XB-ART-35104
PLoS One
2006 Dec 27;1:e106. doi: 10.1371/journal.pone.0000106.
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An NF-kappaB and slug regulatory loop active in early vertebrate mesoderm.
Zhang C
,
Carl TF
,
Trudeau ED
,
Simmet T
,
Klymkowsky MW
.
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BACKGROUND: In both Drosophila and the mouse, the zinc finger transcription factor Snail is required for mesoderm formation; its vertebrate paralog Slug (Snai2) appears to be required for neural crest formation in the chick and the clawed frog Xenopus laevis. Both Slug and Snail act to induce epithelial to mesenchymal transition (EMT) and to suppress apoptosis. METHODOLOGY & PRINCIPLE FINDINGS: Morpholino-based loss of function studies indicate that Slug is required for the normal expression of both mesodermal and neural crest markers in X. laevis. Both phenotypes are rescued by injection of RNA encoding the anti-apoptotic protein Bcl-xL; Bcl-xL's effects are dependent upon IkappaB kinase-mediated activation of the bipartite transcription factor NF-kappaB. NF-kappaB, in turn, directly up-regulates levels of Slug and Snail RNAs. Slug indirectly up-regulates levels of RNAs encoding the NF-kappaB subunit proteins RelA, Rel2, and Rel3, and directly down-regulates levels of the pro-apopotic Caspase-9 RNA. CONCLUSIONS/SIGNIFICANCE: These studies reveal a Slug/Snail-NF-kappaB regulatory circuit, analogous to that present in the early Drosophila embryo, active during mesodermal formation in Xenopus. This is a regulatory interaction of significance both in development and in the course of inflammatory and metastatic disease.
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Species referenced: Xenopus laevis
Genes referenced: bcl2l1 casp9 menf.1 nfkb1 nfkb2 odc1 ptk2b rel rela relb snai1 snai2 sox3 sox9 tbxt vegt
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Slug morpholino effects: Panel A is a comparison of the Slug morpholino sequence (âMOâ) with X. laevis SlugA, SlugB, and Snail RNA sequences; start codons are underlined. BâG: Injection of the Slug MO (10 ng/embryo) blocks the expression of Xbra (B-uninjected, C-Slug MO injected), Xmenf (D-uninjected, E-injected), and Antipodean (Apod)(F-uninjected, G-injected). Arrows (C,E,G) point to region of suppression; vegetal pole (âVPâ) is indicated. In G, the red staining is due to a β-galactosidase lineage marker. H: Injection of the Slug MO into one cell of a two cell embryo blocks the expression of Sox9 on the injected side (arrow); â*â marks otic placode domain of Sox9 expression. I: Sox9 expression in Slug MO injected embryos is rescued by co-injection of mycGFP-Slug RNA (650 pg/embryo). In analogous studies, the effects of the Slug MO (10 ng/embryo) on Xbra (J), Apod (K) and Sox9 (L) expression were rescued by injection of Snail RNA (500 pg/embryo). In H, I and L, the line marks midline of the embryo, with anterior (âAnâ) and posterior (âPsâ) indicated. doi:10.1371/journal.pone.0000106.g001 | |
figure 2. Timing of Slug rescue of Slug MO phenotypes: To analyze the timing of Slug activity in the early embryo, we injected one cell of two cell embryos with Slug MO (10 ng/embryo) together with RNA (650 pg/embryo) encoding the chimeric GR-Slug-GFP protein. A: In the absence of the activating drug dexamethasone, the Slug MO phenotype, i.e. suppression of Xbra expression in stage 11 embryos (A)(arrow) and suppression of Sox9 expression in stage 16 embryos (D), was unaltered. When embryos were treated with dexamethasone (20 µM) beginning at stage 8, there as an essentially complete rescue of Xbra (B,C) and Sox9 expression (E,H). Treatment of embryos with dexamethasone at stage 11 (early gastrulation) was also effective at rescuing Sox9 expression (F,H), while addition of dexamethasone at stage 13 (late gastrulation/early neurulation) produced at most a partial and inefficient rescue of Sox9 expression (G,H). | |
