scholarly journals Transcriptional CDK Inhibitors CYC065 and THZ1 Induce Apoptosis in Glioma Stem Cells Derived from Recurrent GBM

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1182
Author(s):  
Viktorija Juric ◽  
Heiko Düssmann ◽  
Martine L. M. Lamfers ◽  
Jochen H. M. Prehn ◽  
Markus Rehm ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Apoptotic Cell ◽  
Clinical Investigation ◽  
Light Sheet ◽  
Adult Brain ◽  
Glioma Stem Cells ◽  
Stem Cell Markers ◽  
Cdk Inhibitors ◽  
Recurrent Gbm

Glioma stem cells (GSCs) are tumour initiating cells which contribute to treatment resistance, temozolomide (TMZ) chemotherapy and radiotherapy, in glioblastoma (GBM), the most aggressive adult brain tumour. A major contributor to the uncontrolled tumour cell proliferation in GBM is the hyper activation of cyclin-dependent kinases (CDKs). Due to resistance to standard of care, GBMs relapse in almost all patients. Targeting GSCs using transcriptional CDK inhibitors, CYC065 and THZ1 is a potential novel treatment to prevent relapse of the tumour. TCGA-GBM data analysis has shown that the GSC markers, CD133 and CD44 were significantly upregulated in GBM patient tumours compared to non-tumour tissue. CD133 and CD44 stem cell markers were also expressed in gliomaspheres derived from recurrent GBM tumours. Light Sheet Florescence Microscopy (LSFM) further revealed heterogeneous expression of these GSC markers in gliomaspheres. Gliomaspheres from recurrent tumours were highly sensitive to transcriptional CDK inhibitors, CYC065 and THZ1 and underwent apoptosis while being resistant to TMZ. Apoptotic cell death in GSC subpopulations and non-stem tumour cells resulted in sphere disruption. Collectively, our study highlights the potential of these novel CKIs to induce cell death in GSCs from recurrent tumours, warranting further clinical investigation.

scholarly journals Transcriptional CDK inhibitors, CYC065 and THZ1 promote Bim-dependent apoptosis in primary and recurrent GBM through cell cycle arrest and Mcl-1 downregulation

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Viktorija Juric ◽  
Lance Hudson ◽  
Joanna Fay ◽  
Cathy E. Richards ◽  
Hanne Jahns ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Cell Cycle Arrest ◽  
Cortical Neurons ◽  
Apoptotic Cell ◽  
Cdk Inhibitors ◽  
Induce Cell Death ◽  
Viability Loss ◽  
Cycle Arrest ◽  
Recurrent Gbm

AbstractActivation of cyclin-dependent kinases (CDKs) contributes to the uncontrolled proliferation of tumour cells. Genomic alterations that lead to the constitutive activation or overexpression of CDKs can support tumourigenesis including glioblastoma (GBM), the most common and aggressive primary brain tumour in adults. The incurability of GBM highlights the need to discover novel and more effective treatment options. Since CDKs 2, 7 and 9 were found to be overexpressed in GBM, we tested the therapeutic efficacy of two CDK inhibitors (CKIs) (CYC065 and THZ1) in a heterogeneous panel of GBM patient-derived cell lines (PDCLs) cultured as gliomaspheres, as preclinically relevant models. CYC065 and THZ1 treatments suppressed invasion and induced viability loss in the majority of gliomaspheres, irrespective of the mutational background of the GBM cases, but spared primary cortical neurons. Viability loss arose from G2/M cell cycle arrest following treatment and subsequent induction of apoptotic cell death. Treatment efficacies and treatment durations required to induce cell death were associated with proliferation velocities, and apoptosis induction correlated with complete abolishment of Mcl-1 expression, a cell cycle-regulated antiapoptotic Bcl-2 family member. GBM models generally appeared highly dependent on Mcl-1 expression for cell survival, as demonstrated by pharmacological Mcl-1 inhibition or depletion of Mcl-1 expression. Further analyses identified CKI-induced Mcl-1 loss as a prerequisite to establish conditions at which the BH3-only protein Bim can efficiently induce apoptosis, with cellular Bim amounts strongly correlating with treatment efficacy. CKIs reduced proliferation and promoted apoptosis also in chick embryo xenograft models of primary and recurrent GBM. Collectively, these studies highlight the potential of these novel CKIs to suppress growth and induce cell death of patient-derived GBM cultures in vitro and in vivo, warranting further clinical investigation.

