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4.
Cancer Immunol Immunother ; 71(8): 1863-1875, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35001153

ABSTRACT

Glioblastoma multiforme (GBM) is among the most aggressive, treatment-resistant cancers, and despite standard of care surgery, radiation and chemotherapy, is invariably fatal. GBM is marked by local and systemic immunosuppression, contributing to resistance to existing immunotherapies that have had success in other tumor types. Memory T cells specific for previous infections reside in tissues throughout the host and are capable of rapid and potent immune activation. Here, we show that virus-specific memory CD8 + T cells expressing tissue-resident markers populate the mouse and human glioblastoma microenvironment. Reactivating virus-specific memory T cells through intratumoral delivery of adjuvant-free virus-derived peptide triggered local immune activation. This delivery translated to antineoplastic effects, which improved survival in a murine glioblastoma model. Our results indicate that virus-specific memory T cells are a significant part of the glioblastoma immune microenvironment and may be leveraged to promote anti-tumoral immunity.


Subject(s)
Brain Neoplasms , Glioblastoma , Animals , Humans , Immune Tolerance , Immunotherapy/methods , Memory T Cells , Mice , Tumor Microenvironment
6.
Proc Natl Acad Sci U S A ; 118(16)2021 04 20.
Article in English | MEDLINE | ID: mdl-33846242

ABSTRACT

Precision medicine in oncology leverages clinical observations of exceptional response. Toward an understanding of the molecular features that define this response, we applied an integrated, multiplatform analysis of RNA profiles derived from clinically annotated glioblastoma samples. This analysis suggested that specimens from exceptional responders are characterized by decreased accumulation of microglia/macrophages in the glioblastoma microenvironment. Glioblastoma-associated microglia/macrophages secreted interleukin 11 (IL11) to activate STAT3-MYC signaling in glioblastoma cells. This signaling induced stem cell states that confer enhanced tumorigenicity and resistance to the standard-of-care chemotherapy, temozolomide (TMZ). Targeting a myeloid cell restricted an isoform of phosphoinositide-3-kinase, phosphoinositide-3-kinase gamma isoform (PI3Kγ), by pharmacologic inhibition or genetic inactivation disrupted this signaling axis by reducing microglia/macrophage-associated IL11 secretion in the tumor microenvironment. Mirroring the clinical outcomes of exceptional responders, PI3Kγ inhibition synergistically enhanced the anti-neoplastic effects of TMZ in orthotopic murine glioblastoma models. Moreover, inhibition or genetic inactivation of PI3Kγ in murine glioblastoma models recapitulated expression profiles observed in clinical specimens isolated from exceptional responders. Our results suggest key contributions from tumor-associated microglia/macrophages in exceptional responses and highlight the translational potential for PI3Kγ inhibition as a glioblastoma therapy.


Subject(s)
Glioblastoma/metabolism , Microglia/metabolism , Temozolomide/pharmacology , Adult , Animals , Brain Neoplasms/pathology , Cell Line, Tumor , Class Ib Phosphatidylinositol 3-Kinase/metabolism , Drug Resistance, Neoplasm/physiology , Female , Glioblastoma/drug therapy , Glioblastoma/pathology , Humans , Interleukin-11/immunology , Interleukin-11/metabolism , Male , Mice, Inbred C57BL , Mice, Nude , Microglia/physiology , Phosphatidylinositol 3-Kinase/metabolism , Phosphoinositide-3 Kinase Inhibitors/pharmacology , Signal Transduction/drug effects , Temozolomide/metabolism , Tumor Microenvironment/drug effects , Tumor-Associated Macrophages/metabolism , Tumor-Associated Macrophages/physiology
7.
Expert Opin Biol Ther ; 21(2): 183-189, 2021 02.
Article in English | MEDLINE | ID: mdl-32799567

