phenanthrenes and Glioblastoma

Novel delivery strategies are necessary to effectively address glioblastoma without systemic toxicities. Triptolide is a therapy derived from the thunder god vine that has shown potent anti-proliferative and immunosuppressive properties but exhibits significant adverse systemic effects. Dendrimer-based nanomedicines have shown great potential for clinical translation of systemic therapies targeting neuroinflammation and brain tumors. Here we present a novel dendrimer-triptolide conjugate that specifically targets tumor-associated macrophages (TAMs) in glioblastoma from systemic administration and exhibits triggered release under intracellular and intratumor conditions. This targeted delivery improves phenotype switching of TAMs from pro- towards anti-tumor expression in vitro. In an orthotopic model of glioblastoma, dendrimer-triptolide achieved significantly improved amelioration of tumor burden compared to free triptolide. Notably, the triggered release mechanism of dendrimer-mediated triptolide delivery significantly reduced triptolide-associated hepatic and cardiac toxicities. These results demonstrate that dendrimers are a promising targeted delivery platform to achieve effective glioblastoma treatment by improving efficacy while reducing systemic toxicities.

Topics: Dendrimers; Diterpenes; Epoxy Compounds; Glioblastoma; Humans; Phenanthrenes; Tumor-Associated Macrophages

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Topics: Animals; Antineoplastic Agents; Biological Availability; Dogs; Drug Delivery Systems; Drug Liberation; Emulsions; Glioblastoma; Humans; Indolizidines; Madin Darby Canine Kidney Cells; Male; Mice; Mice, Inbred ICR; Phenanthrenes; Rats; Rats, Sprague-Dawley

Etoposide (VP-16) is the topoisomerase 2 (Top2) inhibitor used for treating of glioma patients however at high dose with serious side effects. It induces DNA double-strand breaks (DSBs). These DNA lesions are repaired by non-homologous DNA end joining (NHEJ) mediated by DNA-dependent protein kinase (DNA-PK). One possible approach to decrease the toxicity of etoposide is to reduce the dose while maintaining the anticancer potential. It could be achieved through combined therapy with other anticancer drugs. We have assumed that this objective can be obtained by (1) a parallel topo2 α inhibition and (2) sensitization of cancer cells to DSBs. In this work we investigated the effect of two Top2 inhibitors NK314 and VP-16 in glioma cell lines (MO59 K and MO59 J) sensitized by DNA-PK inhibitor, NU7441. Cytotoxic effect of VP-16, NK314 alone and in combination on human glioblastoma cell lines, was assessed by a colorimetric assay. Genotoxic effect of anticancer drugs in combination with NU7441 was assessed by comet assay. Cell cycle distribution and apoptosis were analysed by flow cytometry. Compared with VP-16 or NK314 alone, the combined treatment significantly inhibited cell proliferation. Combination treatment was associated with a strong accumulation of DSBs, modulated cell cycle phases distribution and apoptotic cell death. NU7441 potentiated these effects and additionally postponed DNA repair. Our findings suggest that NK314 could overcome resistance of MO59 cells to VP-16 and NU7441 could serve as sensitizer to VP-16/NK314 combined treatment. The combined tripartite approach of chemotherapy could reduce the overall toxicity associated with each individual therapy, while concomitantly enhancing the anticancer effect to treat human glioma cells. Thus, the use of a tripartite combinatorial approach could be promising and more efficacious than mono therapy or dual therapy to treat and increase the survival of the glioblastoma patients.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Brain Neoplasms; Cell Cycle; Cell Line, Tumor; Chromones; DNA-Activated Protein Kinase; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Drug Synergism; Enzyme Inhibitors; Etoposide; Glioblastoma; Humans; Morpholines; Phenanthrenes