Rescue of Slug MO effects by Bcl-xL A: Injection of the Slug MO leads to an increase in TUNEL staining. B: This increase is blocked by the injection of Bcl-xL RNA (600 pg/embryo and co-injected with LacZ RNA). Injected sides of embryos are marked by an â*â and red staining; line marks midline of the embryo, with anterior (âAnâ) and posterior (âPsâ) indicated. Injection of Bcl-xL RNA (600 pg/embryo) rescues Apod (C- Slug MO injected, D-Slug MO+Bcl-xl RNA injected), Xbra (ε- Slug MO injected, F-Slug MO+Bcl-xl RNA injected), and Sox9 expression (G- Slug MO injected, H-Slug MO+Bcl-xL RNA injected). I: Injection of Bcl-xL RNA into one cell of a two-cell embryo led to a dramatic increase in the intensity and extent of Slug expression at stage 16; the region of Slug expression on the uninjected (control) side of the embryo is indicated by the dashed circle. J: Injection of Bcl-xL RNA produced an increase in Slug RNA levels in animal caps prepared at stage 8/9 and analyzed by QRT-PCR when uninjected embryos reached stage 11. Ornithine decarboxylase (ODC) was used as normalization control. RNA levels in the control case were set to 100%. | |
Figure 6. NF-κB regulation of mesodermal and neural markers: The Slug MO induced loss of Xbra (A,B), Apod (C,D) and Sox9 (E,F) expression was rescued by injection of RelA RNA (600 pg/embryo)(A, C, E-Slug MO alone, B, D, F-Slug MO+RelA RNA). G: Treatment of early embryos with AKBA (50 µM from the 4-cell stage on) lead to a decrease in Xbra staining (control and AKBA-treated embryos marked). Injection of RNA encoding IκBsa (H,I) or RelAδSP (JâL) had effects similar to that seen in Slug MO injected embryos; that is, both induced the reduction of Xbra (H,J), Apod (K) and Sox9 (I,L) RNA staining. AKBA treatment had no reproducible effect on Sox9 expression (data not shown). Arrows mark affected regions. | |
Figure 1. Slug morpholino effects:Panel A is a comparison of the Slug morpholino sequence (âMOâ) with X. laevis SlugA, SlugB, and Snail RNA sequences; start codons are underlined. BâG: Injection of the Slug MO (10 ng/embryo) blocks the expression of Xbra (B-uninjected, C-Slug MO injected), Xmenf (D-uninjected, E-injected), and Antipodean (Apod)(F-uninjected, G-injected). Arrows (C,E,G) point to region of suppression; vegetal pole (âVPâ) is indicated. In G, the red staining is due to a β-galactosidase lineage marker. H: Injection of the Slug MO into one cell of a two cell embryo blocks the expression of Sox9 on the injected side (arrow); â*â marks otic placode domain of Sox9 expression. I: Sox9 expression in Slug MO injected embryos is rescued by co-injection of mycGFP-Slug RNA (650 pg/embryo). In analogous studies, the effects of the Slug MO (10 ng/embryo) on Xbra (J), Apod (K) and Sox9 (L) expression were rescued by injection of Snail RNA (500 pg/embryo). In H, I and L, the line marks midline of the embryo, with anterior (âAnâ) and posterior (âPsâ) indicated. | |
Figure 2. Timing of Slug rescue of Slug MO phenotypes:To analyze the timing of Slug activity in the early embryo, we injected one cell of two cell embryos with Slug MO (10 ng/embryo) together with RNA (650 pg/embryo) encoding the chimeric GR-Slug-GFP protein. A: In the absence of the activating drug dexamethasone, the Slug MO phenotype, i.e. suppression of Xbra expression in stage 11 embryos (A)(arrow) and suppression of Sox9 expression in stage 16 embryos (D), was unaltered. When embryos were treated with dexamethasone (20 µM) beginning at stage 8, there as an essentially complete rescue of Xbra (B,C) and Sox9 expression (E,H). Treatment of embryos with dexamethasone at stage 11 (early gastrulation) was also effective at rescuing Sox9 expression (F,H), while addition of dexamethasone at stage 13 (late gastrulation/early neurulation) produced at most a partial and inefficient rescue of Sox9 expression (G,H). | |