ABSTRACT

INTRODUCTION: Oncolytic viruses (OVs) have been engineered to selectively replicate in cancer cells. While initially thought to exert its anti-cancer effects through direct cytolysis, it is increasingly appreciated that OVs interact with a multitude of cellular processes during its life cycle; FDA approved pharmacologic agents that modulate these cellular processes have been shown to augment the anti-neoplastic effects of OVs. Moreover, because of the release of tumor antigens as well as the innate immuno-stimulatory nature of viruses, OVs induce potent immune responses that augment the anti-tumor effects of FDA approved immunotherapies. There is mounting interest in OV as a platform for combinational anti-cancer therapy in this context. AREAS COVERED: We will review pre-clinical and clinical data that demonstrate proof-of-principle and potential efficacy for OV-based combination therapies with FDA approved anti-cancer agents. EXPERT OPINION: While the cytolytic activity of OV remains a key driver for its anti-neoplastic effects, understanding the virus-host interactions may afford opportunities for potential synergism with FDA approved therapeutics that target these interactions. Most intriguingly, the immune stimulatory effects of OVs renders combination with FDA approved immunotherapies more potent. While there are growing clinical trials employing such combination therapy, meaningful advances in this paradigm will require improved understanding of virus-host interactions.


Subject(s)
Antineoplastic Agents , Neoplasms , Oncolytic Virotherapy , Oncolytic Viruses , Antineoplastic Agents/therapeutic use , Humans , Immunotherapy , Neoplasms/drug therapy
8.
Acta Neuropathol Commun ; 8(1): 221, 2020 12 11.
Article in English | MEDLINE | ID: mdl-33308315

ABSTRACT

Cancer-associated fibroblasts (CAFs) are activated fibroblasts constituting the major stromal components in many types of cancer. CAFs contribute to hallmarks of cancer such as proliferation, invasion and immunosuppressive tumor microenvironment, and are associated with poor prognosis of patients with cancer. However, in glioblastoma (GBM), the most common and aggressive primary malignant brain tumor, our knowledge about CAFs or CAF-like stromal cells is limited. Here, using commonly accepted CAF markers, we characterized CAF-like cell populations in clinical glioma specimens and datasets along with mouse models of GBM. We found that tumor-associated pericytes marked by co-expression of fibroblast activation protein α (FAP) and PDGFRß represent major stromal cell subsets in both human GBM and mouse GBM models, while a fraction of mesenchymal neoplastic cells also express FAP in patient tumors. Since oncolytic viruses can kill cancer cells and simultaneously modulate the tumor microenvironment by impacting non-neoplastic populations such as immune cells and tumor vasculature, we further investigated the ability of oncolytic viruses to target GBM-associated stromal cells. An oncolytic adenovirus, ICOVIR15, carrying ∆24-E1A and an RGD-fiber, infects and depletes FAP+ pericytes as well as GBM cells in murine GBM. Our study thus identifies FAP+/PDGFRß+ pericytes as a major CAF-like stromal cell population in GBM, and highlights the unique property of this oncolytic adenovirus to target both GBM cells and GBM-associated stromal FAP+ cells.


Subject(s)
Cancer-Associated Fibroblasts/metabolism , Endopeptidases/metabolism , Glioblastoma/metabolism , Membrane Proteins/metabolism , Oncolytic Viruses , Pericytes/metabolism , Animals , Cancer-Associated Fibroblasts/cytology , Cancer-Associated Fibroblasts/virology , Disease Models, Animal , Glioblastoma/pathology , Humans , Mice , Oncolytic Virotherapy , Pericytes/cytology , Pericytes/virology , Receptor, Platelet-Derived Growth Factor beta/metabolism , Stromal Cells/cytology , Stromal Cells/metabolism , Stromal Cells/virology , Tumor Microenvironment
9.
EBioMedicine ; 55: 102736, 2020 May.
Article in English | MEDLINE | ID: mdl-32361246

