Temozolomide and Other Alkylating Agents in Glioblastoma Therapy

The alkylating agent temozolomide (TMZ) together with maximal safe bulk resection and focal radiotherapy comprises the standard treatment for glioblastoma (GB), a particularly aggressive and lethal primary brain tumor. GB affects 3.2 in 100,000 people who have an average survival time of around 14 months after presentation. Several key aspects make GB a difficult to treat disease, primarily including the high resistance of tumor cells to cell death-inducing substances or radiation and the combination of the highly invasive nature of the malignancy, i.e., treatment must affect the whole brain, and the protection from drugs of the tumor bulk—or at least of the invading cells—by the blood brain barrier (BBB). TMZ crosses the BBB, but—unlike classic chemotherapeutics—does not induce DNA damage or misalignment of segregating chromosomes directly. It has been described as a DNA alkylating agent, which leads to base mismatches that initiate futile DNA repair cycles; eventually, DNA strand breaks, which in turn induces cell death. However, while much is assumed about the function of TMZ and its mode of action, primary data are actually scarce and often contradictory. To improve GB treatment further, we need to fully understand what TMZ does to the tumor cells and their microenvironment. This is of particular importance, as novel therapeutic approaches are almost always clinically assessed in the presence of standard treatment, i.e., in the presence of TMZ. Therefore, potential pharmacological interactions between TMZ and novel drugs might occur with unforeseeable consequences.

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KDM6B sensitizes PARthanatos via suppression of O6-methylguanine DNA methyltransferase repair and sustained checkpoint response

10.1101/2021.12.17.473255 ◽

2021 ◽

Author(s):

Mingming Yang ◽

Chenliang Wang ◽

Mi Zhou ◽

Lei Bao ◽

Yanan Wang ◽

...

Keyword(s):

Dna Damage ◽

Cell Death ◽

Dna Repair ◽

Cancer Cell ◽

Dna Methyltransferase ◽

Alkylating Agent ◽

Alkylating Agents ◽

Checkpoint Response ◽

Methylguanine Dna Methyltransferase ◽

Parp 1

Poly(ADP-ribose) polymerase-1 (PARP-1) is a DNA damage sensor and contributes to both DNA repair and cell death processes. However, how PARP-1 signaling is regulated to switch its function from DNA repair to cell death remains largely unknown. Here, we found that PARP-1 plays a central role in alkylating agent-induced PARthanatic cancer cell death. Lysine demethylase 6B (KDM6B) was identified as a key cell death effector in PARthanatos. Knockout of KDM6B or loss of KDM6B demethylase activity conferred cancer cells resistance to PARthanatic cell death in response to alkylating agents. Mechanistically, KDM6B knockout suppressed methylation at the promoter of O6-methylguanine-DNA methyltransferase (MGMT) to enhance MGMT expression and its direct DNA repair function, thereby inhibiting DNA damage-evoked PARP-1 hyperactivation and subsequent cell death. Moreover, KDM6B knockout triggered sustained Chk1 phosphorylation and activated a second repair machinery to fix DNA damage evading from MGMT repair. Inhibition of MGMT or checkpoint response re-sensitized KDM6B deficient cells to PARthanatos induced by alkylating agents. These findings provide new molecular insights into epigenetic regulation of PARP-1 signaling mediating DNA repair or cell death and identify KDM6B as a biomarker for prediction of cancer cell vulnerability to alkylating agent treatment.

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Shikonin induces immunogenic cell death in tumor cells and enhances dendritic cell-based cancer vaccine

Planta Medica ◽

10.1055/s-0032-1320648 ◽

2012 ◽

Vol 78 (11) ◽

Cited By ~ 1

Author(s):

HM Chen ◽

PH Wang ◽

SS Chen ◽

CC Wen ◽

YH Chen ◽

...