Figure 3. Rescue of Slug MO effects by Bcl-xLA: Injection of the Slug MO leads to an increase in TUNEL staining. B: This increase is blocked by the injection of Bcl-xL RNA (600 pg/embryo and co-injected with LacZ RNA). Injected sides of embryos are marked by an â*â and red staining; line marks midline of the embryo, with anterior (âAnâ) and posterior (âPsâ) indicated. Injection of Bcl-xL RNA (600 pg/embryo) rescues Apod (C- Slug MO injected, D-Slug MO+Bcl-xl RNA injected), Xbra (Î- Slug MO injected, F-Slug MO+Bcl-xl RNA injected), and Sox9 expression (G- Slug MO injected, H-Slug MO+Bcl-xL RNA injected). I: Injection of Bcl-xL RNA into one cell of a two-cell embryo led to a dramatic increase in the intensity and extent of Slug expression at stage 16; the region of Slug expression on the uninjected (control) side of the embryo is indicated by the dashed circle. J: Injection of Bcl-xL RNA produced an increase in Slug RNA levels in animal caps prepared at stage 8/9 and analyzed by QRT-PCR when uninjected embryos reached stage 11. Ornithine decarboxylase (ODC) was used as normalization control. RNA levels in the control case were set to 100%. | |
Figure 4. Characterization of Bcl-xL effects on NF-κB activity.A: Fertilized eggs were injected with RNA (650 pg/embryo) encoding Xenopus IκBα-V5. Beginning at stage 8, experimental embryos were treated with 50 µM AKBA and analyzed at stage 11 by SDS-PAGE/immunoblot using an anti-V5 antibody and the antiSOX3c antibody to visualize endogenous Sox3 protein as a loading control. AKBA treatment stabilized the IκBα-V5 polypeptide. B: Fertilized eggs were injected with p3XκB-firefly luciferase (â3κB-Lucâ) and pTK-Renilla luciferase (âRL-TKâ) DNAs (10 pg/embryo each) either alone (âConâ) or together with Bcl-xL (500 pg/embryo) RNA, or Bcl-xL and IκBsa (600 pg/embryo) RNAs. Alternatively, animal caps prepared from Bcl-xL RNA injected embryos were cultured in either control buffer (0.1% DMSO), 20 µM or 50 µM AKBA. At stage 11, caps were analyzed for luciferase activity. Bcl-xL induced an increase in 3XκB-Luc activity that was blocked by either IκBsa or AKBA. Error bars in B reflect standard deviation from the mean of multiple experiments. | |
Figure 5. Bcl-xL regulation of NF-κB RNAs:A: RNA was extracted from eggs and embryos at various stages and analyzed by RT-PCR (28 cycles); levels of RelA, Rel2, Rel3, RelB and Xp100 RNAs drop between stage 7 and 9 and, except for RelB, increase following gastrulation (stage 12/13). Levels of Bcl-xL RNA appear relatively constant throughout this period of development. B: At stage 16, embryos were dissected into anterior dorsal (AD), posterior dorsal (PD), anterior ventral (AV), and posterior ventral (PV) quadrants and RNA was analyzed by RT-PCR; RelB was not expressed at this stage; expression of RelA, Slug and Sox9 are restricted to the anterior dorsal quadrant, while Bcl-xL, Rel2, Rel3, and Xp100 RNAs can be detected throughout the embryo. C, D: Animal caps were prepared from embryos injected with GR-Bcl-xL-GFP RNA (âGRBclxLâ)(600 pg/embryo) and either left untreated (0.1%DMSO)(âConâ), treated with 20 µM dexamethasone (â+Dexâ), treated first with 100 µg/ml emetine and then dexamethasone (â+Dex+Emeâ), or treated with emetine alone (â+Emeâ), and analyzed at stage 11 for Slug, RelA (C), Rel2 and Rel3 (D) RNA levels. Treatment with emetine blocked the increase in Slug and Rel2, but not RelA and Rel3 RNAs; emetine treatment alone produced control or slightly reduced levels of Slug and Rel RNAs. E: Activation of the GR-Bcl-xL-GFP protein in embryos injected with the Slug MO produces an increase in the level of Snail RNA, analyzed at stage 11. F: In animal caps derived from GR-BclxL-GFP RNA injected embryos, AKBA (50 µM) inhibited the dexamethasone-induced increases in Slug, Snail, and RelA RNA levels; while treatment with AKBA alone lead to a decrease in Slug, Snail and RelA RNA levels. G: In animal caps, injection of RelAÎSP RNA (600 pg/embryo) blocked Rel3 and Xp52 RNA induced activation of the 3XκB reporter. H: The ability of Bcl-xL RNA to increase levels of RelA and Slug RNAs in animal caps was blocked by the co-injection of RelAÎSP RNA. Error bars in CâH reflect standard deviation from the mean of multiple experiments. | |