ABSTRACT

BACKGROUND: Recurrence after radiation therapy is nearly universal for glioblastomas, the most common form of adult brain cancer. The study aims to define clinically pertinent mechanisms underlying this recurrence. METHODS: microRNA (miRNA) profiling was performed using matched pre- and post-radiation treatment glioblastoma specimens from the same patients. All specimens harbored unmethylated O6-methylguanine-DNA methyltransferase promoters (umMGMT) and wild-type isocitrate dehydrogenase (wtIDH). The most altered miRNA, miR-603, was characterized. FINDINGS: While nearly all miRNAs remained unchanged after treatment, decreased levels of few, select miRNAs in the post-treatment specimens were observed, the most notable of which involved miR-603. Unbiased profiling of miR-603 targets revealed insulin-like growth factor 1 (IGF1) and IGF1 receptor (IGF1R). Ionizing radiation (IR) induced cellular export of miR-603 through extracellular vesicle (EV) release, thereby de-repressing IGF1 and IGF1R. This de-repression, in turn, promoted cancer stem-cell (CSC) state and acquired radiation resistance in glioblastomas. Export of miR-603 additionally de-repressed MGMT, a DNA repair protein responsible for detoxifying DNA alkylating agents, to promote cross-resistance to these agents. Ectopic miR-603 expression overwhelmed cellular capacity for miR-603 export and synergized with the tumoricidal effects of IR and DNA alkylating agents. INTERPRETATION: Profiling of matched pre- and post-treatment glioblastoma specimens revealed altered homeostasis of select miRNAs in response to radiation. Radiation-induced EV export of miR-603 simultaneously promoted the CSC state and up-regulated DNA repair to promote acquired resistance. These effects were abolished by exogenous miR-603 expression, suggesting potential for clinical translation. FUNDING: NIH 1R01NS097649-01, 9R44GM128223-02, 1R01CA240953-01, the Doris Duke Charitable Foundation Clinical Scientist Development Award, The Sontag Foundation Distinguished Scientist Award, the Kimmel Scholar Award, and BWF 1006774.01 (C.C.C).


Subject(s)
Brain Neoplasms/genetics , DNA Modification Methylases/genetics , DNA Repair Enzymes/genetics , Extracellular Vesicles/radiation effects , Glioblastoma/genetics , Insulin-Like Growth Factor I/genetics , MicroRNAs/genetics , Radiation Tolerance/genetics , Tumor Suppressor Proteins/genetics , Animals , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Cell Line, Tumor , Cell Survival/radiation effects , DNA Modification Methylases/metabolism , DNA Repair/genetics , DNA Repair/radiation effects , DNA Repair Enzymes/metabolism , Extracellular Vesicles/genetics , Extracellular Vesicles/metabolism , Gamma Rays , Gene Expression Regulation, Neoplastic , Glioblastoma/mortality , Glioblastoma/pathology , Glioblastoma/radiotherapy , Histones/genetics , Histones/metabolism , Humans , Insulin-Like Growth Factor I/metabolism , Isocitrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/metabolism , Male , Mice , Mice, Nude , MicroRNAs/metabolism , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Neoplastic Stem Cells/radiation effects , Receptor, IGF Type 1/genetics , Receptor, IGF Type 1/metabolism , Signal Transduction , Survival Analysis , Tumor Suppressor Proteins/metabolism , Xenograft Model Antitumor Assays
10.
Trends Cancer ; 6(2): 147-159, 2020 02.
Article in English | MEDLINE | ID: mdl-32061304

