HDAC6 regulates expression of the oncogenic driver EWSR1-FLI1 through the EWSR1 promoter in Ewing sarcoma

ABSTRACTEwing sarcoma (EWS) is an aggressive developmental sarcoma driven by a fusion gene, EWSR1-FLI1. However, little is known about the regulation of EWSR1-FLI1 chimeric fusion gene expression. Here, we demonstrate that active nuclear HDAC6 in EWS modulates acetylation status of specificity protein 1 (SP1), consequently regulating SP1/P300 activator complex binding to EWSR1 and EWSR1-FLI1 promoters. Selective inhibition of HDAC6 impairs binding of activator complex SP1/P300, thereby inducing EWSR1-FLI1 downregulation and significantly reducing its oncogenic functions. In addition, sensitivity of EWS cell lines to HDAC6 inhibition is higher than other tumor or non-tumor cell lines. Overexpression of HDAC6 in primary EWS tumor clinical samples correlates with a poor prognosis. Notably, a combination treatment of a selective HDAC6 inhibitor and doxorubicin (standard of care in EWS) dramatically inhibits tumor growth in two EWS murine xenograft models. These results could lead to suitable and promising therapeutic alternatives for EWS patients.

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Selective inhibition of HDAC6 regulates expression of the oncogenic driver EWSR1-FLI1 through the EWSR1 promoter in Ewing sarcoma

Oncogene ◽

10.1038/s41388-021-01974-4 ◽

2021 ◽

Author(s):

Daniel J. García-Domínguez ◽

Nabil Hajji ◽

Sara Sánchez-Molina ◽

Elisabet Figuerola-Bou ◽

Rocío M. de Pablos ◽

...

Keyword(s):

Cell Lines ◽

Ewing Sarcoma ◽

Fusion Gene ◽

Selective Inhibition ◽

Oncogenic Driver ◽

Xenograft Models ◽

Children And Young Adults ◽

Specificity Protein ◽

Therapeutic Alternatives ◽

Activator Complex

AbstractEwing sarcoma (EWS) is an aggressive bone and soft tissue tumor of children and young adults in which the principal driver is a fusion gene, EWSR1-FLI1. Although the essential role of EWSR1-FLI1 protein in the regulation of oncogenesis, survival, and tumor progression processes has been described in-depth, little is known about the regulation of chimeric fusion-gene expression. Here, we demonstrate that the active nuclear HDAC6 in EWS modulates the acetylation status of specificity protein 1 (SP1), consequently regulating the SP1/P300 activator complex binding to EWSR1 and EWSR1-FLI1 promoters. Selective inhibition of HDAC6 impairs binding of the activator complex SP1/P300, thereby inducing EWSR1-FLI1 downregulation and significantly reducing its oncogenic functions. In addition, sensitivity of EWS cell lines to HDAC6 inhibition is higher than other tumor or non-tumor cell lines. High expression of HDAC6 in primary EWS tumor samples from patients correlates with a poor prognosis in two independent series accounting 279 patients. Notably, a combination treatment of a selective HDAC6 and doxorubicin (a DNA damage agent used as a standard therapy of EWS patients) dramatically inhibits tumor growth in two EWS murine xenograft models. These results could lead to suitable and promising therapeutic alternatives for patients with EWS.

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Liposomal delivery of methylphosphonate antisense oligodeoxynucleotides in chronic myelogenous leukemia [see comments]

Blood ◽

10.1182/blood.v84.2.601.601 ◽

1994 ◽

Vol 84 (2) ◽

pp. 601-607 ◽

Cited By ~ 35

Author(s):

AM Tari ◽

SD Tucker ◽

A Deisseroth ◽

G Lopez-Berestein

Keyword(s):

Growth Inhibition ◽

Cell Lines ◽

Chronic Myelogenous Leukemia ◽

Fusion Gene ◽

Hematologic Malignancy ◽

Control Cell ◽

Selective Inhibition ◽

Inhibitory Effect ◽

Myelogenous Leukemia ◽

Ph Chromosome

Abstract Chronic myelogenous leukemia (CML) is a hematologic malignancy characterized by the presence of the Philadelphia (Ph) chromosome. Bcr- abl, the fusion gene associated with the Ph chromosome, expresses a p210bcr-abl protein that promotes a selective expansion of mature myeloid progenitor cells. Methylphosphonate (MP) oligodeoxynucleotides complementary to specific regions of the bcr-abl mRNA were incorporated in liposomes. We studied the effects of liposomal MP (L-MP) on the growth inhibition of CML-like cell lines. L-MP targeted to the breakpoint junctions of the bcr-abl mRNA inhibited the growth of CML cells. Fifty percent inhibition was achieved at approximately 1 mumol/L of L-MP oligonucleotide concentrations. The inhibitory effect was selective because growth inhibition was observed only with CML but not with control cell lines. Moreover, CML cell growth inhibition was dependent on the sequence of the MP oligodeoxynucleotides incorporated in the liposomes. The growth inhibition of CML cells by L-MP resulted from selective inhibition of the expression of the p210bcr-abl protein.

