Synergistic Effects of Resveratrol and Temozolomide Against Glioblastoma Cells: Underlying Mechanism and Therapeutic Implications

Temozolomide monotherapy versus combination therapies in melanoma: a meta-analysis of efficacy and safety

Temozolomide is used in melanoma therapy, but the comparative efficacy and safety of monotherapy vs combination therapies are unclear. This meta-analysis evaluates temozolomide monotherapy vs combination therapies in melanoma patients. PubMed, Embase, and Cochrane Library were searched up to August 2024 for studies comparing temozolomide monotherapy with combination therapies in melanoma. Primary outcomes were 1-year survival and objective response rates (RR); secondary outcomes included hematologic and non-hematologic toxicities. Data were pooled using risk ratios with 95% confidence intervals (CIs). Seven studies were included. Combination therapies improved objective RR over temozolomide monotherapy (risk ratio 0.68, 95% CI: 0.53-0.88). One-year survival did not differ significantly between groups (risk ratio 0.81, 95% CI: 0.59-1.12). Temozolomide monotherapy was associated with reduced incidence of leukopenia (risk ratio 0.54, 95% CI: 0.30-0.95). Adding interferon-alpha (IFN-α) to temozolomide significantly improved 1-year survival (risk ratio 0.54, 95% CI: 0.35-0.84) and objective RR (risk ratio 0.57, 95% CI: 0.42-0.78) compared to temozolomide alone, without significantly increasing toxicity. Combination therapies enhance objective RR over temozolomide monotherapy, with similar 1-year survival. Temozolomide monotherapy offers a better hematologic safety profile. Combining temozolomide with IFN-α significantly improves survival and RR without increasing toxicity. Clinicians should balance efficacy and safety when choosing melanoma treatments.

Phytochemicals as Novel Therapeutics for Triple-Negative Breast Cancer: A Comprehensive Review of Current Knowledge

Triple-negative breast cancer is a characteristic subtype of breast cancer that lacks the estrogen receptor, human epidermal growth factor receptor 2, and progesterone receptor. Because of its highly diverse subtypes, increased metastasis capability, and poor prognosis, the risk of mortality for people with triple-negative breast cancers is high as compared with other cancers. Chemotherapy is currently playing a major role in treating triple-negative breast cancer patients; however, poor prognosis due to drug resistance is causing serious concern. Recent studies on several phytochemicals derived from various plants being used in Traditional Chinese Medicine, Traditional Korean Medicine, Ayurveda (Traditional Indian Medicine), and so on, have demonstrated to be a promising agent as a viable therapy against triple-negative breast cancer. Phytochemicals categorized as alkaloids, polyphenols, terpenoids, phytosterols, and organosulfur compounds have been demonstrated to reduce cancer cell proliferation and metastasis by activating various molecular pathways, thereby reducing the spread of triple-negative breast cancer. This review analyzes the molecular mechanisms by which various phytochemicals fight triple-negative breast cancer and offers a perspective on the difficulties and potential prospects for treating triple-negative breast cancer with various phytochemicals.

The Potential Application of Resveratrol and Its Derivatives in Central Nervous System Tumors

Resveratrol, a naturally occurring polyphenolic compound found in various plants, has been extensively studied for its broad spectrum of beneficial biological effects. These encompass its potent antioxidant properties, anti-inflammatory activities, anti-aging capabilities, cardioprotective functions, and neuroprotective potential. The diverse biological actions of resveratrol extend beyond these well-established properties. It also exerts a significant impact on metabolic processes and bioavailability, and critically, it demonstrates the ability to effectively traverse the blood-brain barrier. This capacity to penetrate the central nervous system renders resveratrol a promising therapeutic agent for the management of central nervous system malignancies, as it has been shown to inhibit tumor cell proliferation, induce apoptosis, and modulate key signaling cascades, such as PI3K/Akt, JAK/STAT, and NF-kB. The multifaceted nature of resveratrol's biological effects, including its influence on diverse physiological processes, underscores its potential as a valuable therapeutic option for the treatment of central nervous system tumors.

Potential of Natural Products in the Treatment of Glioma: Focus on Molecular Mechanisms

Despite the waning of traditional treatments for glioma due to possible long-term issues, the healing possibilities of substances derived from nature have been reignited in the scientific community. These natural substances, commonly found in fruits and vegetables, are considered potential alternatives to pharmaceuticals, as they have been shown in prior research to impact pathways surrounding cancer progression, metastases, invasion, and resistance. This review will explore the supposed molecular mechanisms of different natural components, such as berberine, curcumin, coffee, resveratrol, epigallocatechin-3-gallate, quercetin, tanshinone, silymarin, coumarin, and lycopene, concerning glioma treatment. While the benefits of a balanced diet containing these compounds are widely recognized, there is considerable scope for investigating the efficacy of these natural products in treating glioma.

