Nuclear localization of β-catenin and expression of target genes are associated with increased Wnt secretion in oral dysplasia

Reyes, María Isabel Pávez; Peña‐Oyarzún, Daniel; Maturana, Andrea; Torres, Vicente A.

doi:10.1016/j.oraloncology.2019.05.010

Cited by 22 publications

(56 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Multiple co‐transfections in DOK cells are not feasible, as these proceed with low efficiency and cell viability is impaired (data not shown). Hence, we used an alternative approach, by stimulating OKF6 cells with conditioned medium derived from DOK cells, which was previously shown to contain Wnt ligands, thereby stimulating Wnt/β‐catenin signaling and Tcf/Lef‐dependent transcription . First, we evaluated the dependency on Wnt3a, by using the compound Wnt‐C59, which inhibits secretion of Wnt3a, but not other Wnt ligands in DOK cells .…”

Section: Resultsmentioning

confidence: 99%

“…28 Primary cultures of oral keratinocytes were obtained and characterized as previously described. 12 Briefly, tissues were obtained from healthy human oral mucosa of nonsmoking donor subjects (upon previous signature of informed consents, Medical Ethics Committee, Faculty of Dentistry, Universidad de Chile). Tissues were treated with trypsin (0.25%), disintegrated and cultured in K-SFM containing penicillin (10 000 U/mL) and streptomycin (10 μg/mL), and supplemented with bovine pituitary extract and recombinant human epidermal growth factor, plus 0.3mM CaCl 2 .…”

Section: Cell Culturementioning

confidence: 99%

“…For Tcf/Lef transcriptional activity measurements, the luciferase reporter activity system was used, as previously described. 12 This assay is based on transfection with the plasmids pTOP-FLASH, which encodes for the luciferase gene preceded by three tandem Tcf/Lef binding sites, and the pFOP-FLASH, which contains point mutations on these sites. The constitutively active vector encoding for Renilla luciferase (Promega, Madison, WI, USA) was used as co-transfection control.…”

Section: β-Catenin Tcf/lef Reporter Assaymentioning

confidence: 99%

“…The latter is important, based on the ability of Rab5 to control early endosome dynamics, which may impinge in the acquisition of malignant traits in tumor cells, and most importantly, in oral dysplasia. In this context, the accumulation of nuclear β‐catenin in tumor cells and in oral dysplasia is striking, since these phenomena could be due to increased endosomal targeting of the β‐catenin destruction complex. Here, we explored whether endosomal sequestration of the destruction complex accounts for increased accumulation of nuclear β‐catenin in oral dysplasia and assessed the role of the endocytic protein, Rab5, in these events.…”

Section: Introductionmentioning

confidence: 99%

“…[9][10][11] Accordingly, recent studies from our laboratory showed that increased Wnt3a secretion in oral dysplasia leads to nuclear accumulation of β-catenin and Tcf/Lef-dependent transcription of target genes upregulated in oral dysplasia, as shown in patient biopsies and in cell culture models, using dysplastic oral keratinocytes (DOK) and primary cultures of nontumor oral keratinocytes. 12 Nevertheless, the mechanisms involved in nuclear translocation of β-catenin in oral dysplasia remain unclear.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Nuclear accumulation of β‐catenin is associated with endosomal sequestration of the destruction complex and increased activation of Rab5 in oral dysplasia

