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120 result(s) for "Choristoma - genetics"
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Single-cell analysis of endometriosis reveals a coordinated transcriptional programme driving immunotolerance and angiogenesis across eutopic and ectopic tissues
Endometriosis is characterized by the growth of endometrial-like tissue outside the uterus. It affects many women during their reproductive age, causing years of pelvic pain and potential infertility. Its pathophysiology remains largely unknown, which limits early diagnosis and treatment. We characterized peritoneal and ovarian lesions at single-cell transcriptome resolution and compared them to matched eutopic endometrium, unaffected endometrium and organoids derived from these tissues, generating data on over 122,000 cells across 14 individuals. We spatially localized many of the cell types using imaging mass cytometry. We identify a perivascular mural cell specific to the peritoneal lesions, with dual roles in angiogenesis promotion and immune cell trafficking. We define an immunotolerant peritoneal niche, fundamental differences in eutopic endometrium and between lesion microenvironments and an unreported progenitor-like epithelial cell subpopulation. Altogether, this study provides a holistic view of the endometriosis microenvironment that represents a comprehensive cell atlas of the disease in individuals undergoing hormonal treatment, providing essential information for future therapeutics and diagnostics. Using single-cell analysis, Tan et al. map the cellular and spatial hierarchy and heterogeneity of eutopic endometrium and characterize ectopic peritoneal and ovarian endometriosis lesions from individuals receiving hormone treatment.
Frequent CTNNB1 p.S45 Mutations and Aggressive Clinical Behavior in Neuromuscular Choristoma-Associated Fibromatosis
Abstract BACKGROUND Neuromuscular choristoma (NMC) is a peripheral nerve malformation frequently associated with a fibromatosis (NMC-DTF) that mimics sporadic desmoid-type fibromatosis (DTF). Sporadic DTF is often managed conservatively but its clinical behavior varies. CTNNB1 mutational subtypes in sporadic DTF have prognostic value. We have previously identified CTNNB1 mutations in NMC, and 3 paired NMC-DTF but the clinical behavior of NMC-DTF is poorly understood. OBJECTIVE To evaluate patients with NMC-DTF to determine (1) CTNNB1 mutational subtypes in NMC-DTF, and (2) associated clinical behavior and response to treatment. METHODS Retrospective review of clinical, imaging, and pathologic features of patients with NMC and NMC-DTF, and molecular testing for CTNNB1 mutations. RESULTS Among 7 patients with NMC of the sciatic nerve (median age: 18 yr), NMC-DTF (mean size 10.7 cm) developed shortly following NMC biopsy (N = 5) or spontaneously (N = 2): 6 NMC-DTF had CTNNB1 p.S45X mutations and 1 NMC-DTF had a p.T41A mutation. All patients with CTNNB1-p.S45-mutated NMC-DTF developed local progression after wide local excision or active surveillance, including one distal metachronous NMC-DTF. No patient had spontaneous disease stabilization. Following adjuvant radiation or systemic therapy, disease stabilization was achieved in 4 (of 6) patients. One patient progressed on sorafenib treatment. CONCLUSION NMC-DTF frequently contain CTNNB1 p.S45 mutations, behave aggressively, and require adjuvant therapies for disease stabilization. We now use imaging alone to diagnose NMC, and routinely surveille the NMC-affected nerve segment to identify early NMC-DTF. In contrast to sporadic DTF, earlier adoption of systemic therapeutic strategies may be required for optimal disease management of NMC-DTF.
