scholarly journals Molecular dissection of the mechanism by which EWS/FLI expression compromises actin cytoskeletal integrity and cell adhesion in Ewing sarcoma

2014 ◽  
Vol 25 (18) ◽  
pp. 2695-2709 ◽  
Author(s):  
Aashi Chaturvedi ◽  
Laura M. Hoffman ◽  
Christopher C. Jensen ◽  
Yi-Chun Lin ◽  
Allie H. Grossmann ◽  
...  

Ewing sarcoma is the second-most-common bone cancer in children. Driven by an oncogenic chromosomal translocation that results in the expression of an aberrant transcription factor, EWS/FLI, the disease is typically aggressive and micrometastatic upon presentation. Silencing of EWS/FLI in patient-derived tumor cells results in the altered expression of hundreds to thousands of genes and is accompanied by dramatic morphological changes in cytoarchitecture and adhesion. Genes encoding focal adhesion, extracellular matrix, and actin regulatory proteins are dominant targets of EWS/FLI-mediated transcriptional repression. Reexpression of genes encoding just two of these proteins, zyxin and α5 integrin, is sufficient to restore cell adhesion and actin cytoskeletal integrity comparable to what is observed when the EWS/FLI oncogene expression is compromised. Using an orthotopic xenograft model, we show that EWS/FLI-induced repression of α5 integrin and zyxin expression promotes tumor progression by supporting anchorage-independent cell growth. This selective advantage is paired with a tradeoff in which metastatic lung colonization is compromised.

2018 ◽  
Vol 22 (1) ◽  
pp. 30-39
Author(s):  
Francisco Giner ◽  
José A López-Guerrero ◽  
Antonio Fernández-Serra ◽  
Isidro Machado ◽  
Empar Mayordomo-Aranda ◽  
...  

Background Ewing sarcoma (EWS) is the second most common bone cancer in pediatric patients. Angiogenesis is a major factor for tumor growth and metastasis. Our aim was to carry out a histological, immunohistochemical, and molecular characterization of the neovascularization established between xenotransplanted tumors and the host during the initial phases of growth in nude mice in three angiogenesis experiments (ES2, ES3, and ES4). Methods The original human EWS were implanted subcutaneously on the backs of three nude mice. Tumor pieces 3 mm–4 mm in size from early passages of Nu432, Nu495, and Nu471 were also implanted subcutaneously on the backs of three sets (ES2, ES3, and ES4) of athymic Balb-c nude mice (n = 14 each). The animals were sacrificed at 24, 48, and 96 hours and at 7, 14, 21, and 28 days after implantation to perform histological, immunohistochemical, and molecular studies (neovascularization experiments). Results We observed histological, ultrastructural, and immunohistochemical changes in the xenografted tumor at different times after implantation. Chemokine ligand expression peaked twice, once during the first 48 hours and again in the second week. We observed that tumor cells in contact with murine peritumoral stroma presented higher expression of chemokine ligands as well as more tumor cells around the capillary vessels. Mouse serum vascular endothelial growth factor levels peaked twice, once in the first hours and then in the second week after tumor implantation. Conclusion Chemokines and other angiogenic factors may be relevant in the angiogenic mechanism during tumor growth. This model provides information on the early stages of the angiogenic process and could be a useful tool in researching anti-angiogenic drugs for new therapeutic strategies in EWS.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 11532-11532
Author(s):  
Adam Rock ◽  
Warren Allen Chow ◽  
An Uche ◽  
Sherri Z. Millis

