New Avenues and Major Achievements in Phytocompounds Research for Glioblastoma Therapy.

Phytocompounds have been evaluated for their anti-glioblastoma actions for decades, with promising results from preclinical studies but only limited translation into clinics. Indeed, by targeting multiple signaling pathways deregulated in cancer, they often show high efficacy in the in vitro studies, but their poor bioavailability, low tumor accumulation, and rapid clearance compromise their efficacy in vivo. Here, we present the new avenues in phytocompound research for the improvement of glioblastoma therapy, including the ways to enhance the response to temozolomide using phytochemicals, the current focus on phytocompound-based immunotherapy, or the use of phytocompounds as photosensitizers in photodynamic therapy. Moreover, we present new, intensively evaluated approaches, such as chemical modifications of phytochemicals or encapsulation into numerous types of nanoformulations, to improve their bioavailability and delivery to the brain. Finally, we present the clinical trials evaluating the role of phytocompounds or phytocompound-derived drugs in glioblastoma therapy and the less studied phytocompounds or plant extracts that have only recently been found to possess promising anti-glioblastoma properties. Overall, recent advancements in phytocompound research are encouraging; however, only with more 3D glioblastoma models, in vivo studies, and clinical trials it is possible to upgrade the role of phytocompounds in glioblastoma treatment to a satisfactory level.

Diterpenoid honatisine overcomes temozolomide resistance in glioblastoma by inducing mitonuclear protein imbalance through disruption of TFAM-mediated mtDNA transcription.

BACKGROUND: Glioblastoma (GBM) represents as the most formidable intracranial malignancy. The systematic exploration of natural compounds for their potential applications in GBM therapy has emerged as a pivotal and fruitful avenue of research. PURPOSE: In the present study, a panel of 96 diterpenoids was systematically evaluated as a repository of potential antitumour agents. The primary objective was to discern their potency in overcoming resistance to temozolomide (TMZ). Through an extensive screening process, honatisine, a heptacyclic diterpenoid alkaloid, emerged as the most robust candidate. Notably, honatisine exhibited remarkable efficacy in patient-derived primary and recurrent GBM strains. Subsequently, we subjected this compound to comprehensive scrutiny, encompassing GBM cultured spheres, GBM organoids (GBOs), TMZ-resistant GBM cell lines, and orthotopic xenograft mouse models of GBM cells. RESULTS: Our investigative efforts delved into the mechanistic underpinnings of honatisine's impact. It was discerned that honatisine prompted mitonuclear protein imbalance and elicited the mitochondrial unfolded protein response (UPRmt). This effect was mediated through the selective depletion of mitochondrial DNA (mtDNA)-encoded subunits, with a particular emphasis on the diminution of mitochondrial transcription factor A (TFAM). The ultimate outcome was the instigation of deleterious mitochondrial dysfunction, culminating in apoptosis. Molecular docking and surface plasmon resonance (SPR) experiments validated honatisine's binding affinity to TFAM within its HMG-box B domain. This binding may promote phosphorylation of TFAM and obstruct the interaction of TFAM bound to heavy strand promoter 1 (HSP1), thereby enhancing Lon-mediated TFAM degradation. Finally, in vivo experiments confirmed honatisine's antiglioma properties. Our comprehensive toxicological assessments underscored its mild toxicity profile, emphasizing the necessity for a thorough evaluation of honatisine as a novel antiglioma agent. CONCLUSION: In summary, our data provide new insights into the therapeutic mechanisms underlying honatisine's selective inducetion of apoptosis and its ability to overcome chemotherapy resistance in GBM. These actions are mediated through the disruption of mitochondrial proteostasis and function, achieved by the inhibition of TFAM-mediated mtDNA transcription. This study highlights honatisine's potential as a promising agent for glioblastoma therapy, underscoring the need for further exploration and investigation.

Tumor Treating Fields (TTFields) combined with the drug repurposing approach CUSP9v3 induce metabolic reprogramming and synergistic anti-glioblastoma activity in vitro.

