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5,764 result(s) for "beta Catenin - genetics"
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ZNRF3 functions in mammalian sex determination by inhibiting canonical WNT signaling
Mammalian sex determination is controlled by the antagonistic interactions of two genetic pathways: The SRY-SOX9-FGF9 network promotes testis determination partly by opposing proovarian pathways, while RSPO1/WNT-β-catenin/FOXL2 signals control ovary development by inhibiting SRY-SOX9-FGF9. The molecular basis of this mutual antagonism is unclear. Here we show that ZNRF3, a WNT signaling antagonist and direct target of RSPO1-mediated inhibition, is required for sex determination in mice. XY mice lacking ZNRF3 exhibit complete or partial gonadal sex reversal, or related defects. These abnormalities are associated with ectopic WNT/β-catenin activity and reduced Sox9 expression during fetal sex determination. Using exome sequencing of individuals with 46, XY disorders of sex development, we identified three human ZNRF3 variants in very rare cases of XY female presentation. We tested two missense variants and show that these disrupt ZNRF3 activity in both human cell lines and zebrafish embryo assays. Our data identify a testis-determining function for ZNRF3 and indicate a mechanism of direct molecular interaction between two mutually antagonistic organogenetic pathways.
Probiotics ameliorate H. pylori-associated gastric β-catenin and COX-2 carcinogenesis signaling by regulating miR-185
Background This study aimed to investigate whether probiotics can ameliorate the H. pylori -induced Wnt/β-catenin-related COX-2 carcinogenesis signaling pathway by regulating the expression of microRNAs (miRNAs). Methods An H. pylori isolate and GES-1 cells were used to establish a COX-2-associated carcinogenesis axis. Western blot analysis was conducted to investigate Wnt/β-catenin and COX-2 signaling. Next-generation sequencing and DIANA Tools identified significant differences in miRNA expressions. The probiotics Lactobacillus acidophilus and Bifidobacterium lactis were used to study anti-carcinogenesis effects in GES-1 and miRNA-transfected GES-1 cells. The H. pylori -infected patients with intestinal metaplasia (IM) were randomly allocated into probiotic treatment or not after successful eradication, the IM regression was assessed by the 2nd esophagogastroduodenoscopy one year after treatment. Results Pretreatment with probiotics significantly reduced H. pylori -induced nuclear β-catenin phosphorylation and COX-2 levels in GES-1 cells. Among 9 significantly altered miRNAs, miR-185 was the only miRNA targeting the Wnt/β-catenin signaling pathway. H. pylori increased miR-185 expression and upregulated COX-2 carcinogenesis through the Wnt/β-catenin pathway, but not the JAK2/STAT3 pathway. B. lactis ameliorated H. pylori -induced miR-185 expression and nuclear β-catenin/COX-2 signaling in a dose-dependent manner. In the 6-month probiotic-treated patients had a significantly higher IM regression rate than controls (intention-to-treat: 37.5 vs 11.5%, OR: 4.60, 95% CI: 1.134–18.65, p  = 0.025; per-protocol: 46.2 vs 17.6%, OR: 4.00, 95% CI: 0.923–17.33, p  = 0.055). Patients without IM regression had significantly higher miR-185 levels in follow-up biopsies ( p  < 0.01). Conclusions Pretreatment with B. lactis ameliorated the H. pylori -induced COX-2 carcinogenesis pathway by reducing miR-185 expression, which targets Wnt/β-catenin signaling. (ClinicalTrials.gov, NCT05544396).
