BRD4 inhibition potentiates VS-5584-induced RCC cell death and apoptosis. The 786-O xenograft tumor-bearing nude mice were administrated with vehicle control or VS-5584 (20 mg/kg, oral administration, daily), at treatment Day-2 and Day-4, 4 h after the VS-5584 or vehicle administration, two tumors (“Set-1/Set-2”) of each group were isolated, expression of BRD4 and Tubulin in tumor lysates was shown (A). 786-O cells (B) and primary human RCC cells (“RCC1”, E) were treated VS-5584 (or plus BRD4 inhibitors, B) for 24 h, listed proteins in total cell lysates were tested by Western blotting. 786-O cells (C, D), RCC1 primary cancer cells (F, G) or HK-2 cells (H, I) were pretreated with JQ1 (500 nM) or CPI203 (500 nM) for 30 min, followed by VS-5584 (2/5 μM) treatment for 48/72 h, cell survival and apoptosis were tested by MTT (C, F, H) and ssDNA ELISA (D, G, I), respectively. The listed proteins were quantified (B, E). Data were presented as mean ± standard deviation (SD, n=5). *p< 0.05 vs. “C” group. #p< 0.05.