BACKGROUND: Glioblastoma represents a brain tumor with a notoriously poor prognosis. First-line therapy may include adjunctive Tumor Treating Fields (TTFields) which are electric fields that are continuously delivered to the brain through non-invasive arrays. On a different note, CUSP9v3 represents a drug repurposing strategy that includes 9 repurposed drugs plus metronomic temozolomide. Here, we examined whether TTFields enhance the antineoplastic activity of CUSP9v3 against this disease. METHODS: We performed preclinical testing of a multimodal approach of TTFields and CUSP9v3 in different glioblastoma models. RESULTS: TTFields had predominantly synergistic inhibitory effects on the cell viability of glioblastoma cells and non-directed movement was significantly impaired when combined with CUSP9v3. TTFields plus CUSP9v3 significantly enhanced apoptosis, which was associated with a decreased mitochondrial outer membrane potential (MOMP), enhanced cleavage of effector caspase 3 and reduced expression of Bcl-2 and Mcl-1. Moreover, oxidative phosphorylation and expression of respiratory chain complexes I, III and IV was markedly reduced. CONCLUSION: TTFields strongly enhance the CUSP9v3-mediated anti-glioblastoma activity. TTFields are currently widely used for the treatment of glioblastoma patients and CUSP9v3 was shown to have a favorable safety profile in a phase Ib/IIa trial (NCT02770378) which facilitates transition of this multimodal approach to the clinical setting.

Circadian regulation of MGMT expression and promoter methylation underlies daily rhythms in TMZ sensitivity in glioblastoma.

BACKGROUND: Glioblastoma (GBM) is the most common primary brain tumor in adults. Despite extensive research and clinical trials, median survival post-treatment remains at 15 months. Thus, all opportunities to optimize current treatments and improve patient outcomes should be considered. A recent retrospective clinical study found that taking TMZ in the morning compared to the evening was associated with a 6-month increase in median survival in patients with MGMT-methylated GBM. Here, we hypothesized that TMZ efficacy depends on time-of-day and O6-Methylguanine-DNA Methyltransferase (MGMT) activity in murine and human models of GBM. METHODS AND RESULTS: In vitro recordings using real-time bioluminescence reporters revealed that GBM cells have intrinsic circadian rhythms in the expression of the core circadian clock genes Bmal1 and Per2, as well as in the DNA repair enzyme, MGMT. Independent measures of MGMT transcript levels and promoter methylation also showed daily rhythms intrinsic to GBM cells. These cells were more susceptible to TMZ when delivered at the daily peak of Bmal1 transcription. We found that in vivo morning administration of TMZ also decreased tumor size and increased body weight compared to evening drug delivery in mice bearing GBM xenografts. Finally, inhibition of MGMT activity with O6-Benzylguanine abrogated the daily rhythm in sensitivity to TMZ in vitro by increasing sensitivity at both the peak and trough of Bmal1 expression. CONCLUSION: We conclude that chemotherapy with TMZ can be dramatically enhanced by delivering at the daily maximum of tumor Bmal1 expression and minimum of MGMT activity and that scoring MGMT methylation status requires controlling for time of day of biopsy.

A randomised phase II trial of temozolomide with or without cannabinoids in patients with recurrent glioblastoma (ARISTOCRAT): protocol for a multi-centre, double-blind, placebo-controlled trial.

BACKGROUND: Glioblastoma (GBM) is the most common adult malignant brain tumour, with an incidence of 5 per 100,000 per year in England. Patients with tumours showing O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation represent around 40% of newly diagnosed GBM. Relapse/tumour recurrence is inevitable. There is no agreed standard treatment for patients with GBM, therefore, it is aimed at delaying further tumour progression and maintaining health-related quality of life (HRQoL). Limited clinical trial data exist using cannabinoids in combination with temozolomide (TMZ) in this setting, but early phase data demonstrate prolonged overall survival compared to TMZ alone, with few additional side effects. Jazz Pharmaceuticals (previously GW Pharma Ltd.) have developed nabiximols (trade name Sativex®), an oromucosal spray containing a blend of cannabis plant extracts, that we aim to assess for preliminary efficacy in patients with recurrent GBM. METHODS: ARISTOCRAT is a phase II, multi-centre, double-blind, placebo-controlled, randomised trial to assess cannabinoids in patients with recurrent MGMT methylated GBM who are suitable for treatment with TMZ. Patients who have relapsed ≥ 3 months after completion of initial first-line treatment will be randomised 2:1 to receive either nabiximols or placebo in combination with TMZ. The primary outcome is overall survival time defined as the time in whole days from the date of randomisation to the date of death from any cause. Secondary outcomes include overall survival at 12 months, progression-free survival time, HRQoL (using patient reported outcomes from QLQ-C30, QLQ-BN20 and EQ-5D-5L questionnaires), and adverse events. DISCUSSION: Patients with recurrent MGMT promoter methylated GBM represent a relatively good prognosis sub-group of patients with GBM. However, their median survival remains poor and, therefore, more effective treatments are needed. The phase II design of this trial was chosen, rather than phase III, due to the lack of data currently available on cannabinoid efficacy in this setting. A randomised, double-blind, placebo-controlled trial will ensure an unbiased robust evaluation of the treatment and will allow potential expansion of recruitment into a phase III trial should the emerging phase II results warrant this development. TRIAL REGISTRATION: ISRCTN: 11460478. CLINICALTRIALS: Gov: NCT05629702.