Figure 7. NF-κB's regulatory targets:A: In animal caps, RelA lead to an increase in Slug RNA levels, while RelAÎSP produced a decrease. When activated by dexamethasone (+Dex), the hormone-regulated form of RelA, GR-RelA (600 pg RNA/embryo), induced a similar increase in the levels of Slug RNA, as well as Snail, Sox9 (B), and Bcl-xL (C) RNAs compared to animal caps from GR-RelA injected embryos not exposed to dexamethasone. Similar effects were seen in the presence of emetine (+Dex+Eme,), while emetine alone (+Eme) had little effect on any of measured RNA levels. Error bars in reflect standard deviation from the mean of multiple experiments. | |
Figure 8. Slug's regulatory targets:A: In animal caps analyzed at stage 11, the Slug MO (10 ng/embryo) produced a decrease in RelA RNA levels that was rescued by co-injection of mycGFP-Slug RNA (1 ng/embryo). B: Animal caps were prepared from embryos injected with either untagged or mycGFP-Slug RNAs; both produced a similar increase in Sox9 RNA levels. C: Animal caps, from embryos injected with either mt-GFP or mycGFP-Slug RNAs, were analyzed when control embryos reached stage 11 or stage 16; at stage 11 mycGFP-Slug induced an increase in Sox9 RNA levels, which returned to baseline by stage 16. No change in Sox9 RNA levels were observed at either stage in animal caps expressing mt-GFP. In GR-Slug injected caps, levels of Bcl-xL (D), Sox9 (E), RelA, Rel2 and Rel3 (F), and caspase-9, -3 and -6 (G) RNAs were increased in response to dexamethasone; with the sole exception of caspase-9, these increases were blocked by emetine. In all panels, error bars reflect standard deviation from the mean of multiple experiments. | |
Figure 9. Bcl-xL-Slug-NF-κB network:This diagram focuses on the regulatory interactions uncovered in the course of our studies (see text for caveats associated with the identification of direct interactions). Protein names are underlined, gene names are in italics. Bcl-xL appears to activate NF-κB through effects on IκK activity and IκB stability. NF-κB acts directly to regulate Slug, Snail, RelA, and Rel3 levels; NF-κB regulation of the expression of its inhibitor IκB is based on data from mammalian systems. Caspase-9 was the only direct target of Slug identified in our studies; indirect interactions are indicated by dotted lines. |
References [+] :
Ashraf,
The mesoderm determinant snail collaborates with related zinc-finger proteins to control Drosophila neurogenesis.
1999, Pubmed
Ashraf, The mesoderm determinant snail collaborates with related zinc-finger proteins to control Drosophila neurogenesis. 1999, Pubmed
Aybar, Snail precedes slug in the genetic cascade required for the specification and migration of the Xenopus neural crest. 2003, Pubmed , Xenbase
Bachelder, Glycogen synthase kinase-3 is an endogenous inhibitor of Snail transcription: implications for the epithelial-mesenchymal transition. 2005, Pubmed
Baker, The origins of the neural crest. Part I: embryonic induction. 1997, Pubmed , Xenbase
Barrallo-Gimeno, The Snail genes as inducers of cell movement and survival: implications in development and cancer. 2005, Pubmed
Batlle, The transcription factor snail is a repressor of E-cadherin gene expression in epithelial tumour cells. 2000, Pubmed
Beck, Involvement of NF-kappaB associated proteins in FGF-mediated mesoderm induction. 1998, Pubmed , Xenbase
Bolós, The transcription factor Slug represses E-cadherin expression and induces epithelial to mesenchymal transitions: a comparison with Snail and E47 repressors. 2003, Pubmed
Bonstein, Paraxial-fated mesoderm is required for neural crest induction in Xenopus embryos. 1998, Pubmed , Xenbase
Brockman, Coupling of a signal response domain in I kappa B alpha to multiple pathways for NF-kappa B activation. 1995, Pubmed
Cai, A family of snail-related zinc finger proteins regulates two distinct and parallel mechanisms that mediate Drosophila neuroblast asymmetric divisions. 2001, Pubmed
Campbell, Regulation of NF-kappaB function. 2006, Pubmed
Cano, The transcription factor snail controls epithelial-mesenchymal transitions by repressing E-cadherin expression. 2000, Pubmed
Carl, Inhibition of neural crest migration in Xenopus using antisense slug RNA. 1999, Pubmed , Xenbase
Carver, The mouse snail gene encodes a key regulator of the epithelial-mesenchymal transition. 2001, Pubmed