Keyword(s):

Cell Death ◽

Dendritic Cell ◽

Tumor Cells ◽

Cancer Vaccine ◽

Immunogenic Cell Death

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Anticancer Activity of Diosgenin and its Semi-synthetic Derivatives: Role in Autophagy Mediated Cell Death and Induction of Apoptosis

Mini-Reviews in Medicinal Chemistry ◽

10.2174/1389557521666210105111224 ◽

2021 ◽

Vol 21 ◽

Author(s):

Nivedita Bhardwaj ◽

Nancy Tripathi ◽

Bharat Goel ◽

Shreyans K. Jain

Keyword(s):

Cell Death ◽

Cancer Treatment ◽

Anticancer Activity ◽

Tumor Cells ◽

Cancer Progression ◽

Rational Approach ◽

Potential Candidate ◽

Potential Implication ◽

Apoptosis Protein ◽

Synthetic Derivatives

: During cancer progression, the unrestricted proliferation of cells is supported by the impaired cell death response provoked by certain oncogenes. Both autophagy and apoptosis are the signaling pathways of cell death, which are targeted for cancer treatment. Defects in apoptosis result in reduced cell death and ultimately tumor progression. The tumor cells lacking apoptosis phenomena are killed by ROS- mediated autophagy. The autophagic programmed cell death requires apoptosis protein for inhibiting tumor growth; thus, the interconnection between these two pathways determines the fate of a cell. The cross-regulation of autophagy and apoptosis is an important aspect to modulate autophagy, apoptosis and to sensibilise apoptosis-resistant tumor cells under metabolic stress and might be a rational approach for drug designing strategy for the treatment of cancer. Numerous proteins involved in autophagy have been investigated as the druggable target for anticancer therapy. Several compounds of natural origin have been reported, to control autophagy activity through the PI3K/Akt/mTOR key pathway. Diosgenin, a steroidal sapogenin has emerged as a potential candidate for cancer treatment. It induces ROS-mediated autophagy, inhibits PI3K/Akt/mTOR pathway, and produces cytotoxicity selectively in cancer cells. This review aims to focus on optimal strategies using diosgenin to induce apoptosis by modulating the pathways involved in autophagy regulation and its potential implication in the treatment of various cancer. The discussion has been extended to the medicinal chemistry of semi-synthetic derivatives of diosgenin exhibiting anticancer activity.

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Damage-Associated Molecular Patterns Modulation by microRNA: Relevance on Immunogenic Cell Death and Cancer Treatment Outcome

Cancers ◽

10.3390/cancers13112566 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2566

Author(s):

María Julia Lamberti ◽

Annunziata Nigro ◽

Vincenzo Casolaro ◽

Natalia Belén Rumie Vittar ◽

Jessica Dal Col

Keyword(s):

Cell Death ◽

Tumor Cells ◽

Cell Activation ◽

Adaptive Immune Response ◽

Current Status ◽

Immunogenic Cell Death ◽

Basal Expression ◽

Antigen Presenting ◽

Molecular Patterns ◽

Damage Associated Molecular Patterns

Immunogenic cell death (ICD) in cancer is a functionally unique regulated form of stress-mediated cell death that activates both the innate and adaptive immune response against tumor cells. ICD makes dying cancer cells immunogenic by improving both antigenicity and adjuvanticity. The latter relies on the spatiotemporally coordinated release or exposure of danger signals (DAMPs) that drive robust antigen-presenting cell activation. The expression of DAMPs is often constitutive in tumor cells, but it is the initiating stressor, called ICD-inducer, which finally triggers the intracellular response that determines the kinetics and intensity of their release. However, the contribution of cell-autonomous features, such as the epigenetic background, to the development of ICD has not been addressed in sufficient depth. In this context, it has been revealed that several microRNAs (miRNAs), besides acting as tumor promoters or suppressors, can control the ICD-associated exposure of some DAMPs and their basal expression in cancer. Here, we provide a general overview of the dysregulation of cancer-associated miRNAs whose targets are DAMPs, through which new molecular mediators that underlie the immunogenicity of ICD were identified. The current status of miRNA-targeted therapeutics combined with ICD inducers is discussed. A solid comprehension of these processes will provide a framework to evaluate miRNA targets for cancer immunotherapy.