Comprehensive somatic mutational analysis in glioblastoma: Implications for precision medicine approaches.

Glioblastoma multiforme (GBM), a malignant neoplasm originating from glial cells, remains challenging to treat despite the current standard treatment approach that involves maximal safe surgical resection, radiotherapy, and adjuvant temozolomide chemotherapy. This underscores the critical need to identify new molecular targets for improved therapeutic interventions. The current study aimed to explore the somatic mutations and potential therapeutic targets in GBM using somatic mutational information from four distinct GBM datasets including CGGA, TCGA, CPTAC and MAYO-PDX. The analysis included the evaluation of whole exome sequencing (WES) of GBM datasets, tumor mutation burden assessment, survival analysis, drug sensitivity prediction, and examination of domain-specific amino acid changes. The results identified the top ten commonly altered genes in the aforementioned GBM datasets and patients with mutations in OBSCN and AHNAK2 alone or in combination had a more favorable overall survival (OS). Also, the study identified potential drug sensitivity patterns in GBM patients with mutations in OBSCN and AHNAK2, and evaluated the impact of amino acid changes in specific protein domains on the survival of GBM patients. These findings provide important insights into the genetic alterations and somatic interactions in GBM, which could have implications for the development of new therapeutic strategies for this aggressive malignancy.

Magnetic Resonance Imaging of Iron Metabolism with T2* Mapping Predicts an Enhanced Clinical Response to Pharmacologic Ascorbate in Patients with GBM.

PURPOSE: Pharmacologic ascorbate (P-AscH-) is hypothesized to be an iron (Fe)-dependent tumor-specific adjuvant to chemoradiation in treating glioblastoma (GBM). This study determined the efficacy of combining P-AscH- with radiation and temozolomide in a phase II clinical trial while simultaneously investigating a mechanism-based, noninvasive biomarker in T2* mapping to predict GBM response to P-AscH- in humans. PATIENTS AND METHODS: The single-arm phase II clinical trial (NCT02344355) enrolled 55 subjects, with analysis performed 12 months following the completion of treatment. Overall survival (OS) and progression-free survival (PFS) were estimated with the Kaplan-Meier method and compared across patient subgroups with log-rank tests. Forty-nine of 55 subjects were evaluated using T2*-based MRI to assess its utility as an Fe-dependent biomarker. RESULTS: Median OS was estimated to be 19.6 months [90% confidence interval (CI), 15.7-26.5 months], a statistically significant increase compared with historic control patients (14.6 months). Subjects with initial T2* relaxation < 50 ms were associated with a significant increase in PFS compared with T2*-high subjects (11.2 months vs. 5.7 months, P < 0.05) and a trend toward increased OS (26.5 months vs. 17.5 months). These results were validated in preclinical in vitro and in vivo model systems. CONCLUSIONS: P-AscH- combined with temozolomide and radiotherapy has the potential to significantly enhance GBM survival. T2*-based MRI assessment of tumor iron content is a prognostic biomarker for GBM clinical outcomes. See related commentary by Nabavizadeh and Bagley, p. 255.

Artesunate in glioblastoma therapy: Case reports and review of clinical studies.