Catalano, Induction of stem cell factor/c-Kit/slug signal transduction in multidrug-resistant malignant mesothelioma cells. 2004, Pubmed
Cheung, The transcriptional control of trunk neural crest induction, survival, and delamination. 2005, Pubmed
Côme, Roles of the transcription factors snail and slug during mammary morphogenesis and breast carcinoma progression. 2004, Pubmed
Cruz-Reyes, Cloning, characterization and expression of two Xenopus bcl-2-like cell-survival genes. 1995, Pubmed , Xenbase
del Barrio, Overexpression of Snail family members highlights their ability to promote chick neural crest formation. 2002, Pubmed
de Moissac, Bcl-2 activates the transcription factor NFkappaB through the degradation of the cytoplasmic inhibitor IkappaBalpha. 1998, Pubmed
de Moissac, Linkage of the BH4 domain of Bcl-2 and the nuclear factor kappaB signaling pathway for suppression of apoptosis. 1999, Pubmed
Dent, A whole-mount immunocytochemical analysis of the expression of the intermediate filament protein vimentin in Xenopus. 1989, Pubmed , Xenbase
Dobrovolskaia, Inflammation and cancer: when NF-kappaB amalgamates the perilous partnership. 2005, Pubmed
Domínguez, Phosphorylation regulates the subcellular location and activity of the snail transcriptional repressor. 2003, Pubmed
Entner, Inhibition of protein synthesis: a mechanism of amebicide action of emetine and other structurally related compounds. 1973, Pubmed
Feng, Human Bcl-2 activates ERK signaling pathway to regulate activating protein-1, lens epithelium-derived growth factor and downstream genes. 2004, Pubmed
Finkielstein, The midblastula transition in Xenopus embryos activates multiple pathways to prevent apoptosis in response to DNA damage. 2001, Pubmed , Xenbase
Fritzenwanker, Analysis of forkhead and snail expression reveals epithelial-mesenchymal transitions during embryonic and larval development of Nematostella vectensis. 2004, Pubmed
Ganguly, Drosophila WntD is a target and an inhibitor of the Dorsal/Twist/Snail network in the gastrulating embryo. 2005, Pubmed
Gilmore, Rel/NF-kappa B/I kappa B signal transduction in the generation and treatment of human cancer. 2002, Pubmed
Gordon, WntD is a feedback inhibitor of Dorsal/NF-kappaB in Drosophila development and immunity. 2005, Pubmed
Grau, Mutations and Chromosomal Rearrangements Affecting the Expression of Snail, a Gene Involved in Embryonic Patterning in DROSOPHILA MELANOGASTER. 1984, Pubmed
Gupta, The melanocyte differentiation program predisposes to metastasis after neoplastic transformation. 2005, Pubmed
Gurova, Small molecules that reactivate p53 in renal cell carcinoma reveal a NF-kappaB-dependent mechanism of p53 suppression in tumors. 2005, Pubmed
Hajra, The SLUG zinc-finger protein represses E-cadherin in breast cancer. 2002, Pubmed
Hemavathy, Snail/slug family of repressors: slowly going into the fast lane of development and cancer. 2000, Pubmed
Hemavathy, The repressor function of snail is required for Drosophila gastrulation and is not replaceable by Escargot or Worniu. 2004, Pubmed
Hensey, A developmental timer that regulates apoptosis at the onset of gastrulation. 1997, Pubmed , Xenbase
Hensey, Programmed cell death during Xenopus development: a spatio-temporal analysis. 1998, Pubmed , Xenbase
Hoernlein, Acetyl-11-keto-beta-boswellic acid induces apoptosis in HL-60 and CCRF-CEM cells and inhibits topoisomerase I. 1999, Pubmed
Huber, NF-kappaB is essential for epithelial-mesenchymal transition and metastasis in a model of breast cancer progression. 2004, Pubmed
Ikenouchi, Regulation of tight junctions during the epithelium-mesenchyme transition: direct repression of the gene expression of claudins/occludin by Snail. 2003, Pubmed
Inoue, Slug, a highly conserved zinc finger transcriptional repressor, protects hematopoietic progenitor cells from radiation-induced apoptosis in vivo. 2002, Pubmed
Inukai, SLUG, a ces-1-related zinc finger transcription factor gene with antiapoptotic activity, is a downstream target of the E2A-HLF oncoprotein. 1999, Pubmed
Ito, Three NF-kappa B sites in the I kappa B-alpha promoter are required for induction of gene expression by TNF alpha. 1994, Pubmed
