Molecular mechanism of suppression of MDR1 by puerarin fromPueraria lobata viaNF-κB pathway and cAMP-responsive element transcriptional activity-dependent up-regulation of AMP-activated protein kinase in breast cancer MCF-7/adr cells

Abstract

Multidrug resistance (MDR) is a major obstacle in cancer chemotherapy and its inhibition is an effective way to reverse cancer drug resistance. In the present study, we investigated that puerarin, a natural isoflavonoid from Pueraria lobata, down-regulated MDR1 expression in MCF-7/adriamycin (MCF-7/adr), a human breast MDR cancer cell line. Puerarin treatment significantly inhibited MDR1 expression, MDR1 mRNA and MDR1 promoter activity in MCF-7/adr cells. The suppression of MDR1 was accompanied by partial recovery of intracellular drug accumulation, leading to increased toxicity of adriamycin and fluorescence of rhodamine 123, indicating that puerarin reversed the MDR phenotype by inhibiting the drug efflux function of MDR1. Moreover, nuclear factor kappa-B activity and IkappaB degradation were inhibited by puerarin. Puerarin stimulated AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase and glycogen synthase kinase-3beta phosphorylation, but puerarin decreased cAMP-responsive element-binding protein phosphorylation. The puerarin-induced suppression of MDR1 expression was reduced by AMPK inhibitor (compound C). Furthermore, both MDR1 protein expression and the transcriptional activity of cAMP-responsive element (CRE) were inhibited by puerarin and protein kinase A/CRE inhibitor (H89). Taken together, our results suggested that puerarin down-regulated MDR1 expression via nuclear factor kappa-B and CRE transcriptional activity-dependent up-regulation of AMPK in MCF-7/adr cells.

Key Role of Nuclear Factor-κB in the Cellular Pharmacokinetics of Adriamycin in MCF-7/Adr Cells: The Potential Mechanism for Synergy with 20(S)-Ginsenoside Rh2

“…2). These results were in accordance with previous reports of ABCB1 expression regulation (Katayama et al, 2007;Guo et al, 2008;Hien et al, 2010;Kim et al, 2011). Because the cellular pharmacokinetics of Adriamycin was mainly determined by ABCB1 in MCF-7/Adr cells (Supplemental Fig.…”

“…Many transcriptional factors including NF-B (Bentires-Alj et al, 2003), Y-box binding protein-1 (Shen et al, 2011), activator protein-1 (Bark and Choi, 2010), and hypoxia-inducible factor-1 have been found to bind to the promoter region of the MDR gene to initiate the transcription and expression of ABC transporters. Moreover, several signal transduction pathways have also been demonstrated to be involved in regulating the activities of those transcriptional factors, such as MAPK (Katayama et al, 2007;Manov et al, 2007), phosphatidylinositol 3-kinase (Barancík et al, 2006;Choi et al, 2008), protein kinase C (Liu et al, 2009;Rigor et al, 2010), and NF-B (Hien et al, 2010;Kim et al, 2011) pathways. However, reports of signal molecules regulating the cellular pharmacokinetics of anticancer agents in cells are limited.…”

Molecular Cloning and Functional Characterization of Two Divergent 4-Coumarate : Coenzyme A Ligases from Kudzu (<i>Pueraria lobata</i>)

“…1,2) Its pharmacological effects are due to the presence of isoflavonoids, which include puerarin, daidzin, and other related metabolites. Puerarin exhibits diverse medicinal properties including hypotensive, 3) hypolipidemic, 4) hypoglycemic, 5) anti-oxidant, 6) anti-ischaemia, 7) vasodilation 8) and estrogen-like effects. 9) As an isoflavonoid, the biosynthesis of puerarin should derive from phenylpropanoid metabolism, in which the enzymes in the early steps such as phenylalanine ammonia lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate : coenzyme A ligase (4CL), chalcone synthase (CHS), chalcone reductase (CHR), and chalcone isomerase (CHI) are conserved in many plant species.…”

Dioscin strengthens the efficiency of adriamycin in MCF-7 and MCF-7/ADR cells through autophagy induction: More than just down-regulation of MDR1

“…Puerarin, a natural isoflavonoid from Pueraria lobata, was demonstrated to increase cytotoxicity of ADR in MCF-7/ADR cells34. In our previous study, dioscin reversed MDR in K562/ADR cells12.…”