BACKGROUND: Artesunate, a derivative of the active ingredient artemisinin from Artemisia annua L. used for centuries in the traditional Chinese medicine, is being applied as front-line drug in malaria treatment. As it is cytotoxic for cancer cells, trials are ongoing to include this drug as supplement in cancer therapy. In glioblastoma cells, artesunate was shown to induce oxidative stress, DNA base damage and double-strand breaks (DSBs), apoptosis, and necroptosis. It also inhibits DNA repair functions and bears senolytic activity. Compared to ionizing radiation, DNA damages accumulate over the whole exposure period, which makes the agent unique in its genotoxic profile. Artesunate has been used in adjuvant therapy of various cancers. PURPOSE: As artesunate has been used in adjuvant therapy of different types of cancer and clinical trials are lacking in brain cancer, we investigated its activity in glioma patients with focus on possible side effects. STUDY DESIGN: Between 2014 and 2020, twelve patients were treated with artesunate for relapsing glioma and analyzed retrospectively: 8 males and 4 females, median age 45 years. HISTOLOGY: 4 glioblastomas WHO grade 4, 5 astrocytomas WHO grade 3, 3 oligodendrogliomas grade 2 or 3. All patients were pretreated with radiation and temozolomide-based chemotherapy. Artesunate 100 mg was applied twice daily p.o. combined with dose-dense temozolomide alone (100 mg/m2 day 1-5/7, 10 patients) or with temozolomide (50 mg/m2 day 1-5/7) plus lomustine (CCNU, 40 mg day 6/7). Blood count, C-reactive protein (CRP), liver enzymes, and renal parameters were monitored weekly. RESULTS: Apart from one transient grade 3 hematological toxicity, artesunate was well tolerated. No liver toxicity was observed. While 8 patients with late stage of the disease had a median survival of 5 months after initiation of artesunate treatment, 4 patients with treatment for remission maintenance showed a median survival of 46 months. We also review clinical trials that have been performed in other cancers where artesunate was included in the treatment regimen. CONCLUSIONS: Artesunate administered at a dose of 2 × 100 mg/day was without harmful side effects, even if combined with alkylating agents used in glioma therapy. Thus, the phytochemical, which is also utilized as food supplement, is an interesting, well tolerated supportive agent useful for long-term maintenance treatment. Being itself cytotoxic on glioblastoma cells and enhancing the cytotoxicity of temozolomide as well as in view of its senolytic activity, artesunate has clearly a potential to enhance the efficacy of malignant brain cancer therapy.

Efficacy of tumour-treating fields therapy in recurrent glioblastoma: A narrative review of current evidence.

Recurrent Glioblastoma presents a formidable challenge in oncology due to its aggressive nature and limited treatment options. Tumour-Treating Fields (TTFields) Therapy, a novel therapeutic modality, has emerged as a promising approach to address this clinical conundrum. This review synthesizes the current evidence surrounding the efficacy of TTFields Therapy in the context of recurrent Glioblastoma. Diverse academic databases were explored to identify relevant studies published within the last decade. Strategic keyword selection facilitated the inclusion of studies focusing on TTFields Therapy's efficacy, treatment outcomes, and patient-specific factors. The review reveals a growing body of evidence suggesting the potential clinical benefits of TTFields Therapy for patients with recurrent Glioblastoma. Studies consistently demonstrate its positive impact on overall survival (OS) and progression-free survival (PFS). The therapy's safety profile remains favorable, with mild to moderate skin reactions being the most commonly reported adverse events. Our analysis highlights the importance of patient selection criteria, with emerging biomarkers such as PTEN mutation status influencing therapy response. Additionally, investigations into combining TTFields Therapy with other treatments, including surgical interventions and novel approaches, offer promising avenues for enhancing therapeutic outcomes. The synthesis of diverse studies underscores the potential of TTFields Therapy as a valuable addition to the armamentarium against recurrent Glioblastoma. The narrative review comprehensively explains the therapy's mechanisms, clinical benefits, adverse events, and future directions. The insights gathered herein serve as a foundation for clinicians and researchers striving to optimize treatment strategies for patients facing the challenging landscape of recurrent Glioblastoma.

Drug-Loaded Lipid Magnetic Nanoparticles for Combined Local Hyperthermia and Chemotherapy against Glioblastoma Multiforme.

Glioblastoma multiforme (GBM) is a devastating tumor of the central nervous system, currently missing an effective treatment. The therapeutic gold standard consists of surgical resection followed by chemotherapy (usually with temozolomide, TMZ) and/or radiotherapy. TMZ does not, however, provide significant survival benefit after completion of treatment because of development of chemoresistance and of heavy side effects of systemic administration. Improvement of conventional treatments and complementary therapies are urgently needed to increase patient survival and quality of life. Stimuli-responsive lipid-based drug delivery systems offer promising prospects to overcome the limitations of the current treatments. In this work, multifunctional lipid-based magnetic nanovectors functionalized with the peptide angiopep-2 and loaded with TMZ (Ang-TMZ-LMNVs) were tested to enhance specific GBM therapy on an in vivo model. Exposure to alternating magnetic fields (AMFs) enabled magnetic hyperthermia to be performed, that works in synergy with the chemotherapeutic agent. Studies on orthotopic human U-87 MG-Luc2 tumors in nude mice have shown that Ang-TMZ-LMNVs can accumulate and remain in the tumor after local administration without crossing over into healthy tissue, effectively suppressing tumor invasion and proliferation and significantly prolonging the median survival time when combined with the AMF stimulation. This powerful synergistic approach has proven to be a robust and versatile nanoplatform for an effective GBM treatment.

Local administration of shikonin improved the overall survival in orthotopic murine glioblastoma models with temozolomide resistance.

