Ulcerative colitis (UC) increases the risk of colorectal cancer (CRC), but the mechanisms involved in colitis-to-cancer transition (CCT) are not well understood. CCT may involve a inflammation-dysplasia-carcinoma progression sequence compared with the better characterized adenoma-carcinoma progression sequence associated with sporadic CRC. One common thread may be activating mutations in compon...

1. Frączek J, Wojtyra M. Kinematyka układów wieloczłonowych. WNT Warszawa, 2008. Google Scholar

A key step of Wnt signaling activation is the recruitment of b-catenin to the Wnt target-gene promoter in the nucleus, but its mechanisms are largely unknown. Here, we identified FoxM1 as a novel target of Wnt signaling, which is essential for b-catenin/TCF4 transactivation. GSK3 phosphorylates FoxM1 on serine 474 which induces FoxM1 ubiquitination mediated by FBXW7. Wnt signaling activation in...

The Wnt genes encode a large family of secreted polypeptides that mediate cell-cell communication in diverse developmental processes. The loss or inappropriate activation of Wnt expression has been shown to alter cell fate, morphogenesis and mitogenesis. Recent progress has identified Wnt receptors and components of an intracellular signalling pathway that mediate Wnt-dependent transcription. T...

Wnt signaling stimulates cell proliferation by promoting the G1/S transition of the cell cycle through β-catenin/TCF4-mediated gene transcription. However, Wnt signaling peaks in mitosis and contributes to the stabilization of proteins other than β-catenin, a pathway recently introduced as Wnt-dependent stabilization of proteins (Wnt/STOP). Here, we show that Wnt/STOP regulated by basal Wnt sig...

Secreted Wnt ligands appear to activate a variety of signaling pathways. Two papers in this issue now present genetic evidence that "noncanonical" Wnt signaling inhibits the "canonical" Wnt/beta-catenin pathway. Westfall et al. (2003a) show that zebrafish embryos lacking maternal Wnt-5 function are dorsalized due to ectopic activation of beta-catenin, whereas Topol et al. (2003) report that cho...

Since the first Wnt gene was identified in 1982, the functions and mechanisms of Wnt signaling have been extensively studied. Wnt signaling is conserved from invertebrates to vertebrates and regulates early embryonic development as well as the homeostasis of adult tissues. In addition, both embryonic stem cells and adult stem cells are regulated by Wnt signaling. Deregulation of Wnt signaling i...

Regulation of transcriptionally active nuclear β-catenin during the Wnt-on phase is crucial to ensure controlled induction of Wnt target genes. Several ubiquitin E3 ligases are known to regulate cytosolic β-catenin during the Wnt-off phase, but little is known about the fate of active nuclear β-catenin in the Wnt-on phase. We now describe ubiquitination of active β-catenin in the Wnt-on phase b...

BACKGROUND The Wnt pathway mediates differentiation of epithelial tissues; depending on the tissue types, Wnt can either drive or inhibit the differentiation process. We hypothesized that key genes in the Wnt pathway are suppressed in the human airway epithelium under the stress of cigarette smoking, a stress associated with dysregulation of the epithelial differentiated state. METHODOLOGY/PR...

Wnt signaling affects cell-fate specification processes throughout embryonic development. Here we take advantage of the well-studied gene regulatory networks (GRNs) that control pregastrular sea urchin embryogenesis to reveal the gene regulatory functions of the entire Wnt-signaling system. Five wnt genes, three frizzled genes, two secreted frizzled-related protein 1 genes, and two Dickkopf gen...