Background: Functional inactivation of ATRX characterizes large subgroups of malignant gliomas in adults and children. ATRX deficiency in glioma induces widespread chromatin remodeling, driving transcriptional shifts and oncogenic phenotypes. Effective strategies to therapeutically target these broad epigenomic sequelae remain undeveloped.

Methods: We utilized integrated multiomics and the Broad Institute Connectivity Map (CMAP) to identify drug candidates that could potentially revert ATRX-deficient transcriptional changes. We then employed disease-relevant experimental models to evaluate functional phenotypes, coupling these studies with epigenomic profiling to elucidate molecular mechanism(s).

Results: CMAP analysis and transcriptional/epigenomic profiling implicated the Class III HDAC Sirtuin2 (SIRT2) as a central mediator of ATRX-deficient cellular phenotypes and a driver of unfavorable prognosis in ATRX-deficient glioma. SIRT2 inhibitors reverted Atrx-deficient transcriptional signatures in murine neuroepithelial progenitor cells (mNPCs), impaired cell migration in Atrx/ATRX-deficient mNPCs and human glioma stem cells (GSCs), and increased expression of senescence markers in glioma models. Moreover, SIRT2 inhibition impaired growth and increased senescence in ATRX-deficient GSCs in vivo. These effects were accompanied by genome-wide shifts in enhancer-associated H3K27ac and H4K16ac marks, with the latter in particular demonstrating compelling transcriptional links to SIRT2-dependent phenotypic reversals. Motif analysis of these data identified the transcription factor KLF16 as a mediator of phenotype reversal in Atrx-deficient cells upon SIRT2 inhibition.

Conclusions: Our findings indicate that SIRT2 inhibition selectively targets ATRX-deficient gliomas for senescence through global chromatin remodeling, while demonstrating more broadly a viable approach to combat complex epigenetic rewiring in cancer.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10769000PMC
http://dx.doi.org/10.1093/neuonc/noad155DOI Listing

Publication Analysis

Top Keywords

atrx-deficient
8
senescence atrx-deficient
8
chromatin remodeling
8
atrx-deficient transcriptional
8
sirt2 inhibition
8
glioma
5
sirt2
5
sirtuin inhibition
4
inhibition modulates
4
modulates chromatin
4

Similar Publications

Article Synopsis
  • Inactivation of the ATRX gene is a key feature of malignant gliomas, leading to G-quadruplex (G4) DNA structures that cause replication stress and genomic instability.
  • The study tested a drug, CX-5461, on glioma stem cells and mouse models, both alone and with radiation, showing it was particularly effective against ATRX-deficient tumors.
  • The results revealed that CX-5461 increased DNA damage and cell death specifically in ATRX-deficient models, reduced tumor growth, and improved survival in mice, highlighting its potential as a new treatment approach for this type of cancer.
View Article and Find Full Text PDF
Article Synopsis
  • Researchers are investigating how stimulating the innate immune system could help treat gliomas, especially focusing on the interaction between ATRX mutations and IDH mutations.
  • ATRX-deficient glioma models show increased sensitivity to dsRNA treatments, leading to reduced tumor lethality and higher T-cell infiltration, but IDH1 mutations negatively affect immune gene expression.
  • IDH1 doesn't prevent the sensitivity to dsRNA, but it does diminish the immune response, suggesting that targeting innate immunity could be a promising therapeutic strategy for astrocytomas.
View Article and Find Full Text PDF

Glioblastomas are the most common IDH-wildtype adult high-grade gliomas, frequently harboring mutations in the TERT gene promoter (pTERT) and utilizing the subsequent telomerase overexpression for telomere length maintenance. However, some rare cases show loss of ATRX and use alternative mechanisms of telomere lengthening. In this study, we performed the first complex genomic analysis specifically concentrating on the latter subgroup.

View Article and Find Full Text PDF

Background: Functional inactivation of ATRX characterizes large subgroups of malignant gliomas in adults and children. ATRX deficiency in glioma induces widespread chromatin remodeling, driving transcriptional shifts and oncogenic phenotypes. Effective strategies to therapeutically target these broad epigenomic sequelae remain undeveloped.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!