Jiang, Binding affinities and cooperative interactions with bHLH activators delimit threshold responses to the dorsal gradient morphogen. 1993, Pubmed
Jiang, Individual dorsal morphogen binding sites mediate activation and repression in the Drosophila embryo. 1992, Pubmed
Jiang, The Slug gene is not essential for mesoderm or neural crest development in mice. 1998, Pubmed
Jonas, Epidermal keratin gene expressed in embryos of Xenopus laevis. 1985, Pubmed , Xenbase
Kajita, Aberrant expression of the transcription factors snail and slug alters the response to genotoxic stress. 2004, Pubmed
Kao, Negative regulation of dorsal patterning in early embryos by overexpression of XrelA, a Xenopus homologue of NF-kappa B. 1996, Pubmed , Xenbase
Kao, Expression of a mRNA related to c-rel and dorsal in early Xenopus laevis embryos. 1991, Pubmed , Xenbase
Karin, Nuclear factor-kappaB in cancer development and progression. 2006, Pubmed
Kengaku, Basic fibroblast growth factor induces differentiation of neural tube and neural crest lineages of cultured ectoderm cells from Xenopus gastrula. 1993, Pubmed , Xenbase
Khoshnan, The NF-kappa B cascade is important in Bcl-xL expression and for the anti-apoptotic effects of the CD28 receptor in primary human CD4+ lymphocytes. 2000, Pubmed
Kirshenbaum, Bcl-2 intersects the NFkappaB signalling pathway and suppresses apoptosis in ventricular myocytes. 2000, Pubmed
Kishi, Requirement of Sox2-mediated signaling for differentiation of early Xenopus neuroectoderm. 2000, Pubmed , Xenbase
Kolm, Efficient hormone-inducible protein function in Xenopus laevis. 1995, Pubmed , Xenbase
Kucharczak, To be, or not to be: NF-kappaB is the answer--role of Rel/NF-kappaB in the regulation of apoptosis. 2003, Pubmed
Kumano, The nodal target gene Xmenf is a component of an FGF-independent pathway of ventral mesoderm induction in Xenopus. 2002, Pubmed , Xenbase
Kurrey, Snail and Slug are major determinants of ovarian cancer invasiveness at the transcription level. 2005, Pubmed
LaBonne, Snail-related transcriptional repressors are required in Xenopus for both the induction of the neural crest and its subsequent migration. 2000, Pubmed , Xenbase
Lake, Xrel3 is required for head development in Xenopus laevis. 2001, Pubmed , Xenbase
Lespinet, Characterisation of two snail genes in the gastropod mollusc Patella vulgata. Implications for understanding the ancestral function of the snail-related genes in Bilateria. 2002, Pubmed
Li, Bcl-2 expression decreases cadherin-mediated cell-cell adhesion. 2003, Pubmed
Li, NF-kappaB regulation in the immune system. 2002, Pubmed
Li, Nuclear factor-kappaB and IkappaB kinase are constitutively active in human pancreatic cells, and their down-regulation by curcumin (diferuloylmethane) is associated with the suppression of proliferation and the induction of apoptosis. 2004, Pubmed
Locascio, Modularity and reshuffling of Snail and Slug expression during vertebrate evolution. 2002, Pubmed
Lu, bcl-2 overexpression inhibits cell death and promotes the morphogenesis, but not tumorigenesis of human mammary epithelial cells. 1995, Pubmed
Manzanares, The increasing complexity of the Snail gene superfamily in metazoan evolution. 2001, Pubmed
Mayor, Development of neural crest in Xenopus. 1999, Pubmed , Xenbase
Mayor, Induction of the prospective neural crest of Xenopus. 1995, Pubmed , Xenbase
Mayor, A novel function for the Xslug gene: control of dorsal mesendoderm development by repressing BMP-4. 2000, Pubmed , Xenbase
Metzstein, The C. elegans cell death specification gene ces-1 encodes a snail family zinc finger protein. 1999, Pubmed
Meulemans, Gene-regulatory interactions in neural crest evolution and development. 2004, Pubmed
Monsoro-Burq, Neural crest induction by paraxial mesoderm in Xenopus embryos requires FGF signals. 2003, Pubmed , Xenbase
Moreno-Bueno, Genetic profiling of epithelial cells expressing E-cadherin repressors reveals a distinct role for Snail, Slug, and E47 factors in epithelial-mesenchymal transition. 2006, Pubmed
