Activation of the Wnt/β-catenin pathway crucially depends on the polymerization of dishevelled 2 (DVL2) into biomolecular condensates. However, given the low affinity of known DVL2 self-interaction sites and its low cellular concentration, it is unclear how polymers can form. Here, we detect oligomeric DVL2 complexes at endogenous protein levels in human cell lines, using a biochemical ultracentrifugation assay. We identify a low-complexity region (LCR4) in the C-terminus whose deletion and fusion decreased and increased the complexes, respectively. Notably, LCR4-induced complexes correlated with the formation of microscopically visible multimeric condensates. Adjacent to LCR4, we mapped a conserved domain (CD2) promoting condensates only. Molecularly, LCR4 and CD2 mediated DVL2 self-interaction via aggregating residues and phenylalanine stickers, respectively. Point mutations inactivating these interaction sites impaired Wnt pathway activation by DVL2. Our study discovers DVL2 complexes with functional importance for Wnt/β-catenin signaling. Moreover, we provide evidence that DVL2 condensates form in two steps by pre-oligomerization via high-affinity interaction sites, such as LCR4, and subsequent condensation via low-affinity interaction sites, such as CD2.
- MeSH
- beta-katenin metabolismus genetika MeSH
- HEK293 buňky MeSH
- lidé MeSH
- multimerizace proteinu MeSH
- protein dishevelled * metabolismus genetika MeSH
- signální dráha Wnt * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Members of the casein kinase 1 (CK1) family are important regulators of multiple signaling pathways. CK1α is a well-known negative regulator of the Wnt/β-catenin pathway, which promotes the degradation of β-catenin via its phosphorylation of Ser45. In contrast, the closest paralog of CK1α, CK1α-like, is a poorly characterized kinase of unknown function. In this study, we show that the deletion of CK1α, but not CK1α-like, resulted in a strong activation of the Wnt/β-catenin pathway. Wnt-3a treatment further enhanced the activation, which suggests there are at least two modes, a CK1α-dependent and Wnt-dependent, of β-catenin regulation. Rescue experiments showed that only two out of ten naturally occurring splice CK1α/α-like variants were able to rescue the augmented Wnt/β-catenin signaling caused by CK1α deficiency in cells. Importantly, the ability to phosphorylate β-catenin on Ser45 in the in vitro kinase assay was required but not sufficient for such rescue. Our compound CK1α and GSK3α/β KO models suggest that the additional nonredundant function of CK1α in the Wnt pathway beyond Ser45-β-catenin phosphorylation includes Axin phosphorylation. Finally, we established NanoBRET assays for the three most common CK1α splice variants as well as CK1α-like. Target engagement data revealed comparable potency of known CK1α inhibitors for all CK1α variants but not for CK1α-like. In summary, our work brings important novel insights into the biology of CK1α, including evidence for the lack of redundancy with other CK1 kinases in the negative regulation of the Wnt/β-catenin pathway at the level of β-catenin and Axin.
- MeSH
- alternativní sestřih MeSH
- beta-katenin * metabolismus genetika MeSH
- fosforylace MeSH
- GSK3B metabolismus genetika MeSH
- HEK293 buňky MeSH
- kasein kinasa Ialfa * metabolismus genetika MeSH
- kinasa 3 glykogensynthasy metabolismus genetika MeSH
- lidé MeSH
- protein Wnt3A metabolismus genetika MeSH
- signální dráha Wnt * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The aim of this study was to investigate the prognostic significance of membranous β-catenin and cytoplasmic β-catenin expression in pancreatic cancer patients (pts). One hundred pts with histologically verified exocrine pancreatic ductal adenocarcinoma were retrospectively studied. The membranous β-catenin, cytoplasmic β-catenin, and cell nucleus β-catenin expression were immunohistochemically evaluated. The expression of membranous β-catenin was <5% in none of the pts, 5-25% in one patient, 26-50% in 2 pts, 51-75% in 14 pts, and >75% in 81 pts. The expression of cytoplasmic β-catenin was <5% in 34 pts, 5-25% in 42 pts, 26-50% in 18 pts, 51-75% in 3 pts, and >75% in one patient. The expression of β-catenin in the cell nucleus was negative in all pts. At the time of the last follow-up, 21 pts were alive and 79 pts had died. Median OS was 1.3 (0.4-2.3) years in pts with membranous β-catenin expression ≤75% and 1.7 (1.3-2.1) years in pts with membranous β-catenin expression >75% (p=0.045). Median OS was (1.3-2.0) 1.6 years in pts with cytoplasmic β-catenin expression ≤25% and 0.9 (0.5-1.2) years in pts with cytoplasmic β-catenin expression >25% (p=0.040). In the univariate Cox proportional hazard models HR (95% CI) was 0.556 (0.311-0.995) in pts with membranous β-catenin expression >75% (p=0.048) and 2.200 (1.216-3.980) in pts with cytoplasmic β-catenin expression >25% (p=0.009). The present results indicate a favorable prognostic significance of membranous β-catenin expression in pancreatic cancer.