Effects of letrozole and clomiphene citrate on Wnt signaling pathway in endometrium of polycystic ovarian syndrome and healthy women
Polycystic ovary syndrome (PCOS) is an endocrine disorder in women of reproductive age. In addition to anovulation, endometrial dysfunction can reduce fertility in PCOS. The cyclical changes of endometrium are controlled by estrogen and progesterone via modulating the Wnt/B-catenin pathway. Clomiphene citrate (CC) and letrozole are used to induce ovulation; unlike letrozole, there is a discrepancy between ovulation and pregnancy rates in CC-treated cycles. Because of the antiestrogenic effects of CC on endometrium, we compared the expression of the key molecules of the Wnt/B-catenin pathway in the endometrium of women taking CC and letrozole. This study included PCOS and healthy women divided into the groups stimulated with letrozole (5 mg) or CC (100 mg) as well as NO-treatment groups. The endometrial thickness and hormonal profile were measured on day 12 of the menses. Using real-time polymerase chain reaction and western blot, we evaluated mRNA and protein expression of B-catenin, glycogen synthase kinase 3 beta (GSK3B), dickkopf Wnt signaling pathway inhibitor 1 (DKK1), and estrogen receptor 1 (ESR1) in the endometrial samples. Significantly, the mean serum estrogen and progesterone were lower and higher, respectively, in letrozole than CC groups. The endometrial thickness was significantly reduced in CC. The proteins expression of active B-catenin, inactive GSK3B, and ESR1 were significantly decreased in CC-treated groups. The mRNA and protein assessment of DKK1 showed significantly higher expression in CC. Our results indicate that letrozole can provide an acceptable activation of the Wnt/B-catenin pathway, resulting in adequate proliferation of endometrium in the women receiving letrozole compared to CC. Summary Sentence The expression of B-catenin, GSK3B, DKK1, and ESR1 were adversely affected in the endometrium of women induced with clomiphene citrate compared to letrozole, resulting in inefficacity of endometrium.
Relapse patterns and outcome after relapse in standard risk medulloblastoma: a report from the HIT-SIOP-PNET4 study
The HIT-SIOP-PNET4 randomised trial for standard risk medulloblastoma (MB) (2001–2006) included 338 patients and compared hyperfractionated and conventional radiotherapy. We here report the long-term outcome after a median follow up of 7.8 years, including detailed information on relapse and the treatment of relapse. Data were extracted from the HIT Group Relapsed MB database and by way of a specific case report form. The event-free and overall (OS) survival at 10 years were 76 ± 2 % and 78 ± 2 % respectively with no significant difference between the treatment arms. Seventy-two relapses and three second malignant neoplasms were reported. Thirteen relapses (18 %) were isolated local relapses in the posterior fossa (PF) and 59 (82 %) were craniospinal, metastatic relapses (isolated or multiple) with or without concurrent PF disease. Isolated PF relapse vs all other relapses occurred at mean/median of 38/35 and 28/26 months respectively (p = 0.24). Late relapse, i.e. >5 years from diagnosis, occurred in six patients (8 %). Relapse treatment consisted of combinations of surgery (25 %), focal radiotherapy (RT 22 %), high dose chemotherapy with stem cell rescue (HDSCR 21 %) and conventional chemotherapy (90 %). OS at 5 years after relapse was 6.0 ± 4 %. In multivariate analysis; isolated relapse in PF, and surgery were significantly associated with prolonged survival whereas RT and HDSCR were not. Survival after relapse was not related to biological factors and was very poor despite several patients receiving intensive treatments. Exploration of new drugs is warranted, preferably based on tumour biology from biopsy of the relapsed tumour.
