scholarly journals Activation of RAS Signalling is Associated with Altered Cell Adhesion in Phaeochromocytoma

2020 ◽  
Vol 21 (21) ◽  
pp. 8072
Author(s):  
Hugo M. Rossitti ◽  
Ravi Kumar Dutta ◽  
Catharina Larsson ◽  
Hans K. Ghayee ◽  
Peter Söderkvist ◽  
...  

Phaeochromocytomas and paragangliomas (PPGLs) are neuroendocrine catecholamine-producing tumours that may progress into inoperable metastatic disease. Treatment options for metastatic disease are limited, indicating a need for functional studies to identify pharmacologically targetable pathophysiological mechanisms, which require biologically relevant experimental models. Recently, a human progenitor phaeochromocytoma cell line named “hPheo1” was established, but its genotype has not been characterised. Performing exome sequencing analysis, we identified a KIF1B T827I mutation, and the oncogenic NRAS Q61K mutation. While KIF1B mutations are recurring somatic events in PPGLs, NRAS mutations have hitherto not been detected in PPGLs. Therefore, we aimed to assess its implications for the hPheo1 cell line, and possible relevance for the pathophysiology of PPGLs. We found that transient downregulation of NRAS in hPheo1 led to elevated expression of genes associated with cell adhesion, and enhanced adhesion to hPheo1 cells’ extracellular matrix. Analyses of previously published mRNA data from two independent PPGL patient cohorts (212 tissue samples) revealed a subcluster of PPGLs featuring hyperactivated RAS pathway-signalling and under-expression of cell adhesion-related gene expression programs. Thus, we conclude that NRAS activity in hPheo1 decreases adhesion to their own extracellular matrix and mirrors a transcriptomic RAS-signalling-related phenomenon in PPGLs.

Author(s):  
Nicole Bechmann ◽  
Graeme Eisenhofer

AbstractGermline or somatic driver mutations linked to specific phenotypic features are identified in approximately 70% of all catecholamine-producing pheochromocytomas and paragangliomas (PPGLs). Mutations leading to stabilization of hypoxia-inducible factor 2α (HIF2α) and downstream pseudohypoxic signaling are associated with a higher risk of metastatic disease. Patients with metastatic PPGLs have a variable prognosis and treatment options are limited. In most patients with PPGLs, germline mutations lead to the stabilization of HIF2α. Mutations in HIF2α itself are associated with adrenal pheochromocytomas and/or extra-adrenal paragangliomas and about 30% of these patients develop metastatic disease; nevertheless, the frequency of these specific mutations is low (1.6–6.2%). Generally, mutations that lead to stabilization of HIF2α result in distinct catecholamine phenotype through blockade of glucocorticoid-mediated induction of phenylethanolamine N-methyltransferase, leading to the formation of tumors that lack epinephrine. HIF2α, among other factors, also contributes importantly to the initiation of a motile and invasive phenotype. Specifically, the expression of HIF2α supports a neuroendocrine-to-mesenchymal transition and the associated invasion-metastasis cascade, which includes the formation of pseudopodia to facilitate penetration into adjacent vasculature. The HIF2α-mediated expression of adhesion and extracellular matrix genes also promotes the establishment of PPGL cells in distant tissues. The involvement of HIF2α in tumorigenesis and in multiple steps of invasion-metastasis cascade underscores the therapeutic relevance of targeting HIF2α signaling pathways in PPGLs. However, due to emerging resistance to current HIF2α inhibitors that target HIF2α binding to specific partners, alternative HIF2α signaling pathways and downstream actions should also be considered for therapeutic intervention.