P13.11 Transcriptional CDK inhibitors, CYC065 and THZ1 promote apoptosis in preclinical models of primary and recurrent GBM tumour cells and glioma stem cells

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii34-ii35
Author(s):  
V Juric ◽  
H Duessmann ◽  
H Jahns ◽  
M Verreault ◽  
A Idbaih ◽  
...  
Keyword(s):  
Stem Cells ◽  
Chick Embryo ◽  
Cortical Neurons ◽  
Tumour Cells ◽  
Glioma Stem Cells ◽  
Cdk Inhibitors ◽  
Dependent Manner ◽  
Xenograft Models ◽  
Induced Apoptosis ◽  
Recurrent Gbm

Abstract BACKGROUND Activation of cyclin-dependent kinases (CDKs) contributes to the uncontrolled proliferation of tumour cells. Genomic alterations that lead to the constitutive activation of CDKs are a feature of many tumours including glioblastoma (GBM), the most common and aggressive primary brain tumour. Patient resistance to the current standard of care, temozolomide and radiotherapy, is common and highlights the need to discover more effective treatment strategies. Additionally, glioma stem cells (GSCs), tumour initiating cells contribute to treatment resistance in GBM. Targeting GBM tumour cells and GSCs using transcriptional CDK inhibitors, CYC065 and THZ1 is a potential novel treatment to prevent relapse of the tumour. MATERIAL AND METHODS The therapeutic efficacy of two CDK inhibitors (CKIs) was tested in a panel of ten low-passage GBM patient-derived gliomasphere cultures and semi-in vivo chick embryo xenograft models. Specifically, transcriptional inhibitors targeting CDK9/2 (CYC065) and CDK7 (THZ1) were used. Mechanism of cell death was examined following CKI treatment. Additionally, dependence on anti-apoptotic proteins was studied using genetic depletion and BH3 profiling. Fluorescence activated cell sorting (FACS) and light-sheet fluorescence microscopy (LSFM) were employed to study stem cell populations in recurrent GBM and evaluation of CKI efficacy against GSCs. RESULTS We here demonstrate that CYC065 and THZ1 treatments cause loss of cell viability and induce caspase-dependent apoptosis in primary and recurrent patient-derived gliomaspheres while sparing primary cortical neurons. Importantly, apoptosis responses manifested across a range of time points that significantly correlated with the cell doubling time. Mechanistically, CYC065 and THZ1 downregulate the anti-apoptotic protein Mcl-1, which suffices to sensitise gliomasphere cultures to treatment-induced apoptosis in a Bim-dependent manner. Additionally, high expression levels of chemo- and radio-resistant GSCs were found in recurrent gliomaspheres. CKIs induced apoptosis in isolated CD133 and CD44 biomarker-positive cells while TMZ was ineffective, highlighting the potential of these drugs to overcome resistance to conventional chemotherapy. Additionally, using LSFM we shown that CD133, CD44 GSC biomarker-negative cells convert into GSC biomarker-positive cells and contribute to the enrichment in GSCs in recurrent GBM which could potentially explain the TMZ ineffectiveness. Finally, CKIs reduced proliferation and promoted apoptosis in chick embryo xenograft models of primary and recurrent GBM. CONCLUSION Collectively, these data demonstrate that CYC065 and THZ1 display high anti-cancer activity in primary and recurrent GBM and provide scientific rationale for the further development of CDK inhibitors to potentiate their clinical utilization in the future.

scholarly journals Proneurotrophins Induce Apoptotic Neuronal Death After Controlled Cortical Impact Injury in Adult Mice

ASN NEURO ◽  
2020 ◽  
Vol 12 ◽  
pp. 175909142093086
Author(s):  
Laura E. Montroull ◽  
Deborah E. Rothbard ◽  
Hur D. Kanal ◽  
Veera D’Mello ◽  
Vincent Dodson ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Cell Death ◽  
Brain Injury ◽  
Neuronal Death ◽  
Apoptotic Cell ◽  
Neuronal Cell ◽  
Adult Brain ◽  
Neurotrophin Receptor ◽  
Cortical Impact ◽  
Impact Injury

