scholarly journals Cell Cycle Deregulation in Ewing's Sarcoma Pathogenesis

Sarcoma ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Ashley A. Kowalewski ◽  
R. Lor Randall ◽  
Stephen L. Lessnick

Ewing's sarcoma is a highly aggressive pediatric tumor of bone that usually contains the characteristic chromosomal translocation t(11;22)(q24;q12). This translocation encodes the oncogenic fusion protein EWS/FLI, which acts as an aberrant transcription factor to deregulate target genes necessary for oncogenesis. One key feature of oncogenic transformation is dysregulation of cell cycle control. It is therefore likely that EWS/FLI and other cooperating mutations in Ewing's sarcoma modulate the cell cycle to facilitate tumorigenesis. This paper will summarize current published data associated with deregulation of the cell cycle in Ewing's sarcoma and highlight important questions that remain to be answered.

2003 ◽  
Vol 23 (14) ◽  
pp. 5031-5042 ◽  
Author(s):  
Marcin Rylski ◽  
John J. Welch ◽  
Ying-Yu Chen ◽  
Danielle L. Letting ◽  
J. Alan Diehl ◽  
...  

ABSTRACT Transcription factor GATA-1 is essential for erythroid and megakaryocytic maturation. GATA-1 mutations are associated with hematopoietic precursor proliferation and leukemogenesis, suggesting a role in cell cycle control. While numerous GATA-1 target genes specifying mature hematopoietic phenotypes have been identified, how GATA-1 regulates proliferation remains unknown. We used a complementation assay based on synchronous inducible rescue of GATA-1− erythroblasts to show that GATA-1 promotes both erythroid maturation and G1 cell cycle arrest. Molecular studies combined with microarray transcriptome analysis revealed an extensive GATA-1-regulated program of cell cycle control in which numerous growth inhibitors were upregulated and mitogenic genes were repressed. GATA-1 inhibited expression of cyclin-dependent kinase (Cdk) 6 and cyclin D2 and induced the Cdk inhibitors p18 INK4C and p27 Kip1 with associated inactivation of all G1 Cdks. These effects were dependent on GATA-1-mediated repression of the c-myc (Myc) proto-oncogene. GATA-1 inhibited Myc expression within 3 h, and chromatin immunoprecipitation studies indicated that GATA-1 occupies the Myc promoter in vivo, suggesting a direct mechanism for gene repression. Surprisingly, enforced expression of Myc prevented GATA-1-induced cell cycle arrest but had minimal effects on erythroid maturation. Our results illustrate how GATA-1, a lineage-determining transcription factor, coordinates proliferation arrest with cellular maturation through distinct, interrelated genetic programs.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1300
Author(s):  
Fatu Badiane Markey ◽  
Brigette Romero ◽  
Vijay Parashar ◽  
Mona Batish

Ewing’s sarcoma (ES) is caused by a chromosomal translocation leading to the formation of the fused EWSFLI1 gene, which codes for an aberrant transcription factor EWSFLI1. The transcriptional targets of EWSFLI1 have been viewed as promising and novel drug targets in the treatment of ES. One such target is six transmembrane epithelial antigen of the prostate 1 (STEAP1), a transmembrane protein that is upregulated by EWSFLI1 in ES. STEAP1 is a hallmark of tumor invasiveness and an indicator of tumor responsiveness to therapy. EWSFLI1 binds to the STEAP1 promoter region, but the mechanism of action by which it upregulates STEAP1 expression in ES is not entirely understood. Upon analysis of the STEAP1 promoter, we predicted two binding sites for NKX2.2, another crucial transcription factor involved in ES pathogenesis. We confirmed the interaction of NKX2.2 with the STEAP1 promoter using chromatin immunoprecipitation (ChIP) analysis. We used single-molecule RNA imaging, biochemical, and genetic studies to identify the novel role of NKX2.2 in regulating STEAP1 expression in ES. Our results show that NKX2.2 is a co-regulator of STEAP1 expression and functions by interacting with the STEAP1 promoter at sites proximal to the reported EWSFLI1 sites. The co-operative interaction of NKX2.2 with EWSFLI1 in regulating STEAP1 holds potential as a new target for therapeutic interventions for ES.