et al. 2020

Self Cite

View full text Add to dashboard Cite

Potentially malignant lesions, commonly referred to as dysplasia, are associated with malignant transformation by mechanisms that remain unclear. We recently reported that increased Wnt secretion promotes the nuclear accumulation of β‐catenin and expression of target genes in oral dysplasia. However, the mechanisms accounting for nuclear re‐localization of β‐catenin in oral dysplasia remain unclear. In this study, we show that endosomal sequestration of the β‐catenin destruction complex allows nuclear accumulation of β‐catenin in oral dysplasia, and that these events depended on the endocytic protein Rab5. Tissue immunofluorescence analysis showed aberrant accumulation of enlarged early endosomes in oral dysplasia biopsies, when compared with healthy oral mucosa. These observations were confirmed in cell culture models, by comparing dysplastic oral keratinocytes (DOK) and non‐dysplastic oral keratinocytes (OKF6). Intriguingly, DOK depicted higher levels of active Rab5, a critical regulator of early endosomes, when compared with OKF6. Increased Rab5 activity in DOK was necessary for nuclear localization of β‐catenin and Tcf/Lef‐dependent transcription, as shown by expression of dominant negative and constitutively active mutants of Rab5, along with immunofluorescence, subcellular fractionation, transcription, and protease protection assays. Mechanistically, elevated Rab5 activity in DOK accounted for endosomal sequestration of components of the destruction complex, including GSK3β, Axin, and adenomatous polyposis coli (APC), as observed in Rab5 dominant negative experiments. In agreement with these in vitro observations, tissue immunofluorescence analysis showed increased co‐localization of GSK3β, APC, and Axin, with early endosome antigen 1‐ and Rab5‐positive early endosomes in clinical samples of oral dysplasia. Collectively, these data indicate that increased Rab5 activity and endosomal sequestration of the β‐catenin destruction complex leads to stabilization and nuclear accumulation of β‐catenin in oral dysplasia.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Cell Culturementioning

confidence: 99%

Section: β-Catenin Tcf/lef Reporter Assaymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Nuclear accumulation of β‐catenin is associated with endosomal sequestration of the destruction complex and increased activation of Rab5 in oral dysplasia

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

The dishevelled associated activator of morphogenesis protein 2 (Daam2) regulates neural tube closure

Nama,

Su,

Marquez

et al. 2024

Developmental Dynamics

View full text Add to dashboard Cite

BackgroundThe Wnt signaling pathway is highly conserved in metazoans and regulates a large array of cellular processes including motility, polarity and fate determination, and stem cell homeostasis. Modulation of the actin cytoskeleton via the non‐canonical Wnt pathway regulate cell polarity and cell migration that are required for proper vertebrate gastrulation and subsequent neurulation. However, the mechanism(s) of how the non‐canonical pathway mediates actin cytoskeleton modulation is not fully understood.ResultsHerein, we characterize the role of the Formin‐homology protein; dishevelled associated activator of morphogenesis 2 (Daam2) protein in the Wnt signaling pathway. Co‐immunoprecipitation assays confirm the binding of Daam2 to dishevelled2 (Dvl2) as well as the domains within these proteins required for interaction; additionally, the interaction between Daam2 and Dvl2 was Wnt‐regulated. Sub‐cellular localization studies reveal Daam2 is cytoplasmic and regulates the cellular actin cytoskeleton by modulating actin filament formation. During Xenopus development, a knockdown or loss of Daam2 specifically produces neural tube closure defects indicative of a role in non‐canonical signaling. Additionally, our studies did not identify any role for Daam2 in canonical Wnt signaling in mammalian culture cells or the Xenopus embryo.ConclusionsOur studies together identify Daam2 as a component of the non‐canonical Wnt pathway and Daam2 is a regulator of neural tube morphogenesis during vertebrate development.

show abstract

Targeting the genetic landscape of oral potentially malignant disorders has the potential as a preventative strategy in oral cancer

et al. 2021

View full text Add to dashboard Cite

Nuclear localization of β-catenin and expression of target genes are associated with increased Wnt secretion in oral dysplasia

Cited by 22 publications

References 36 publications

Nuclear accumulation of β‐catenin is associated with endosomal sequestration of the destruction complex and increased activation of Rab5 in oral dysplasia

Nuclear accumulation of β‐catenin is associated with endosomal sequestration of the destruction complex and increased activation of Rab5 in oral dysplasia

The dishevelled associated activator of morphogenesis protein 2 (Daam2) regulates neural tube closure

Targeting the genetic landscape of oral potentially malignant disorders has the potential as a preventative strategy in oral cancer

Contact Info

Product

Resources

About