BACKGROUND: Glioblastoma is a type of intracranial malignancy. Shikonin, a Chinese traditional medicine, has been shown to have anti-tumor efficacy toward human glioblastoma cells in vitro. However, shikonin cannot easily cross the blood-brain barrier. To address this issue, we evaluated the anti-tumor effects of direct intracranial infusion of shikonin in in vivo orthotopic syngeneic murine glioblastoma models using C57BL/6 mice. MATERIALS AND METHODS: The cytotoxic effects of shikonin against murine glioblastoma cells, SB28 and CT-2A, were reported resistance to temozolomide, were evaluated using an allophycocyanin-conjugated annexin V and propidium iodide assay with flow cytometry. Impedance-based real-time cell analysis (RTCA) was used to analyze the inhibitory effects of shikonin on growth and proliferation. To evaluate the anti-tumor activity of shikonin in vivo, we used orthotopic syngeneic murine glioblastoma models with SB28 and CT-2A cells. RESULTS: In flow cytometry-based cytotoxic assays, shikonin induced apoptosis. RTCA indicated that shikonin decreased the cell index of murine glioblastoma cells, SB28 and CT-2A, in a dose-dependent manner (p < 0.0001 for both cell lines), while temozolomide did not (p = 0.91 and 0.82, respectively). In murine glioblastoma models, SB28 and CT-2A, direct intracranial infusion of shikonin, as a local chemotherapy, improved the overall survival of mice in a dose-dependent manner compared with control groups (p < 0.0001 and p = 0.02, respectively). While temozolomide did not (p = 0.48 and 0.52, respectively). CONCLUSIONS: The direct intracranial infusion of shikonin has potential as a local therapy for patients with glioblastoma.

Ex vivo drug sensitivity screening predicts response to temozolomide in glioblastoma patients and identifies candidate biomarkers.

BACKGROUND: Patient-derived glioma stem-like cells (GSCs) have become the gold-standard in neuro-oncological research; however, it remains to be established whether loss of in situ microenvironment affects the clinically-predictive value of this model. We implemented a GSC monolayer system to investigate in situ-in vitro molecular correspondence and the relationship between in vitro and patient response to temozolomide (TMZ). METHODS: DNA/RNA-sequencing was performed on 56 glioblastoma tissues and 19 derived GSC cultures. Sensitivity to TMZ was screened across 66 GSC cultures. Viability readouts were related to clinical parameters of corresponding patients and whole-transcriptome data. RESULTS: Tumour DNA and RNA sequences revealed strong similarity to corresponding GSCs despite loss of neuronal and immune interactions. In vitro TMZ screening yielded three response categories which significantly correlated with patient survival, therewith providing more specific prediction than the binary MGMT marker. Transcriptome analysis identified 121 genes related to TMZ sensitivity of which 21were validated in external datasets. CONCLUSION: GSCs retain patient-unique hallmark gene expressions despite loss of their natural environment. Drug screening using GSCs predicted patient response to TMZ more specifically than MGMT status, while transcriptome analysis identified potential biomarkers for this response. GSC drug screening therefore provides a tool to improve drug development and precision medicine for glioblastoma.

Quercetin induces MGMT+ glioblastoma cells apoptosis via dual inhibition of Wnt3a/ß-Catenin and Akt/NF-κB signaling pathways.