Murray, Snail family genes are required for left-right asymmetry determination, but not neural crest formation, in mice. 2006, Pubmed
Nakakura, Mammalian Scratch: a neural-specific Snail family transcriptional repressor. 2001, Pubmed
Nakata, A novel member of the Xenopus Zic family, Zic5, mediates neural crest development. 2000, Pubmed , Xenbase
Nieto, Control of cell behavior during vertebrate development by Slug, a zinc finger gene. 1994, Pubmed
Nüsslein-Volhard, Mutations affecting the pattern of the larval cuticle inDrosophila melanogaster : I. Zygotic loci on the second chromosome. 1984, Pubmed
Penzel, Characterization and early embryonic expression of a neural specific transcription factor xSOX3 in Xenopus laevis. 1997, Pubmed , Xenbase
Pérez-Losada, Zinc-finger transcription factor Slug contributes to the function of the stem cell factor c-kit signaling pathway. 2002, Pubmed
Pérez-Mancera, SLUG in cancer development. 2005, Pubmed
Pikarsky, NF-kappaB functions as a tumour promoter in inflammation-associated cancer. 2004, Pubmed
Pise-Masison, Inactivation of p53 by human T-cell lymphotropic virus type 1 Tax requires activation of the NF-kappaB pathway and is dependent on p53 phosphorylation. 2000, Pubmed
Poser, Loss of E-cadherin expression in melanoma cells involves up-regulation of the transcriptional repressor Snail. 2001, Pubmed
Read, NF-kappa B and I kappa B alpha: an inducible regulatory system in endothelial activation. 1994, Pubmed
Regula, IKK beta is required for Bcl-2-mediated NF-kappa B activation in ventricular myocytes. 2002, Pubmed
Richardson, XrelA, a Xenopus maternal and zygotic homologue of the p65 subunit of NF-kappa B. Characterisation of transcriptional properties in the developing embryo and identification of a negative interference mutant. 1994, Pubmed , Xenbase
Roark, scratch, a pan-neural gene encoding a zinc finger protein related to snail, promotes neuronal development. 1995, Pubmed
Safayhi, Mechanism of 5-lipoxygenase inhibition by acetyl-11-keto-beta-boswellic acid. 1995, Pubmed
Saint-Germain, Specification of the otic placode depends on Sox9 function in Xenopus. 2004, Pubmed , Xenbase
Sakai, Cooperative action of Sox9, Snail2 and PKA signaling in early neural crest development. 2006, Pubmed
Sánchez-Martín, Deletion of the SLUG (SNAI2) gene results in human piebaldism. 2003, Pubmed
Sandur, Plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) suppresses NF-kappaB activation and NF-kappaB-regulated gene products through modulation of p65 and IkappaBalpha kinase activation, leading to potentiation of apoptosis induced by cytokine and chemotherapeutic agents. 2006, Pubmed
Savagner, The zinc-finger protein slug causes desmosome dissociation, an initial and necessary step for growth factor-induced epithelial-mesenchymal transition. 1997, Pubmed
Savagner, Developmental transcription factor slug is required for effective re-epithelialization by adult keratinocytes. 2005, Pubmed
Sefton, Conserved and divergent roles for members of the Snail family of transcription factors in the chick and mouse embryo. 1998, Pubmed
Shih, Transcription repressor slug promotes carcinoma invasion and predicts outcome of patients with lung adenocarcinoma. 2005, Pubmed
Simpson, Maternal-Zygotic Gene Interactions during Formation of the Dorsoventral Pattern in Drosophila Embryos. 1983, Pubmed
Sinner, Sox17 and beta-catenin cooperate to regulate the transcription of endodermal genes. 2004, Pubmed , Xenbase
Sitcheran, NF-kappaB mediates inhibition of mesenchymal cell differentiation through a posttranscriptional gene silencing mechanism. 2003, Pubmed
Smith, Expression of a Xenopus homolog of Brachyury (T) is an immediate-early response to mesoderm induction. 1991, Pubmed , Xenbase
Spokony, The transcription factor Sox9 is required for cranial neural crest development in Xenopus. 2002, Pubmed , Xenbase
Stack, Developmentally regulated activation of apoptosis early in Xenopus gastrulation results in cyclin A degradation during interphase of the cell cycle. 1997, Pubmed , Xenbase
Stennard, Differential expression of VegT and Antipodean protein isoforms in Xenopus. 1999, Pubmed , Xenbase
