Inhibitor of ATX-LPA signaling enhances the TSA-induced cell apoptosis. A, The SW480 cells were pretreated with BrP-LPA (10 μM) for 1 hr, and then treated with TSA (250 nM) in the presence of LPC (100 μM) or LPA (5 μM). The apoptosis of SW480 cells were measured after TSA treatment for 24 hrs. B and C, MDA-MB-435 (B) and colo320 cells (C) were treated with TSA (250 nM) with or without the pre-treatment of BrP-LPA (10 μM) in the presence of indicated lipids in serum-free conditional medium. The cell apoptosis was measured after TSA treatment for 24 hrs. The p value derived from Student's t test is (**) p < 0.001.