The p75 neurotrophin receptor (p75NTR) can regulate multiple cellular functions including proliferation, survival, and apoptotic cell death. The p75NTR is widely expressed in the developing brain and is downregulated as the nervous system matures, with only a few neuronal subpopulations retaining expression into adulthood. However, p75NTR expression is induced following damage to the adult brain, including after traumatic brain injury, which is a leading cause of mortality and disability worldwide. A major consequence of traumatic brain injury is the progressive neuronal loss that continues secondary to the initial trauma, which ultimately contributes to cognitive decline. Understanding mechanisms governing this progressive neuronal death is key to developing targeted therapeutic strategies to provide neuroprotection and salvage cognitive function. In this study, we demonstrate that a cortical impact injury to the sensorimotor cortex elicits p75NTR expression in apoptotic neurons in the injury penumbra, confirming previous studies. To establish whether preventing p75NTR induction or blocking the ligands would reduce the extent of secondary neuronal cell death, we used a noninvasive intranasal strategy to deliver either siRNA to block the induction of p75NTR, or function-blocking antibodies to the ligands pro-nerve growth factor and pro-brain-derived neurotrophic factor. We demonstrate that either preventing the induction of p75NTR or blocking the proneurotrophin ligands provides neuroprotection and preserves sensorimotor function.

scholarly journals MDA-9/Syntenin regulates protective autophagy in anoikis-resistant glioma stem cells

2018 ◽  
Vol 115 (22) ◽  
pp. 5768-5773 ◽  
Author(s):  
Sarmistha Talukdar ◽  
Anjan K. Pradhan ◽  
Praveen Bhoopathi ◽  
Xue-Ning Shen ◽  
Laura A. August ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Therapy Resistance ◽  
Protective Mechanism ◽  
Glioma Stem Cells ◽  
Loss Of Function ◽  
Egfr Signaling ◽  
Anoikis Resistance ◽  
Functional Link ◽  
Small Subpopulation

Glioma stem cells (GSCs) comprise a small subpopulation of glioblastoma multiforme cells that contribute to therapy resistance, poor prognosis, and tumor recurrence. Protective autophagy promotes resistance of GSCs to anoikis, a form of programmed cell death occurring when anchorage-dependent cells detach from the extracellular matrix. In nonadherent conditions, GSCs display protective autophagy and anoikis-resistance, which correlates with expression of melanoma differentiation associated gene-9/Syntenin (MDA-9) (syndecan binding protein; SDCBP). When MDA-9 is suppressed, GSCs undergo autophagic death supporting the hypothesis that MDA-9 regulates protective autophagy in GSCs under anoikis conditions. MDA-9 maintains protective autophagy through phosphorylation of BCL2 and by suppressing high levels of autophagy through EGFR signaling. MDA-9 promotes these changes by modifying FAK and PKC signaling. Gain-of-function and loss-of-function genetic approaches demonstrate that MDA-9 regulates pEGFR and pBCL2 expression through FAK and pPKC. EGFR signaling inhibits autophagy markers (ATG5, Lamp1, LC3B), helping to maintain protective autophagy, and along with pBCL2 maintain survival of GSCs. In the absence of MDA-9, this protective mechanism is deregulated; EGFR no longer maintains protective autophagy, leading to highly elevated and sustained levels of autophagy and consequently decreased cell survival. In addition, pBCL2 is down-regulated in the absence of MDA-9, leading to cell death in GSCs under conditions of anoikis. Our studies confirm a functional link between MDA-9 expression and protective autophagy in GSCs and show that inhibition of MDA-9 reverses protective autophagy and induces anoikis and cell death in GSCs.

The effect of BMI-1 inhibition on brain cancer stem cells.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13543-e13543
Author(s):  
Monal Mehta ◽  
Atif J. Khan ◽  
Hatem E. Sabaawy ◽  
Bruce George Haffty
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Stem Cell ◽  
Cancer Stem Cells ◽  
Cell Lines ◽  
Brain Cancer ◽  
Insertion Site ◽  
Stem Cell Markers ◽  
Primary Cells ◽  
Self Renewal

e13543 Background: Glioblastoma (GBM) is the most frequent and deadly brain cancer. Despite tolerance doses of radiation, control of tumor growth within the brain remains a formidable failure. Since the identification of brain cancer stem cells (BCSCs), efforts are underway to target the pathways regulating these cells. The role of Bmi-1 (B-cell specific MMLV insertion site-1), a polycomb member of chromatin-remodeling complex, in BCSCs self-renewal was elucidated. Here we utilize shRNA targeting or pharmacological inhibition of Bmi-1 in GBM cell lines and primary cells as a radiosensitizer to examine the effects of combination therapy on cell death and BCSCs differentiation. Methods: Cells were pre-treated with a Bmi-1 inhibitor before being irradiated. Serial neurosphere assay, a measure of self-renewal potential, was employed to study the effects of radiation, Bmi-1 inhibition, or the combination on BCSCs. The efficacy of this combination on cell death was assessed with MTT and clonogenic assays. Next, the abilities of the inhibitor and radiation to induce differentiation in GBM cell lines and primary cells were quantified. Further, by utilizing a novel zebrafish orthotropic xenograft model, small molecules targeting Bmi-1 and other BCSC pathways can be identified, and used to predict response to combination therapies. Results: Targeting of Bmi-1 in combination with radiation, specifically as a radiosensitizer, induced significant cell death in GBM cells, and was five-fold more effective than radiation only. Importantly, the neurosphere forming ability of BCSCs was severely compromised when the cells were treated with the combination, indicating a potent effect on the stem cell constituency. These effects may be due to loss of BCSC self-renewal potential, increased differentiation, and/or apoptosis as cells treated with the combination exhibited decreased expression of neural stem cell markers and abnormal phenotypes compared to single treatment. Conclusions: Targeting of Bmi-1 may eliminate the subpopulation of radioresistant BCSCs. Bmi-1 inhibition when combined with radiotherapy might provide an effective therapy for GBM patients specifically through its effect on BCSCs by affecting their survival, proliferation, and stem cell features.