BACKGROUND: Surgical resection combined with radiotherapy and chemotherapy remains a common clinical treatment for glioblastoma multiforme (GBM). However, the therapeutic outcomes have not been satisfying due to drug resistance and other factors. Quercetin, a phytoingredient capable of crossing the blood-brain barrier, has shown effectiveness in the treatment of various solid tumors. Nevertheless, the potential of quercetin in GBM treatment has not been adequately explored. PURPOSE: This study aims to investigate the effects and mechanisms of quercetin on MGMT+GBM cells. METHODS: The potential targets and mechanisms of quercetin in glioma treatment were predicted based on network pharmacology and molecular docking. The effects of quercetin on cell inhibition rate, cell migration ability, cell cycle arrest, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), Mitochondrial superoxide formation and apoptosis were measured by the CCK8 assay, wound healing assay, PI/RNase staining, JC-1 assay, DCFH-DA assay, MitoSOX staining and Annexin V-FITC/PI double staining, respectively. The methylation status of the MGMT promoter was assessed through methylation-specific polymerase chain reaction (MS-PCR). DNA damage was quantified by alkaline/neutral comet assay and TUNEL assay. The intracellular localization and expression of NF-κB and MGMT were revealed by immunofluorescence. The expression of migration-related proteins, matrix metalloproteinases, apoptosis-related proteins, cyclins, DNA damage/repair enzymes and related pathway proteins was detected by Western blot. RESULTS: Network pharmacology identified 96 targets and potential molecular mechanisms of quercetin in glioma treatment. Subsequent experiments confirmed the synergistic effect of quercetin in combination with temozolomide (TMZ) on T98G cells. Quercetin significantly suppressed the growth and migration of human GBM T98G cells, induced apoptosis, and arrested cells in the S-phase cell cycle. The collapse of mitochondrial membrane potential, ROS generation, enhanced Bax/Bcl-2 ratio, and strengthened cleaved-Caspase 9 and cleaved-Caspase 3 suggested the involvement of ROS-mediated mitochondria-dependent apoptosis in the process of quercetin-induced apoptosis. In addition, quercetin-induced apoptosis was accompanied by intense DNA double-strand breaks (DSBs), γH2AX foci formation, methylation of MGMT promoter, increased cleaved-PARP, and reduced MGMT expression. Quercetin may influence the expression of the key DNA repair enzyme, MGMT, by dual suppression of the Wnt3a/ß-Catenin and the Akt/NF-κB signaling pathways, thereby promoting apoptosis. Inhibition of Wnt3a and Akt using specific inhibitors hindered MGMT expression. CONCLUSION: Our study provides the first evidence that quercetin may induce apoptosis in MGMT+GBM cells via dual inhibition of the Wnt3a/ß-Catenin pathway and the Akt/NF-κB signaling pathway. These findings suggest that quercetin could be a novel agent for improving GBM treatment, especially in TMZ-resistant GBM with high MGMT expression.

Association of Tumor Treating Fields (TTFields) therapy with survival in newly diagnosed glioblastoma: a systematic review and meta-analysis.

PURPOSE: Tumor Treating Fields (TTFields) therapy, an electric field-based cancer treatment, became FDA-approved for patients with newly diagnosed glioblastoma (GBM) in 2015 based on the randomized controlled EF-14 study. Subsequent approvals worldwide and increased adoption over time have raised the question of whether a consistent survival benefit has been observed in the real-world setting, and whether device usage has played a role. METHODS: We conducted a literature search to identify clinical studies evaluating overall survival (OS) in TTFields-treated patients. Comparative and single-cohort studies were analyzed. Survival curves were pooled using a distribution-free random-effects method. RESULTS: Among nine studies, seven (N = 1430 patients) compared the addition of TTFields therapy to standard of care (SOC) chemoradiotherapy versus SOC alone and were included in a pooled analysis for OS. Meta-analysis of comparative studies indicated a significant improvement in OS for patients receiving TTFields and SOC versus SOC alone (HR: 0.63; 95% CI 0.53-0.75; p < 0.001). Among real-world post-approval studies, the pooled median OS was 22.6 months (95% CI 17.6-41.2) for TTFields-treated patients, and 17.4 months (95% CI 14.4-21.6) for those not receiving TTFields. Rates of gross total resection were generally higher in the real-world setting, irrespective of TTFields use. Furthermore, for patients included in studies reporting data on device usage (N = 1015), an average usage rate of ≥ 75% was consistently associated with prolonged survival (p < 0.001). CONCLUSIONS: Meta-analysis of comparative TTFields studies suggests survival may be improved with the addition of TTFields to SOC for patients with newly diagnosed GBM.

Differences in clinical outcomes based on molecular markers in glioblastoma patients treated with concurrent tumor-treating fields and chemoradiation: exploratory analysis of the SPARE trial.

BACKGROUND: Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Despite enormous research efforts, GBM remains a deadly disease. The standard-of-care treatment for patients with newly diagnosed with GBM as per the National Cancer Comprehensive Cancer Network (NCCN) is maximal safe surgical resection followed by concurrent chemoradiation and maintenance temozolomide (TMZ) with adjuvant tumor treating fields (TTF). TTF is a non-pharmacological intervention that delivers low-intensity, intermediate frequency alternating electric fields that arrests cell proliferation by disrupting the mitotic spindle. TTF have been shown in a large clinical trial to improve patient outcomes when added to radiation and chemotherapy. The SPARE trail (Scalp-sparing radiation with concurrent temozolomide and tumor treating fields) evaluated adding TTF concomitantly to radiation and chemotherapy. METHODS: This study is an exploratory analysis of the SPARE trial looking at the prognostic significance of common GBM molecular alterations, namely MGMT, EGFR, TP53, PTEN and telomerase reverse transcriptase (TERT), in this cohort of patients treated with concomitant TTF with radiation and chemotherapy. RESULTS: As expected, MGMT promoter methylation was associated with improved overall survival (OS) and progression-free survival (PFS) in this cohort. In addition, TERT promoter mutation was associated with improved OS and PFS in this cohort as well. CONCLUSIONS: Leveraging the molecular characterization of GBM alongside advancing treatments such as chemoradiation with TTF presents a new opportunity to improve precision oncology and outcomes for GBM patients.

