Flowchart: Preparation: NFKB


Text Box: I3C

Text Box: Her2

Text Box: Tnfr


Text Box: ErbB2


Text Box:  Egfr

Colorectal cancer                            

Breast cancer

Ovarian Tumor

Text Box: NFKBLung cancer

Prostate Tumor

Text Box: Atm





Text Box: P38

Text Box: IRF






Breast Cancer Res Treat. 2007 Jul 26; [Epub ahead of print]Click here to read Links

Indole-3-carbinol-induced modulation of NF-kappaB signalling is breast cancer cell-specific and does not correlate with cell death.

Moiseeva EP, Heukers R.

Departments of Biochemistry and Cancer Studies, Cancer Biomarkers and Prevention Group, Biocentre, University of Leicester, Leicester, LE1 7RH, UK, em9@le.ac.uk.

Indole-3-carbinol (I3C), a dietary chemopreventive compound, induces cell death in human breast cancer cells by modulating activities of Src and epidermal growth factor receptor (EGFR). The effect of I3C on NF-kappaB, constitutively activated in breast cancer cells, was investigated. Nuclear extracts of MDA-MB-468, MDA-MB-231 and HBL100 cells contained all of the Rel proteins with similar expression patterns in the latter two. The level of NF-kappaB-regulated reporter gene expression was in the order HBL100 << MDA-MB-468 << MDA-MB-231. Upstream inhibition, using PI3K, EGFR or IKKbeta inhibitors, resulted in cell-specific effects on expression of the NF-kappaB-regulated reporter gene and endogenous genes Bcl-xL, IkappaBalpha and IL-6, as well as on cell viability. The expression patterns of Rel and several NF-kappaB-regulated genes and the response to LY249002 in MDA-MB-468 cells contrasted with those in other cells. I3C induced NF-kappaB-regulated reporter gene expression at 12 h in MDA-MB-468 cells. Conversely, it was reduced at 24 h in HBL100 cells. I3C treatment for 6 h alone or in combination with TNFalpha induced NF-kappaB-regulated reporter gene expression, detected 5 h later, in MDA-MB-468, but not HBL100 cells. I3C induced NF-kappaB p65/p50 DNA binding at 6.5 h, preceded by association of IKKbeta with the Src/EGFR complex and increased phospho-IkappaBalpha in MDA-MB468 cells. TNFalpha increased I3C-induced apoptosis in MDA-MB-468 and MDA-MB-231 cells. It also induced apoptosis, enhanced by I3C, in HBL100 cells. Hence, regulation of constitutive NF-kappaB was cell-specific. I3C influenced the NF-kappaB pathway in a cell-specific manner, which was not related to apoptosis. However, the combination of I3C and TNFalpha increased apoptosis in all cell lines.

PMID: 17653853 [PubMed - as supplied by publisher]Mol Cancer Ther. 2007 Jul;6(7):1973-82.Click here to read Links

Nuclear factor-kappaB activation: a molecular therapeutic target for estrogen receptor-negative and epidermal growth factor receptor family receptor-positive human breast cancer.

Singh S, Shi Q, Bailey ST, Palczewski MJ, Pardee AB, Iglehart JD, Biswas DK.

Department of Cancer Biology, Dana-Farber Cancer Institute, Smith Room 1058, 44 Binney Street, Boston, MA 02115, USA.

Nuclear factor-kappaB (NF-kappaB), a transcription factor with pleotropic effects, is a downstream mediator of growth signaling in estrogen receptor (ER)-negative and erbB family particularly erbB2 (HER-2/neu) receptor-positive cancer. We previously reported activation of NF-kappaB in ER-negative breast cancer cells and breast tumor specimens, but the consequence of inhibiting NF-kappaB activation in this subclass of breast cancer has not been shown. In this study, we investigated the role of NF-kappaB activation by studying the tumorigenic potential of cells expressing genetically manipulated, inducible, dominant-negative inhibitory kappaB kinase (IKK) beta in xenograft tumor model. Conditional inhibition of NF-kappaB activation by the inducible expression of dominant-negative IKKbeta simultaneously blocked cell proliferation, reinstated apoptosis, and dramatically blocked xenograft tumor formation. Secondly, the humanized anti-erbB2 antibody trastuzumab (Herceptin) and the specific IKK inhibitor NF-kappaB essential modifier-binding domain peptide both blocked NF-kappaB activation and cell proliferation and reinstated apoptosis in two ER-negative and erbB2-positive human breast cancer cell lines that are used as representative model systems. Combinations of these two target-specific inhibitors synergistically blocked cell proliferation at concentrations that were singly ineffective. Inhibition of NF-kappaB activation with two other low molecular weight compounds, PS1145 and PS341, which inhibited IKK activity and proteasome-mediated phosphorylated inhibitory kappaB protein degradation, respectively, blocked erbB2-mediated cell growth and reversed antiapoptotic machinery. These results implicate NF-kappaB activation in the tumorigenesis and progression of ER-negative breast cancer. It is postulated that this transcription factor and its activation cascade offer therapeutic targets for erbB2-positive and ER-negative breast cancer.