Su, Curcumin inhibits cell migration of human colon cancer colo 205 cells through the inhibition of nuclear factor kappa B /p65 and down-regulates cyclooxygenase-2 and matrix metalloproteinase-2 expressions. 2006, Pubmed
Suzuki, Molecular cloning of cDNA encoding the Xenopus homolog of mammalian RelB. 1995, Pubmed , Xenbase
Suzuki, Identification and expression of the Xenopus homolog of mammalian p100-NFkappaB2. 1998, Pubmed , Xenbase
Syrovets, Inhibition of IkappaB kinase activity by acetyl-boswellic acids promotes apoptosis in androgen-independent PC-3 prostate cancer cells in vitro and in vivo. 2005, Pubmed
Syrovets, Acetyl-boswellic acids are novel catalytic inhibitors of human topoisomerases I and IIalpha. 2000, Pubmed
Syrovets, Acetyl-boswellic acids inhibit lipopolysaccharide-mediated TNF-alpha induction in monocytes by direct interaction with IkappaB kinases. 2005, Pubmed
Takada, Acetyl-11-keto-beta-boswellic acid potentiates apoptosis, inhibits invasion, and abolishes osteoclastogenesis by suppressing NF-kappa B and NF-kappa B-regulated gene expression. 2006, Pubmed
Takayama, Involvement of caspase-9 in execution of the maternal program of apoptosis in Xenopus late blastulae overexpressed with S-adenosylmethionine decarboxylase. 2004, Pubmed , Xenbase
Tannahill, Control of axis formation in Xenopus by the NF-kappa B-I kappa B system. 1995, Pubmed , Xenbase
Technau, Origin and evolution of endoderm and mesoderm. 2003, Pubmed
Thellmann, The Snail-like CES-1 protein of C. elegans can block the expression of the BH3-only cell-death activator gene egl-1 by antagonizing the function of bHLH proteins. 2003, Pubmed
Thiery, Complex networks orchestrate epithelial-mesenchymal transitions. 2006, Pubmed
Tríbulo, A balance between the anti-apoptotic activity of Slug and the apoptotic activity of msx1 is required for the proper development of the neural crest. 2004, Pubmed , Xenbase
Trisciuoglio, bcl-2 induction of urokinase plasminogen activator receptor expression in human cancer cells through Sp1 activation: involvement of ERK1/ERK2 activity. 2004, Pubmed
Tsukahara, Induction of Bcl-x(L) expression by human T-cell leukemia virus type 1 Tax through NF-kappaB in apoptosis-resistant T-cell transfectants with Tax. 1999, Pubmed
Vallin, Cloning and characterization of three Xenopus slug promoters reveal direct regulation by Lef/beta-catenin signaling. 2001, Pubmed , Xenbase
Vega, Snail blocks the cell cycle and confers resistance to cell death. 2004, Pubmed
Vernon, Slug stability is dynamically regulated during neural crest development by the F-box protein Ppa. 2006, Pubmed , Xenbase
Vickaryous, Human cell type diversity, evolution, development, and classification with special reference to cells derived from the neural crest. 2006, Pubmed
Wahl, Sulfasalazine: a potent and specific inhibitor of nuclear factor kappa B. 1998, Pubmed
Webster, Transcriptional cross talk between NF-kappaB and p53. 1999, Pubmed
Whiteley, The Drosophila gene escargot encodes a zinc finger motif found in snail-related genes. 1992, Pubmed , Xenbase
Wu, Slug antagonizes p53-mediated apoptosis of hematopoietic progenitors by repressing puma. 2005, Pubmed
Yang, Pak1 phosphorylation of snail, a master regulator of epithelial-to-mesenchyme transition, modulates snail's subcellular localization and functions. 2005, Pubmed
Yang, Overexpression of a novel Xenopus rel mRNA gene induces tumors in early embryos. 1998, Pubmed , Xenbase
Yeo, Early neural cell death: dying to become neurons. 2004, Pubmed
Yook, Wnt-dependent regulation of the E-cadherin repressor snail. 2005, Pubmed , Xenbase
Zhang, The beta-catenin/VegT-regulated early zygotic gene Xnr5 is a direct target of SOX3 regulation. 2003, Pubmed , Xenbase
Zhang, SOX7 and SOX18 are essential for cardiogenesis in Xenopus. 2005, Pubmed , Xenbase
Zhang, SOX7 is an immediate-early target of VegT and regulates Nodal-related gene expression in Xenopus. 2005, Pubmed , Xenbase
Zhou, Dual regulation of Snail by GSK-3beta-mediated phosphorylation in control of epithelial-mesenchymal transition. 2004, Pubmed