scholarly journals CDK Inhibitors Roscovitine and CR8 Trigger Mcl-1 Down-Regulation and Apoptotic Cell Death in Neuroblastoma Cells

2010 ◽  
Vol 1 (4) ◽  
pp. 369-380 ◽  
Author(s):  
K. Bettayeb ◽  
D. Baunbaek ◽  
C. Delehouze ◽  
N. Loaec ◽  
A. J. Hole ◽  
...  
Keyword(s):  
Cell Death ◽  
Apoptotic Cell ◽  
Neuroblastoma Cells ◽  
Apoptotic Cell Death ◽  
Cdk Inhibitors ◽  
Down Regulation

scholarly journals EZH2 Protects Glioma Stem Cells from Radiation-Induced Cell Death in a MELK/FOXM1-Dependent Manner

2015 ◽  
Vol 4 (2) ◽  
pp. 226-238 ◽  
Author(s):  
Sung-Hak Kim ◽  
Kaushal Joshi ◽  
Ravesanker Ezhilarasan ◽  
Toshia R. Myers ◽  
Jason Siu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Glioma Stem Cells ◽  
Dependent Manner ◽  
Radiation Induced

scholarly journals Adenovirus infection promotes the formation of glioma stem cells by glioblastoma cells through the TLR9/NEAT1/STAT3 pathway

2020 ◽  
Author(s):  
Jian Zang ◽  
Min-hua Zheng ◽  
Xiu-li Cao ◽  
Yi-zhe Zhang ◽  
Yu-fei Zhang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Glioma Cells ◽  
Tumor Model ◽  
Glioma Stem Cells ◽  
Stem Cell Markers ◽  
Qrt Pcr ◽  
Lineage Differentiation ◽  
Stat3 Signaling

Abstract BackgroundGlioma stem cells (GSCs) are glioma cells with stemness and are responsible for a variety of malignant behaviors of glioma. Evidence has shown that signals from tumor microenvironment (TME) enhance stemness of glioma cells, but the identity of the signaling molecules and underlying mechanisms have been incompletely elucidated.MethodsHuman samples and glioma cell lines were cultured in vitro to determine the effects of viral infection by sphere formation, qRT-PCR, Western blot, FACS and immunofluorescence; for in vivo analysis, mice subcutaneous tumor model was carried; while bioinformatics analysis and qRT-PCR were applied for further mechanistic studies.ResultsIn this study, we show that infection of patient-derived glioma cells with adenovirus (ADV) increases the formation of tumor spheres. ADV infection upregulated stem cell markers, and the resultant tumor spheres held the capacities of self-renewal and multi-lineage differentiation, and had stronger potential to form xenograft tumors in immune-compromised mice. ADV promoted GSC formation likely via TLR9, because TLR9 was upregulated after ADV infection, and knockdown of TLR9 reduced ADV-induced GSCs. Consistently, MYD88, as well as total STAT3 and phosphorylated (p-)STAT3, were also upregulated in ADV-induced GSCs. Knockdown of MYD88 or pharmaceutical inhibition of STAT3 attenuated stemness of ADV-induced GSCs. Moreover, we found that ADV infection upregulated lncRNA NEAT1, which is downstream to TLRs and play important roles in cancer stem cells via multiple mechanisms including strengthening STAT3 signaling. Indeed, knockdown of NEAT1 impaired stemness of ADV-induced GSCs. Lastly, we show that HMGB1, a damage associated molecular pattern (DAMP) that also triggers TLR signaling, upregulated stemness markers in glioma cells.ConclusionsIn summary, our data indicate that ADV, which has been developed as vectors for gene therapy and oncolytic virus, promotes the formation of GSCs via TLR9/NEAT1/STAT3 signaling.

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