ABSTRACT

In response to a variety of cellular stresses, poly(ADP-ribose) polymerase 1 (PARP1) has vital roles in orchestrating DNA damage repair and preserving genomic integrity. Clinical activity of PARP inhibitors (PARPis) in BRCA1/2 mutant cancers validated the concept of synthetic lethality between PARP inhibition and deleterious BRCA1/2 mutations, leading to clinical approval of several PARPis. Preclinical and clinical studies aiming to broaden the therapeutic application of PARPis identified sensitivity biomarkers and rationale combination strategies that can target BRCA wild-type and homologous recombination (HR) DNA repair-proficient cancers, including central nervous system (CNS) malignancies. In this review, we summarize recent progress in PARPi therapy in brain tumors, and discuss current opportunities for, and challenges to, the use of PARPis in neuro-oncology.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Brain Neoplasms/therapy , Chemoradiotherapy/methods , Oncolytic Virotherapy/methods , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Animals , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , BRCA1 Protein/genetics , BRCA2 Protein/genetics , Biomarkers, Tumor/analysis , Biomarkers, Tumor/genetics , Blood-Brain Barrier/metabolism , Brain Neoplasms/diagnosis , Brain Neoplasms/genetics , Brain Neoplasms/mortality , DNA Damage/drug effects , DNA Damage/immunology , DNA Damage/radiation effects , Disease Models, Animal , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/immunology , Drug Resistance, Neoplasm/radiation effects , Humans , Mice , Mutation , Oncolytic Viruses/immunology , Permeability , Poly (ADP-Ribose) Polymerase-1/metabolism , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Progression-Free Survival , Recombinational DNA Repair/drug effects , Recombinational DNA Repair/immunology , Recombinational DNA Repair/radiation effects , Synthetic Lethal Mutations/drug effects , Temozolomide/pharmacology , Temozolomide/therapeutic use
11.
Clin Cancer Res ; 26(7): 1690-1699, 2020 04 01.
Article in English | MEDLINE | ID: mdl-31900275

ABSTRACT

PURPOSE: Emergence of mismatch repair (MMR) deficiency is a frequent mechanism of acquired resistance to the alkylating chemotherapeutic temozolomide (TMZ) in gliomas. Poly(ADP-ribose) polymerase inhibitors (PARPi) have been shown to potentiate TMZ cytotoxicity in several cancer types, including gliomas. We tested whether PARP inhibition could re-sensitize MSH6-null MMR-deficient gliomas to TMZ, and assessed the role of the base excision repair (BER) DNA damage repair pathway in PARPi-mediated effects. EXPERIMENTAL DESIGN: Isogenic pairs of MSH6 wild-type and MSH6-inactivated human glioblastoma (GBM) cells (including both IDH1/2 wild-type and IDH1 mutant), as well as MSH6-null cells derived from a patient with recurrent GBM were treated with TMZ, the PARPi veliparib or olaparib, and combination thereof. Efficacy of PARPi combined with TMZ was assessed in vivo. We used genetic and pharmacological approaches to dissect the contribution of BER. RESULTS: While having no detectable effect in MSH6 wild-type GBMs, PARPi selectively restored TMZ sensitivity in MSH6-deficient GBM cells. This genotype-specific restoration of activity translated in vivo, where combination treatment of veliparib and TMZ showed potent suppression of tumor growth of MSH6-inactivated orthotopic xenografts, compared with TMZ monotherapy. Unlike PARPi, genetic and pharmacological blockage of BER pathway did not re-sensitize MSH6-inactivated GBM cells to TMZ. Similarly, CRISPR PARP1 knockout did not re-sensitize MSH6-inactivated GBM cells to TMZ. CONCLUSIONS: PARPi restoration of TMZ chemosensitivity in MSH6-inactivated glioma represents a promising strategy to overcome acquired chemoresistance caused by MMR deficiency. Mechanistically, this PARPi-mediated synthetic phenotype was independent of BER blockage and was not recapitulated by loss of PARP1.


Subject(s)
DNA Mismatch Repair , DNA Repair , Drug Resistance, Neoplasm , Glioblastoma/drug therapy , Phthalazines/pharmacology , Piperazines/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Temozolomide/pharmacology , Animals , Antineoplastic Agents, Alkylating/pharmacology , Cell Line, Tumor , Female , Glioblastoma/genetics , Glioblastoma/metabolism , Glioblastoma/pathology , Humans , Mice , Xenograft Model Antitumor Assays
12.
Cell Oncol (Dordr) ; 42(6): 783-799, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31332647