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HOTAIRprimes the Ewing sarcoma family of tumors for tumorigenesis via epigenetic dysregulation involving LSD1

10.1101/244558 ◽

2018 ◽

Cited By ~ 1

Author(s):

Hasan Siddiqui ◽

Julia Selich-Anderson ◽

Joshua Felgenhauer ◽

James Fitch ◽

Vijay Nadella ◽

...

Keyword(s):

Cell Viability ◽

Cell Lines ◽

Ewing Sarcoma ◽

Colony Formation ◽

Fusion Gene ◽

Tumor Xenograft ◽

Cell Physiology ◽

Cell Of Origin

AbstractThe EWS-FLI1 fusion protein drives oncogenesis in the Ewing sarcoma family of tumors (ESFT) in humans, but its toxicity in normal cells requires additional cellular events for oncogenesis. We show that the lncRNAHOTAIRmaintains cell viability in the presence of EWS-FLI1 and redirects epigenetic regulation in ESFT.HOTAIRis consistently overexpressed in ESFTs and is not driven by EWS-FLI1. Repression ofHOTAIRin ESFT cell lines significantly reduces anchorage-independent colony formation in vitro and impairs tumor xenograft growth in vivo. Overexpression ofHOTAIRin human mesenchymal stem cells (hMSCs), a putative cell of origin of ESFT, and IMR90 cells induces colony formation. Critically, HOTAIR-expressing hMSCs and IMR90 cells remain viable with subsequentEWS-FLI1expression.HOTAIRinduces histone modifications and gene repression through interaction with the epigenetic modifier LSD1 in ESFT cell lines and hTERT-hMSCs. Our findings suggest thatHOTAIRmaintains ESFT viability through epigenetic dysregulation.SignificanceWhile theEWS-FLI1fusion gene was determined to be the oncogenic driver in the overwhelming majority of ESFT, it is toxic to cell physiology and requires one or more additional molecular events to maintain cell viability. As these tumors have surprisingly few genetic mutations at diagnosis, epigenetic changes have been considered to be such an event, but the mechanism by which these changes are driven remains unclear. Our work shows thatHOTAIRis consistently expressed among ESFT and induces epigenetic and gene expression changes that cooperate in tumorigenesis. Furthermore, expression ofHOTAIRallows for cell viability in the setting of subsequentEWS-FLI1expression. Our findings elucidate new steps of malignant transformation in this cancer and identify novel therapeutic targets.

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Liposomal delivery of methylphosphonate antisense oligodeoxynucleotides in chronic myelogenous leukemia [see comments]

Blood ◽

10.1182/blood.v84.2.601.bloodjournal842601 ◽

1994 ◽

Vol 84 (2) ◽

pp. 601-607 ◽

Cited By ~ 2

Author(s):

AM Tari ◽

SD Tucker ◽

A Deisseroth ◽

G Lopez-Berestein

Keyword(s):

Growth Inhibition ◽

Cell Lines ◽

Chronic Myelogenous Leukemia ◽

Fusion Gene ◽

Hematologic Malignancy ◽

Control Cell ◽

Selective Inhibition ◽

Inhibitory Effect ◽

Myelogenous Leukemia ◽

Ph Chromosome

Chronic myelogenous leukemia (CML) is a hematologic malignancy characterized by the presence of the Philadelphia (Ph) chromosome. Bcr- abl, the fusion gene associated with the Ph chromosome, expresses a p210bcr-abl protein that promotes a selective expansion of mature myeloid progenitor cells. Methylphosphonate (MP) oligodeoxynucleotides complementary to specific regions of the bcr-abl mRNA were incorporated in liposomes. We studied the effects of liposomal MP (L-MP) on the growth inhibition of CML-like cell lines. L-MP targeted to the breakpoint junctions of the bcr-abl mRNA inhibited the growth of CML cells. Fifty percent inhibition was achieved at approximately 1 mumol/L of L-MP oligonucleotide concentrations. The inhibitory effect was selective because growth inhibition was observed only with CML but not with control cell lines. Moreover, CML cell growth inhibition was dependent on the sequence of the MP oligodeoxynucleotides incorporated in the liposomes. The growth inhibition of CML cells by L-MP resulted from selective inhibition of the expression of the p210bcr-abl protein.

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Establishment of multiplex RT-PCR to detect fusion genes for the diagnosis of Ewing sarcoma

Diagnostic Pathology ◽

10.1186/s13000-021-01164-6 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Hitomi Ueno-Yokohata ◽

Hajime Okita ◽

Keiko Nakasato ◽

Chikako Kiyotani ◽

Motohiro Kato ◽

...

