Characterization of a novel curcumin analog P1 as potent inhibitor of the NF-KB signaling pathway with distinct mechanisms

• Published in: 中国药理学报：英文版 no. 7; pp. 939 - 950
• Main Author: Yan-min PENG Jian-bin ZHENG Yu-bo ZHOU Jia LI
• Format: Journal Article
• Language: English
• Published: 2013
• Subjects: HeLa细胞; NF-κB; Western印迹; 信号通路; 姜黄素; 抑制剂; 机制; 模拟
• ISSN: 1671-4083; 1745-7254

Aim： Curcumin has shown promising anticancer activity, which relies on its inhibition on NF-KB pathway. In this study, we characterized the pharmacological profile of a novel curcumin analog P1 and elucidate the related mechanisms. Methods： HEK293/NF-KB cells, stably transfected with an NF-KB-responsive luciferase reporter plasmid, were generated for high- throughput screen （HTS）. Eight cancer cell lines, including PC3, COLO 205, HeLa cells etc. were tested. Cell viability was assessed using the sulforhodamine B （SRB） assays. Cell apoptosis was evaluated using FACS, immunocytochemistry, and Western blotting. H2-DCFDA and MitoSOX Red were used to detect cellular and mitochondrial reactive oxygen species （ROS）. The mitochondrial function was evaluated using mitochondrial oxygen consumption assay. Results： P1, a tropinone curcumin, was found in HTS targeting the NF-KB pathway. Its ICso value in inhibition of TNF-a-induced NF-KB activation was 0.8 pmol/L, whereas its IC5o values in inhibiting the growth of A549 and HeLa cells were 1.24 and 0.69 pmol/L, respec- tively, which was 20- to 30-fold more potent than curcumin. The inhibition of P1 on the NF-KB pathway was further addressed in HeLa cells. The compound up to 10 pmol/L did not affect the binding of NF-KB to DNA, but markedly inhibited NF-KB nuclear translocation, IKB degradation and IKB kinase phosphorylation. The compound （1 and 3 pmol/L） concentration-dependently induced ROS genera- tion, whereas curcumin up to 20 pmol/L had no effect. Pl-induced ROS generation was mainly localized in mitochondria, and reversed by NAC. Moreover, the compound significantly enhanced TNF-a-induced apoptosis. Conclusion： P1 is a novel curcumin analog with potent anticancer activities, which exerts a distinct inhibition on the NF-KB pathway.