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Gene-Directed Enzyme Prodrug Therapy by Dendrimer-Like Mesoporous Silica Nanoparticles against Tumor Cells

Nanomaterials ◽

10.3390/nano11051298 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1298

Author(s):

Vicente Candela-Noguera ◽

Gema Vivo-Llorca ◽

Borja Díaz de Greñu ◽

María Alfonso ◽

Elena Aznar ◽

...

Keyword(s):

Cell Death ◽

Mesoporous Silica ◽

Silica Nanoparticles ◽

Tumor Cells ◽

Mesoporous Silica Nanoparticles ◽

Combined Treatment ◽

Bond Rupture ◽

Enzyme Prodrug Therapy ◽

Bacterial Gene ◽

Reducing Environment

We report herein a gene-directed enzyme prodrug therapy (GDEPT) system using gated mesoporous silica nanoparticles (MSNs) in an attempt to combine the reduction of side effects characteristic of GDEPT with improved pharmacokinetics promoted by gated MSNs. The system consists of the transfection of cancer cells with a plasmid controlled by the cytomegalovirus promoter, which promotes β-galactosidase (β-gal) expression from the bacterial gene lacZ (CMV-lacZ). Moreover, dendrimer-like mesoporous silica nanoparticles (DMSNs) are loaded with the prodrug doxorubicin modified with a galactose unit through a self-immolative group (DOXO-Gal) and modified with a disulfide-containing polyethyleneglycol gatekeeper. Once in tumor cells, the reducing environment induces disulfide bond rupture in the gatekeeper with the subsequent DOXO-Gal delivery, which is enzymatically converted by β-gal into the cytotoxic doxorubicin drug, causing cell death. The combined treatment of the pair enzyme/DMSNs-prodrug are more effective in killing cells than the free prodrug DOXO-Gal alone in cells transfected with β-gal.

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Calreticulin—Multifunctional Chaperone in Immunogenic Cell Death: Potential Significance as a Prognostic Biomarker in Ovarian Cancer Patients

Cells ◽

10.3390/cells10010130 ◽

2021 ◽

Vol 10 (1) ◽

pp. 130

Author(s):

Michal Kielbik ◽

Izabela Szulc-Kielbik ◽

Magdalena Klink

Keyword(s):

Ovarian Cancer ◽

Cell Death ◽

Cancer Patients ◽

Tumor Cells ◽

Cytotoxic T Cells ◽

Adaptive Immune Response ◽

Ovarian Cancer Cells ◽

Immunogenic Cell Death ◽

Antigen Presenting ◽

Molecular Patterns

Immunogenic cell death (ICD) is a type of death, which has the hallmarks of necroptosis and apoptosis, and is best characterized in malignant diseases. Chemotherapeutics, radiotherapy and photodynamic therapy induce intracellular stress response pathways in tumor cells, leading to a secretion of various factors belonging to a family of damage-associated molecular patterns molecules, capable of inducing the adaptive immune response. One of them is calreticulin (CRT), an endoplasmic reticulum-associated chaperone. Its presence on the surface of dying tumor cells serves as an “eat me” signal for antigen presenting cells (APC). Engulfment of tumor cells by APCs results in the presentation of tumor’s antigens to cytotoxic T-cells and production of cytokines/chemokines, which activate immune cells responsible for tumor cells killing. Thus, the development of ICD and the expression of CRT can help standard therapy to eradicate tumor cells. Here, we review the physiological functions of CRT and its involvement in the ICD appearance in malignant disease. Moreover, we also focus on the ability of various anti-cancer drugs to induce expression of surface CRT on ovarian cancer cells. The second aim of this work is to discuss and summarize the prognostic/predictive value of CRT in ovarian cancer patients.

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Dual Specificity Kinase DYRK3 Promotes Aggressiveness of Glioblastoma by Altering Mitochondrial Morphology and Function

International Journal of Molecular Sciences ◽

10.3390/ijms22062982 ◽

2021 ◽

Vol 22 (6) ◽

pp. 2982

Author(s):

Kyeongmin Kim ◽

Sungmin Lee ◽

Hyunkoo Kang ◽

Eunguk Shin ◽

Hae Yu Kim ◽

...