1995 ◽  
Vol 15 (8) ◽  
pp. 4623-4630 ◽  
Author(s):  
B S Braun ◽  
R Frieden ◽  
S L Lessnick ◽  
W A May ◽  
C T Denny

The EWS/FLI-1 fusion gene results from the 11;22 chromosomal translocation in Ewing's sarcoma. The product of the gene is one of a growing number of structurally altered transcription factors implicated in oncogenesis. We have employed a subtractive cloning strategy of representational difference analysis in conjunction with a model transformation system to identify genes transcribed in response to EWS/FLI. We have characterized eight transcripts that are dependent on EWS/FLI for expression and two transcripts that are repressed in response to EWS/FLI. Three of the former were identified by sequence analysis as stromelysin 1, a murine homolog of cytochrome P-450 F1 and cytokeratin 15. Stromelysin 1 is induced rapidly after expression of EWS/FLI, suggesting that the stromelysin 1 gene may be a direct target gene of EWS/FLI. These results demonstrate that expression of EWS/FLI leads to significant changes in the transcription of specific genes and that these effects are at least partially distinct from those caused by expression of germ line FLI-1. The representational difference analysis technique can potentially be applied to investigate transformation pathways activated by a broad array of genes in different tumor systems.


2000 ◽  
Vol 18 (1) ◽  
pp. 204-204 ◽  
Author(s):  
Enrique de Alava ◽  
William L. Gerald

ABSTRACT: Ewing’s sarcoma (ES) and primitive neuroectodermal tumor (PNET) are members of a tumor family consistently associated with chromosomal translocation and functional fusion of the EWS gene to any of several structurally related transcription factor genes. Similar gene fusion events occur in other mesenchymal and hematopoietic tumors and are tumor-specific. The resulting novel transcription factor–like chimeric proteins are believed to contribute to tumor biology by aberrant regulation of gene expression altering critical controls of cell proliferation and differentiation. These tumor-specific molecular rearrangements are useful for primary diagnosis, may provide prognostic information, and present potential therapeutic targets. The recent advances in our understanding of the molecular biology of ES and PNET represent a paradigm for the application of the basic biology of neoplasia to clinical management of patients.


2007 ◽  
Vol 27 (23) ◽  
pp. 8259-8270 ◽  
Author(s):  
Ulrich Schüller ◽  
Qing Zhao ◽  
Susana A. Godinho ◽  
Vivi M. Heine ◽  
René H. Medema ◽  
...  

ABSTRACT The forkhead transcription factor FoxM1 has been reported to regulate, variously, proliferation and/or spindle formation during the G2/M transition of the cell cycle. Here we define specific functions of FoxM1 during brain development by the investigation of FoxM1 loss-of-function mutations in the context of Sonic hedgehog (Shh)-induced neuroproliferation in cerebellar granule neuron precursors (CGNP). We show that FoxM1 is expressed in the cerebellar anlagen as well as in postnatal proliferating CGNP and that it is upregulated in response to activated Shh signaling. To determine the requirements for FoxM1 function, we used transgenic mice carrying conventional null alleles or conditionally targeted alleles in conjunction with specific Cre recombinase expression in CGNP or early neural precursors driven by Math1 or Nestin enhancers. Although the overall cerebellar morphology was grossly normal, we observed that the entry into mitosis was postponed both in vivo and in Shh-treated CGNP cultures. Cell cycle analysis and immunohistochemistry with antibodies against phosphorylated histone H3 indicated a significant delay in the G2/M transition. Consistent with this, FoxM1-deficient CGNP showed decreased levels of the cyclin B1 and Cdc25b proteins. Furthermore, the loss of FoxM1 resulted in spindle defects and centrosome amplification. These findings indicate that the functions of FoxM1 in Shh-induced neuroproliferation are restricted to the regulation of the G2/M transition in CGNP, most probably through transcriptional effects on target genes such as those coding for B-type cyclins.


