WNT1 explained

WNT1 is a gene that encodes the WNT1 protein.^{[1] [2]} It is a proto-oncogene involved in regulating embryonic development and is highly conserved among animals.^[3] WNT1 was previously known as INT1 in mammals and Wg (or "wingless") in Drosophila.^[4] In 1987, it was discovered that they were the same gene (i.e. they were homologous),^[5] and the gene was subsequently renamed WNT1 as a portmanteau of wingless and int-1.

The WNT gene family consists of structurally related genes that encode secreted signaling proteins. These proteins have been implicated in oncogenesis and in several developmental processes, including regulation of cell fate and patterning during embryogenesis. This gene is a member of the WNT gene family. It is very conserved in evolution, and the protein encoded by this gene is known to be 98% identical to the mouse Wnt1 protein at the amino acid level. The studies in mouse indicate that the Wnt1 protein functions in the induction of the mesencephalon and cerebellum.

Gene

This gene is clustered with another family member, WNT10B, in the chromosome 12q13 region.^[6]

Structure

The WNT1 protein is a secreted glycoprotein, typically composed of approximately 343 amino acids after cleavage of a precursor peptide. It belongs to the Wnt family, which is characterized by several unique structural features. WNT1 displays a highly conserved primary structure, notably containing 22–24 conserved cysteine residues critical for multiple intramolecular disulfide bonds that stabilize a complex, folded conformation.^{[7] [8] [9]}

Wnt proteins exhibit a two-domain organization: an N-terminal domain rich in alpha-helices stabilized by disulfide bridges, and a C-terminal domain dominated by beta-sheets, also supported by disulfide bonds. This overall folding pattern is unique among known protein structures. The protein is highly hydrophobic, a property related to post-translational lipid modifications, particularly palmitoleic acid addition at conserved serine residues, which is essential for functional interaction with Frizzled family receptors.^[10] WNT1 has a globular configuration with distinct "thumb" and "index finger" regions that engage specific receptor domains, facilitating canonical and non-canonical Wnt signaling. The mature WNT1 protein is glycosylated and forms complexes with Frizzled receptors, initiating developmental and oncogenic signaling cascades.

Function

WNT1 is a secreted glycoprotein that plays an important role in regulating embryonic development and adult tissue homeostasis, primarily through its function as a morphogen and signaling molecule. As a canonical Wnt ligand, WNT1 activates the Wnt/β-catenin pathway by binding to Frizzled and LRP5/LRP6 receptors, leading to the stabilization and nuclear translocation of beta-catenin. This activation facilitates the transcription of genes crucial for cell proliferation, survival, differentiation, and migration.^[11] In development, WNT1 is essential for proper patterning and proliferation of neural progenitor cells, particularly influencing midbrain and hindbrain formation, neural crest cell expansion, and dopaminergic neuron development.^{[12] [13]} In adult tissues, WNT1-mediated signaling contributes to stem cell maintenance and tissue repair.

Aberrant WNT1 activation is strongly implicated in oncogenesis. Elevated WNT1 signaling can disrupt normal cell adhesion, promote uncontrolled proliferation, and contribute to tumor initiation and progression by upregulating oncogenic targets such as c-Myc and cyclin D1. It also influences tumor immune evasion and metastasis in several cancer types, making WNT1 a significant target for potential cancer therapeutics.^{[14] [15]}

Clinical significance

The WNT1 gene has notable clinical significance due to its role in both inherited bone disorders and cancer biology. Pathogenic variants in WNT1 are recognized as a cause of osteogenesis imperfecta (OI) and early-onset osteoporosis (EOOP), with homozygous mutations typically leading to severe, life-threatening bone fragility, while heterozygous mutations can result in milder phenotypes such as reduced bone mass or early fractures without significant deformity. WNT1 is crucial for normal skeletal development and bone homeostasis, and impairment of its function disrupts osteoblastogenesis via the Wnt/β-Catenin signaling pathway, leading to compromised bone strength. In oncology, overexpression of WNT1 has been identified in non-small cell lung cancer (NSCLC) and correlates with increased tumor proliferation, angiogenesis, and a poorer prognosis.^{[16] [17]} Its status has been shown to serve as a significant independent prognostic factor in NSCLC, likely through the upregulation of proliferation-related target genes such as c-Myc.^{[18] [19]}