Correlation of CTNNB1 Mutation Status with Progression Arrest Rate in RECIST Progressive Desmoid-Type Fibromatosis Treated with Imatinib: Translational Research Results from a Phase 2 Study of the German Interdisciplinary Sarcoma Group (GISG-01)
Background CTNNB1 gene mutations are the molecular key events in the majority of sporadic desmoid-type fibromatosis (DF). The specific S45F mutation has been reported to be associated with a more aggressive clinical course in DF. For the current study, the CTNNB1 mutation status was analyzed in DF samples from the prospective German Interdisciplinary Sarcoma Group (GISG) phase 2 study evaluating imatinib to induce progression arrest in DF Response Evaluation Criteria In Solid Tumors (RECIST) progressive patients. Methods Thirty-seven patients were treated with a planned dose of imatinib 800 mg daily over 2 years (NCT01137916). The progression arrest rate (PAR) after 6 months of treatment was the primary endpoint of the study. CTNNB1 exon 3 mutation status was analyzed using Sanger sequencing. Results Thirty-three (97 %) of 34 patients reaching the primary endpoint were evaluable for CTNNB1 mutation exon 3 status. T41A mutations accounted for 30.3 % of the study samples and S45 mutations for 48.5 %, whereas CTNNB1 wild-type status was found in 21.2 %. The respective PAR at 6 months was 70, 81, and 43 %. Patients harboring CTNNB1 mutations demonstrated a higher PAR compared to wild-type DF. There was a statistically significant difference comparing patients with S45F mutations (85 % PAR) versus wild-type status ( p  = 0.05). Conclusions Mutations at position S45 were overrepresented in the GISG-01 trial recruiting RECIST progressive patients only. The positive correlation of CTNNB1 mutation status with the progression arrest rate after imatinib therapy supports the idea of a potential predictive impact of the mutation status on DF treatment decision making.
Tailored Beta-catenin mutational approach in extra-abdominal sporadic desmoid tumor patients without therapeutic intervention
Background The efficacy of the classical treatment modalities surgery and radiotherapy in the treatment of aggressive fibromatosis is presently disputed and there is a shift towards a more conservative approach. The aim of the present study is to objectify tumor growth in patients with extra-abdominal or abdominal wall aggressive fibromatosis, while adhering to a “watchful waiting” policy. Other objectives are to investigate quality of life and to identify factors associated with tumor growth, in particular the relation with the presence of a CTNNB1-gene mutation in the tumor. Design and methods GRAFITI is a nationwide, multicenter, prospective registration trial. All patients with extra-abdominal or abdominal wall aggressive fibromatosis are eligible for inclusion in the study. Main exclusion criteria are: history of familiar adenomatous polyposis, severe pain, functional impairment, life/limb threating situations in case of progressive disease. Patients included in the study will be treated with a watchful waiting policy during a period of 5 years. Imaging studies with ultrasound and magnetic resonance imaging scan will be performed during follow-up to monitor possible growth: the first years every 3 months, the second year twice and the yearly. In addition patients will be asked to complete a quality of life questionnaire on specific follow-up moments. The primary endpoint is the rate of progression per year, defined by the Response Evaluation Criteria In Solid Tumors (RECIST). Secondary endpoints are quality of life and the rate of influence on tumor progression for several factors, such as CTNNB1-mutations, age and localization. Discussion This study will provide insight in tumor behavior, the effect on quality of life and clinicopathological factors predictive of tumor progression. Trial registration The GRAFITI trial is registered in the Netherlands National Trial Register (NTR), number 4714 .
Biologic Evaluation of Diabetes and Local Recurrence in Non-Small Cell Lung Cancer
A recent multicenter study led by our institution demonstrated that local recurrence of non-small cell lung cancer (NSCLC) was significantly more frequent in patients with diabetes, raising the possibility of different tumor biology in diabetics. Epithelial-to-mesenchymal transition (EMT) plays a key role in local tumor recurrence and metastasis. In the present study, we investigated differences of tumor microenvironment between patients with and without diabetes by examining expression of EMT markers. Seventy-nine NSCLC patients were selected from the cohort of our early multicenter study. These patients were classified into 4 groups: 39 with adenocarcinoma with ( n  = 19) and without ( n  = 20) diabetes, and 40 with squamous cell carcinoma with ( n  = 20) and without ( n  = 20) diabetes. Immunohistochemical expression of eight EMT markers was analyzed, including transforming growth factor-beta (TGF-β), epidermal growth factor receptor (EGFR), insulin-like growth factor 1 receptor (IGF-1R), vimentin, E-cadherin, N-cadherin, HtrA1, and beta-catenin. Five markers (E-cadherin, HtrA1, TGF-β, IGF-1R and vimentin) demonstrated significantly higher expression in diabetics than in non-diabetics in both histology types. N-cadherin had higher expression in diabetics, though the difference did not reach statistical significance. EGFR showed a higher expression in diabetics in squamous cell carcinoma only. Beta-catenin was the only marker with no difference in expression between diabetics versus non-diabetics. Our findings suggest that diabetes is associated with enhanced EMT in NSCLC, which may contribute to growth and invasiveness of NSCLC.