2002 ◽  
Vol 48 (1) ◽  
pp. 31-38
Author(s):  
SHINJI NAKAMURA ◽  
NOBUYUKI EBIHARA ◽  
AKIRA MURAKAMI ◽  
NORIYOSHI SUEYOSHI

Biomolecules ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1506
Author(s):  
Nicola Cirillo ◽  
Stephen S. Prime

Pemphigus and pemphigoid diseases are potentially life-threatening autoimmune blistering disorders that are characterized by intraepithelial and subepithelial blister formation, respectively. In both disease groups, skin and/or mucosal blistering develop as a result of a disruption of intercellular adhesion (pemphigus) and cell-extracellular matrix (ECM) adhesion (pemphigoid). Given that metalloproteinases can target cell adhesion molecules, the purpose of the present study was to investigate the role of these enzymes in the pathogenesis of these bullous dermatoses. Studies examining MMPs (matrix metalloproteinases) and the ADAM (a disintegrin and metalloproteinase) family of proteases in pemphigus and pemphigoid were selected from articles published in the repository of the National Library of Medicine (MEDLINE/PubMed) and bioRxiv. Multiple phases of screening were conducted, and relevant data were extracted and tabulated, with 29 articles included in the final qualitative analysis. The majority of the literature investigated the role of specific components of the MMP family primarily in bullous pemphigoid (BP) whereas studies that focused on pemphigus were rarer. The most commonly studied metalloproteinase was MMP-9 followed by MMP-2; other MMPs included MMP-1, MMP-3, MMP-8, MMP-12 and MMP-13. Molecules related to MMPs were also included, namely, ADAM5, 8, 10, 15, 17, together with TIMP-1 and TIMP-3. The results demonstrated that ADAM10 and MMP-9 activity is necessary for blister formation in experimental models of pemphigus vulgaris (PV) and BP, respectively. The data linking MMPs to the pathogenesis of experimental BP were relatively strong but the evidence for involvement of metalloproteinases in PV was more tentative. These molecules represent potential candidates for the development of mechanism-based treatments of these blistering diseases.


1992 ◽  
Vol 116 (3) ◽  
pp. 809-815 ◽  
Author(s):  
K M Neugebauer ◽  
K A Venstrom ◽  
L F Reichardt

The adhesive interactions of circulating blood cells are tightly regulated, receptor-mediated events. To establish a model for studies on regulation of cell adhesion, we have examined the adhesive properties of the HD11 chick myeloblast cell line. Function-perturbing antibodies were used to show that integrins containing the beta 1 subunit mediate HD11 cell attachment to several distinct extracellular matrix proteins, specifically fibronectin, collagen, vitronectin, and fibrinogen. This is the first evidence that an integrin heterodimer in the beta 1 family functions as a receptor for fibrinogen. While the alpha v beta 1 heterodimer has been shown to function as a vitronectin receptor on some cells, this heterodimer could not be detected on HD11 cells. Instead, results suggest that the beta 1 subunit associates with different, unidentified alpha subunit(s) to form receptors for vitronectin and fibrinogen. Results using function-blocking antibodies also demonstrate that on these cells, additional receptors for vitronectin are formed by alpha v beta 3 and alpha v associated with an unidentified 100-kD beta subunit. The adhesive interactions of HD11 cells with these extracellular matrix ligands were shown to be regulated by lipopolysaccharide treatment, making the HD11 cell line attractive for studies of mechanisms regulating cell adhesion. In contrast to primary macrophage which rapidly exhibit enhanced adhesion to laminin and collagen upon activation, activated HD11 cells exhibited reduced adhesion to most extracellular matrix constituents.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 736
Author(s):  
Cian Gavin ◽  
Nele Geerts ◽  
Brenton Cavanagh ◽  
Meagan Haynes ◽  
C. Patrick Reynolds ◽  
...  