History

The WNT1 gene name derives its name from the fusion of two earlier gene discoveries: wingless (wg) in Drosophila melanogaster and int-1 in mice. The wingless gene, identified through mutagenesis screens in the 1970s, was found to be critical for segment polarity in fly embryos, a discovery that contributed to the 1995 Nobel Prize in Physiology or Medicine to Edward B. Lewis, Christiane Nüsslein-Volhard and Eric F. Wieschaus.^[20] Independently, int-1 was discovered as a common integration site for mouse mammary tumor virus (MMTV) and shown to induce tumors, work that was part of the oncogene research recognized by the 1989 Nobel Prize to J. Michael Bishop and Harold E. Varmus.^{[21] [22]}

Later, int-1 was found to be the mammalian ortholog of wingless, linking developmental biology and cancer research. To unify and standardize the growing list of orthologs and paralogs, scientists proposed the name Wnt as a portmanteau of wingless and int-1—with Wnt1 becoming the founding member of this conserved gene family.^[23]

See also

• Wnt signaling pathway

Further reading

• McMahon AP, Moon RT . int-1--a proto-oncogene involved in cell signalling . Development . Cambridge, England . 107 Suppl . 161–167 . 1990 . 2534596 . 10.1242/dev.107.Supplement.161 .
• Chance PF, Cavalier L, Satran D, Pellegrino JE, Koenig M, Dobyns WB . Clinical nosologic and genetic aspects of Joubert and related syndromes . Journal of Child Neurology . 14 . 10 . 660–6; discussion 669–72 . October 1999 . 10511339 . 10.1177/088307389901401007 . 38298436 .
• De Ferrari GV, Moon RT . The ups and downs of Wnt signaling in prevalent neurological disorders . Oncogene . 25 . 57 . 7545–7553 . December 2006 . 17143299 . 10.1038/sj.onc.1210064 . free . 35684619 . 10533/178151 .
• Thomas KR, Capecchi MR . Targeted disruption of the murine int-1 proto-oncogene resulting in severe abnormalities in midbrain and cerebellar development . Nature . 346 . 6287 . 847–850 . August 1990 . 2202907 . 10.1038/346847a0 . 4341682 . 1990Natur.346..847T .
• Turc-Carel C, Pietrzak E, Kakati S, Kinniburgh AJ, Sandberg AA . The human int-1 gene is located at chromosome region 12q12-12q13 and is not rearranged in myxoid liposarcoma with t(12;16) (q13;p11) . Oncogene Research . 1 . 4 . 397–405 . 1988 . 3329717 .
• Wang YK, Samos CH, Peoples R, Pérez-Jurado LA, Nusse R, Francke U . A novel human homologue of the Drosophila frizzled wnt receptor gene binds wingless protein and is in the Williams syndrome deletion at 7q11.23 . Human Molecular Genetics . 6 . 3 . 465–472 . March 1997 . 9147651 . 10.1093/hmg/6.3.465 . free .