A cytosine deaminase for programmable single-base RNA editing
Programmable RNA editing enables reversible recoding of RNA information for research and disease treatment. Previously, we developed a programmable adenosine-to-inosine (A-to-I) RNA editing approach by fusing catalytically inactivate RNA-targeting CRISPR-Cas13 (dCas13) with the adenine deaminase domain of ADAR2. Here, we report a cytidine-to-uridine (C-to-U) RNA editor, referred to as RNA Editing for Specific C-to-U Exchange (RESCUE), by directly evolving ADAR2 into a cytidine deaminase. RESCUE doubles the number of mutations targetable by RNA editing and enables modulation of phosphosignaling-relevant residues. We apply RESCUE to drive β-catenin activation and cellular growth. Furthermore, RESCUE retains A-to-I editing activity, enabling multiplexed C-to-U and A-to-I editing through the use of tailored guide RNAs.
HGF/c-Met related activation of β-catenin in hepatoblastoma
Background Activation of beta-catenin is a hallmark of hepatoblastoma (HB) and appears to play a crucial role in its pathogenesis. While aberrant accumulation of the beta-catenin is a common event in HB, mutations or deletions in CTNNB1 (beta-catenin gene) do not always account for the high frequency of protein expression. In this study we have investigated alternative activation of beta-catenin by HGF/c-Met signaling in a large cohort of 98 HB patients enrolled in the SIOPEL-3 clinical trial. Methods We performed immunohistochemistry, using antibodies to total beta-catenin and tyrosine654-phosphorylated beta-catenin, which is a good surrogate marker of HGF/c-Met activation. CTNNB1 mutation analysis was also carried out on all samples. We also investigated beta-catenin pathway activation in two liver cancer cell lines, HuH-6 and HuH-7. Results Aberrant beta-catenin expression was seen in the cytoplasm and/or nucleus of 87% of tumour samples. Our results also revealed a large subset of HB, 83%, with cytoplasmic expression of tyrosine654-phosphorylated beta-catenin and 30% showing additional nuclear accumulation. Sequence analysis revealed mutations in 15% of our cohort. Statistical analysis showed an association between nuclear expression of c-Met-activated beta-catenin and wild type CTNNB1 (P-value = 0.015). Analysis of total beta-catenin and Y654-beta-catenin in response to HGF activation in the cell lines, mirrors that observed in our HB tumour cohort. Results We identified a significant subset of hepatoblastoma patients for whom targeting of the c-Met pathway may be a treatment option and also demonstrate distinct mechanisms of beta-catenin activation in HB.
β-Catenin signaling in hepatocellular carcinoma
Deregulated Wnt/β-catenin signaling is one of the main genetic alterations in human hepatocellular carcinoma (HCC). Comprehensive genomic analyses have revealed that gain-of-function mutation of CTNNB1, which encodes β-catenin, and loss-of-function mutation of AXIN1 occur in approximately 35% of human HCC samples. Human HCCs with activation of the Wnt/β-catenin pathway demonstrate unique gene expression patterns and pathological features. Activated Wnt/β-catenin synergizes with multiple signaling cascades to drive HCC formation, and it functions through its downstream effectors. Therefore, strategies targeting Wnt/β-catenin have been pursued as possible therapeutics against HCC. Here, we review the genetic alterations and oncogenic roles of aberrant Wnt/β-catenin signaling during hepatocarcinogenesis. In addition, we discuss the implication of this pathway in HCC diagnosis, classification, and personalized treatment.