ABT-737 induces cancer cell necrosis and inhibits cell viability and invasion when the RIP1 gene is knocked down in bladder cancer cells. (A) Expression levels of RIP1 in UMUC3 and 5637 cells were analyzed via western blotting after treatment with RIP1 siRNA for 12 h, and the results were (B) semi-quantified. (C) Protein expression levels of HMGB1, ZBP1, RIP3 and MLKL were analyzed in RIP1-KD UMUC3 and RIP1-KD 5637 cells treated with Z-VAD-FMK combined with ABT-737 for 12 h. The results were semi-quantified in (D) UMUC3 and (E) 5637 cells. (F) Transwell invasion assays were performed with RIP1-KD UMUC3 cells. (G) Quantification of Transwell assay results (H) MTT assays were performed to examine the viability of RIP1-KD UMUC3 cells treated with Z-VAD-FMK combined with ABT-737 for 12 h. (I) Transwell invasion assays were performed with RIP1-KD 5637 cells. (J) Quantification of Transwell assay results. (K) MTT assays were performed to examine the viability of RIP1-KD 5637 cells treated with Z-VAD-FMK combined with ABT-737 for 12 h. *P<0.05 vs. control or siRNA NC. OD, optical density; scale bar=50 µm; ZBP1, Z-DNA binding protein 1; RIP, receptor-interacting protein; HMGB1, high mobility group box 1; MLKL, mixed-lineage kinase domain-like protein; siRNA, small interfering RNA; NC, negative control; KD, knockdown.