Current Combinatorial Therapeutic Aspects: The Future Prospect for Glioblastoma Treatment

There are several types of brain tumors but glioblastoma (GBM) is one of the highly malignant tumors. A primary concern with GBM is that the treatment is inadequate. Even after giving many multi-stacked combinations of therapies to patients, inclusive of chemotherapy, radiation, and surgery, the median survival rate remains poor. Due to its heterogeneous nature, the use of selective therapy for specific targeting of tumor cells is of particular importance. Although many treatment alternatives which include surgery with adjuvant chemotherapy and radiotherapy are available, the prognosis of the disease is very poor. Combination therapy is becoming the foundation of modern antitumor therapy and it is continuously evolving and developing innovative drug regimens as evidenced by ongoing preclinical and clinical trials. In this review, we discuss the current treatment options and emerging therapeutic approaches for the treatment of GBM. The prospects for alternative glioblastoma therapy are also discussed.

Nrf2/Keap1/ARE regulation by plant secondary metabolites: a new horizon in brain tumor management

Brain cancer is regarded as one of the most life-threatening forms of cancer worldwide. Oxidative stress acts to derange normal brain homeostasis, thus is involved in carcinogenesis in brain. The Nrf2/Keap1/ARE pathway is an important signaling cascade responsible for the maintenance of redox homeostasis, and regulation of anti-inflammatory and anticancer activities by multiple downstream pathways. Interestingly, Nrf2 plays a somewhat, contradictory role in cancers, including brain cancer. Nrf2 has traditionally been regarded as a tumor suppressor since its cytoprotective functions are considered to be the principle cellular defense mechanism against exogenous and endogenous insults, such as xenobiotics and oxidative stress. However, hyperactivation of the Nrf2 pathway supports the survival of normal as well as malignant cells, protecting them against oxidative stress, and therapeutic agents. Plants possess a pool of secondary metabolites with potential chemotherapeutic/chemopreventive actions. Modulation of Nrf2/ARE and downstream activities in a Keap1-dependant manner, with the aid of plant-derived secondary metabolites exhibits promise in the management of brain tumors. Current article highlights the effects of Nrf2/Keap1/ARE cascade on brain tumors, and the potential role of secondary metabolites regarding the management of the same.

Dynamic structural remodeling of LINC01956 enhances temozolomide resistance in MGMT-methylated glioblastoma

The mechanisms underlying stimuli-induced dynamic structural remodeling of RNAs for the maintenance of cellular physiological function and survival remain unclear. Here, we showed that in MGMT promoter-methylated glioblastoma (GBM), the RNA helicase DEAD-box helicase 46 (DDX46) is phosphorylated by temozolomide (TMZ)-activated checkpoint kinase 1 (CHK1), resulting in a dense-to-loose conformational change and an increase in DDX46 helicase activity. DDX46-mediated tertiary structural remodeling of LINC01956 exposes the binding motifs of LINC01956 to the 3' untranslated region of O6-methylguanine DNA methyltransferase (MGMT). This accelerates recruitment of MGMT mRNA to the RNA export machinery and transportation of MGMT mRNA from the nucleus to the cytoplasm, leading to increased MGMT abundance and TMZ resistance. Using patient-derived xenograft (PDX) and tumor organoid models, we found that treatment with the CHK1 inhibitor SRA737abolishes TMZ-induced structural remodeling of LINC01956 and subsequent MGMT up-regulation, resensitizing TMZ-resistant MGMT promoter-methylated GBM to TMZ. In conclusion, these findings highlight a mechanism underlying temozolomide-induced RNA structural remodeling and may represent a potential therapeutic strategy for patients with TMZ-resistant MGMT promoter-methylated GBM.