11532 Background: Ewing Sarcoma (ES) is an aggressive, translocation-associated, bone cancer associated with a poor prognosis in the recurrent or metastatic setting. ES is identified by the canonical balanced reciprocal chromosomal translocation involving EWSR1 and ETS transcription factors. Secondary somatic alterations in ES are rarely described and genomic alterations (GA) affecting various molecular pathways may work synergistically with ETS-FL1 translocations to promote oncogenesis. Alterations in fibroblast growth factor receptor 4 (FGFR4), a receptor tyrosine kinase protein that functions in cellular processes, have been observed to affect carcinogenesis. Moreover, the FGFR4-Gly388Arg (G388R) single nucleotide polymorphism (SNP) is found to increase the risk of cancer with mouse embryonic fibroblasts derived from knock-in strain of homologous Fgfr4 G385R mice exhibiting a transformed phenotype. We sought to further evaluate the frequency of FGFR4 G388R SNP in relation to other identifiable pathway alterations observed with Comprehensive Genomic Profiling (CGP). Methods: Next generation sequencing (NGS) analysis was obtained in the context of clinical care with clinical status, outcomes, and source acquisition (primary tumor, metastasis, or recurrence) unknown to Foundation Medicine. CGP, FoundationOne Heme, evaluated GAs including base substitutions, indels, amplifications, copy number alterations, gene fusions and rearrangements. 189 samples were assayed by hybrid-capture based CGP, including 406 DNA-sequenced genes in addition to 265 RNA-sequenced genes commonly reported to be rearranged in cancer, as previously described. Tumor mutational burden was assessed from a minimum 1.4 Mb sequenced DNA. Microsatellite instability (MSI) status was determined by a novel algorithm analyzing 114 specific loci. Results: The median age of evaluated patients was 20 (range 0-70) with the number of alterations averaging 7 per patient. Pathways noted to be altered in the presence of FGFR388R SNP occurred frequently with the following pathways most observed: MAPK (33%), WNT (32%), NOTCH1 (20%), HRR (19%), Histone/chromatin remodeling (18%). FGFR388R SNP was observed in more than half (51%) of evaluated samples. Most affected pathways irrespective of FGFR388R SNP status included: MAPK (n = 89), HRR (n = 75), and PIK3 (n = 64). All evaluated samples were TMB low ( < 10 mut/mb) and Microsatellite Stable. Conclusions: Secondary GAs affecting major pathways were observed in high frequency, often co-occurring with the FGFR4 G388R SNP. Secondary alteration of known oncogenic pathways may contribute to sarcoma formation in ES potentially informing further therapeutic strategies in the future.


PLoS Biology ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. e3001138
Author(s):  
Sarah A. Head ◽  
Xavier Hernandez-Alias ◽  
Jae-Seong Yang ◽  
Ludovica Ciampi ◽  
Violeta Beltran-Sastre ◽  
...  

RNA splicing is widely dysregulated in cancer, frequently due to altered expression or activity of splicing factors (SFs). Microexons are extremely small exons (3–27 nucleotides long) that are highly evolutionarily conserved and play critical roles in promoting neuronal differentiation and development. Inclusion of microexons in mRNA transcripts is mediated by the SF Serine/Arginine Repetitive Matrix 4 (SRRM4), whose expression is largely restricted to neural tissues. However, microexons have been largely overlooked in prior analyses of splicing in cancer, as their small size necessitates specialized computational approaches for their detection. Here, we demonstrate that despite having low expression in normal nonneural tissues, SRRM4 is further silenced in tumors, resulting in the suppression of normal microexon inclusion. Remarkably, SRRM4 is the most consistently silenced SF across all tumor types analyzed, implying a general advantage of microexon down-regulation in cancer independent of its tissue of origin. We show that this silencing is favorable for tumor growth, as decreased SRRM4 expression in tumors is correlated with an increase in mitotic gene expression, and up-regulation of SRRM4 in cancer cell lines dose-dependently inhibits proliferation in vitro and in a mouse xenograft model. Further, this proliferation inhibition is accompanied by induction of neural-like expression and splicing patterns in cancer cells, suggesting that SRRM4 expression shifts the cell state away from proliferation and toward differentiation. We therefore conclude that SRRM4 acts as a proliferation brake, and tumors gain a selective advantage by cutting off this brake.


2021 ◽  
Author(s):  
Megann A Boone ◽  
Cenny Taslim ◽  
Jesse C Crow ◽  
Julia Selich-Anderson ◽  
Mike Watson ◽  
...  

