ATR inhibition using gartisertib enhances cell death and synergises with temozolomide and radiation in patient-derived glioblastoma cell lines
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE211272 | GEO | 2024/01/18
REPOSITORIES: GEO
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Project description:Overexpression of histone deacetylases (HDACs) in cancer commonly causes resistance to genotoxic based therapies. Here we report on the novel mechanism whereby overexpressed class I HDACs increase the resistance of glioblastoma cells to the SN1 methylating agent temozolomide (TMZ). The chemotherapeutic TMZ triggers the activation of the DNA damage response (DDR) in resistant glioma cells, leading to DNA lesion bypass and cellular survival. Mass spectrometry analysis revealed that the catalytic activity of class I HDACs stimulates the expression of the E3 ubiquitin ligase RAD18. Furthermore, the data show that RAD18 is part of the O6-methylguanine-induced DDR as TMZ induces the formation of RAD18 foci at sites of DNA damage. Downregulation of RAD18 by HDAC inhibition prevents glioma cells from activating the DDR upon TMZ exposure. Lastly, RAD18 or O6-methylguanine-DNA methyltransferase (MGMT) overexpression abolishes the sensitization effect of HDAC inhibition on TMZ-exposed glioma cells. Our study describes the mechanism whereby class I HDAC overexpression in glioma cells causes resistance to TMZ treatment. HDACs accomplish this by promoting the bypass of O6-methylguanine DNA lesions via enhancing RAD18 expression. It also provides a treatment option with HDAC inhibition to undermine this mechanism.
2022-04-01 | PXD028683 | Pride
Project description:The PIKK superfamily member ATR is a key factor in DNA damage response (DDR) and is vital for the maintenance of genomic stability. DNA single strand breaks (SSBs) and replication stress activate ATR to phosphorylate a wide range of downstream substrates, which activates cell cycle checkpoint, senescence induction, cell death, and R-loop disintegration. ATR mutation causes the human ATR-Seckel syndrome, characterized by dwarfism, microcephaly and intellectual disabilities. Recent studies have implied ATR in non-nuclear functions; however, ATR's function in mitochondrial metabolism and a link to human diseases remains largely unknown. Here we show that ATR is located in mitochondria and its deletion alters mitochondrial dynamics prior to the DDR. ATR deletion disturbs the electron transfer chain (ETC) resulting in ROS overproduction and switches energy production from OXPHOS to the TCA cycle. Multi-omics analyses together with biochemical studies showed an imbalance of ETC proteins and membrane lipids accompanied with a dysregulation of key metabolic signaling pathways, including AMPK, mTOR and PGC1α. Pharmacological intervention of AMPK signaling or ETC functions delineates the metabolic pathways affected in ATR deleted cells. Mitochondrial metabolic dysfunction is more pronounced in ATR deleted neural cells and brain tissues, implicating a connection with neuropathological processes. Thus, ATR plays, beyond its well-known DDR function, an important role for cell metabolism and mitochondrial functionality, which contributes to the manifestation of neuronal deficit of ATR-Seckel.
2021-05-05 | PXD013414 | Pride
Project description:Abstract:
Despite intensive treatments including temozolomide (TMZ) administration, glioblastoma patient prognosis remains dismal and innovative therapeutic strategies are urgently needed. A systems pharmacology approach was undertaken to investigate TMZ pharmacokinetics‐pharmacodynamics (PK‐PD) incorporating the effect of local pH, tumor spatial configuration and micro‐environment. A hybrid mathematical framework was designed coupling ordinary differential equations describing the intracellular reactions, with a spatial cellular automaton to individualize the cells. A differential drug impact on tumor and healthy cells at constant extracellular pH was computationally demonstrated as TMZ‐induced DNA damage was larger in tumor cells as compared to normal cells due to less acidic intracellular pH in cancer cells. Optimality of TMZ efficacy defined as maximum difference between damage in tumor and healthy cells was reached for extracellular pH between 6.8 and 7.5. Next, TMZ PK‐PD in a solid tumor was demonstrated to highly depend on its spatial configuration as spread cancer cells or fragmented tumors presented higher TMZ‐induced damage as compared to compact tumor spheroid. Simulations highlighted that smaller tumors were less acidic than bigger ones allowing for faster TMZ activation and their closer distance to blood capillaries allowed for better drug penetration. For model parameters corresponding to U87 glioma cells, inter‐cell variability in TMZ uptake play no role regarding the mean drug‐induced damage in the whole cell population whereas this quantity was increased by inter‐cell variability in TMZ efflux which was thus a disadvantage in terms of drug resistance. Overall, this study revealed pH as a new potential target to significantly improve TMZ antitumor efficacy.
