PARP and RIP1K cleavage, and Bcl-xL and COX2 downregulation characterize the results of a combination of BEI with CPT or TNFα. A. SW620 cells were treated as shown with single agents or combinations. Immunoblotting results show that dual treatment induces PARP cleavage (an indicator of apoptosis) and a reduction of expression of the NF-kB response gene, Bcl-xL. Target engagements are noticeable by an increase in p53 levels and a decrease in TOPO1 levels. B. The expressions of additional NF-kB pathway target genes, RIP and COX2, were assessed by imunoblotting. Although RIP cleavage was specific for the TNFα-BEI combination, the expression of COX2 was essentially eliminated by BEI alone and by the combination of BEI and CPT or TNFα.