S-allyl-cysteine triggers cytotoxic events in rat glioblastoma RG2 and C6 cells and improves the effect of temozolomide through the regulation of oxidative responses

Glioblastoma (GBM) is an aggressive form of cancer affecting the Central Nervous System (CNS) of thousands of people every year. Redox alterations have been shown to play a key role in the development and progression of these tumors as Reactive Oxygen Species (ROS) formation is involved in the modulation of several signaling pathways, transcription factors, and cytokine formation. The second-generation oral alkylating agent temozolomide (TMZ) is the first-line chemotherapeutic drug used to treat of GBM, though patients often develop primary and secondary resistance, reducing its efficacy. Antioxidants represent promising and potential coadjutant agents as they can reduce excessive ROS formation derived from chemo- and radiotherapy, while decreasing pharmacological resistance. S-allyl-cysteine (SAC) has been shown to inhibit the proliferation of several types of cancer cells, though its precise antiproliferative mechanisms remain poorly investigated. To date, SAC effects have been poorly explored in GBM cells. Here, we investigated the effects of SAC in vitro, either alone or in combination with TMZ, on several toxic and modulatory endpoints-including oxidative stress markers and transcriptional regulation-in two glioblastoma cell lines from rats, RG2 and C6, to elucidate some of the biochemical and cellular mechanisms underlying its antiproliferative properties. SAC (1-750 µM) decreased cell viability in both cell lines in a concentration-dependent manner, although C6 cells were more resistant to SAC at several of the tested concentrations. TMZ also produced a concentration-dependent effect, decreasing cell viability of both cell lines. In combination, SAC (1 µM or 100 µM) and TMZ (500 µM) enhanced the effects of each other. SAC also augmented the lipoperoxidative effect of TMZ and reduced cell antioxidant resistance in both cell lines by decreasing the TMZ-induced increase in the GSH/GSSG ratio. In RG2 and C6 cells, SAC per se had no effect on Nrf2/ARE binding activity, while in RG2 cells TMZ and the combination of SAC + TMZ decreased this activity. Our results demonstrate that SAC, alone or in combination with TMZ, exerts antitumor effects mediated by regulatory mechanisms of redox activity responses. SAC is also a safe drug for testing in other models as it produces non-toxic effects in primary astrocytes. Combined, these effects suggest that SAC affords antioxidant properties and potential antitumor efficacy against GBM.

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.

Resveratrol as a Promising Nutraceutical: Implications in Gut Microbiota Modulation, Inflammatory Disorders, and Colorectal Cancer

Natural products have been a long-standing source for exploring health-beneficial components from time immemorial. Modern science has had a renewed interest in natural-products-based drug discovery. The quest for new potential secondary metabolites or exploring enhanced activities for existing molecules remains a pertinent topic for research. Resveratrol belongs to the stilbenoid polyphenols group that encompasses two phenol rings linked by ethylene bonds. Several plant species and foods, including grape skin and seeds, are the primary source of this compound. Resveratrol is known to possess potent anti-inflammatory, antiproliferative, and immunoregulatory properties. Among the notable bioactivities associated with resveratrol, its pivotal role in safeguarding the intestinal barrier is highlighted for its capacity to prevent intestinal inflammation and regulate the gut microbiome. A better understanding of how oxidative stress can be controlled using resveratrol and its capability to protect the intestinal barrier from a gut microbiome perspective can shed more light on associated physiological conditions. Additionally, resveratrol exhibits antitumor activity, proving its potential for cancer treatment and prevention. Moreover, cardioprotective, vasorelaxant, phytoestrogenic, and neuroprotective benefits have also been reported. The pharmaceutical industry continues to encounter difficulties administering resveratrol owing to its inadequate bioavailability and poor solubility, which must be addressed simultaneously. This report summarizes the currently available literature unveiling the pharmacological effects of resveratrol.

Mitochondrial Mechanisms in Temozolomide Resistance: Unraveling the Complex Interplay and Therapeutic Strategies in Glioblastoma

Glioblastoma (GBM) is a highly aggressive and lethal brain tumor, with temozolomide (TMZ) being the standard chemotherapeutic agent for its treatment. However, TMZ resistance often develops, limiting its therapeutic efficacy and contributing to poor patient outcomes. Recent evidence highlights the crucial role of mitochondria in the development of TMZ resistance through various mechanisms, including alterations in reactive oxygen species (ROS) production, metabolic reprogramming, apoptosis regulation, biogenesis, dynamics, stress response, and mtDNA mutations. This review article aims to provide a comprehensive overview of the mitochondrial mechanisms involved in TMZ resistance and discuss potential therapeutic strategies targeting these mechanisms to overcome resistance in GBM. We explore the current state of clinical trials targeting mitochondria or related pathways in primary GBM or recurrent GBM, as well as the challenges and future perspectives in this field. Understanding the complex interplay between mitochondria and TMZ resistance will facilitate the development of more effective therapeutic strategies and ultimately improve the prognosis for GBM patients.