Telomerase modulates Wnt signalling by association with target gene chromatin
Stem cells are controlled, in part, by genetic pathways frequently dysregulated during human tumorigenesis. Either stimulation of Wnt/β-catenin signalling or overexpression of telomerase is sufficient to activate quiescent epidermal stem cells in vivo , although the mechanisms by which telomerase exerts these effects are not understood. Here we show that telomerase directly modulates Wnt/β-catenin signalling by serving as a cofactor in a β-catenin transcriptional complex. The telomerase protein component TERT (telomerase reverse transcriptase) interacts with BRG1 (also called SMARCA4), a SWI/SNF-related chromatin remodelling protein, and activates Wnt-dependent reporters in cultured cells and in vivo . TERT serves an essential role in formation of the anterior–posterior axis in Xenopus laevis embryos, and this defect in Wnt signalling manifests as homeotic transformations in the vertebrae of Tert -/- mice. Chromatin immunoprecipitation of the endogenous TERT protein from mouse gastrointestinal tract shows that TERT physically occupies gene promoters of Wnt-dependent genes. These data reveal an unanticipated role for telomerase as a transcriptional modulator of the Wnt/β-catenin signalling pathway. Telomerase link to Wnt signalling The Wnt/β-catenin signalling pathway plays a central role in stem cell biology and has been implicated in tumorigenesis. Telomerase-catalysed addition of DNA repeats to chromosome ends is crucial for stem cell self-renewal and for progenitor cell survival and has also been implicated in tumorigenesis. Park et al . report an unanticipated link between these two pathways with prominent roles in tissue stem cells and cancer. The telomerase component TERT (telomerase reverse transcriptase) is shown act as a transcriptional modulator of the Wnt/β-catenin signalling pathway. The chromatin remodelling protein BRG1, a modulator of Wnt signalling, is identified as a TERT-interacting protein. The genetic pathways controlling stem cells are frequently dysregulated during tumorigenesis, with either stimulation of Wnt/β-catenin signalling or overexpression of telomerase sufficient to activate epidermal stem cells in vivo . Here, the telomerase protein component TERT (telomerase reverse transcriptase) is shown to have a role as a transcriptional modulator of the Wnt/β-catenin pathway, revealing a significant level of integration between the two pathways.
Neuromuscular Choristoma: Report of Five Cases With CTNNB1 Sequencing
Abstract Neuromuscular choristoma (NMC) are lesions of the peripheral nervous system characterized by an admixture of skeletal muscle fibers and nerves fascicles that are frequently associated with desmoid fibromatosis (DF). Mutations in CTNNB1, the gene for β-catenin protein, are common in DF and related to its pathogenesis. They are restricted to exon 3, with 3 point mutations: T41A, S45F, and S45P. To understand the pathogenesis of NMC, we tested CTNNB1 status in 5 cases of NMC whether or not they were associated with DF. The screening of mutations in CTNNB1 gene was based on amplicon deep sequencing using the ION Proton platform. Three patients had the S45F mutation; in 2 the mutation was common to both lesions and in one the DF was wild type while the NMC had the S45F mutation. One patient had a T41A mutation in the NMC and no associated DF. In the last patient, the DF lesion had a T41A mutation; there was no lesion with the S45P mutation. The presence of similar CTNNB1 mutations in NMC/DF-associated lesions and sporadic DF reinforces the relationship between both lesions and points to a common pathogenic mechanism.
CTNNB1 mutation-driven hybrid tumor: desmoid fibromatosis with an unusual associated epithelioid component arising in association with a neuromuscular choristoma
CTNNB1 mutations play important roles in the development of soft tissue tumors, such as desmoid fibromatosis (DF), sinonasal tract angiofibroma, sinonasal glomangiopericytoma, intranodal palisaded myofibroblastoma, neuromuscular choristoma (NMC), and the recently reported pseudoendocrine sarcoma. Here, we report a unique hybrid soft tissue tumor with classic DF, unusual epithelioid component, and NMC in a 23-year-old female. The classic DF and NMC and the unusual epithelioid component and NMC were locally intermixed and closely related to each other. Immunohistochemically, the DF, unusual epithelioid component, and NMC exhibited nuclear positivity for β-catenin to varying degrees. More critically, all of the above components harbored identical CTNNB1 p.Ser45Pro missense mutations. To the best of our knowledge, this is the only reported CTNNB1 mutation-driven hybrid tumor with DF, unusual epithelioid component, and NMC. The present case further confirmed that CTNNB1-mutational soft tissue tumors are highly heterogeneous, but the morphological spectrum is wide and consecutive.