Ewing sarcoma is an aggressive pediatric bone cancer defined by a chromosomal translocation fusing one of the FET family members to a member of the ETS transcription factor family. To date, there have been seven reported translocations, with the most recent translocation reported over a decade ago. We now report the first identification of a novel translocation occurring between the FUS gene and ETS family member ETV4 detected in a neonatal patient with Ewing sarcoma. Given its apparent rarity, we conducted an initial characterization of FUS/ETV4 function by performing genomic localization and transcriptional regulatory studies. We knocked down endogenous EWS/FLI in the A673 cell line, and expressed FUS/ETV4 in its stead, and performed CUT&Tag and RNA-sequencing analyses. We compared these data to similar knock-down/rescue analyses of other rare (non-EWS/FLI) Ewing sarcoma-associated translocation products. Through this comparative analysis in the same genetic background, we demonstrate significant similarities across these fusions, and in doing so, validate this novel FUS/ETV4 translocation as a bona fide Ewing sarcoma translocation. This study presents the first genomic comparisons of the rare Ewing sarcoma-associated translocation products, and reveals that the FET/ETS fusions share highly similar, but not identical, genomic localization and transcriptional regulation patterns. These data provide insights into the roles of both the FET and ETS sides of these fusions, and provide a generic strategy to provide further strength to the notion that FET/ETS fusions are key drivers of, and thus pathognomonic for, Ewing sarcoma.


Oncogenesis ◽  
2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lisa Bierbaumer ◽  
Anna M. Katschnig ◽  
Branka Radic-Sarikas ◽  
Maximilian O. Kauer ◽  
Jeffrey A. Petro ◽  
...  

AbstractEwing sarcoma (EwS) is a highly metastatic bone cancer characterized by the ETS fusion oncoprotein EWS-FLI1. EwS cells are phenotypically highly plastic and switch between functionally distinct cell states dependent on EWS-FLI1 fluctuations. Whereas EWS-FLI1high cells proliferate, EWS-FLI1low cells are migratory and invasive. Recently, we reported activation of MRTFB and TEAD, effectors of RhoA and Hippo signalling, upon low EWS-FLI1, orchestrating key steps of the EwS migratory gene expression program. TEAD and its co-activators YAP and TAZ are commonly overexpressed in cancer, providing attractive therapeutic targets. We find TAZ levels to increase in the migratory EWS-FLI1low state and to associate with adverse prognosis in EwS patients. We tested the effects of the potent YAP/TAZ/TEAD complex inhibitor verteporfin on EwS cell migration in vitro and on metastasis in vivo. Verteporfin suppressed expression of EWS-FLI1 regulated cytoskeletal genes involved in actin signalling to the extracellular matrix, effectively blocked F-actin and focal-adhesion assembly and inhibited EwS cell migration at submicromolar concentrations. In a mouse EwS xenograft model, verteporfin treatment reduced relapses at the surgical site and delayed lung metastasis. These data suggest that YAP/TAZ pathway inhibition may prevent EwS cell dissemination and metastasis, justifying further preclinical development of YAP/TAZ inhibitors for EwS treatment.


Author(s):  
Han-Wen Chen ◽  
Xiao-Xia Zhang ◽  
Zhu-Ding Peng ◽  
Zu-Min Xing ◽  
Yi-Wen Zhang ◽  
...  

AbstractTreatment of bone cancer pain (BCP) caused by bone metastasis in advanced cancers remains a challenge in clinical oncology, and the underlying mechanisms of BCP are poorly understood. This study aimed to investigate the pathogenic roles of circular RNAs (circRNAs) in regulating cancer cell proliferation and BCP development. Eight differentially expressed circRNAs in the rat spinal cord were validated by agarose gel electrophoresis and Sanger sequencing. Expression of circRNAs and mRNAs was detected by quantitative RT-PCR. MTS assay and flow cytometry were performed to analyze cell proliferation and apoptosis, respectively. Differentially expressed mRNA profiles were characterized by deep RNA sequencing, hierarchical clustering, and functional categorization. The interactions among circRNAs, microRNAs (miRNAs), and mRNAs were predicted using TargetScan. Additionally, western blot was performed to determine the protein levels of Pax8, Isg15, and Cxcl10. Multiple circRNAs were differentially expressed in the spinal cords of BCP model rats; of these, circSlc7a11 showed the greatest increase in expression. The overexpression of circSlc7a11 significantly promoted cell proliferation and repressed apoptosis of LLC-WRC 256 and UMR-106 cells, whereas circSlc7a11 silencing produced the opposite effects. Altered expression of circSlc7a11 also induced substantial changes in the mRNA expression profiles of LLC-WRC 256 cells; these changes were linked to multiple apoptotic processes and signaling pathways, such as the chemokine signaling pathway, and formed a complex circRNA/miRNA/mRNA network. Additionally, Pax8, Isg15, and Cxc110 protein level in LLC-WRC 256 cells was consistent with the mRNA results. The circRNA circSlc7a11 regulates rat BCP development by modulating LLC-WRC 256 cell proliferation and apoptosis through multiple-signaling mechanisms.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Hyma Polimera ◽  
Prashanth Moku ◽  
Shady Piedra Abusharar ◽  
Monali Vasekar ◽  
Jayakrishna Chintanaboina