Topoisomerase II (Topo2) inhibitors in combination with cisplatin represent a common treatment modality used for glioma patients. The main mechanism of their action involves induction of DNA double-strand breaks (DSBs). DSBs are repaired via the homology-dependent DNA repair (HRR) and non-homologous end-joining (NHEJ). Inhibition of the NHEJ or HRR pathway sensitizes cancer cells to the treatment. In this work, we investigated the effect of three Topo2 inhibitors-etoposide, NK314, or HU-331 in combination with cisplatin in the U-87 human glioblastoma cell line. Etoposide as well as NK314 inhibited Topo2 activity by stabilizing Topo2-DNA cleavable complexes whereas HU-331 inhibited the ATPase activity of Topo2 using a noncompetitive mechanism. To increase the effectiveness of the treatment, we combined cisplatin and Topo2 inhibitor treatment with DSB repair inhibitors (DRIs). The cells were sensitized with NHEJ inhibitor, NU7441, or the novel HRR inhibitor, YU238259, prior to drug treatment. All of the investigated Topo2 inhibitors in combination with cisplatin efficiently killed the U-87 cells. The most cytotoxic effect was observed for the cisplatin + HU331 treatment scheme and this effect was significantly increased when a DRI pretreatment was used; however, we did not observed DSBs. Therefore, the molecular mechanism of cytotoxicity caused by the cisplatin + HU331 treatment scheme is yet to be evaluated. We observed a concentration-dependent change in DSB levels and accumulation at the G2/M checkpoint and S-phase in glioma cells incubated with NK314/cisplatin and etoposide/cisplatin. In conclusion, in combination with cisplatin, HU331 is the most potent Topo2 inhibitor of human glioblastoma cells.

Topics: Apoptosis; Benzamides; Brain Neoplasms; Cannabidiol; Cell Cycle; Cell Line, Tumor; Chromones; Cisplatin; DNA Breaks, Double-Stranded; DNA Repair; Etoposide; Glioblastoma; Humans; Morpholines; Phenanthrenes; Sulfonamides; Topoisomerase II Inhibitors

Temozolomide is the primary chemotherapeutic agent used to treat glioblastoma. However, many tumors are initially resistant to or develop resistance to temozolomide, mainly due to high levels of O. MTS cellular proliferation assays or trypan blue viability assays were used to determine the effects of DHT/temozolomide combinatorial treatment. Enzyme-linked immunosorbent assay (ELISA) was used to determine effects on MGMT and P-glycoprotein levels after singular and combinatorial treatment.. DHT had a synergistic oncolytic effect in a MGMT-deficient cell line and a sensitizing effect in a MGMT-expressing cell line. Cytotoxicity due to DHT was shown to be reactive oxygen species-dependent, while the combinatorial effect of DHT and temozolomide synergistically reduced MGMT and P-glycoprotein levels.. DHT was shown to augment temozolomide efficacy, indicating that, since DHT can penetrate the blood-brain barrier, temozolomide in combination with DHT may represent a promising therapeutic option for glioblastoma.

Topics: Antineoplastic Agents, Alkylating; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Proliferation; Dacarbazine; Drug Resistance, Neoplasm; Drug Synergism; Furans; Glioblastoma; Humans; In Vitro Techniques; Phenanthrenes; Quinones; Temozolomide; Tumor Cells, Cultured

Medulloblastoma (MB) and glioblastoma (GBM) are the most prevalent malignant brain tumors. The identification of novel therapeutic strategies is urgent for MB and GBM patients. Herein, we discovered 13a-(S)-3-Hydroxyl-6,7-dimethoxyphenanthro[9,10-b]-indolizidine (PF403) strongly exhibited inhibitory activity against Hedgehog (Hh) pathway-hyperactivated MB and GBM cells with a 50% inhibitory concentration (IC50) of 0.01 nM. CAT3 was designed and synthesized as the prodrug of PF403 and displayed significant in vivo efficacy against MB and GBM. Mechanistic study revealed that CAT3 inhibited MB and GBM primarily by interrupting the Hh signaling pathway. At the molecular level, PF403 inhibited the cell surface accumulation of the Smoothened (Smo) receptor by directly binding or enhancing the interaction of Smo with the repressor Ptch1. Furthermore, PF403 significantly repressed Gli1 nuclear accumulation and transcription by promoting Sufu-Gli1 and PKA-Gli1 interactions. Collectively, our studies support the hypothesis that CAT3 is a promising therapeutic agent for the treatment of Hh-driven MB and GBM.