The significance of long non-coding RNAs (lncRNAs) in the development and progression of human cancers has attracted increasing attention in recent years of investigations. Having versatile interactions and diverse functions, lncRNAs can act as oncogenes or tumor-suppressors to actively regulate cell proliferation, survival, stemness, drug resistance, invasion and metastasis. LINC00467, an oncogenic member of long intergenic non-coding RNAs, is upregulated in numerous malignancies and its high expression is often related to poor clinicopathological features. LINC00467 facilitates the progression of cancer via sponging tumor-suppressive microRNAs, inhibiting cell death cascade, modulating cell cycle controllers, and regulating signalling pathways including AKT, STAT3, NF-κB and Wnt/β-catenin. A growing number of studies have revealed that LINC00467 may serve as a novel prognostic biomarker and its inhibitory targeting has a valuable therapeutic potential to suppress the malignant phenotypes of cancer cells. In the present review, we discuss the importance of LINC00467 and provide a comprehensive collection of its functions and molecular mechanisms in a variety of cancer types.
- MeSH
- beta-katenin genetika MeSH
- biologické markery MeSH
- karcinogeneze genetika MeSH
- lidé MeSH
- mikro RNA * genetika MeSH
- nádorové buněčné linie MeSH
- nádory * genetika MeSH
- NF-kappa B MeSH
- onkogeny genetika MeSH
- proliferace buněk genetika MeSH
- protoonkogenní proteiny c-akt genetika MeSH
- regulace genové exprese u nádorů MeSH
- RNA dlouhá nekódující * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND: Hepatocellular carcinoma (HCC) is a fatal disease characterized by early genetic alterations in telomerase reverse transcriptase promoter (TERTp) and β-catenin (CTNNB1) genes and immune cell activation in the tumor microenvironment. As a novel approach, we wanted to assess patient survival influenced by combined presence of mutations and densities of CD8+ cytotoxic T cells. METHODS: Tissue samples were obtained from 67 HCC patients who had undergone resection. We analysed CD8+ T cells density, TERTp mutations, rs2853669 polymorphism, and CTNNB1 mutations. These variables were evaluated for time to recurrence (TTR) and disease free survival (DFS). RESULTS: TERTp mutations were found in 75.8% and CTNNB1 mutations in 35.6% of the patients. TERTp mutations were not associated with survival but polymorphism rs2853669 in TERTp was associated with improved TTR and DFS. CTNNB1 mutations were associated with improving TTR. High density of CD8+ T-lymphocytes in tumor center and invasive margin correlated with longer TTR and DFS. Combined genetic and immune factors further improved survival showing higher predictive values. E.g., combining CTNNB1 mutations and high density of CD8+ T-lymphocytes in tumor center yielded HRs of 0.12 (0.03-0.52), p = 0.005 for TTR and 0.25 (0.09-0.74), p = 0.01 for DFS. CONCLUSION: The results outline a novel integrative approach for prognostication through combining independent predictive factors from genetic and immune cell profiles. However, larger studies are needed to explore multiple cell types in the tumor microenvironment.
- MeSH
- beta-katenin genetika MeSH
- CD8-pozitivní T-lymfocyty patologie MeSH
- hepatocelulární karcinom * genetika patologie chirurgie MeSH
- jednonukleotidový polymorfismus MeSH
- lidé MeSH
- mutace MeSH
- nádorové mikroprostředí genetika MeSH
- nádory jater * genetika patologie chirurgie MeSH
- počet buněk MeSH
- telomerasa * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Genetic predisposition affects the penetrance of tumor-initiating mutations, such as APC mutations that stabilize β-catenin and cause intestinal tumors in mice and humans. However, the mechanisms involved in genetically predisposed penetrance are not well understood. Here, we analyzed tumor multiplicity and gene expression in tumor-prone ApcMin/+ mice on highly variant C57BL/6J (B6) and PWD/Ph (PWD) genetic backgrounds. (B6 × PWD) F1 APCMin offspring mice were largely free of intestinal adenoma, and several chromosome substitution (consomic) strains carrying single PWD chromosomes on the B6 genetic background displayed reduced adenoma numbers. Multiple dosage-dependent modifier loci on PWD chromosome 5 each contributed to tumor suppression. Activation of β-catenin-driven and stem cell-specific gene expression in the presence of ApcMin or following APC loss remained moderate in intestines carrying PWD chromosome 5, suggesting that PWD variants restrict adenoma initiation by controlling stem cell homeostasis. Gene expression of modifier candidates and DNA methylation on chromosome 5 were predominantly cis controlled and largely reflected parental patterns, providing a genetic basis for inheritance of tumor susceptibility. Human SNP variants of several modifier candidates were depleted in colorectal cancer genomes, suggesting that similar mechanisms may also affect the penetrance of cancer driver mutations in humans. Overall, our analysis highlights the strong impact that multiple genetic variants acting in networks can exert on tumor development. SIGNIFICANCE: These findings in mice show that, in addition to accidental mutations, cancer risk is determined by networks of individual gene variants.