ABSTRACT

PURPOSE: Exosomes play important roles in intercellular communication through signaling pathways affecting tumor microenvironment modulation and tumor proliferation, including those in glioblastoma (GBM). As yet, however, limited studies have been conducted on the inhibitory effect of human bone marrow-derived mesenchymal stem cell (hBMSC)-derived exosomes on GBM development. Therefore, we set out to assess the role of hBMSC secreted exosomes, in particular those carrying microRNA-34a (miR-34a), in the development of GBM. METHODS: Microarray-based expression analysis was employed to identify differentially expressed genes and to predict miRNAs regulating MYCN expression. Next, hBMSCs were transfected with a miR-34a mimic or inhibitor after which exosomes were isolated. Proliferation, apoptosis, migration, invasion and temozolomide (TMZ) chemosensitivity of exosome-exposed GBM cells (T-98G, LN229 and A-172) were measured in vitro. The mechanism underlying MYCN regulation was investigated using lentiviral transfections. The in vivo inhibitory effect of exosomal miR-34a was measured in nude mice xenografted with GBM cells through subcutaneous injection of hBMSCs with an upregulated miR34a content. RESULTS: We found that poorly-expressed miR-34a specifically targeted and negatively regulated the expression of MYCN in GBM cells. In addition we found that miR-34a was delivered to T-98G, LN229 and A-172 GBM cells via hBMSC-derived exosomes. Exogenous overexpression of miR-34a in hBMSC-derived exosomes resulted in inhibition of GBM cell proliferation, invasion, migration and tumorigenesis in vitro and in vivo, while promoting the chemosensitivity of GBM cells to TMZ by silencing MYCN. CONCLUSIONS: From our data we conclude that hBMSC-derived exosomes overexpressing miR-34a may be instrumental for the therapeutic targeting and clinical management of GBM.


Subject(s)
Down-Regulation , Exosomes/metabolism , Glioblastoma/therapy , Mesenchymal Stem Cells/metabolism , MicroRNAs/metabolism , N-Myc Proto-Oncogene Protein/genetics , Animals , Base Sequence , Cell Differentiation/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Drug Resistance, Neoplasm/drug effects , Exosomes/drug effects , Exosomes/ultrastructure , Gene Expression Regulation, Neoplastic/drug effects , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Male , Mesenchymal Stem Cells/drug effects , Mice, Inbred BALB C , Mice, Nude , MicroRNAs/genetics , Models, Biological , N-Myc Proto-Oncogene Protein/metabolism , Neoplasm Invasiveness , Temozolomide/pharmacology , Temozolomide/therapeutic use
13.
Nat Commun ; 10(1): 2910, 2019 07 02.
Article in English | MEDLINE | ID: mdl-31266951

ABSTRACT

PARP inhibitors (PARPis) have clinical efficacy in BRCA-deficient cancers, but not BRCA-intact tumors, including glioblastoma (GBM). We show that MYC or MYCN amplification in patient-derived glioblastoma stem-like cells (GSCs) generates sensitivity to PARPi via Myc-mediated transcriptional repression of CDK18, while most tumors without amplification are not sensitive. In response to PARPi, CDK18 facilitates ATR activation by interacting with ATR and regulating ATR-Rad9/ATR-ETAA1 interactions; thereby promoting homologous recombination (HR) and PARPi resistance. CDK18 knockdown or ATR inhibition in GSCs suppressed HR and conferred PARPi sensitivity, with ATR inhibitors synergizing with PARPis or sensitizing GSCs. ATR inhibitor VE822 combined with PARPi extended survival of mice bearing GSC-derived orthotopic tumors, irrespective of PARPi-sensitivity. These studies identify a role of CDK18 in ATR-regulated HR. We propose that combined blockade of ATR and PARP is an effective strategy for GBM, even for low-Myc GSCs that do not respond to PARPi alone, and potentially other PARPi-refractory tumors.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/genetics , Cyclin-Dependent Kinases/genetics , Drug Resistance, Neoplasm , Glioblastoma/metabolism , Homologous Recombination , Poly(ADP-ribose) Polymerase Inhibitors/administration & dosage , Proto-Oncogene Proteins c-myc/metabolism , Animals , Antigens, Surface/genetics , Antigens, Surface/metabolism , Ataxia Telangiectasia Mutated Proteins/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cyclin-Dependent Kinases/metabolism , Female , Glioblastoma/drug therapy , Glioblastoma/genetics , Humans , Mice , Mice, SCID , N-Myc Proto-Oncogene Protein/genetics , N-Myc Proto-Oncogene Protein/metabolism , Neoplastic Stem Cells/metabolism , Poly (ADP-Ribose) Polymerase-1/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Protein Binding , Proto-Oncogene Proteins c-myc/genetics , Xenograft Model Antitumor Assays
14.
Mol Ther Oncolytics ; 13: 58-66, 2019 Jun 28.
Article in English | MEDLINE | ID: mdl-31016228

