Establishment and Characterization of FusionRed Stable Transfected Canine Prostate Adenocarcinoma and Transitional Cell Carcinoma Cells.

BACKGROUND/AIM: Cancer cell inoculation is routinely used to evaluate novel therapeutic approaches in vivo. However, without reporter genes enabling deep tissue imaging, study of early tumor progression and therapeutic responses is often limited. We describe the establishment and characterization of two canine cancer cell lines stably expressing red fluorescence proteins as tools for later in vivo imaging. MATERIALS AND METHODS: Two red fluorescence cell lines were generated by plasmid transfection. Fluorescence protein expression was confirmed by flow cytometry and microscopy. Deep tissue imaging was demonstrated in mice using a NightOWL LB 983. Gene expression changes after transfection were analyzed by RNAseq. RESULTS: Both cell lines were detectable in vivo by subcutaneous injection of 1×106 cells. RNAseq revealed up to 2005 transfection-induced differentially expressed genes but no significant changes in cellular key pathways. CONCLUSION: The fluorescent cell lines provide a solid basis for future in vivo studies on canine cancer.

Pan- and Isoform-specific Inhibition of the Bromodomain and Extra-terminal Proteins and Evaluation of Synergistic Potential With Entospletinib in Canine Lymphoma.

BACKGROUND/AIM: Canine B-cell lymphoma represents a useful in vivo model for human diffuse large B-cell lymphoma (DLBCL). Pan-Bromodomain and extra-terminal (BET) inhibition targeting BRD2/3/4 and selective inhibition of BRD4, as well as spleen tyrosine kinase (SYK) inhibition, are currently evaluated as haematologic cancer therapy. Herein, we characterized the differences in the biologic response of isoform-specific or pan-BET inhibition alone or in combination with SYK inhibition. MATERIALS AND METHODS: I-BET151 (pan-inhibitor) and AZD5153 (BRD4 inhibitor) were combined with Entospletinib (SYK inhibitor) and comparatively analysed in the canine DLBCL cell line CLBL-1. Dose- and time-dependent cellular responses were analysed by cell number, metabolic activity, apoptosis/necrosis, and cell morphology. The synergistic potential was evaluated through the Bliss independence model. RESULTS: I-BET151 and AZD5153 showed significant dose- and time-dependent inhibitory effects. Adding Entospletinib to I-BET151 or AZD5153 had no additional synergistic effects. CONCLUSION: Entospletinib did not enhance the inhibitory effects of the pan- or isoform-specific BET.