Functional Diversity of Flavonoids in the Inhibition of the Proinflammatory NF-{kappa}B, IRF, and Akt Signaling Pathways in Murine Intestinal Epithelial Cells.

Ruiz PA, Haller D.

Else Kroener-Fresenius-Centre for Experimental Nutritional Medicine, Technical University of Munich, Am Forum 5, 85350 Freising-Weihenstephan, Germany.

The molecular understanding of nutritional factors in the process of host factor-mediated activation of the intestinal epithelium may play an important role in the assessment of adjunct nutritional therapy for chronic intestinal inflammation. We characterized the molecular mechanisms of flavonoids including apigenin, luteolin, genistein, 3'-hydroxy-flavone, and flavone in inhibiting tumor necrosis factor-alpha (TNF)-induced interferon-induced protein (IP)-10 gene expression in the murine intestinal epithelial cell (IEC) line Mode-K. We demonstrated that 3'-hydroxy-flavone but not the chemical core structure flavone blocked TNF-alpha-induced nuclear factor (NF)-kappaB transcriptional activity and IP-10 expression at the level of NF-kappaB/IkappaBalpha phosphorylation/degradation by inhibiting IkappaB kinase activity. Although 3'-hydroxy-flavone effectively triggered p38 mitogen-activated protein kinase signaling and late caspase-3 cleavage, the induction of apoptotic cell death in TNF-activated IEC was not the primary mechanism inhibiting NF-kappaB transcriptional activity and IP-10 expression. In addition to the compound-specific inhibition of TNF-induced NF-kappaB DNA binding and NF-kappaB transcriptional activity, apigenin and luteolin selectively blocked Akt phosphorylation/activity. The ability of these polyphenolic compounds to target various signal transduction pathways was further supported by the observation that luteolin and 3'-hydroxy-flavone selectively induced interferon regulatory factor (IRF)-1 degradation. Finally, we showed that genistein blocked IP-10 but not IL-6 expression through NF-kappaB, IRF, and Akt independent mechanisms, demonstrating the functional diversity of flavonoids in inhibiting proinflammatory processes in IEC. In conclusion, we provide molecular evidence for the presence of characteristic inhibition patterns of these polyphenolic compounds to inhibit proinflammatory gene expression in IEC through the specific modulation of the NF-kappaB, IRF and Akt signaling pathways.

PMID: 16484540 [PubMed - in process]




Halofuginone induces matrix metalloproteinases in rat hepatic stellate cells via activation of p38 and NFKB.

Popov Y, Patsenker E, Bauer M, Niedobitek E, Schulze-Krebs A, Schuppan D.

Division of Gastroenterology and Hepatology, Harvard Medical School, Boston, MA 02115.

The semisynthetic plant alkaloid Halofuginone (HAL) was reported to prevent and partly reverse experimental liver fibrosis. However, its mechanisms of action are poorly understood. We therefore aimed to determine the antifibrotic potential of HAL and to characterize involved signal transduction pathways in hepatic stellate cells (HSC). Results were compared to its in vivo effects in a rat model of reversal of established liver fibrosis induced by thioacetamide. In vitro HAL inhibited HSC proliferation and migration dose-dependently at submicromolar concentrations. 200nM of HAL up-regulated matrix metalloproteinase (MMP)-3 and MMP-13 expression between 10-50-fold, resulting in a 2-3-fold increase of interstitial collagenase activity. Procollagen alpha1(I) and MMP-2 transcript levels were suppressed 2-3 fold, while expression of other profibrogenic mRNAs remained unaffected. p38 mitogen-activated protein kinase (p38 MAPK) and nuclear factor kappa B (NFkB) pathways were activated by HAL, and specific inhibitors of p38 MAPK and NFkB dose-dependently inhibited MMP-13 induction. Treatment with HAL did not affect HSC viability and observed effects were reversible after its removal. In vivo HAL up-regulated MMP-3 and -13 mRNA expression 1.5- and 2-fold, respectively, in cirrhotic rats, while tissue inhibitor of metalloproteinase-1 (TIMP-1) was suppressed by 50%. In conclusion, submicromolar concentrations of HAL inhibit HSC proliferation and migration, and upregulate their expression of fibrolytic MMP-3 and -13 via activation of p38 MAPK and NFkB. The remarkable induction of MMP-3 and -13 make HAL a promising agent for antifibrotic combination therapies.