Fisetin, a natural flavonoid, targets chemoresistant human pancreatic cancer AsPC-1 cells through DR3-mediated inhibition of NF-kappaB

Int J Cancer. 2009 Nov 15;125(10):2465-73. doi: 10.1002/ijc.24628.

Abstract

Death receptors of the tumor necrosis factor (TNF) receptor super family have been implicated in constitutive activation of nuclear factor-kappa B (NF-kappaB) in pancreatic cancer (PaC) cells. In this study, we demonstrate that fisetin, a natural flavonoid, induces apoptosis and inhibits invasion of chemoresistant PaC AsPC-1 cells through suppression of DR3-mediated NF-kappaB activation. Fisetin treatment resulted in dose-dependent inhibition of PaC cell growth and cell proliferation with concomitant induction of apoptosis. A cDNA array analysis revealed that fisetin modulates expression of more than 20 genes at transcription level with maximum decrease observed in DR3 expression and a parallel increase observed in the expression levels of IkappaBalpha, an NF-kappaB inhibitor. Down-regulation of DR3 in PaC cells was found to down regulate activated pNF-kappaB/p65, pIkBalpha/beta kinases (pIKK's), MMP9 and XIAP that mostly impart chemoresistance in PaC. Immunoblotting and EMSA analysis showed a marked decrease in pNF-kappaB and NF-kappaB DNA binding activity, respectively, with modest decrease in NF-kappaB promoter activity and significant decrease in MMP9 promoter activity with fisetin treatment. Importantly, consistent with these findings, we further found that transient down-regulation of DR3 by RNA interference significantly augmented fisetin induced changes in cell proliferation, cell invasion and apoptosis paralleled with decrease in pNF-kappaB, pIKKalpha/beta, MMP9, XIAP and NF-kappaB DNA binding activity. Blocking of DR3 receptor with an extra cellular domain blocking antibody demonstrated similar effects. These data provide evidence that fisetin could provide a biological rationale for treatment of pancreatic cancer or as an adjuvant with conventional therapeutic regimens.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Blotting, Western
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Drug Resistance, Neoplasm*
  • Electrophoretic Mobility Shift Assay
  • Flavonoids / pharmacology*
  • Gene Expression Profiling
  • Humans
  • I-kappa B Proteins / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • NF-KappaB Inhibitor alpha
  • NF-kappa B / antagonists & inhibitors*
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Neoplasm Invasiveness
  • Oligonucleotide Array Sequence Analysis
  • Pancreatic Neoplasms / drug therapy*
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Promoter Regions, Genetic
  • RNA, Small Interfering / pharmacology
  • Receptors, Tumor Necrosis Factor, Member 25 / antagonists & inhibitors
  • Receptors, Tumor Necrosis Factor, Member 25 / genetics
  • Receptors, Tumor Necrosis Factor, Member 25 / metabolism*
  • Signal Transduction
  • X-Linked Inhibitor of Apoptosis Protein / metabolism

Substances

  • Flavonoids
  • I-kappa B Proteins
  • NF-kappa B
  • NFKBIA protein, human
  • RNA, Small Interfering
  • Receptors, Tumor Necrosis Factor, Member 25
  • TNFRSF25 protein, human
  • X-Linked Inhibitor of Apoptosis Protein
  • XIAP protein, human
  • NF-KappaB Inhibitor alpha
  • Matrix Metalloproteinase 9
  • fisetin