ABSTRACT

Novel therapies to override chemo-radiation resistance in prostate cancer (PCa) are needed. Prostate cancer sphere-forming cells (PCSCs) (also termed prostate cancer stem-like cells) likely participate in tumor progression and recurrence, and they are important therapeutic targets. We established PCSC-enriched spheres by culturing human (DU145) and murine (TRAMP-C2) PCa cells in growth factor-defined serum-free medium, and we characterized stem-like properties of clonogenicity and tumorigenicity. The efficacy of two different oncolytic herpes simplex viruses (oHSVs) (G47Δ and MG18L) in PCSCs was tested alone and in combination with radiation; chemotherapy; and inhibitors of phosphoinositide 3-kinase (PI3K), Wnt, and NOTCH in vitro; and, G47Δ was tested with the PI3K inhibitor BKM120 in a PCSC-derived tumor model in vivo. PCSCs were more tumorigenic than serum-cultured parental cells. Human and murine PCSCs were sensitive to oHSV and BKM120 killing in vitro, while the combination was synergistic. oHSV combined with radiation, docetaxel, Wnt, or NOTCH inhibitors was not. In athymic mice bearing DU145 PCSC-derived tumors, the combination of intra-tumoral G47Δ and systemic BKM120 induced complete regression of tumors in 2 of 7 animals, and it exhibited superior anti-tumor activity compared to either monotherapy alone, with no detectable toxicity. oHSV synergizes with BKM120 in killing PCSCs in vitro, and the combination markedly inhibits tumor growth, even inducing regression in vivo.

15.
Clin Cancer Res ; 25(11): 3374-3383, 2019 06 01.
Article in English | MEDLINE | ID: mdl-30796030

ABSTRACT

PURPOSE: Previous studies have shown that the PI3K/Akt/mTOR pathway is activated in up to 70% of breast cancer brain metastases, but there are no approved agents for affected patients. GDC-0084 is a brain penetrant, dual PI3K/mTOR inhibitor that has shown promising activity in a preclinical model of glioblastoma. The aim of this study was to analyze the efficacy of PI3K/mTOR blockade in breast cancer brain metastases models.Experimental Design: The efficacy of GDC-0084 was evaluated in PIK3CA-mutant and PIK3CA wild-type breast cancer cell lines and the isogenic pairs of PIK3CA wild-type and mutant (H1047R/+) MCF10A cells in vitro. In vitro studies included cell viability and apoptosis assays, cell-cycle analysis, and Western blots. In vivo, the effect of GDC-0084 was investigated in breast cancer brain metastasis xenograft mouse models and assessed by bioluminescent imaging and IHC. RESULTS: In vitro, GDC-0084 considerably decreased cell viability, induced apoptosis, and inhibited phosphorylation of Akt and p70 S6 kinase in a dose-dependent manner in PIK3CA-mutant breast cancer brain metastatic cell lines. In contrast, GDC-0084 led only to growth inhibition in PIK3CA wild-type cell lines in vitro. In vivo, treatment with GDC-0084 markedly inhibited the growth of PIK3CA-mutant, with accompanying signaling changes, and not PIK3CA wild-type brain tumors. CONCLUSIONS: The results of this study suggest that the brain-penetrant PI3K/mTOR targeting GDC-0084 is a promising treatment option for breast cancer brain metastases with dysregulated PI3K/mTOR signaling pathway conferred by activating PIK3CA mutations. A national clinical trial is planned to further investigate the role of this compound in patients with brain metastases.