Quality by design engineered, enhanced anticancer activity of temozolomide and resveratrol coloaded NLC and brain targeting via lactoferrin conjugation in treatment of glioblastoma

The most dangerous type of high-grade astrocytoma is glioblastoma multiforme. The objective of the work was to engineer lactoferrin conjugated temozolomide and resveratrol co-loaded NLC for the treatment of glioblastoma using intranasal delivery for brain targeting. Synergistic activity of temozolomide and resveratrol was determined using combination index method and 1:1 ratio was selected. QbD approach was used to formulate and optimize NLC, with minimum particle size, maximum transmittance and entrapment efficiency using Central Composite Rotable Design (CCRD) method. The optimized LTR-NLC had desired average particle size (209.3 nm), narrow PDI along, high percentage transmittance (>95%) and better entrapment efficiency (95.26% of TEM and 87.59% of RES). From ex-vivo permeation studies it was found that the permeation at 24 h was 77.43 %, and 88.55 % from LTR-NLC and 25.76 % and 31.10% from suspension for resveratrol and temozolomide respectively. In comparison to drug suspension, NLC had nearly 3-fold increase in drug penetration. IC50 value was also significantly better in the groups treated with LTR-NLC. Hence it can be concluded that LTR-NLC may be an effective formulation for the treatment of glioblastoma, according to the findings of this investigation.

Multiple therapeutic approaches of glioblastoma multiforme: From terminal to therapy

Glioblastoma multiforme (GBM) is an aggressive brain cancer showing poor prognosis. Currently, treatment methods of GBM are limited with adverse outcomes and low survival rate. Thus, advancements in the treatment of GBM are of utmost importance, which can be achieved in recent decades. However, despite aggressive initial treatment, most patients develop recurrent diseases, and the overall survival rate of patients is impossible to achieve. Currently, researchers across the globe target signaling events along with tumor microenvironment (TME) through different drug molecules to inhibit the progression of GBM, but clinically they failed to demonstrate much success. Herein, we discuss the therapeutic targets and signaling cascades along with the role of the organoids model in GBM research. Moreover, we systematically review the traditional and emerging therapeutic strategies in GBM. In addition, we discuss the implications of nanotechnologies, AI, and combinatorial approach to enhance GBM therapeutics.

Autophagic-Related Proteins in Brain Gliomas: Role, Mechanisms, and Targeting Agents

The present review focuses on the phenomenon of autophagy, a catabolic cellular process, which allows for the recycling of damaged organelles, macromolecules, and misfolded proteins. The different steps able to activate autophagy start with the formation of the autophagosome, mainly controlled by the action of several autophagy-related proteins. It is remarkable that autophagy may exert a double role as a tumour promoter and a tumour suppressor. Herein, we analyse the molecular mechanisms as well as the regulatory pathways of autophagy, mainly addressing their involvement in human astrocytic neoplasms. Moreover, the relationships between autophagy, the tumour immune microenvironment, and glioma stem cells are discussed. Finally, an excursus concerning autophagy-targeting agents is included in the present review in order to obtain additional information for the better treatment and management of therapy-resistant patients.

Inhibition of STAT3 signaling as critical molecular event in HUC-MSCs suppressed Glioblastoma Cells

Objective: We investigated the effect of human umbilical cord mesenchymal stem cells (HUC-MSCs) supernatants on proliferation, migration, invasion, and apoptosis in glioblastoma (GBM) cell lines RG-2, U251, U87-MG, and LN-428, as well as their apoptosis and autophagy-mediated through IL-6/JAK2/STAT3 signaling pathway to explore the molecular mechanisms. Methods: In this study, RG-2, U251, U87-MG, and LN-428 cells were treated with 9 mg/ml HUC-MSCs supernatants. Their responses to HUC-MSCs supernatants treatment and the status of STAT3 signaling were analyzed by multiple experimental approaches to elucidate the importance of HUC-MSCs supernatants for GBM. Results: The results demonstrated that after treatment with HUC-MSCs supernatants, in vitro proliferation of RG-2, U251, U87-MG, and LN-428 cells were inhibited, and their sustained growth was also blocked. RG-2, U251, and U87-MG cells showed significant S phase accumulation, while LN-428 cells were blocked in G0/G1 phase. Their migratory invasive capacities were inhibited, and their apoptosis and autophagy ratios were increased. These effects were mediated through the IL-6/JAK2/STAT3 and its downstream signaling pathway. Conclusion: Our data showed that HUC-MSCs supernatants had anti-tumor effects on GBM cells. It inhibited the proliferation, migration, and invasion of GBM cells and promoted their apoptosis. Negative regulation of the IL-6/JAK2/STAT3 signaling pathway enhanced apoptosis and autophagy in tumor cells, thereby improving the therapeutic effect on GBM.