Change the value of pH for different cases.
2019-09-30 | MODEL1909300003 | BioModels
Project description:Cells activate various stress response pathways when exposed to chemicals that can damage cellular macromolecules and organelles. Whether different chemical stressors activate common and/or stressor-specific pathways and to what extent is largely unclear. Here, we used quantitative phosphoproteomics to compare the phosphorylation signaling cascades induced by four stressors with different modes of action: the DNA damaging agent: cisplatin (CDDP), the topoisomerase II inhibitor: etoposide (ETO), the pro-oxidant: diethyl maleate (DEM) and the immunosuppressant: cyclosporine A (CsA). We show that equitoxic doses of these stressors induce distinctive and complex phosphorylation signaling cascades. Our results reveal stressor-specific kinase motifs and pathways. CDDP activates the DNA damage response (DDR) predominantly through the replication-stress related Atr kinase, whereas ETO triggers the DDR through Atr as well as the DNA double stranded break associated Atm kinase. CsA shares with ETO, a strong activation of CK2 kinase and significant Atm phosphorylation but lacks prominent activation of the DDR. Congruent with their known modes of action, CsA-mediated signaling is related to down-regulation of pathways that control hematopoietic differentiation and immunity whereas oxidative stress is the most prominent initiator of DEM-modulated stress signaling. This study presents an unprecedented molecular insight into the activated phosphorylation signaling cascades after various types of stressors.
2020-03-23 | PXD012559 | Pride
Project description:The overall transcriptome changes were discriminated by the radiation dose rather than the radiation type and manifested mainly by DNA damage response (DDR) genes. Transcription levels of major DDR genes were found to increase in a dose-dependent manner but were rarely affected by the radiation type.
2023-03-15 | GSE218435 | GEO
Project description:Cancer cells are under constant proteotoxic stress and have an increased genomic instability. They therefore rely on upregulation of protein homeostasis and the DNA damage response (DDR) for survival. The ubiquitin-dependent ATPase p97 is a central component of the ubiquitin-proteasome degradation system (UPS), involved in both protein homeostasis and DDR. p97 is overexpressed in many tumours and its overexpression correlates with poor prognosis in patients. To explore the concept of cancer cell killing by combined targeting of DDR and proteostasis, we induced DNA damage by ionising radiation (IR) and inhibited proteostasis by CB-5083, a specific small molecule inhibitor of p97, in bladder cancer cell lines and a mouse xenograft model. Combined therapy induced radiosensitivity and supressed xenograft tumour growth. Mechanistically, inactivation of the p97 ATPase activity results in proteotoxic accumulation of the nuclease MRE11 at the sites of IR-induced DNA lesions. This leads to excessive formation of single-stranded DNA (ssDNA), inhibition of HR, reliance on SSA for DSB repair and synthetic lethality after IR exposure in non-homologous end-joining-defective tumour cells such as those in muscle-invasive bladder carcinoma patients
2021-05-18 | PXD016279 | Pride
Project description:Glioblastoma (GBM) is the most lethal brain tumour that occurs in adults and treatment for GBM has been largely unsuccessful. Ionizing radiation (IR) and chemotherapeutic agents are employed as standard of care treatment for GBM patients and both result in DNA damage. Previous data identified phosphorylation of PTEN at tyrosine 240 (pY240) in samples from patients with recurrent GBM receiving standard of care treatment and was associated with decreased overall survival. Here we demonstrate that pY240 PTEN that was triggered by FGFR2 signaling, enhanced DNA repair by facilitating the loading of PTEN onto chromatin through its interaction with KI-67 and subsequent recruitment of the DNA repair protein, RAD51, to sites of DNA damage. Thus, tumour cells with pY240 PTEN are efficient at repairing DNA damage which would be predicted to result in resistance to therapy. These findings suggest the FGFR-pY240 PTEN-DNA repair mechanism as a therapeutic target for enhancing GBM therapy.
