Similar Datasets
Project description:Ewing sarcoma is the second most common solid bone malignancy diagnosed in pediatric and young adolescent populations. Despite global co-operative efforts, outcomes for patients with relapsed and refractory disease remains obstinately poor. It has become increasingly clear that disruption of the epigenome as a result of alterations in epigenetic regulators, plays a pivotal role in tumorigenesis. As such, this study investigated Ewing sarcoma mechanisms of acquired resistance to the small molecule reversible lysine specific demethylase (LSD1/KDM1A) inhibitor SP-2509. Surprisingly, whole exome sequencing analysis of our generated A673 SP-2509 drug resistant cell line revealed an absence of mutations in KDM1A. Compared to parental counterparts, SP-2509 drug resistant cells demonstrated decreased anchorage independent growth capacity, enhanced sensitivity to the HDAC inhibitors vorinostat/entinostat and a distinct transcriptional profile that was enriched for extracellular matrix proteins. SP-2509 drug resistant cells also exhibited elevated expression levels of the multi-drug resistance genes ABCB1, ABCC3, and ABBC5 and decreased expression of the transcriptional repressor RCOR1/CoREST. Following several months of SP-2509 withdrawal, low level SP-2509 resistance was still apparent (6.3 fold increase in IC50), with drug resistant cell populations maintaining their distinct transcriptional profile. Furthermore, compared to parental cells, washout drug resistant lines displayed equal sensitivity to the standard Ewing sarcoma chemotherapeutic agent's vincristine and doxorubicin. Together these findings indicate that resistance to SP-2509 is not fully reversible or driven by direct mutation in KDM1A.
| S-EPMC6284858 | biostudies-literature
Project description:The transcriptional profile of A673 parental, and SP-2509 drug resistant washout cells (4 and 6 months)
2018-12-26 | GSE118870 | GEO
Project description:The transcriptional profile of A673 parental and SP-2509 Drug resistant cells treated with DMSO and SP-2509 (2uM 48hrs)
2018-12-26 | GSE118864 | GEO
Project description:Multi-agent chemotherapeutic regimes remain the cornerstone treatment for Ewing sarcoma, the second most common bone malignancy diagnosed in pediatric and young adolescent populations. We have reached a therapeutic ceiling with conventional cytotoxic agents, highlighting the need to adopt novel approaches that specifically target the drivers of Ewing sarcoma oncogenesis. As KDM1A/lysine-specific demethylase 1 (LSD1) is highly expressed in Ewing sarcoma cell lines and tumors, with elevated expression levels associated with worse overall survival (P = 0.033), this study has examined biomarkers of sensitivity and mechanisms of cytotoxicity to targeted KDM1A inhibition using SP-2509 (reversible KDM1A inhibitor). We report, that innate resistance to SP-2509 was not observed in our Ewing sarcoma cell line cohort (n = 17; IC50 range, 81 -1,593 nmol/L), in contrast resistance to the next-generation KDM1A irreversible inhibitor GSK-LSD1 was observed across multiple cell lines (IC50 > 300 μmol/L). Although TP53/STAG2/CDKN2A status and basal KDM1A mRNA and protein levels did not correlate with SP-2509 response, induction of KDM1B following SP-2509 treatment was strongly associated with SP-2509 hypersensitivity. We show that the transcriptional profile driven by SP-2509 strongly mirrors KDM1A genetic depletion. Mechanistically, RNA-seq analysis revealed that SP-2509 imparts robust apoptosis through engagement of the endoplasmic reticulum stress pathway. In addition, ETS1/HIST1H2BM were specifically induced/repressed, respectively following SP-2509 treatment only in our hypersensitive cell lines. Together, our findings provide key insights into the mechanisms of SP-2509 cytotoxicity as well as biomarkers that can be used to predict KDM1A inhibitor sensitivity in Ewing sarcoma. Mol Cancer Ther; 17(9); 1902-16. ©2018 AACR.
