Macrophage Colony Stimulating Factor (M-CSF) and Interleukin-34 (IL-34) Expression in Canine Osteosarcoma in the Context of the Tumour Immune Microenvironment.

Canine osteosarcoma (OSA) is a malignancy that has been shown to modulate the host immune system. Macrophage colony-stimulating factor (M-CSF; CSF1) and interleukin-34 (IL-34; IL34) are both ligands of colony stimulating factor 1 receptor (CSF-1R), and may play a role in the pathogenesis of a variety of human cancers, including OSA. This study aimed to, (1) assess M-CSF and IL-34 expression in canine OSA cell lines and tissue samples, and (2) determine any correlations between M-CSF and IL-34 expression and immune cell infiltrates within canine OSA tissues.

Effect of stimulator of interferon genes (STING) signaling on radiation-induced chemokine expression in human osteosarcoma cells.

Cancer cell-intrinsic mechanisms affecting radiation immunomodulation could be exploited to optimize systemic effects of localized radiation. Radiation-induced DNA damage is sensed by cyclic GMP-AMP synthase (cGAS), which ultimately activates stimulator of interferon (IFN) genes (STING). Resultant expression of soluble mediators such as CCL5 and CXCL10 can facilitate recruitment of dendritic cells and immune effector cells into the tumor.

The Effect of Arginase on Canine T-Lymphocyte Functions and its Modulation by All-Trans Retinoid Acid (ATRA) in Canine Monocyte-Derived Macrophages.

Immunosuppressive myeloid cells in the tumor microenvironment play a major role in suppressing tumor immunity via the production of arginase, IL-10, and others. The objectives of this study were to determine the ability of all-trans retinoic acid (ATRA) to decrease the expression of arginase and other soluble mediators by canine monocyte-derived macrophages (MDMs) and to determine the inhibitory activity of arginase on canine T-lymphocytes. The immunomodulatory ability of ATRA (2 µM) on canine MDMs was evaluated via reverse transcription quantitative PCR (RT-qPCR), flow cytometry, arginase activity assay, and enzyme-linked immunoassay (ELISA).