Keyword(s):

Tumor Cells ◽

Metabolic Flux ◽

Mitochondrial Fission ◽

Mammalian Target Of Rapamycin ◽

Primary Brain Tumor ◽

Metabolic Reprogramming ◽

Migration And Invasion ◽

Mitochondrial Morphology ◽

Dual Specificity ◽

Novel Strategy

Glioblastoma multiforme (GBM) is a malignant primary brain tumor with poor patient prognosis. Although the standard treatment of GBM is surgery followed by chemotherapy and radiotherapy, often a small portion of surviving tumor cells acquire therapeutic resistance and become more aggressive. Recently, altered kinase expression and activity have been shown to determine metabolic flux in tumor cells and metabolic reprogramming has emerged as a tumor progression regulatory mechanism. Here we investigated novel kinase-mediated metabolic alterations that lead to acquired GBM radioresistance and malignancy. We utilized transcriptomic analyses within a radioresistant GBM orthotopic xenograft mouse model that overexpresses the dual specificity tyrosine-phosphorylation-regulated kinase 3 (DYRK3). We find that within GBM cells, radiation exposure induces DYRK3 expression and DYRK3 regulates mammalian target of rapamycin complex 1 (mTORC1) activity through phosphorylation of proline-rich AKT1 substrate 1 (PRAS40). We also find that DYRK3 knockdown inhibits dynamin-related protein 1 (DRP1)-mediated mitochondrial fission, leading to increased oxidative phosphorylation (OXPHOS) and reduced glycolysis. Importantly, enforced DYRK3 downregulation following irradiation significantly impaired GBM cell migration and invasion. Collectively, we suggest DYRK3 suppression may be a novel strategy for preventing GBM malignancy through regulating mitochondrial metabolism.

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STEM-09. INTRINSIC INTERFERON SIGNALING REGULATES THE CELL DEATH OF GLIOBLASTOMA STEM CELLS

Neuro-Oncology ◽

10.1093/neuonc/noaa215.826 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii198-ii198

Author(s):

Sabbi Khan Khan ◽

Emmanuel Martinez-Ledesma ◽

Sandeep Mittal ◽

Kaitlin Gandy ◽

Kristin Alfaro-Munoz ◽

...

Keyword(s):

Cell Death ◽

Treatment Resistance ◽

Primary Brain Tumor ◽

The Cancer Genome Atlas ◽

Cytokine Signaling ◽

Type I ◽

Type Ii ◽

Mechanistic Investigation ◽

Differential Cell ◽

Stat1 Signaling

Abstract Glioblastoma (GBM) is the most common, highly aggressive, and lethal primary brain tumor in adults. Interferon (IFN)-mediated signal transducer and activator of transcription 1 (STAT1) signaling contributes to various aspects of stemness, cell death, cytokine signaling in immune and non-immune cells. However, the role of IFN/STAT1 signaling in stemness, cell death and treatment resistance in GBM is unclear. This study aimed to investigate the cancer cell-intrinsic IFN/STAT1 signaling and its role in cell proliferation, stemness, and apoptosis. By using the metagene scores for type I and type II IFN-responsive genes, we evaluated basal IFN/STAT1 signaling in The Cancer Genome Atlas (TCGA) and in patient-derived cohorts of stem-like cells (GSCs) RNA expression datasets. In-silico analyses were further validated for the constitutive IFN signaling in a subset of GSCs using qPCR, WB and ELISA assays. We employed pharmacological activators and/or inhibitors of IFN/STAT1 signaling in GSCs to study its role in stemness and cell death. We found differential cell-intrinsic type I and type II IFN-signaling markers in GSCs and GBM tumors. High IFN-signaling is associated with mesenchymal phenotype and poor survival outcomes. Acute and chronic GSC exposure to recombinant IFNs reversibly activated both type I and II IFN-signaling in GSCs. IFN-β exposure induced apoptosis in intrinsically high IFN/STAT1-signaling GSCs, but not in the low IFN/STAT1-signaling GSCs. In summary, our findings demonstrate that GBM exhibit differential cell-intrinsic IFN-signaling, and basal IFN/STAT1 is a key factor for IFN-β-mediated cell death in GSCs. However, further mechanistic investigation of intrinsic IFN signaling in GBM, particularly in the stem cell compartment is needed.