Sequential Treatment with Temozolomide Plus Naturally Derived AT101 as an Alternative Therapeutic Strategy: Insights into Chemoresistance Mechanisms of Surviving Glioblastoma Cells.

Glioblastoma (GBM) is a poorly treatable disease due to the fast development of tumor recurrences and high resistance to chemo- and radiotherapy. To overcome the highly adaptive behavior of GBMs, especially multimodal therapeutic approaches also including natural adjuvants have been investigated. However, despite increased efficiency, some GBM cells are still able to survive these advanced treatment regimens. Given this, the present study evaluates representative chemoresistance mechanisms of surviving human GBM primary cells in a complex in vitro co-culture model upon sequential application of temozolomide (TMZ) combined with AT101, the R(-) enantiomer of the naturally occurring cottonseed-derived gossypol. Treatment with TMZ+AT101/AT101, although highly efficient, yielded a predominance of phosphatidylserine-positive GBM cells over time. Analysis of the intracellular effects revealed phosphorylation of AKT, mTOR, and GSK3ß, resulting in the induction of various pro-tumorigenic genes in surviving GBM cells. A Torin2-mediated mTOR inhibition combined with TMZ+AT101/AT101 partly counteracted the observed TMZ+AT101/AT101-associated effects. Interestingly, treatment with TMZ+AT101/AT101 concomitantly changed the amount and composition of extracellular vesicles released from surviving GBM cells. Taken together, our analyses revealed that even when chemotherapeutic agents with different effector mechanisms are combined, a variety of chemoresistance mechanisms of surviving GBM cells must be taken into account.

Temozolomide Chronotherapy in Glioma: A Systematic Review.

Outcomes for patients with high-grade glioma remain poor. Temozolomide (TMZ) is the only drug approved for first-line treatment of glioblastoma multiforme, the most aggressive form of glioma. Chronotherapy highlights the potential benefit of timed TMZ administration. This is based on pre-clinical studies of enhanced TMZ-induced glioma cytotoxicity dependent on circadian, oscillating expression of key genes involved in apoptosis, DNA damage repair, and cell-cycle mediated cell death. The current systematic review's primary aim was to evaluate the efficacy and toxicity of TMZ chronotherapy. A systemic review of literature following PRISMA guidelines looking at clinical outcomes on TMZ chronotherapy on gliomas was performed. The search in the English language included three databases (PubMed, EMBASE, and Cochrane) and five conferences from 1946 to April 2022. Two independent reviewers undertook screening, data extraction, and risk-of-bias assessment. A descriptive analysis was conducted due to limited data. Of the 269 articles screened, two unique studies were eligible and underwent abstraction for survival and toxicity findings. Both studies-one a retrospective cohort study (n = 166) and the other a prospective randomized feasibility study (n = 35)-were conducted by the same academic group and suggested a trend for improved overall survival, but possibly increased toxicity when TMZ was administered in the morning (vs. evening). There was limited evidence suggesting possible therapeutic value from administering TMZ in the morning, which may be consistent with the pre-clinical observations of the importance of the timing of TMZ administration in vitro. Larger, pragmatic, prospective randomized controlled trials are needed to ascertain the value of TMZ chronotherapy to provide optimized and equitable care for this population.

Novel Synergistic Combination of Pamidronate and Temozolomide for Breast Cancer Therapeutics.

OBJECTIVE: Human breast cancer is among one major health concerns with high prevalence and mortality among women worldwide. Various cellular signaling pathways are implicated in carcinogenesis. One of the major pathways that affect the downstream cellular growth cascades is Mevalonate pathway (MVA). The inhibition of MVA is therapeutically beneficial for various cancers. Pamidronate (PAM) (MVA inhibitor), a nitrogen-containing bisphosphosphonate, is an antiresorptive FDAapproved drug. The objective of our study was to explore adjuvant therapy using a combination of PAM and an alkylating agent, Temozolomide (TMZ) against breast cancer. METHODS: We have examined the differential gene and protein expression in response to the combination treatment strategy. For gene expression analysis RT-qPCR and for proteomic study, twodimensional gel electrophoresis and mass spectrometry techniques were utilized. RESULTS: Combination treatment (PAM+TMZ) showed more pronounced cytotoxic effect as compared to single agent treatment. Our results indicate that MVA pathway regulatory genes (FDFT1, FDPS, KRAS) are significantly (p<0.05) downregulated in combination-treated breast cancer cells. The differential proteomic analysis showed lower expression of GFAP, PPA1 and TRIM68 proteins after synergistic treatment whereas, these proteins are found to be up-regulated in multiple cancers. CONCLUSION: The present study reveals that a combination of PAM and TMZ produces an effective anti-cancerous effect on breast cancer cells. Therefore, this novel therapeutic regimen is likely to provide a better treatment strategy for breast cancer.