Ewing sarcoma (ES) is a highly aggressive malignant bone cancer. ES is part of the Ewing sarcoma family of tumors (ESFT), which express characteristic t(11;22) translocation as well as higher levels of CD99. Given that metastasis and tumor burden are significant prognostic factors in patient’s response to treatment, prompt diagnosis is needed to effectively treat ESFT patients. However, the challenges in classifying and characterizing ESFT complicate effective management and treatment of ES. In this report, we present a rare case of ES metastasis to the pancreas. Upon review of the literature, we found 39 cases of ESFT involving the pancreas, but only 3 were metastatic to the pancreas while the remaining cases of ESFT primarily originated from the pancreas. Given the rarity of such metastasis, the positive outcome in our patient’s case may explain the importance of prompt diagnosis in order to initiate appropriate treatment.


2008 ◽  
Vol 94 (2) ◽  
pp. 341-347 ◽  
Author(s):  
G. M. SCHUERMANN ◽  
A. E. ABER-BISHOP ◽  
P. FACER ◽  
J. C. LEE ◽  
D. S. RAMPTON ◽  
...  

2007 ◽  
Vol 31 (3) ◽  
pp. 441-457 ◽  
Author(s):  
Miroslaw Mackiewicz ◽  
Keith R. Shockley ◽  
Micah A. Romer ◽  
Raymond J. Galante ◽  
John E. Zimmerman ◽  
...  

The function(s) of sleep remains a major unanswered question in biology. We assessed changes in gene expression in the mouse cerebral cortex and hypothalamus following different durations of sleep and periods of sleep deprivation. There were significant differences in gene expression between behavioral states; we identified 3,988 genes in the cerebral cortex and 823 genes in the hypothalamus with altered expression patterns between sleep and sleep deprivation. Changes in the steady-state level of transcripts for various genes are remarkably common during sleep, as 2,090 genes in the cerebral cortex and 409 genes in the hypothalamus were defined as sleep specific and changed (increased or decreased) their expression during sleep. The largest categories of overrepresented genes increasing expression with sleep were those involved in biosynthesis and transport. In both the cerebral cortex and hypothalamus, during sleep there was upregulation of multiple genes encoding various enzymes involved in cholesterol synthesis, as well as proteins for lipid transport. There was also upregulation during sleep of genes involved in synthesis of proteins, heme, and maintenance of vesicle pools, as well as antioxidant enzymes and genes encoding proteins of energy-regulating pathways. We postulate that during sleep there is a rebuilding of multiple key cellular components in preparation for subsequent wakefulness.


2003 ◽  
Vol 160 (3) ◽  
pp. 433-449 ◽  
Author(s):  
Steven H. Myster ◽  
Robert Cavallo ◽  
Charles T. Anderson ◽  
Donald T. Fox ◽  
Mark Peifer

Cadherin–catenin complexes, localized to adherens junctions, are essential for cell–cell adhesion. One means of regulating adhesion is through the juxtamembrane domain of the cadherin cytoplasmic tail. This region is the binding site for p120, leading to the hypothesis that p120 is a key regulator of cell adhesion. p120 has also been suggested to regulate the GTPase Rho and to regulate transcription via its binding partner Kaiso. To test these hypothesized functions, we turned to Drosophila, which has only a single p120 family member. It localizes to adherens junctions and binds the juxtamembrane region of DE-cadherin (DE-cad). We generated null alleles of p120 and found that mutants are viable and fertile and have no substantial changes in junction structure or function. However, p120 mutations strongly enhance mutations in the genes encoding DE-cadherin or Armadillo, the β-catenin homologue. Finally, we examined the localization of p120 during embryogenesis. p120 localizes to adherens junctions, but its localization there is less universal than that of core adherens junction proteins. Together, these data suggest that p120 is an important positive modulator of adhesion but that it is not an essential core component of adherens junctions.


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