Topics: Administration, Oral; Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Cerebellar Neoplasms; Cyclic AMP-Dependent Protein Kinases; Dose-Response Relationship, Drug; Drug Design; Female; Glioblastoma; Hedgehog Proteins; Indolizidines; Inhibitory Concentration 50; Male; Medulloblastoma; Mice, Inbred BALB C; Mice, Inbred ICR; Mice, Nude; Patched-1 Receptor; Phenanthrenes; Prodrugs; Repressor Proteins; Signal Transduction; Smoothened Receptor; Tumor Burden; Xenograft Model Antitumor Assays; Zinc Finger Protein GLI1

We have studied the anti-cancer activities of antofine N-oxide isolated and purified from the medicinal plant Cynanchum vincetoxicum. Antofine N-oxide displayed a strong inhibitory effect on several solid tumor cell lines (glioblastoma, breast carcinoma and lung carcinoma) and on a T-cell leukemia cell line. Remarkably, its cytotoxic effect was considerably weaker in non-cancer cells. Antofine N-oxide was found to inhibit proliferation of the solid tumor cells whereas it caused apoptotic cell death in the leukemia cells. A microarray analysis after a short treatment revealed that the number of differentially expressed genes was considerably higher in solid tumor than in leukemia cells. Up-regulated genes in the three solid tumor cell lines include genes related to TNFα signaling, of which TNFα was among the most significantly induced. A functional analysis revealed that TNFR1 signaling was most likely activated in the solid tumor cells. The increased mRNA levels of several genes of this pathway (namely TNFα, TNFAIP3 and BIRC3) were confirmed by real-time quantitative PCR after different treatment durations. Finally a slight inhibition of NFκB-mediated transcription was observed in the same cells. Together our results suggest that inhibition of cell proliferation in solid tumor cells essentially occurs through TNFα signaling whereas this pathway is not activated in leukemia cells. Apoptotic cell death in the latter is induced by a distinct yet unknown pathway.

Topics: Alkaloids; Antineoplastic Agents, Phytogenic; Apoptosis; Breast Neoplasms; Cell Line, Tumor; Cynanchum; Gene Expression Profiling; Glioblastoma; Humans; Indolizines; Leukemia, T-Cell; Lung Neoplasms; NF-kappa B; Phenanthrenes; Receptors, Tumor Necrosis Factor, Type I; RNA, Messenger; Signal Transduction; Transcription, Genetic; Tumor Necrosis Factor-alpha

Poly(ADP-ribose) polymerases (PARPs) are recognized as key regulators of cell survival or death. PARP-1 is essential to the repair of DNA single-strand breaks via the base excision repair pathway. The enzyme may be overactivated in response to inflammatory cues, thus depleting cellular energy pools and eventually causing cell death. Accordingly, PARP-1 inhibitors, acting by competing with its physiological substrate NAD(+), have been proposed to play a protective role in a wide range of inflammatory and ischemia/reperfusion-associated diseases. Recently, it has also been reported that PARP-1 regulates proinflammatory mediators, including cytokines, chemokines, adhesion molecules, and enzymes (e.g., iNOS). Furthermore, PARP-1 has been shown to act as a coactivator of NF-κB- and other transcription factors implicated in stress/inflammation, as AP-1, Oct-1, SP-1, HIF, and Stat-1. To further substantiate this hypothesis, we tested the biomolecular effects of PARP-1 inhibitors DPQ and PJ-34 on human glioblastoma cells, induced to a proinflammatory state with lipopolysaccharide and Interferon-γ. PARP-1 expression was evaluated by laser scanning confocal microscopy immunofluorescence (LSM); nitrite production, LDH release and cell viability were also determined. LSM of A-172, SNB-19 and CAS-1 cells demonstrated that DPQ and PJ-34 downregulate PARP-1 expression; they also cause a decrease of LDH release and nitrite production, while increasing cell viability. Similar effects were caused in all three cell lines by N-mono-methyl-arginine, a well known iNOS inhibitor, and by L-carnosine and trehalose, two antioxidant molecules. These results demonstrate that, similar to other well characterized drugs, DPQ and PJ-34 reduce cell inflammation and damage that follow PARP-1 overexpression, while they increase cell survival: this suggests their potential exploitation in clinical Medicine.

