Abstract 728: Molecular mechanisms of resistance to anti-IGF-1R therapies in Ewing's sarcoma

Abstract IGF system contributes significantly to many human malignancies. Targeting IGF-I receptor (IGF-IR) has been reported to be active against several tumors, but particular efficacy was observed only against a minority of Ewing's sarcoma patients. Identification of mechanisms of acquired resistance to anti-IGF-IR agents is mandatory to individualize their use in clinics and optimize cure costs. In this study, we compared gene expression profiles of cells made resistant with three different anti-IGF-IR drugs (human antibodies AVE1642, Figitumumab, or tyrosine kinase inhibitor NVP-AEW541) to highlight common and distinctive mechanisms of resistance. Among common mechanisms, we identified two molecular signatures that distinguish sensitive from resistant cells. Annotation analysis indicated some common altered pathways, such as insulin signaling, MAPK pathway, endocytosis, and modulation of some members of the interferon-induced transmembrane protein family. Among distinctive pathways/processes, resistance to human antibodies involves mainly genes regulating neural differentiation and angiogenesis, whereas resistance to NVP-AEW541 is mainly associated with alterations in genes concerning inflammation and antigen presentation. Evaluation of the common altered pathways indicated that resistant cells seem to maintain intact the IGF-IR internalization/degradation route of sensitive cells but constantly down-regulated its expression. In resistant cells, the loss of proliferative stimulus, normally sustained by IGF-I/IGF-IR autocrine loop in Ewing's sarcoma cells, is compensated by transcriptional up-regulation of IGF-II and insulin receptor-A; this signaling seems to favor the MAPK pathway over the v-akt murine thymoma viral oncogene homolog 1 pathway. Overall, complexity of IGF system requires analytical evaluation of its components to select those patients that may really benefit from this targeted therapy and support the idea of cotargeting IGF-IR and insulin receptor-A to increase the efficacy.

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Cooperative treatment effectiveness of ATR and HSP90 inhibition in Ewing’s sarcoma cells

10.21203/rs.3.rs-101230/v1 ◽

2020 ◽

Author(s):

Christian Marx ◽

Marc U. Schaarschmidt ◽

Joanna Kirkpatrick ◽

Lisa Marx-Blümel ◽

Doerte Hoelzer ◽

...

Keyword(s):

Dna Damage ◽

Er Stress ◽

Molecular Mechanisms ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Wild Type ◽

Gene And Protein Expression ◽

Ewing's Sarcoma Cells ◽

P53 Status ◽

Sarcoma Cells

Abstract Introduction: Ewing's sarcoma is an aggressive childhood malignancy whose outcome has not substantially improved over the last two decades. In this study, combination treatments of the HSP90 inhibitor AUY922 with either the ATR inhibitor VE821 or the ATM inhibitor KU55933 were investigated for their effectiveness in Ewing's sarcoma cells.Methods: Effects were determined in p53 wild-type and p53 null Ewing's sarcoma cell lines by flow cytometric analyses of cell death, mitochondrial depolarization and cell-cycle distribution. They were molecularly characterized by gene and protein expression profiling, and by quantitative whole proteome analysis.Results: AUY922 alone induced DNA damage, apoptosis and ER stress, while reducing the abundance of DNA repair proteins. The combination of AUY922 with VE821 led to strong apoptosis induction independent of the cellular p53 status, yet based on different molecular mechanisms. p53 wild-type cells activated pro-apoptotic gene transcription and underwent mitochondria-mediated apoptosis. p53 null cells, however, accumulated higher levels of DNA damage, ER stress and autophagy, eventually leading to apoptosis. Impaired PI3K/AKT/mTOR signaling further contributed to the antineoplastic combination effects of AUY922 and VE821 in p53 null cells. In contrast, the combination of AUY922 with KU55933 did not produce a cooperative effect.Conclusion: Our study reveals that HSP90 and ATR inhibitor combination treatment may be an effective therapeutic approach for Ewing's sarcoma irrespective of the p53 status.