Subject(s)
Brain Neoplasms/metabolism , Brain Neoplasms/secondary , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Class I Phosphatidylinositol 3-Kinases/genetics , Class I Phosphatidylinositol 3-Kinases/metabolism , Oxazines/pharmacology , Pyrimidines/pharmacology , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , Animals , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Brain Neoplasms/drug therapy , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Disease Models, Animal , Female , Humans , Immunohistochemistry , Mice , Protein Kinase Inhibitors/pharmacology
16.
J Natl Cancer Inst ; 109(3): 1-13, 2017 03 01.
Article in English | MEDLINE | ID: mdl-28376211

ABSTRACT

Background: Clinical success of poly(ADP-ribose) polymerase inhibitors (PARP i ) has been limited to repair-deficient cancers and by resistance. Oncolytic herpes simplex viruses (oHSVs) selectively kill cancer cells, irrespective of mutation, and manipulate DNA damage responses (DDR). Here, we explore potential synthetic lethal-like interactions between oHSV and PARP i . Methods: The efficacy of combining PARP i , oHSV MG18L, and G47Δ in killing patient-derived glioblastoma stem cells (GSCs) was assessed using cell viability assays and Chou-Talalay synergy analysis. Effects on DDR pathways, apoptosis, and cell cycle after manipulation with pharmacological inhibitors and lentivirus-mediated knockdown or overexpression were examined by immunoblotting and FACS. In vivo efficacy was evaluated in two GSC-derived orthotopic xenograft models (n = 7-8 per group). All statistical tests were two-sided. Results: GSCs are differentially sensitive to PARP i despite uniform inhibition of PARP activity. oHSV sensitized GSCs to PARP i , irrespective of their PARP i sensitivity through selective proteasomal degradation of key DDR proteins; Rad51, mediating the combination effects; and Chk1. Rad51 degradation required HSV DNA replication. This synthetic lethal-like interaction increased DNA damage, apoptosis, and cell death in vitro and in vivo. Combined treatment of mice bearing PARP i -sensitive or -resistant GSC-derived brain tumors greatly extended median survival compared to either agent alone (vs olaparib: P ≤.001; vs MG18L: P = .005; median survival for sensitive of 83 [95% CI = 77 to 86], 94 [95% CI = 75 to 107], 102 [95% CI = 85 to 110], and 131 [95% CI = 108 to 170] days and for resistant of 54 [95% CI = 52 to 58], 56 [95% CI = 52 to 61], 62 [95% CI = 56 to 72], and 75 [95% CI = 64 to 90] days for mock, PARPi, oHSV, and combination, respectively). Conclusions: The unique oHSV property to target multiple components of DDR generates cancer selective sensitivity to PARP i . This combination of oHSV with PARP i is a new anticancer strategy that overcomes the clinical barriers of PARP i resistance and DNA repair proficiency and is applicable not only to glioblastoma, an invariably lethal tumor, but also to other tumor types.


Subject(s)
Brain Neoplasms/therapy , DNA, Viral/biosynthesis , Glioblastoma/therapy , Oncolytic Virotherapy , Phthalazines/therapeutic use , Piperazines/therapeutic use , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Rad51 Recombinase/metabolism , Simplexvirus/physiology , Animals , Apoptosis , Brain Neoplasms/enzymology , Cell Cycle , Cell Survival/drug effects , Checkpoint Kinase 1/metabolism , Combined Modality Therapy , DNA Repair , DNA Replication , Drug Resistance, Neoplasm , Female , Glioblastoma/enzymology , Humans , Mice , Neoplasm Transplantation , Neoplastic Stem Cells , Oncolytic Viruses/physiology , Phthalazines/pharmacology , Piperazines/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Poly(ADP-ribose) Polymerases/metabolism , Signal Transduction , Tumor Cells, Cultured , Tumor Stem Cell Assay
17.
J Huazhong Univ Sci Technolog Med Sci ; 34(4): 529-534, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25135722