• Bafico A, Gazit A, Pramila T, Finch PW, Yaniv A, Aaronson SA . Interaction of frizzled related protein (FRP) with Wnt ligands and the frizzled receptor suggests alternative mechanisms for FRP inhibition of Wnt signaling . The Journal of Biological Chemistry . 274 . 23 . 16180–16187 . June 1999 . 10347172 . 10.1074/jbc.274.23.16180 . free .
• Gazit A, Yaniv A, Bafico A, Pramila T, Igarashi M, Kitajewski J, Aaronson SA . Human frizzled 1 interacts with transforming Wnts to transduce a TCF dependent transcriptional response . Oncogene . 18 . 44 . 5959–5966 . October 1999 . 10557084 . 10.1038/sj.onc.1202985 . 2009505 .
• Lee CS, Buttitta LA, May NR, Kispert A, Fan CM . SHH-N upregulates Sfrp2 to mediate its competitive interaction with WNT1 and WNT4 in the somitic mesoderm . Development . Cambridge, England . 127 . 1 . 109–118 . January 2000 . 10654605 . 10.1242/dev.127.1.109 .
• Tanaka K, Okabayashi K, Asashima M, Perrimon N, Kadowaki T . The evolutionarily conserved porcupine gene family is involved in the processing of the Wnt family . European Journal of Biochemistry . 267 . 13 . 4300–4311 . July 2000 . 10866835 . 10.1046/j.1432-1033.2000.01478.x .
• Tamai K, Semenov M, Kato Y, Spokony R, Liu C, Katsuyama Y, Hess F, Saint-Jeannet JP, He X . LDL-receptor-related proteins in Wnt signal transduction . Nature . 407 . 6803 . 530–535 . September 2000 . 11029007 . 10.1038/35035117 . 4400159 . 2000Natur.407..530T .
• Mao J, Wang J, Liu B, Pan W, Farr GH, Flynn C, Yuan H, Takada S, Kimelman D, Li L, Wu D . Low-density lipoprotein receptor-related protein-5 binds to Axin and regulates the canonical Wnt signaling pathway . Molecular Cell . 7 . 4 . 801–809 . April 2001 . 11336703 . 10.1016/S1097-2765(01)00224-6 . free .
• Kirikoshi H, Sekihara H, Katoh M . WNT10A and WNT6, clustered in human chromosome 2q35 region with head-to-tail manner, are strongly coexpressed in SW480 cells . Biochemical and Biophysical Research Communications . 283 . 4 . 798–805 . May 2001 . 11350055 . 10.1006/bbrc.2001.4855 . 2001BBRC..283..798K .
• Semënov MV, Tamai K, Brott BK, Kühl M, Sokol S, He X . Head inducer Dickkopf-1 is a ligand for Wnt coreceptor LRP6 . Current Biology . 11 . 12 . 951–961 . June 2001 . 11448771 . 10.1016/S0960-9822(01)00290-1 . 15702819 . free . 2001CBio...11..951S .
• Mizushima T, Nakagawa H, Kamberov YG, Wilder EL, Klein PS, Rustgi AK . Wnt-1 but not epidermal growth factor induces beta-catenin/T-cell factor-dependent transcription in esophageal cancer cells . Cancer Research . 62 . 1 . 277–282 . January 2002 . 11782388 .
• Tice DA, Szeto W, Soloviev I, Rubinfeld B, Fong SE, Dugger DL, Winer J, Williams PM, Wieand D, Smith V, Schwall RH, Pennica D, Polakis P . Synergistic induction of tumor antigens by Wnt-1 signaling and retinoic acid revealed by gene expression profiling . The Journal of Biological Chemistry . 277 . 16 . 14329–14335 . April 2002 . 11832495 . 10.1074/jbc.M200334200 . free .

