So, they confirmed the maintenance of cell line D-17 of the pulmonary metastatic OSA characteristics. The selected cells also demonstrated the ability to interact with the microorganism, this suggests that they may be a possible model for the preliminary evaluation of new therapeutic approaches based on the use of bacteria. ABSTRACT: Osteosarcoma (OSA) is a rare cancer both in human and dog although the incidence rate in dogs is 27 times higher than in human. Many studies employed D-17 as cell line for in vitro test to evaluate conventional anticancer therapies; however, little is known about D-17 cell line. The aim of our study was to evaluate the basal level of gene expression of pivotal molecules in the innate immune response and cell cycle regulation and to establish the ability of this cell line to react to Salmonella typhimurium (ST) infective stressor. IL15, IL10, iNOS, TLR5, CD14, PTEN and IL18 were expressed in an inconsistent manner among experiments. The other genes under study were expressed in all samples. ST showed ability to penetrate D-17 causing pro-inflammatory response. Our results outline the expression in D-17 of important genes involved in innate immune response. These results provide important data on D-17 basal gene expression profile useful for in vitro preliminary evaluation of new therapeutic approaches.