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CBIO-11. NOVEL THERAPY TO TARGET PR-RECURRENT GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa215.071 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii17-ii18

Author(s):

Masum Rahman ◽

Ian E Olson ◽

Rehan Saber ◽

Jibo Zhang ◽

Lucas P Carlstrom ◽

...

Keyword(s):

Tumor Cells ◽

Tumor Recurrence ◽

Primary Brain Tumor ◽

Differential Sensitivity ◽

Proliferating Cells ◽

Novel Therapy ◽

Conventional Radiation ◽

Long Time ◽

Radiation Induced

Abstract BACKGROUND Glioblastoma is a fatal infiltrative primary brain tumor, and standard care includes maximal safe surgical resection followed by radiation and Temozolomide (TMZ). Therapy-resistant residual cells persist in a latent state a long time before inevitable recurrence. Conventional radiation and Temozolomide (TMZ) treatment cause oxidative stress and DNA damage resulting senescent-like state of cell-cycle arrest. However, increasing evidence demonstrates escaping senescence leads to tumor recurrence. Thus, the ablation of senescent tumor cells after chemoradiation may be an avenue to limit tumor recurrence. METHODS 100uM TMZ for 7days or 10-20Gy radiation (cesium gamma radiator) was used for senescence induction in human glioblastoma in vitro and confirmed by SA-Beta gal staining and PCR. Replication arrest assessed by automated quantification of cellular confluence (Thermo Scientific Series 8000 WJ Incubator). We evaluated the IC50 for several senolytics targeting multiple SCAPs, including Dasatinib, Quercetin, AMG-232, Fisetin, Onalespib, Navitoclax, and A1331852, and in senescent vs. proliferating cells. RESULTS Among the senolytic tested, the Bcl-XL inhibitors A1331852 and Navitoclax both shown senolytic effect by selectively killing radiated, senescent tumor cells at lower concentrations as compared to 0Gy treated non-senescent cells. Across 12 GBM cell lines, IC50 for senescent cells was 6–500 times lower than non-senescent GBM(p< 0.005). Such differential sensitivity to Bcl-XL inhibition after radiation has also observed by BCL-XL knockdown in radiated glioma. CONCLUSION These findings suggest the potential to harness radiation-induced biology to ablate surviving quiescent cells and demonstrate Bcl-XL dependency as a potential vulnerability of surviving tumor cells after exposure to chemoradiation.

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Biomarkers of Radiotherapy-Induced Immunogenic Cell Death

Cells ◽

10.3390/cells10040930 ◽

2021 ◽

Vol 10 (4) ◽

pp. 930

Author(s):

Rianne D. W. Vaes ◽

Lizza E. L. Hendriks ◽

Marc Vooijs ◽

Dirk De Ruysscher

Keyword(s):

Cell Death ◽

Immune Responses ◽

Tumor Cells ◽

Immunogenic Cell Death ◽

Type I ◽

Future Studies ◽

Regulated Cell Death ◽

Molecular Patterns ◽

Damage Associated Molecular Patterns ◽

Potential Biomarkers

Radiation therapy (RT) can induce an immunogenic variant of regulated cell death that can initiate clinically relevant tumor-targeting immune responses. Immunogenic cell death (ICD) is accompanied by the exposure and release of damage-associated molecular patterns (DAMPs), chemokine release, and stimulation of type I interferon (IFN-I) responses. In recent years, intensive research has unraveled major mechanistic aspects of RT-induced ICD and has resulted in the identification of immunogenic factors that are released by irradiated tumor cells. However, so far, only a limited number of studies have searched for potential biomarkers that can be used to predict if irradiated tumor cells undergo ICD that can elicit an effective immunogenic anti-tumor response. In this article, we summarize the available literature on potential biomarkers of RT-induced ICD that have been evaluated in cancer patients. Additionally, we discuss the clinical relevance of these findings and important aspects that should be considered in future studies.

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