- MeSH
- beta-katenin genetika metabolismus MeSH
- genetická predispozice k nemoci MeSH
- geny APC * MeSH
- kolorektální nádory genetika patologie prevence a kontrola MeSH
- mutace * MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nádorová transformace buněk genetika metabolismus patologie MeSH
- proteiny Wnt genetika metabolismus MeSH
- střeva patologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The canonical Wnt signaling pathway is mediated by interaction of β-catenin with the T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) transcription factors and subsequent transcription activation of Wnt-target genes. In the hematopoietic system, the function of the pathway has been mainly investigated by rather unspecific genetic manipulations of β-catenin that yielded contradictory results. Here, we used a mouse expressing a truncated dominant negative form of the human TCF4 transcription factor (dnTCF4) that specifically abrogates β-catenin-TCF/LEF interaction. Disruption of the β-catenin-TCF/LEF interaction resulted in the accumulation of immature cells and reduced granulocytic differentiation. Mechanistically, dnTCF4 progenitors exhibited downregulation of the Csf3r gene, reduced granulocyte colony-stimulating factor (G-CSF) receptor levels, attenuation of downstream Stat3 phosphorylation after G-CSF treatment, and impaired G-CSF-mediated differentiation. Chromatin immunoprecipitation assays confirmed direct binding of TCF/LEF factors to the promoter and putative enhancer regions of CSF3R. Inhibition of β-catenin signaling compromised activation of the emergency granulopoiesis program, which requires maintenance and expansion of myeloid progenitors. Consequently, dnTCF4 mice were more susceptible to Candida albicans infection and more sensitive to 5-fluorouracil-induced granulocytic regeneration. Importantly, genetic and chemical inhibition of β-catenin-TCF/LEF signaling in human CD34+ cells reduced granulocytic differentiation, whereas its activation enhanced myelopoiesis. Altogether, our data indicate that the β-catenin-TCF/LEF complex directly regulates G-CSF receptor levels, and consequently controls proper differentiation of myeloid progenitors into granulocytes in steady-state and emergency granulopoiesis. Our results uncover a role for the β-catenin signaling pathway in fine tuning the granulocytic production, opening venues for clinical intervention that require enhanced or reduced production of neutrophils.
- MeSH
- beta-katenin genetika metabolismus MeSH
- Candida albicans MeSH
- granulocyty metabolismus MeSH
- kandidóza genetika metabolismus MeSH
- myelopoéza * MeSH
- myši transgenní MeSH
- myši MeSH
- protein 2 podobný transkripčnímu faktoru 7 metabolismus MeSH
- receptory faktoru stimulujícího kolonie biosyntéza genetika MeSH
- signální transdukce * MeSH
- transkripční faktory TCF genetika metabolismus MeSH
- upregulace * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Wnt/β-catenin signaling is a primary pathway for stem cell maintenance during tissue renewal and a frequent target for mutations in cancer. Impaired Wnt receptor endocytosis due to loss of the ubiquitin ligase RNF43 gives rise to Wnt-hypersensitive tumors that are susceptible to anti-Wnt-based therapy. Contrary to this paradigm, we identify a class of RNF43 truncating cancer mutations that induce β-catenin-mediated transcription, despite exhibiting retained Wnt receptor downregulation. These mutations interfere with a ubiquitin-independent suppressor role of the RNF43 cytosolic tail that involves Casein kinase 1 (CK1) binding and phosphorylation. Mechanistically, truncated RNF43 variants trap CK1 at the plasma membrane, thereby preventing β-catenin turnover and propelling ligand-independent target gene transcription. Gene editing of human colon stem cells shows that RNF43 truncations cooperate with p53 loss to drive a niche-independent program for self-renewal and proliferation. Moreover, these RNF43 variants confer decreased sensitivity to anti-Wnt-based therapy. Our data demonstrate the relevance of studying patient-derived mutations for understanding disease mechanisms and improved applications of precision medicine.