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PRDX2 Performs the Oncogenic Functions in Ewing’s Sarcoma

10.21203/rs.3.rs-51646/v1 ◽

2020 ◽

Author(s):

Ruifeng Xue ◽

Zhengfu Fan ◽

Yunhe An

Keyword(s):

Western Blot ◽

Signaling Pathway ◽

Molecular Mechanisms ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Es Cells ◽

Mtor Signaling ◽

Mtor Signaling Pathway ◽

Strong Basis ◽

Apoptotic Protein

Abstract Background: Ewing's sarcoma (ES) is the second most common malignant primary bone tumor in children and adolescents, characterized by malignant proliferation of small round cells. The survival rate of this disease continues to be low. Peroxiredoxin2 (PRDX2) is a multifunctional peroxidase family member with anti-oxidation, involvement in intracellular signaling, chaperones, and tumor. But the function and underlying mechanism of PRDX2 in ES is still unknown. Herein we investigated the role and mechanism of PRDX2 in the development of ES, and tested its potential for the treatment of ES.Methods: We explored the function of PRDX2 on ES through knocking down the expression of NKAP in A673 and RDES cells by siRNA interference (siPRDX2). We examined the effects of siPRDX2 on cell motility and apoptosis using CCK8, colony formation, transwell, gelatin zymography, flow cytometry, PI/Hoechst33342 double dye and western blot assays. In addition, western blot was used to analyze the activation of the AKT/mTOR signaling pathway.Results: Here we showed that downregulation of PRDX2 strongly inhibited the motility of A673 and RDES cells. Interestingly, siPRDX2 induced cell apoptosis. Furthermore, the expression of anti-apoptotic protein Bcl2 in siPRDX2 group was significantly decreased, while the expression of pro-apoptotic protein Bax and cleaved Caspase-9 was strongly increased. Finally to identify the molecular mechanisms involved, we examined related proteins of the AKT/mTOR signaling pathway and found that siPRDX2 significantly inhibited the phosphorylation of AKT and the expression of Cyclin D1.Conclusion: These observations suggest that siPRDX2 inhibited the ES cells motility and induced apoptosis in which the AKT/mTOR signaling pathway involved. The enhanced understanding to this molecular mechanism has provided a strong basis for the development of novel therapeutic strategies for ES.

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Cooperative treatment effectiveness of ATR and HSP90 inhibition in Ewing’s sarcoma cells

Cell & Bioscience ◽

10.1186/s13578-021-00571-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Christian Marx ◽

Marc U. Schaarschmidt ◽

Joanna Kirkpatrick ◽

Lisa Marx-Blümel ◽

Melisa Halilovic ◽

...

Keyword(s):

Dna Damage ◽

Er Stress ◽

Molecular Mechanisms ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Wild Type ◽

Gene And Protein Expression ◽

Ewing's Sarcoma Cells ◽

P53 Status ◽

Sarcoma Cells

Abstract Introduction Ewing's sarcoma is an aggressive childhood malignancy whose outcome has not substantially improved over the last two decades. In this study, combination treatments of the HSP90 inhibitor AUY922 with either the ATR inhibitor VE821 or the ATM inhibitor KU55933 were investigated for their effectiveness in Ewing's sarcoma cells. Methods Effects were determined in p53 wild-type and p53 null Ewing's sarcoma cell lines by flow cytometric analyses of cell death, mitochondrial depolarization and cell-cycle distribution as well as fluorescence and transmission electron microscopy. They were molecularly characterized by gene and protein expression profiling, and by quantitative whole proteome analysis. Results AUY922 alone induced DNA damage, apoptosis and ER stress, while reducing the abundance of DNA repair proteins. The combination of AUY922 with VE821 led to strong apoptosis induction independent of the cellular p53 status, yet based on different molecular mechanisms. p53 wild-type cells activated pro-apoptotic gene transcription and underwent mitochondria-mediated apoptosis, while p53 null cells accumulated higher levels of DNA damage, ER stress and autophagy, eventually leading to apoptosis. Impaired PI3K/AKT/mTOR signaling further contributed to the antineoplastic combination effects of AUY922 and VE821. In contrast, the combination of AUY922 with KU55933 did not produce a cooperative effect. Conclusion Our study reveals that HSP90 and ATR inhibitor combination treatment may be an effective therapeutic approach for Ewing's sarcoma irrespective of the p53 status.