Notes and References

1. van Ooyen A, Kwee V, Nusse R . The nucleotide sequence of the human int-1 mammary oncogene; evolutionary conservation of coding and non-coding sequences . The EMBO Journal . 4 . 11 . 2905–2909 . November 1985 . 2998762 . 554596 . 10.1002/j.1460-2075.1985.tb04021.x .
2. Arheden K, Mandahl N, Strömbeck B, Isaksson M, Mitelman F . Chromosome localization of the human oncogene INT1 to 12q13 by in situ hybridization . Cytogenetics and Cell Genetics . 47 . 1–2 . 86–87 . May 1988 . 3281802 . 10.1159/000132513 .
3. Klaus A, Birchmeier W . Wnt signalling and its impact on development and cancer . Nature Reviews. Cancer . 8 . 5 . 387–398 . May 2008 . 18432252 . 10.1038/nrc2389 . 31382024 .
4. Web site: Dmel\wg . FlyBase . 18 July 2025 .
5. Rijsewijk F, Schuermann M, Wagenaar E, Parren P, Weigel D, Nusse R . The Drosophila homolog of the mouse mammary oncogene int-1 is identical to the segment polarity gene wingless . Cell . 50 . 4 . 649–657 . August 1987 . 3111720 . 10.1016/0092-8674(87)90038-9 .
6. Web site: Entrez Gene: WNT1 wingless-type MMTV integration site family, member 1 .
7. Willert K, Nusse R . Wnt proteins . Cold Spring Harbor Perspectives in Biology . 4 . 9 . a007864 . September 2012 . 22952392 . 3428774 . 10.1101/cshperspect.a007864 .
8. MacDonald BT, Hien A, Zhang X, Iranloye O, Virshup DM, Waterman ML, He X . Disulfide bond requirements for active Wnt ligands . The Journal of Biological Chemistry . 289 . 26 . 18122–36 . June 2014 . 24841207 . 4140276 . 10.1074/jbc.M114.575027 . free .
9. Ke J, Xu HE, Williams BO . Lipid modification in Wnt structure and function . Current Opinion in Lipidology . 24 . 2 . 129–33 . April 2013 . 23348724 . 10.1097/MOL.0b013e32835df2bf .
10. Liu J, Xiao Q, Xiao J, Niu C, Li Y, Zhang X, Zhou Z, Shu G, Yin G . Wnt/β-catenin signalling: function, biological mechanisms, and therapeutic opportunities . Signal Transduction and Targeted Therapy . 7 . 1 . 3 . January 2022 . 34980884 . 8724284 . 10.1038/s41392-021-00762-6 .
11. Sharma M, Pruitt K . Wnt Pathway: An Integral Hub for Developmental and Oncogenic Signaling Networks . International Journal of Molecular Sciences . 21 . 21 . October 2020 . 8018 . 33126517 . 7663720 . 10.3390/ijms21218018 . free .
12. Panhuysen M, Vogt Weisenhorn DM, Blanquet V, Brodski C, Heinzmann U, Beisker W, Wurst W . Effects of Wnt1 signaling on proliferation in the developing mid-/hindbrain region . Molecular and Cellular Neurosciences . 26 . 1 . 101–11 . May 2004 . 15121182 . 10.1016/j.mcn.2004.01.011 .
13. Patapoutian A, Reichardt LF . Roles of Wnt proteins in neural development and maintenance . Current Opinion in Neurobiology . 10 . 3 . 392–9 . June 2000 . 10851180 . 4943213 . 10.1016/s0959-4388(00)00100-8 .
14. Wang H, Zhang L, Hu C, Li H, Jiang M . Wnt signaling and tumors (Review) . Molecular and Clinical Oncology . 21 . 1 . 45 . July 2024 . 38798312 . 11117032 . 10.3892/mco.2024.2743 .
15. You L, Kim J, He B, Xu Z, McCormick F, Jablons DM . Wnt-1 signal as a potential cancer therapeutic target . Drug News & Perspectives . 19 . 1 . 27–31 . 2006 . 16550254 . 10.1358/dnp.2005.19.1.965871 .
16. Xue W, Cai L, Li S, Hou Y, Wang YD, Yang D, Xia Y, Nie X . WNT ligands in non-small cell lung cancer: from pathogenesis to clinical practice . Discover Oncology . 14 . 1 . 136 . July 2023 . 37486552 . 10366069 . 10.1007/s12672-023-00739-7 .
17. Jin J, Zhan P, Qian H, Wang X, Katoh M, Phan K, Chung JH, Lv T, Song Y . Prognostic value of wingless-type proteins in non-small cell lung cancer patients: a meta-analysis . Translational Lung Cancer Research . 5 . 4 . 436–42 . August 2016 . 27652206 . 5009088 . 10.21037/tlcr.2016.08.08 . free .
18. Hayat R, Manzoor M, Hussain A . Wnt signaling pathway: A comprehensive review . Cell Biology International . 46 . 6 . 863–877 . June 2022 . 35297539 . 10.1002/cbin.11797 .
19. Kenzerki ME, Ahmadi M, Mousavi P, Ghafouri-Fard S . MYC and non-small cell lung cancer: A comprehensive review. . Human Gene . September 2023 . 37 . 201185 . 10.1016/j.humgen.2023.201185 .
20. Web site: The Nobel Prize in Physiology or Medicine 1995 - Press release . NobelPrize.org.
21. Web site: The Nobel Prize in Physiology or Medicine 1989 - Press release . NobelPrize.org . 9 October 1989 .
22. Marx JL . Cancer gene research wins medicine Nobel . Science . New York, N.Y. . 246 . 4928 . 326–7 . October 1989 . 2678473 . 10.1126/science.2678473 . 1989Sci...246..326M .
23. Lekven AC, Empie S, Saoud R . One Wnt to lead them all: a Wnt1 primer . Differentiation; Research in Biological Diversity . 144 . 100884 . 2025 . 40580644 . 10.1016/j.diff.2025.100884 .