Guggulsterone from Commiphora mukul potentiates anti-glioblastoma efficacy of temozolomide in vitro and in vivo via down-regulating EGFR/PI3K/Akt signaling and NF-κB activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Myrrh is an aromatic oleo-gum resin extracted from the stem of Commiphora myrrha (Nees) Engl., and has the efficacies to promote blood circulation and remove blood stasis. Myrrh is mainly used for the treatment of chronic diseases including cancer. Guggulsterone, a major active steroid extracted from myrrh, has been found to inhibit cancer cell growth. Glioblastoma is the most common malignancy of central nervous system, and its prognosis remains very poor mainly due to chemotherapeutic resistance. The active status of EGFR/PI3K/Akt and NF-κB signaling in glioblastoma contributed to poor response for chemotherapy, and blocking this signaling with antagonists sensitized glioblastoma cells to chemotherapy. AIM OF THE STUDY: The present study will investigate whether guggulsterone potentiates the anti-glioblastoma efficacy of temozolomide by down-regulating EGFR/PI3K/Akt signaling and NF-κB activation. MATERIALS AND METHODS: Cell viability and proliferation was determined by cell counting Kit-8 and colony formation assays. Cell apoptosis was evaluated by Annexin V/PI and hoechst 33342 staining assays. Molecular techniques such as western blotting and real-time quantitative PCR were used to demonstrate guggulsterone in vitro effect on EGFR/PI3K/Akt signaling and NF-κB activation. Finally, in vivo studies were performed in orthotopic mouse models of glioblastoma. RESULTS: The results demonstrated that guggulsterone enhanced temozolomide-induced growth inhibition and apoptosis in human glioblastoma U251 and U87 cells. Furthermore, the synergistic anti-glioblastoma efficacy between guggulsterone and temozolomide was intimately associated with the inhibition of EGFR/PI3K/Akt signaling and NF-κB activation in U251 and U87 cells. Our in vivo results on orthotopic xenograft models similarly indicated that guggulsterone potentiated temozolomide-induced tumor growth inhibition through suppressing EGFR/PI3K/Akt signaling pathway and NF-кB activity. CONCLUSIONS: The present study suggested that guggulsterone potentiated anti-glioblastoma efficacy of temozolomide through down-regulating EGFR/PI3K/Akt signaling pathway and NF-кB activation.

Blood-brain Barrier Permeable and Multi-stimuli Responsive Nanoplatform for Orthotopic Glioma Inhibition by Synergistic Enhanced Chemo-/Chemodynamic/Photothermal/Starvation Therapy.

Glioblastoma (GBM) is a common malignant tumor in brain, and the treatment is still a challenge owing to the high invasiveness and the existence of blood-brain barrier (BBB). Although temozolomide (TMZ) is the first line medication, its efficacy is not ideal, which is related to the defect of dose distribution and drug resistance. It is urgent to develop a novel BBB-permeable nanoagent with multiple therapeutic modalities for improving the treatment effect of GBM. In this work, we constructed an intelligent BBB-permeable nanoplatform (CTHG-Lf NPs) with hollow mesoporous copper sulfide nanoparticles (HM-CuS NPs) as temozolomide (TMZ) carrier and hyaluronic acid (HA) as gatekeeper, as well as further modification with glucose oxidase (GOx) and lactoferrin (Lf) for highly efficient synergistic therapy of orthotopic GBM. The modification of Lf endows CTHG-Lf NPs with good target and BBB-permeable ability. HA not only prevents the TMZ leakage during circulation, but also achieves responsive drug release at tumor site for effective chemotherapy (CT). GOx provides high hydrogen peroxide (H2O2) and gluconic acid for improving the treatment effect of chemodynamic therapy (CDT), and realizes the starvation therapy (ST) by consuming glucose. The good photothermal effect of CTHG-Lf NPs achieves the "mild" photothermal therapy (PTT), while enhancing the efficiency of Fenton-like reaction. The synergistic strategy with CT/CDT/PTT/ST can not only promote brain drug delivery, but also realize the combination of multiple mechanisms for effective tumor growth suppression in vivo.