Global gene expression of canine bladder K9TCC cells and cancer stem cells after COX-2 inhibition

Cancer stem cells (CSCs) are fundamental to bladder cancer progression and the cyclooxygenase-2 (COX-2) pathway has a pro-tumorigenic role in CSC function. Naturally occurring bladder cancer in dogs has the potential to be a natural model of the human disease. Here, we used canine specific microarrays to determine changes in global gene expression of canine bladder cancer cells (the K9TCC cell line) and bladder cancer stem cells isolated from the K9TCC cell line after treatment with the selective COX-2 inhibitor mavacoxib or a COX-2 siRNA. K9TCC cells were grown as aherent cells or in anchorage dependent conditions to form cancer stem cell spheres for at least 5 passages to maintain self-renwal properties. Both adherent cells (Adh) and cancer stem cell spheres (Sphs) were treated with either 0 or 50uM mavacoxib (0uM treatment was DMSO, the vehicle control for the drug) for 24 hours, or transfected with a COX-2 siRNA or negative control siRNA for 48 hours. Cells were harvested and RNA extracted for microarray analysis on the Affymetrix Canine Gene 1.1 ST microarray (by Edinburgh Genomics). 3 replicates of each condition and cell type were assessed.