Nobiletin alleviates endometriosis via down-regulating NF-κB activity in endometriosis mouse model
Nobiletin exhibits protective potential on inflammation and inhibits the activation of transcription factors nuclear factor-κB (NF-κB). However, its effects on the progression of endometriosis remain unsettled. The present study aimed to explore the in vivo alleviation of nobiletin on endometriosis and its mechanism of action. The mouse model of endometriosis was established and administered with nobiletin. The ectopic lesion size was measured and the hotplate test was performed to assess the amelioration of nobiletin on endometriosis. The expression of proliferation and angiogenesis relevant genes including proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and E-cadherin was measured by immunostaining and the mRNA expression of proinflammatory mediators including interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, matrix metalloproteinases (MMP)-1, and MMP-3 was measured by RT-PCR. The change of NF-κB activity in endometriotic cells was evaluated by Western blotting and confirmed by luciferase assay. Administration of nobiletin significantly reduced lesions size and pain in endometriosis mice. Nobiletin significantly altered the expression of PCNA, VEGF, and E-cadherin in ectopic endometrium, as well as the levels of IL-6, IL-1β, TNF-α, MMP-1, and MMP-3. Nobiletin also showed remarkably impairment on the activation of NF-κB in promoting endometriotic cells, likely targeting on the activity of IκB kinases (IKKs). The present study provides the first evidence that nobiletin exerts protection on endometriosis via inhibition the activation of NF-κB, specifically on the activity of IκB kinases.
Lack of CD45 in FLT3-ITD mice results in a myeloproliferative phenotype, cortical porosity, and ectopic bone formation
The receptor tyrosine kinase FLT3 is expressed in myeloid and lymphoid progenitor cells. Activating mutations in FLT3 occur in 25–30% of acute myeloid leukaemia (AML) patients. Most common are internal tandem duplications of sequence (ITD) leading to constitutive FLT3-ITD kinase activity with an altered signalling quality promoting leukaemic cell transformation. Here, we observed the attenuating role of the receptor-like protein tyrosine phosphatase (RPTP) CD45/Ptprc in FLT3 signalling in vivo. Low level expression of this abundant RPTP correlates with a poor prognosis of FLT3-ITD-positive AML patients. To get a further insight into the regulatory role of Ptprc in FLT3-ITD activity in vivo, Ptprc knock-out mice were bred with FLT3-ITD knock-in mice. Inactivation of the Ptprc gene in FLT3-ITD mice resulted in a drastically shortened life span and development of severe monocytosis, a block in B-cell development and anaemia. The myeloproliferative phenotype was associated with extramedullary haematopoiesis, splenohepatomegaly and severe alterations of organ structures. The phenotypic alterations were associated with increased transforming signalling of FLT3-ITD, including activation of its downstream target STAT5. These data reveal the capacity of Ptprc for the regulation of FLT3-ITD signalling activity in vivo. In addition, histopathology and computed tomography (CT) revealed an unexpected bone phenotype; the FLT3-ITD Ptprc -/- mice, but none of the controls, showed pronounced alterations in bone morphology and, in part, apparent features of osteoporosis. In the spleen, ectopic bone formation was observed. The observed bone phenotypes suggest a previously unappreciated capacity of FLT3-ITD (and presumably FLT3) to regulate bone development/remodelling, which is under negative control of CD45/Ptprc. Key points Low PTPRC expression of FLT3-ITD-positive AML patients correlates with poor prognosis FLT3-ITD/ Ptprc -/- mice develop severe monocytosis, a block in B-cell formation and anaemia FLT3-ITD/ Ptprc -/- mice develop myeloproliferative neoplasm with extramedullary haematopoiesis and splenohepatomegaly Inactivation of Ptprc in the presence of FLT3-ITD results in cortical porosity and ectopic bone formation Ptprc is negatively regulating transforming FLT3-ITD signalling in vivo
PreImplantation Factor in endometriosis: A potential role in inducing immune privilege for ectopic endometrium
Endometriosis is a chronic inflammatory condition characterised by the growth of endometrial epithelial and stromal cells outside the uterine cavity. In addition to Sampson's theory of retrograde menstruation, endometriosis pathogenesis is facilitated by a privileged inflammatory microenvironment, with T regulatory FoxP3+ expressing T cells (Tregs) being a significant factor. PreImplantation Factor (PIF) is a peptide essential for pregnancy recognition and development. An immune modulatory function of the synthetic PIF analog (sPIF) has been successfully confirmed in multiple animal models. We report that PIF is expressed in the epithelial ectopic cells in close proximity to FoxP3+ stromal cells. We provide evidence that PIF interacts with FoxP3+ cells and modulates cell viability, dependent on cell source and presence of inflammatory mediators. Our finding represent a novel PIF-based mechanism in endometriosis that has potential for novel therapeutics.