ABSTRACT

Penaeidin-2 (Pen-2) is an important antimicrobial peptide derived from the Pacific white shrimp, Penaeus vannamei, and possesses both antibacterial and antifungal activities. Recent studies suggest that recombinant penaeidins show similar activities to the native Pen-2 protein. Previous researches have shown that some antimicrobial peptides (AMPs) exhibit cytotoxic activity against cancer cells. To date, there have been no studies on the antitumor effects of Pen-2. This study evaluated the potential of recombinant pen-2 (rPen-2) in the selective killing of kidney cancer cell lines ACHN and A498, and its action mechanism. MTT assays found the maximal growth inhibition of HK-2, ACHN and A498 cells treated with 100 µg/mL rPen-2 at 48 h was 13.2%, 62.4%, and 70.4%, respectively. DNA-specific fluorescent dye staining showed a high percentage of apoptosis on cancer cells. Flow cytometry revealed that the apoptosis rate of HK-2, ACHN and A498 cells was 15.2%, 55.2%, and 61.5% at 48 h respectively, suggesting that rPen-2 induced higher apoptosis rate in cancer cells than in HK-2 cells. Laser confocal scanning microscopy demonstrated that the plasma membrane was the key site where rPen-2 interacted with and destroyed tumor cells. Scanning electron microscopy showed the morphologic changes of the cell membranes of kidney cancer cells treated with rPen-2. These results suggest that rPen-2 is a novel potential therapeutic agent that may be useful in treating kidney cancers.


Subject(s)
Antimicrobial Cationic Peptides/pharmacology , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Arthropod Proteins/pharmacology , Kidney Neoplasms/drug therapy , Animals , Antimicrobial Cationic Peptides/genetics , Arthropod Proteins/genetics , Drug Screening Assays, Antitumor , Humans , Kidney Neoplasms/metabolism , Kidney Neoplasms/pathology , Penaeidae/genetics , Recombinant Proteins/genetics , Recombinant Proteins/pharmacology
18.
Front Microbiol ; 5: 303, 2014.
Article in English | MEDLINE | ID: mdl-24999342

ABSTRACT

Oncolytic viruses (OV) are a class of antitumor agents that selectively kill tumor cells while sparing normal cells. Oncolytic herpes simplex virus (oHSV) has been investigated in clinical trials for patients with the malignant brain tumor glioblastoma for more than a decade. These clinical studies have shown the safety of oHSV administration to the human brain, however, therapeutic efficacy of oHSV as a single treatment remains unsatisfactory. Factors that could hamper the anti-glioblastoma efficacy of oHSV include: attenuated potency of oHSV due to deletion or mutation of viral genes involved in virulence, restricting viral replication and spread within the tumor; suboptimal oHSV delivery associated with intratumoral injection; virus infection-induced inflammatory and cellular immune responses which could inhibit oHSV replication and promote its clearance; lack of effective incorporation of oHSV into standard-of-care, and poor knowledge about the ability of oHSV to target glioblastoma stem cells (GSCs). In an attempt to address these issues, recent research efforts have been directed at: (1) design of new engineered viruses to enhance potency, (2) better understanding of the role of the cellular immunity elicited by oHSV infection of tumors, (3) combinatorial strategies with different antitumor agents with a mechanistic rationale, (4) "armed" viruses expressing therapeutic transgenes, (5) use of GSC-derived models in oHSV evaluation, and (6) combinations of these. In this review, we will describe the current status of oHSV clinical trials for glioblastoma, and discuss recent research advances and future directions toward successful oHSV-based therapy of glioblastoma.

19.
Oncoimmunology ; 3(1): e27218, 2014 Jan 01.
Article in English | MEDLINE | ID: mdl-24575383

ABSTRACT

We have recently described a new murine model of glioblastoma, generated by the implantation of syngeneic glioblastoma stem cells into immunocompetent mice, that recapitulates the salient histopathological and immunological features of the human disease. We employed this model to demonstrate the multifaceted activity of an oncolytic herpes simplex virus genetically modified to express interleukin-12, G47∆-IL12.

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