Topics: Anti-Inflammatory Agents; Biomarkers; Brain Neoplasms; Carnosine; Cell Line, Tumor; Cell Survival; Coloring Agents; Down-Regulation; Fluorescent Antibody Technique; Glioblastoma; Humans; Isoquinolines; L-Lactate Dehydrogenase; Microscopy, Confocal; Nitrites; Phenanthrenes; Piperidines; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Tetrazolium Salts; Thiazoles; Trehalose

Denbinobin, a phenanthraquinone derivative, was shown to exert antitumor activities in several types of cancer cell lines. However, the precise mechanism underlying denbinobin-induced cell death remains unclear. In this study, we investigated the apoptotic signaling cascade elicited by denbinobin in human glioblastoma multiforme (GBM) cells. Denbinobin concentration-dependently caused a decrease in the cell viability of GBM cells. A flow cytometric analysis of propidium iodide (PI)-stained cells demonstrated that denbinobin induced GBM cell apoptosis. Denbinobin evoked caspase-3 activation and degradation of poly (ADP-ribose) polymerase (PARP) and N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk), a broad-spectrum caspase inhibitor that prevented denbinobin-induced cell death. In addition, denbinobin-induced cell death was diminished by the transfection of wild-type (WT) Akt or IκB kinase (IKK) into GBM cells. Denbinobin reduced IKK phosphorylation in a time-dependent manner, and denbinobin-dephosphorylated IKK was accompanied by a decrease in Akt phosphorylation. The phosphorylation status of forkhead in rhabdomyosarcoma (FKHR), a downstream signal molecule of Akt, was also diminished by the presence of denbinobin. Furthermore, transfection of GBM cells with WT IKKα markedly suppressed the decreases in Akt and FKHR phosphorylation caused by denbinobin. In contrast, transfection with WT IKKβ only slightly affected denbinobin's action against IKK, Akt, and FKHR. These results suggest that IKKα inactivation, followed by Akt and FKHR dephosphorylation and caspase-3 activation, contributes to denbinobin-induced GBM cell apoptosis.

Topics: Anthraquinones; Antineoplastic Agents; Apoptosis; Caspase 3; Cell Line, Tumor; Enzyme Activation; Forkhead Box Protein O1; Forkhead Transcription Factors; Glioblastoma; Humans; I-kappa B Kinase; Phenanthrenes; Phosphorylation; Poly(ADP-ribose) Polymerases; Proteolysis; Proto-Oncogene Proteins c-akt; Signal Transduction

(1) A new human glioblastoma multiforme (GBM) cell line, WJ1, was established from the tissue derived from a 29-year-old patient diagnosed with a grade IV GBM. (2) The WJ1 cell line has been subcultured for more than 80 passages in standard culture media without feeder layer or collagen coatings. (3) GBM cells grow in vitro with distinct morphological appearance. Ultrastructural examination revealed large irregular nuclei and pseudo-inclusion bodies in nuclei. The cytoplasm contained numerous immature organelles and a few glia filaments. Growth kinetic studies demonstrated an approximate population doubling time of 60 h and a colony forming efficiency of 4.04%. The karyotype of the cells was hyperdiploid, with a large subpopulation of polyploid cells. Drug sensitivities of DDP, VP-16, tanshinone IIA of this cell line were assayed. They showed a dose- and time-dependent growth inhibition effect on the cells. (4) Orthotopic transplantation of GBM cells into athymic nude mice induced the formation of solid tumor masses about 6 weeks. The cells obtained from mouse tumor masses when cultivated in vitro had the same morphology and ultrastructure as those of the initial cultures. (5) This cell line may provide a useful model in vitro and in vivo in the cellular and molecular studies as well as in testing novel therapies for human glioblastoma multiforme.

Topics: Abietanes; Adult; Animals; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Brain Neoplasms; Cell Culture Techniques; Cell Division; Cell Line, Tumor; Cisplatin; Etoposide; Glial Fibrillary Acidic Protein; Glioblastoma; Humans; Intermediate Filament Proteins; Karyotyping; Male; Mice; Mice, Nude; Nerve Tissue Proteins; Nestin; Phenanthrenes; Xenograft Model Antitumor Assays