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Molecular Mechanisms of Gradient Sensing in Ewing's Sarcoma Cells

Biophysical Journal ◽

10.1016/j.bpj.2011.11.2807 ◽

2012 ◽

Vol 102 (3) ◽

pp. 513a

Author(s):

Elena Beletkaia ◽

Susanne F. Fenz ◽

Ewa Snaar-Jagalska ◽

Pancras Hogendoorn ◽

Thomas Schmidt

Keyword(s):

Molecular Mechanisms ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Gradient Sensing ◽

Ewing's Sarcoma Cells ◽

Sarcoma Cells

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Current Status and Perspectives of Patient-Derived Models for Ewing’s Sarcoma

Cancers ◽

10.3390/cancers12092520 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2520

Author(s):

Tadashi Kondo

Keyword(s):

Cell Lines ◽

Molecular Mechanisms ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Model Development ◽

Biological Significance ◽

Current Status ◽

Antitumor Effects ◽

Molecular Features ◽

Cancer Models

Patient-derived cancer models, including cell lines, organoids, and xenografts, are indispensable tools in cancer research. These models, which recapitulate molecular features of original tumors, allow studies on the biological significance of cancer-associated genes, antitumor effects of novel agents, and molecular mechanisms underlying clinical behaviors of tumors. Moreover, the predictive utility of patient-derived cancer models is expected to facilitate drug development and precision medicine. Ewing’s sarcoma is a highly aggressive mesenchymal tumor with a high metastasis rate. Previous studies demonstrated the utility of cell lines and xenografts in Ewing’s sarcoma research and clinical studies. However, the number of Ewing’s sarcoma models available from public biobanks is limited; this creates an obstacle for research on Ewing’s sarcoma. Novel Ewing’s sarcoma models are needed to establish their utility, further our understanding of the molecular mechanisms, and help develop effective therapeutic strategies. In this review, the current status of patient-derived cancer models is overviewed, and future prospects of model development are discussed from the perspective of Ewing’s sarcoma research. It should be of interest to researchers and clinicians who work on patient-derived cancer models.

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Molecular mechanisms of CD99-induced caspase-independent cell death and cell–cell adhesion in Ewing's sarcoma cells: actin and zyxin as key intracellular mediators

Oncogene ◽

10.1038/sj.onc.1207741 ◽

2004 ◽

Vol 23 (33) ◽

pp. 5664-5674 ◽

Cited By ~ 77

Author(s):

Vanessa Cerisano ◽

Yan Aalto ◽

Stefania Perdichizzi ◽

Ghislaine Bernard ◽

Maria Cristina Manara ◽

...

Keyword(s):

Cell Death ◽

Cell Adhesion ◽

Molecular Mechanisms ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Ewing's Sarcoma Cells ◽

Sarcoma Cells ◽

Intracellular Mediators ◽

Cell Cell

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Is There a Predisposition Gene for Ewing's Sarcoma?

Journal of Oncology ◽

10.1155/2010/397632 ◽

2010 ◽

Vol 2010 ◽

pp. 1-6 ◽

Cited By ~ 25

Author(s):

R. L. Randall ◽

S. L. Lessnick ◽

K. B. Jones ◽

L. G. Gouw ◽

J. E. Cummings ◽

...

Keyword(s):

Molecular Mechanisms ◽

Ewing’S Sarcoma ◽

Ewing's Sarcoma ◽

Current Evidence ◽

Sibling Pairs ◽

Familial Cases ◽

Ets Family ◽

Children And Young Adults ◽

Mapping Techniques ◽

Genetic Events

Ewing's sarcoma is a highly malignant tumor of children and young adults. The molecular mechanisms that underlie Ewing's Sarcoma development are beginning to be understood. For example, most cases of this disease harbor somatic chromosomal translocations that fuse theEWSR1gene on chromosome 22 with members of the ETS family. While some cooperative genetic events have been identified, such as mutations inTP53or deletions of theCDKN2Alocus, these appear to be absent in the vast majority of cases. It is therefore uncertain whether EWS/ETS translocations are the only consistently present alteration in this tumor, or whether there are other recurrent abnormalities yet to be discovered. One method to discover such mutations is to identify familial cases of Ewing's sarcoma and to then map the susceptibility locus using traditional genetic mapping techniques. Although cases of sibling pairs with Ewing's sarcoma exist, familial cases of Ewing's sarcoma have not been reported. While Ewing's sarcoma has been reported as a 2nd malignancy after retinoblastoma, significant associations of Ewing's sarcoma with classic tumor susceptibility syndromes have not been identified. We will review the current evidence, or lack thereof, regarding the potential of a heritable condition predisposing to Ewing's sarcoma.

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