2017-08-07 | MSV000081423 | MassIVE
Project description:The clinical success of combined androgen deprivation therapy (ADT) and radiation therapy (RT) in prostate cancer (PCa) created interest in understanding the mechanistic links between androgen receptor (AR) signaling and the DNA damage response (DDR). Convergent data have led to a model where AR both regulates, and is regulated by, the DDR. Integral to this model is that the AR regulates the transcription of DDR genes both at steady state and in response to ionizing radiation (IR). In this study, we sought to determine which immediate transcriptional changes are induced by IR in an AR-dependent manner. Using PRO-seq to quantify changes in nascent RNA transcription in response to IR, the AR antagonist enzalutamide, or the combination of the two, we find that enzalutamide treatment significantly decreased expression of canonical AR target genes but had no effect on DDR gene sets in PCa cells. Surprisingly, we also found that the AR is not a primary regulator of DDR genes either in response to IR or at steady state in asynchronously growing PCa cells. Our data indicate that the clinical benefit of ADT and RT is not due to the direct regulation of DDR gene transcription by AR.
2023-09-18 | GSE235902 | GEO
Project description:Genomic instability is one of the hallmarks of cancer. Several chemotherapeutic drugs and radiotherapy induce DNA damage to prevent cancer cell replication. Cells in turn activate different DNA damage response (DDR) pathways to either repair the damage or induce cell death. These DDR pathways also elicit metabolic alterations which can play a significant role in the proper functioning of the cells. The understanding of these metabolic effects resulting from different types of DNA damage and repair mechanisms is currently lacking. In this study, we used NMR metabolomics to identify metabolic pathways which are altered in response to different DNA damaging agents. By comparing the metabolic responses in MCF-7 cells, we identified the activation of poly (ADP-ribose) polymerase (PARP) in methyl methanesulfonate (MMS)-induced DNA damage. PARP activation led to a significant depletion of NAD+. PARP inhibition using veliparib (ABT-888) was able to successfully restore the NAD+ levels in MMS-treated cells. In addition, double strand break induction by MMS and veliparib exhibited similar metabolic responses as zeocin, suggesting an application of metabolomics to classify the types of DNA damage responses. This prediction was validated by studying the metabolic responses elicited by radiation. Our findings indicate that cancer cell metabolic responses depend on the type of DNA damage responses and can also be used to classify the type of DNA damage.
2015-08-01 | MTBLS177 | MetaboLights
Project description:Maintaining genome integrity presents a particular challenge for plants due to their sedentary lifestyle, which disables direct avoidance of unfavorable external conditions. Additionally, plants’ metabolic processes generate reactive molecules as by-products of e.g. photosynthesis, creating internal DNA-damaging conditions. Due to this, plants have developed a unique and strictly regulated web of DNA damage responses (DDR). We initiated analysis of the DDR system in cultivated barley (Hordeum vulgare), a temperate cereal model with a large and repeat rich genome. A series of DNA damaging assays was established to describe barley plants’ phenotypic response to chemically induced DNA double-strand breaks. The efficacy of assays as a tool to be used for assessing potential new DDR barley mutants was demonstrated. DNA damage response network activation in barley was assessed by transcriptome analysis using RNA sequencing for wild type and mutant in the DDR signaling kinase ATAXIA TELANGIECTASIA MUTATED AND RAD3-RELATED (ATR). Considering the barley genome had only recently been sequenced, and it lacks the in-depth gene analysis, a list of potential DNA damage response genes in barley was compiled based on their homology with Arabidopsis genes. The comparison of transcripts in wild-type plants and atr mutants following genotoxic stress
2023-10-19 | GSE235051 | GEO