Original ArticleBAY61-3606 potentiates the anti-tumor effects of TRAIL against colon cancer through up-regulating DR4 and down-regulating NF-κB

- BAY61-3606 sensitized TRAIL-induced apoptosis, especially in KRAS mutant cell lines.
- It is discovery firstly that BAY61-3606 had ability of up-regulation p53 expression.
- BAY61-3606 improved expression of DR4 through a p53-dependent way.
- BAY61-3606 inhibited NF-κB activity and down-regulated the expression of Bcl-2 and Bcl-xL.
- Combination treatment significantly suppressed tumor growth in xenograft model.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is well known for its ability to preferentially induce apoptosis in malignant cells without causing damage to most normal cells. However, inherent and acquired resistance of tumor to TRAIL-induced apoptosis limits its therapeutic applicability. Here we show that the orally available tyrosine kinase inhibitor, BAY61-3606, enhances the sensitivity of human colon cancer cells, especially those harboring active mutations in Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) gene, to TRAIL-induced apoptosis in vitro and in vivo. The sensitization was achieved by up-regulating death receptor 4 (DR4) and the tumor suppressor p53. BAY61-3606-induced the up-regulation of DR4 is p53-dependent. Knockout of p53 decreased BAY61-3606-induced DR4 expression and inhibited the effect of BAY61-3606 on TRAIL-induced apoptosis. In addition, BAY61-3606 suppressed activity of NF-κB and regulated its gene products, which might also contribute to TRAIL-induced apoptosis. In conclusion, our results showed that BAY61-3606 sensitizes colon cancer cells to TRAIL-induced apoptosis via up-regulating DR4 expression in p53-dependent manner and inhibiting NF-κB activity, suggesting that the combination of TRAIL and BAY61-3606 may be a promising therapeutic approach in the treatment of colon cancer.