| S-EPMC6201274 | biostudies-literature
Project description:Ewing sarcoma resistance to SP-2509 is not mediated through KDM1A/LSD1 mutation
| PRJNA487068 | ENA
Project description:Ewing sarcoma resistance to SP-2509 is not mediated through KDM1A/LSD1 mutation II
| PRJNA487073 | ENA
Project description:Ewing sarcoma resistance to SP-2509 is not mediated through KDM1A/LSD1 mutation I
| PRJNA487071 | ENA
Project description:Expression of the fusion oncoprotein EWS/FLI causes Ewing sarcoma, an aggressive pediatric tumor characterized by widespread epigenetic deregulation. These epigenetic changes are targeted by novel lysine-specific demethylase-1 (LSD1) inhibitors, which are currently in early-phase clinical trials. Single-agent-targeted therapy often induces resistance, and successful clinical development requires knowledge of resistance mechanisms, enabling the design of effective combination strategies. Here, we used a genome-scale CRISPR-Cas9 loss-of-function screen to identify genes whose knockout (KO) conferred resistance to the LSD1 inhibitor SP-2509 in Ewing sarcoma cell lines. Multiple genes required for mitochondrial electron transport chain (ETC) complexes III and IV function were hits in our screen. We validated this finding using genetic and chemical approaches, including CRISPR KO, ETC inhibitors, and mitochondrial depletion. Further global transcriptional profiling revealed that altered complex III/IV function disrupted the oncogenic program mediated by EWS/FLI and LSD1 and blunted the transcriptomic response to SP-2509.ImplicationsThese findings demonstrate that mitochondrial dysfunction modulates SP-2509 efficacy and suggest that new therapeutic strategies combining LSD1 with agents that prevent mitochondrial dysfunction may benefit patients with this aggressive malignancy.
| S-EPMC9284474 | biostudies-literature
Project description:Lysine-specific demethylase 1 (LSD1) targets cellular proteins, including histone H3, p53, E2F, and Dnmt1, and is involved in the regulation of gene expression, DNA replication, the cell cycle, and the DNA damage response. LSD1 catalyzes demethylation of histone H3K9 associated with herpes simplex virus 1 (HSV-1) immediate early (IE) promoters and is necessary for IE gene expression, viral DNA replication, and reactivation from latency. We previously found that LSD1 associates with HSV-1 replication forks and replicating viral DNA, suggesting that it may play a direct role in viral replication or coupled processes. We investigated the effects of the LSD1 inhibitor SP-2509 on the HSV-1 life cycle. Unlike previously investigated LSD1 inhibitors tranylcypromine (TCP) and OG-L002, which covalently attach to the LSD1 cofactor flavin adenine dinucleotide (FAD) to inhibit demethylase activity, SP-2509 has previously been shown to inhibit LSD1 protein-protein interactions. We found that SP-2509 does not inhibit HSV-1 IE gene expression or transcription factor and RNA polymerase II (Pol II) association with viral DNA prior to the onset of replication. However, SP-2509 does inhibit viral DNA replication, late gene expression, and virus production. We used EdC labeling of nascent viral DNA to image aberrant viral replication compartments that form in the presence of SP-2509. Treatment resulted in the formation of small replication foci that colocalize with replication proteins but are defective for Pol II recruitment. Taken together, these data highlight a potential new role for LSD1 in the regulation of HSV-1 DNA replication and gene expression after the onset of DNA replication.IMPORTANCE Treatment of HSV-1-infected cells with SP-2509 blocked viral DNA replication, gene expression after the onset of DNA replication, and virus production. These data support a potential new role for LSD1 in the regulation of viral DNA replication and successive steps in the virus life cycle, and further highlight the promising potential to utilize LSD1 inhibition as an antiviral approach.
| S-EPMC7495396 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2019-05-03 | GSE98787 | GEO