Osteopontin induces nuclear factor kappa B-mediated promatrix metalloproteinase-2 activation through I kappa B alpha /IKK signaling pathways, and curcumin (diferulolylmethane) down-regulates these pathways.
We have recently reported that osteopontin (OPN) stimulates tumor growth and activation of promatrix metalloproteinase-2 (pro-MMP-2) through nuclear factor kappa B (NF kappa B)-mediated induction of membrane type 1 matrix metalloproteinase (MT1-MMP) in murine melanoma cells (Philip, S., Bulbule, A., and Kundu, G. C. (2001) J. Biol. Chem. 276, 44926-44935). However, the molecular mechanism by which OPN activates NF kappa B and regulates pro-MMP-2 activation in murine melanoma (B16F10) cells is not well defined. We also investigated the mechanism of action of curcumin (diferulolylmethane) on OPN-induced NF kappa B-mediated activation of pro-MMP-2 in B16F10 cells. Here we report that OPN induces phosphorylation and degradation of the inhibitor of nuclear factor kappa B (I kappa B alpha) by inducing the activity of I kappa B kinase (IKK) in these cells. OPN also induces the nuclear accumulation of NF kappa B p65, NF kappa B-DNA binding, and transactivation. However, curcumin a known anti-inflammatory and anticarcinogenic agent suppressed OPN-induced I kappa B alpha phosphorylation and degradation by inhibiting the IKK activity. Moreover, our data revealed that curcumin inhibited the OPN-induced translocation of p65, NF kappa B-DNA binding, and NF kappa B transcriptional activity. The OPN-induced pro-MMP-2 activation and MT1-MMP expression were also drastically reduced by curcumin. Curcumin also inhibited OPN-induced cell proliferation, cell migration, extracellular matrix invasion, and synergistically induced apoptotic morphology with OPN in these cells. Most importantly, curcumin suppressed the OPN-induced tumor growth in nude mice, and the levels of pro-MMP-2 expression and activation in OPN-induced tumor were inhibited by curcumin. To our knowledge, this is the first report that OPN induces NF kappa B activity through phosphorylation and degradation of I kappa B alpha by activating IKK that ultimately triggers the activation of pro-MMP-2 and further demonstrates that curcumin potently suppresses OPN-induced cell migration, tumor growth, and NF kappa B-mediated pro-MMP-2 activation by blocking the IKK/I kappa B alpha signaling pathways.
Philip
Subha
S
National Center for Cell Science, NCCS Complex, Pune-411 007, India.
Kundu
Gopal C
GC
D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002465:Cell Movement; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D003474:Curcumin / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004789:Enzyme Activation; D017930:Genes, Reporter; D020672:I-kappa B Proteins / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D051379:Mice; D008819:Mice, Nude; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000737:chemistry / Q000378:metabolism*; D009368:Neoplasm Transplantation; D053495:Osteopontin; D010766:Phosphorylation; D011485:Protein Binding; D011498:Protein Precursors / Q000737:chemistry* / Q000378:metabolism; D012795:Sialoglycoproteins / Q000502:physiology*; D015398:Signal Transduction; D051996:Transcription Factor RelA; D015533:Transcriptional Activation
D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; D011498:Protein Precursors; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D051996:Transcription Factor RelA; D053495:Osteopontin; D000072000:NF-KappaB Inhibitor alpha; D008156:Luciferases; D020778:Matrix Metalloproteinase 2; D003474:Curcumin