Keyword(s):

Ewing Sarcoma ◽

Fusion Gene ◽

Fusion Transcript ◽

Terminal Region ◽

Clinical Samples ◽

Rt Pcr ◽

Polymerase Chain ◽

Pcr Assays ◽

Generation Sequencing

Abstract Background Detection of the tumor-specific EWSR1/FUS-ETS fusion gene is essential to diagnose Ewing sarcoma. Reverse transcription–polymerase chain reaction (RT–PCR) and fluorescence in situ hybridization are commonly used to detect the fusion gene, and assays using next-generation sequencing have recently been reported. However, at least 28 fusion transcript variants have been reported, making rapid and accurate detection difficult. Methods We constructed two sets of multiplex PCR assays and evaluated their utility using cell lines and clinical samples. Results EWSR1/FUS-ETS was detected in five of six tumors by the first set, and in all six tumors by the second set. The fusion gene detected only by the latter was EWSR1-ERG, which completely lacked exon 7 of EWSR1. The fusion had a short N-terminal region of EWSR1 and showed pathologically atypical features. Conclusions We developed multiplex RT–PCR assays to detect EWSR1-ETS and FUS-ETS simultaneously. These assays will aid the rapid and accurate diagnosis of Ewing sarcoma. In addition, variants of EWSR1/FUS-ETS with a short N-terminal region that may have been previously missed can be easily detected.

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Faculty Opinions recommendation of Ewing sarcoma fusion protein EWSR1/FLI1 interacts with EWSR1 leading to mitotic defects in zebrafish embryos and human cell lines.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1160530.620894 ◽

2009 ◽

Author(s):

Stephen Lessnick

Keyword(s):

Fusion Protein ◽

Cell Lines ◽

Human Cell ◽

Ewing Sarcoma ◽

Zebrafish Embryos ◽

Human Cell Lines

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Selective Inhibition of Aurora Kinase A by AK-01/LY3295668 Attenuates MCC Tumor Growth by Inducing MCC Cell Cycle Arrest and Apoptosis

Cancers ◽

10.3390/cancers13153708 ◽

2021 ◽

Vol 13 (15) ◽

pp. 3708

Author(s):

Bhaba K. Das ◽

Aarthi Kannan ◽

Quy Nguyen ◽

Jyoti Gogoi ◽

Haibo Zhao ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Checkpoint Inhibitors ◽

Treatment Options ◽

Standard Of Care ◽

Aurora Kinase ◽

Selective Inhibition ◽

Potential Candidate ◽

Cycle Arrest

Merkel cell carcinoma (MCC) is an often-lethal skin cancer with increasing incidence and limited treatment options. Although immune checkpoint inhibitors (ICI) have become the standard of care in advanced MCC, 50% of all MCC patients are ineligible for ICIs, and amongst those treated, many patients develop resistance. There is no therapeutic alternative for these patients, highlighting the urgent clinical need for alternative therapeutic strategies. Using patient-derived genetic insights and data generated in our lab, we identified aurora kinase as a promising therapeutic target for MCC. In this study, we examined the efficacy of the recently developed and highly selective AURKA inhibitor, AK-01 (LY3295668), in six patient-derived MCC cell lines and two MCC cell-line-derived xenograft mouse models. We found that AK-01 potently suppresses MCC survival through apoptosis and cell cycle arrest, particularly in MCPyV-negative MCC cells without RB expression. Despite the challenge posed by its short in vivo durability upon discontinuation, the swift and substantial tumor suppression with low toxicity makes AK-01 a strong potential candidate for MCC management, particularly in combination with existing regimens.

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Constitutive activation of the Wnt canonical pathway in mantle cell lymphoma

Blood ◽

10.1182/blood-2008-02-139212 ◽

2008 ◽

Vol 112 (13) ◽

pp. 5171-5179 ◽

Cited By ~ 58

Author(s):

Pascal Gelebart ◽

Mona Anand ◽

Hanan Armanious ◽

Anthea C. Peters ◽

Jennifer Dien Bard ◽

...

Keyword(s):

Mantle Cell Lymphoma ◽

Cell Lines ◽

Cell Lymphoma ◽

Selective Inhibition ◽

Canonical Pathway ◽

Oligonucleotide Arrays ◽

Downstream Target ◽

Naturally Occurring ◽

Inactive Form ◽

Mantle Cell

Abstract Aberrations of the Wnt canonical pathway (WCP) are known to contribute to the pathogenesis of various types of cancer. We hypothesize that these defects may exist in mantle cell lymphoma (MCL). Both the upstream and downstream aspects of WCP were examined in MCL cell lines and tumors. Using WCP-specific oligonucleotide arrays, we found that MCL highly and consistently expressed Wnt3 and Wnt10. β-catenin, a transcriptional factor that is a downstream target of WCP, is localized to the nucleus and transcriptionally active in all 3 MCL cell lines examined. By immunohistochemistry, 33 (52%) of 64 MCL tumors showed nuclear localization of β-catenin, which significantly correlated with the expression of the phosphorylated/inactive form of GSK3β (p-GSK3β; P = .011, Fisher). GSK3β inactivation is directly linked to WCP stimulation, since addition of recombinant sFRP proteins (a naturally occurring decoy for the Wnt receptors) resulted in a significant decrease in p-GSK3β. Down-regulation of DvL-2 (an upstream signaling protein in WCP) by siRNA or selective inhibition of β-catenin using quercetin significantly decreased cell growth in MCL cell lines. To conclude, WCP is constitutively activated in a subset of MCL and it appears to promote tumorigenesis in MCL.

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