Neuroblastoma is a paediatric malignancy of the developing sympathetic nervous system. About half of the patients have metastatic disease at the time of diagnosis and a survival rate of less than 50%. Our understanding of the cellular processes promoting neuroblastoma metastases will be facilitated by the development of appropriate experimental models. In this study, we aimed to explore the invasion of neuroblastoma cells and organoids from patient-derived xenografts (PDXs) grown embedded in 3D extracellular matrix (ECM) hydrogels by time-lapse microscopy and quantitative image analysis. We found that the ECM composition influenced the growth, viability and local invasion of organoids. The ECM compositions induced distinct cell behaviours, with Matrigel being the preferred substratum for local organoid invasion. Organoid invasion was cell line- and PDX-dependent. We identified six distinct phenotypes in PDX-derived organoids. In contrast, NB cell lines were more phenotypically restricted in their invasion strategies, as organoids isolated from cell line-derived xenografts displayed a broader range of phenotypes compared to clonal cell line clusters. The addition of FBS and bFGF induced more aggressive cell behaviour and a broader range of phenotypes. In contrast, the repression of the prognostic neuroblastoma marker, MYCN, resulted in less aggressive cell behaviour. The combination of PDX organoids, real-time imaging and the novel 3D culture assays developed herein will enable rapid progress in elucidating the molecular mechanisms that control neuroblastoma invasion.


2022 ◽  
Author(s):  
Hao Li ◽  
Zihan Yan ◽  
Ran Huo ◽  
Xiaolong Ya ◽  
Hongyuan Xu ◽  
...  

Abstract BackgroundBrain arteriovenous malformation (BAVM) arises as congenital vascular abnormalities with a significant risk for intracerebral hemorrhage (ICH). RNA sequencing technology has been recently used to investigate the mechanism of diseases owing to its ability to identify the gene changes on a transcriptome-wide level. In this study, we aimed to gain insights into the potential mechanism involved in BAVM rupture. MethodsSixty-five BAVM nidus samples were collected among which 28 were ruptured and 37 were un-ruptured. Then next-generation RNA sequencing were performed on all of them to obtain differential expressed genes (DEGs) between these two groups. In addition, bioinformatics analysis was performed to evaluate the involved biological processes and pathways by GO and KEGG analysis. Finally, univariate Cox regression analysis was utilized to obtain the early rupture-prone DEGs. Results: A total of 951 genes were differentially expressed between ruptured and un-ruptured BAVM group, of which 740 genes were up-regulated and 211 genes were down-regulated in ruptured BAVMs. Then bioinformatics analysis showed the biological processes and pathways related to the inflammatory processes and extracellular matrix organization were significantly enriched. Meanwhile, some of down-regulated genes are involved in cell adhesion and genes participating in response to muscle activity, as well as the terms about nervous system development. Finally, one hundred and twenty-five genes, a large number of which were involved in inflammation, were correlated with the early rupture of BAVMs. Conclusions: The up-regulated genes in ruptured BAVM group were involved in inflammatory processes and extracellular matrix organization while some of the down-regulated genes were participating in cell adhesion and myofibril assembly, indicating the role of enhanced inflammation and reduced vessel strength in BAVMs rupture.


2021 ◽  
Vol 10 (4) ◽  
pp. 711
Author(s):  
Byung-Chul Lee ◽  
Insung Kang ◽  
Kyung-Rok Yu

Identification of the immunomodulatory and regenerative properties of mesenchymal stem cells (MSCs) have made them an attractive alternative therapeutic option for diseases with no effective treatment options. Numerous clinical trials have followed; however, issues such as infusional toxicity and cellular rejection have been reported. To address these problems associated with cell-based therapy, MSC exosome therapy was developed and has shown promising clinical outcomes. MSC exosomes are nanosized vesicles secreted from MSCs and represent a non-cellular therapeutic agent. MSC exosomes retain therapeutic features of the cells from which they originated including genetic material, lipids, and proteins. Similar to MSCs, exosomes can induce cell differentiation, immunoregulation, angiogenesis, and tumor suppression. MSC exosomes have therefore been employed in several experimental models and clinical studies. Here, we review the therapeutic potential of MSC-derived exosomes and summarize currently ongoing clinical trials according to disease type. In addition, we propose several functional enhancement strategies for the effective clinical application of MSC exosome therapy.


Sign in / Sign up

Export Citation Format

Share Document