1993 ◽  
Vol 13 (12) ◽  
pp. 7393-7398 ◽  
Author(s):  
W A May ◽  
S L Lessnick ◽  
B S Braun ◽  
M Klemsz ◽  
B C Lewis ◽  
...  

EWS/FLI-1 is a chimeric protein formed by a tumor-specific 11;22 translocation found in both Ewing's sarcoma and primitive neuroectodermal tumor of childhood. EWS/FLI-1 has been shown to be a potent transforming gene, suggesting that it plays an important role in the genesis of these human tumors. We now demonstrate that EWS/FLI-1 has the characteristics of an aberrant transcription factor. Subcellular fractionation experiments localized the EWS/FLI-1 protein to the nucleus of primitive neuroectodermal tumor cells. EWS/FLI-1 specifically bound in vitro an ets-2 consensus sequence similarly to normal FLI-1. When coupled to a GAL4 DNA-binding domain, the amino-terminal EWS/FLI-1 region was a much more potent transcriptional activator than the corresponding amino-terminal domain of FLI-1. Finally, EWS/FLI-1 efficiently transformed NIH 3T3 cells, but FLI-1 did not. These data suggest that EWS/FLI-1, functioning as a transcription factor, leads to a phenotype dramatically different from that of cells expressing FLI-1. EWS/FLI-1 could disrupt normal growth and differentiation either by more efficiently activating FLI-1 target genes or by inappropriately modulating genes normally not responsive to FLI-1.


2020 ◽  
Author(s):  
Vadim Saratov ◽  
Qui A. Ngo ◽  
Gloria Pedot ◽  
Felix K. Niggli ◽  
Beat W. Schaefer

2020 ◽  
Vol 295 (13) ◽  
pp. 4212-4223 ◽  
Author(s):  
Chun Guo ◽  
Jian Li ◽  
Nickolas Steinauer ◽  
Madeline Wong ◽  
Brent Wu ◽  
...  

In up to 15% of acute myeloid leukemias (AMLs), a recurring chromosomal translocation, termed t(8;21), generates the AML1–eight–twenty-one (ETO) leukemia fusion protein, which contains the DNA-binding domain of Runt-related transcription factor 1 (RUNX1) and almost all of ETO. RUNX1 and the AML1–ETO fusion protein are coexpressed in t(8;21) AML cells and antagonize each other's gene-regulatory functions. AML1–ETO represses transcription of RUNX1 target genes by competitively displacing RUNX1 and recruiting corepressors such as histone deacetylase 3 (HDAC3). Recent studies have shown that AML1–ETO and RUNX1 co-occupy the binding sites of AML1–ETO–activated genes. How this joined binding allows RUNX1 to antagonize AML1–ETO–mediated transcriptional activation is unclear. Here we show that RUNX1 functions as a bona fide repressor of transcription activated by AML1–ETO. Mechanistically, we show that RUNX1 is a component of the HDAC3 corepressor complex and that HDAC3 preferentially binds to RUNX1 rather than to AML1–ETO in t(8;21) AML cells. Studying the regulation of interleukin-8 (IL8), a newly identified AML1–ETO–activated gene, we demonstrate that RUNX1 and HDAC3 collaboratively repress AML1–ETO–dependent transcription, a finding further supported by results of genome-wide analyses of AML1–ETO–activated genes. These and other results from the genome-wide studies also have important implications for the mechanistic understanding of gene-specific coactivator and corepressor functions across the AML1–ETO/RUNX1 cistrome.


2017 ◽  
Vol 10 (499) ◽  
pp. eaam8429 ◽  
Author(s):  
Stefan K. Zöllner ◽  
Saravana P. Selvanathan ◽  
Garrett T. Graham ◽  
Ryan M. T. Commins ◽  
Sung Hyeok Hong ◽  
...  

PLoS ONE ◽  
2012 ◽  
Vol 7 (11) ◽  
pp. e49819 ◽  
Author(s):  
Maria J. Camões ◽  
Paula Paulo ◽  
Franclim R. Ribeiro ◽  
João D. Barros-Silva ◽  
Mafalda Almeida ◽  
...  

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