Mutations in Eml1 lead to ectopic progenitors and neuronal heterotopia in mouse and human
Kielar and colleagues identified mutations in the microtubule-associated protein Eml1 in patients with severe cortical heterotopia. Using animal and cell models, the authors found that Eml1 inactivation alters spindle orientation in dividing neuronal progenitors during early corticogenesis, leading to their detachment from the ventricular zone, their accumulation in the intermediate zone and the subsequent development of subcortical heterotopia. Neuronal migration disorders such as lissencephaly and subcortical band heterotopia are associated with epilepsy and intellectual disability. DCX , PAFAH1B1 and TUBA1A are mutated in these disorders; however, corresponding mouse mutants do not show heterotopic neurons in the neocortex. In contrast, spontaneously arisen HeCo mice display this phenotype, and our study revealed that misplaced apical progenitors contribute to heterotopia formation. While HeCo neurons migrated at the same speed as wild type, abnormally distributed dividing progenitors were found throughout the cortical wall from embryonic day 13. We identified Eml1 , encoding a microtubule-associated protein, as the gene mutated in HeCo mice. Full-length transcripts were lacking as a result of a retrotransposon insertion in an intron. Eml1 knockdown mimicked the HeCo progenitor phenotype and reexpression rescued it. We further found EML1 to be mutated in ribbon-like heterotopia in humans. Our data link abnormal spindle orientations, ectopic progenitors and severe heterotopia in mouse and human.
MicroRNA-202 inhibits endometrial stromal cell migration and invasion by suppressing the K-Ras/Raf1/MEK/ERK signaling pathway
The enhanced migratory ability of endometrial stromal cells (ESCs) is a key factor in the formation of functional endometrium-like tissues outside the uterine cavity during endometriosis (EMS). Although accumulating evidence has suggested the importance of microRNAs (miRNAs) in the pathogenesis of EMS, the role of particular miRNAs in the invasiveness of ESCs remain poorly understood. In the present study, the function of miRNAs in the invasiveness of ESCs, along with the associated underlying mechanism involved, were investigated. Initially, the expression patterns of miRNAs in the ectopic and eutopic endometrium isolated from patients with EMS were analyzed using microarray. MicroRNA-202-5p (miR-202) was selected for further study due to its previously reported suppressive effects on the invasion in various types of cancers. The expression of miR-202 and K-Ras in eutopic and ectopic endometrioma tissues were detected using reverse transcription-quantitative PCR, immunohistochemistry and western blotting. The migration and invasion ability of ESCs was determined using wound healing and Transwell invasion assays, respectively. Compared with that from healthy individuals, miR-202 expression was demonstrated to be lower in the eutopic endometrium from patients with EMS, which was even lower in ectopic endometrium. Functional experiments in primary ESCs revealed that enhanced miR-202 expression suppressed the cell invasion and migration abilities, which was also accompanied with increased E-cadherin and reduced N-cadherin expression in ESCs, suggesting its potentially suppressive role in epithelial-mesenchymal transition. K-Ras is a well-known regulator of the ERK signaling pathway that was shown to be directly targeted and negatively regulated by miR-202. In addition, K-Ras expression was found to be upregulated in the ectopic endometrium, where it correlated negatively with that of miR-202. Knocking down K-Ras expression mimicked the anti-invasive effects of miR-202 overexpression on ESCs, whilst K-Ras overexpression attenuated the inhibitory role of miR-202 overexpression in ESC invasion. The K-Ras/Raf1/MEK/ERK signaling pathway was also blocked by miR-202 overexpression. These findings suggested that miR-202 inhibited ESC migration and invasion by inhibiting the K-Ras/Raf1/MEK/ERK signaling pathway, rendering miR-202 a candidate for being a therapeutic target for EMS.