====== Wnt signaling pathway ======

The [[Wnt]] [[signaling pathway]]s are a group of [[signal transduction]] pathways that begin with proteins that pass signals into a cell through [[cell surface receptor]]s. The name [[Wnt]] is a portmanteau created from the names Wingless and Int-1.

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Using [[Caenorhabditis elegans]] as a model, Shi et al. uncover that a [[Wnt signaling pathway]] in the [[gut]] regulates synaptic development in the brain. A canonical Wnt signaling pathway promotes [[synapse]] formation through regulating the expression of the [[neuropeptide]]s encoding gene nlp-40 in the gut, which functions through the neuronally expressed GPCR/AEX-2 receptor during development. Wnt-NLP-40-AEX-2 signaling likely acts to modulate neuronal activity. The study revealed a genetic role of the [[gut]] in [[synaptogenesis]] and identifies a novel contribution of the [[gut-brain axis]]
((Shi Y, Qin L, Wu M, Zheng J, Xie T, Shao Z. Gut neuroendocrine signaling regulates synaptic assembly in C. elegans. EMBO Rep. 2022 Jun 24:e53267. doi: 10.15252/embr.202153267. Epub ahead of print. PMID: 35748387.))
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Aberrant [[regulation]] of the [[Wnt]] signaling pathway plays an important role in [[tumorigenesis]].

It plays many essential [[role]]s in the [[regulation]] of the progenitor cell fate, developmental decisions, [[proliferation]] during embryonic development, and adult tissue homeostasis. 

In a paper, Majidinia et al., briefly introduce Wnt/β-catenin signaling pathway and discuss how it integrally contributes to both stem and cancer stem cell maintenance. Finally, they summarize the current understanding of the role of Wnt/β-catenin signaling in the development and regeneration of heart, lung, liver, bone, and cartilage
((Majidinia M, Aghazadeh J, Jahanban-Esfahlani R, Yousefi B. The roles of
Wnt/β-catenin pathway in tissue development and regenerative medicine. J Cell
Physiol. 2017 Nov 18. doi: 10.1002/jcp.26265. [Epub ahead of print] Review.
PubMed PMID: 29150936.
)).

Wnt [[signaling pathway]]s regulate proliferation, motility and survival in a variety of human cell types. [[DKK1]] gene codes for a secreted Wnt inhibitory factor. It functions as tumour suppressor gene in breast cancer and as a pro-apoptotic factor in glioma cells. 

{{ ::signaling_pathway.jpg|}}

Wnt/β-[[catenin]] and [[Hepatocyte Growth Factor]] (HGF)/c-Met signaling are hyperactive in human gliomas, where they regulate cell proliferation, migration and stem cell behavior.
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[[Wnt]]/β-catenin [[signaling pathway]] is frequently dysregulated in human tumors and plays a critical role in [[tumorigenesis]]; however, the roles of [[microRNA]]s in mediating [[Wnt]]/β-[[catenin]] pathway are not well understood.
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Expression of WNT3a, cytoplasmic β-catenin and TCF4 was significantly associated with the histological malignancy grade and with a worse prognosis for patients with glioma
((Denysenko T, Annovazzi L, Cassoni P, Melcarne A, Mellai M, Schiffer D.
WNT/β-catenin Signaling Pathway and Downstream Modulators in Low- and High-grade 
Glioma. Cancer Genomics Proteomics. 2016 01-02;13(1):31-45. PubMed PMID:
26708597.
)).