- MeSH
- beta-katenin genetika metabolismus MeSH
- HEK293 buňky MeSH
- kasein kinasa I genetika metabolismus MeSH
- lidé MeSH
- nádorový supresorový protein p53 genetika metabolismus MeSH
- nádory genetika metabolismus patologie MeSH
- signální dráha Wnt * MeSH
- ubikvitinligasy genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Papillary thyroid carcinoma with desmoid-type fibromatosis or nodular fasciitis-like stroma is an extremely unusual and poorly understood subtype of papillary thyroid cancer. Although prior studies have demonstrated alterations in the Wnt/β-catenin signaling pathway in some of these tumors, controversy still exists regarding the nature of the stromal spindle component. We have studied seven cases of papillary thyroid carcinoma with prominent myofibroblastic stroma, including six men and one woman aged 20-65 years (mean age = 44). All cases displayed areas consistent with conventional papillary thyroid carcinoma embedded in abundant myofibroblastic-like stroma. The myofibroblastic stroma in six cases resembled desmoid-type fibromatosis and in one case it more closely resembled nodular fasciitis. By immunohistochemical staining, the stromal spindle component showed positivity for SMA and low MIB1 proliferation index in all cases, and there was at least patchy strong nuclear positivity for beta-catenin in six/seven cases. Stains for cytokeratin AE1/AE3 and PAX8 were positive in the epithelial elements but negative in the stromal component. Next-generation sequencing was performed on six of seven cases. CTNNB1 gene mutations were identified in six/seven cases. The epithelial component showed BRAF mutations in two cases and an NRAS mutation in one case. The case with fasciitis-like stroma was negative for beta-catenin by sequencing and immunostaining as well as negative for USP6 gene rearrangement. Our findings indicate that papillary thyroid carcinoma with prominent myofibroblastic stroma may represent more than one category of lesions.
- MeSH
- beta-katenin genetika metabolismus MeSH
- buňky stromatu metabolismus patologie MeSH
- dospělí MeSH
- imunohistochemie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mutace MeSH
- myofibroblasty metabolismus patologie MeSH
- nádorové biomarkery metabolismus MeSH
- nádory štítné žlázy genetika metabolismus patologie MeSH
- papilární karcinom štítné žlázy genetika metabolismus patologie MeSH
- protoonkogenní proteiny B-raf genetika metabolismus MeSH
- senioři MeSH
- štítná žláza metabolismus patologie MeSH
- transkripční faktor PAX8 genetika metabolismus MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND & AIMS: Hepatoblastoma (HB) is a rare disease. Nevertheless, it is the predominant pediatric liver cancer, with limited therapeutic options for patients with aggressive tumors. Herein, we aimed to uncover the mechanisms of HB pathobiology and to identify new biomarkers and therapeutic targets in a move towards precision medicine for patients with advanced HB. METHODS: We performed a comprehensive genomic, transcriptomic and epigenomic characterization of 159 clinically annotated samples from 113 patients with HB, using high-throughput technologies. RESULTS: We discovered a widespread epigenetic footprint of HB that includes hyperediting of the tumor suppressor BLCAP concomitant with a genome-wide dysregulation of RNA editing and the overexpression of mainly non-coding genes of the oncogenic 14q32 DLK1-DIO3 locus. By unsupervised analysis, we identified 2 epigenomic clusters (Epi-CA, Epi-CB) with distinct degrees of DNA hypomethylation and CpG island hypermethylation that are associated with the C1/C2/C2B transcriptomic subtypes. Based on these findings, we defined the first molecular risk stratification of HB (MRS-HB), which encompasses 3 main prognostic categories and improves the current clinical risk stratification approach. The MRS-3 category (28%), defined by strong 14q32 locus expression and Epi-CB methylation features, was characterized by CTNNB1 and NFE2L2 mutations, a progenitor-like phenotype and clinical aggressiveness. Finally, we identified choline kinase alpha as a promising therapeutic target for intermediate and high-risk HBs, as its inhibition in HB cell lines and patient-derived xenografts strongly abrogated tumor growth. CONCLUSIONS: These findings provide a detailed insight into the molecular features of HB and could be used to improve current clinical stratification approaches and to develop treatments for patients with HB. LAY SUMMARY: Hepatoblastoma is a rare childhood liver cancer that has been understudied. We have used cutting-edge technologies to expand our molecular knowledge of this cancer. Our biological findings can be used to improve clinical management and pave the way for the development of novel therapies for this cancer.
- MeSH
- beta-katenin genetika MeSH
- cholinkinasa * antagonisté a inhibitory metabolismus MeSH
- epigeneze genetická MeSH
- hepatoblastom * genetika metabolismus mortalita patologie MeSH
- hodnocení rizik metody MeSH
- kojenec MeSH
- lidé MeSH
- membránové proteiny genetika MeSH
- metylace DNA MeSH
- nádorové biomarkery analýza MeSH
- nádorové proteiny genetika MeSH
- nádory jater * genetika metabolismus mortalita patologie MeSH
- objevování léků metody MeSH
- prognóza MeSH
- proteiny vázající vápník genetika MeSH
- rychlé screeningové testy MeSH
- stanovení celkové genové exprese MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