Saikosaponin D Inducing Apoptosis and Autophagy through the Activation of Endoplasmic Reticulum Stress in Glioblastoma

Saikosaponin D (SSD), a saponin derivative, is extracted from Bupleurum falcatum. It exhibits an inhibitory effect on a number of tumor cells and is relatively safe when used at therapeutic doses. However, its effects on glioblastoma multiforme (GBM) have not been fully explored. This study is aimed at investigating the cytotoxic effects of SSD in GBM cell lines. SSD induces apoptosis and autophagy by activating endoplasmic reticulum (ER) stress in GBM cells. GBM cell proliferation activity and morphology were observed using the Cell Counting Kit-8 assay and hematoxylin and eosin staining. Hoechst 33258 fluorescence staining and flow cytometry were performed to assess apoptosis. Western blotting and immunocytochemical staining were used to detect protein expression and distribution. SSD significantly inhibited the proliferation of RG-2, U87-MG, and U251 cells in a dose-dependent manner, and the proportion of apoptotic cells increased significantly. Additionally, the expressions of ER-, apoptosis-, and autophagy-related proteins were significantly upregulated and distributed in the cytoplasm and nucleus. Therefore, SSD may be considered a novel treatment option for GBM. This study demonstrated the anti-GBM effect of SSD from the perspectives of cell apoptosis and autophagy.

Involvement of Resveratrol against Brain Cancer: A Combination Strategy with a Pharmaceutical Approach

A brain tumor (BT) is a condition in which there is growth or uncontrolled development of the brain cells, which usually goes unrecognized or is diagnosed at the later stages. Since the mechanism behind BT is not clear, and the various physiological conditions are difficult to diagnose, the success rate of BT is not very high. This is the central issue faced during drug development and clinical trials with almost all types of neurodegenerative disorders. In the first part of this review, we focus on the concept of brain tumors, their barriers, and the types of delivery possible to target the brain cells. Although various treatment methods are available, they all have side effects or toxic effects. Hence, in the second part, a correlation was made between the use of resveratrol, a potent antioxidant, and its advantages for brain diseases. The relationship between brain disease and the blood-brain barrier, multi-drug resistance, and the use of nanomedicine for treating brain disorders is also mentioned. In short, a hypothetical concept is given with a background investigation into the use of combination therapy with resveratrol as an active ingredient, the possible drug delivery, and its formulation-based approach.

Novel Compound, ND-17, Regulates the JAK/STAT, PI3K/AKT, and MAPK Pathways and Restrains Human T-Lymphoid Leukemia Development

Background:

T cell acute lymphoblastic leukemia (T-ALL) is an invasive hematological malignant disorder of T cell progenitors. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway plays an important role in the development of T-ALL and in the inhibition of the key molecule, JAK2, and could suppress T-ALL cell proliferation.

Objective:

The objective of this study was to investigate the in vitro anti-tumor effects of a novel nilotinib derivative, ND-17, on cancer cell lines via its interactions with JAK2.

Methods:

The effects of ND-17 on cell proliferation and on cell cycle and apoptosis were evaluated using the tetrazolium assay and flow cytometry, respectively. In addition, the ND-17/JAK2 binding interactions were evaluated using surface plasmon resonance and western blot analyses.

Results:

ND-17 exerted the greatest inhibitory effects on T-ALL cells amongst all hematological cancer cell lines tested. Flow cytometric analysis indicated that ND-17 blocked the cell cycle at the S phase in T-ALL cells. Nilotinib did not significantly inhibit T-ALL cell growth or regulate cell cycle. Preliminary investigations revealed that the regulation of cyclin-dependent kinases/cyclins was attributed to ND-17-induced cell cycle arrest. Furthermore, ND-17 could bind to JAK2 with strong affinity and more importantly, ND-17 bound to the ATP pocket of JAK2 in a manner similar to the potent inhibitor. Thus, ND-17 treatment exhibited a prominent effect in inhibiting the phosphorylation of JAK2 in T-ALL cells. An increase in the phosphorylation of JAK2 was observed in interleukin-6-stimulated Jurkat cells, which was reversed by ND-17 treatment. Meanwhile, the combination of TG-101348 and ND-17 led to further improvement in inhibiting phosphorylation of JAK2. Moreover, the transfection and knockdown of JAK2 altered the inhibitory effect of ND-17 on Jurkat cell viability. In addition, ND-17 treatment suppressed the JAK/STAT, phosphatidylinositol-3-kinase/protein kinase B/mechanistic target of rapamycin, and mitogen-activated protein kinase/extracellular signal-regulated protein kinases 1 and 2 signaling pathways.

Conclusion:

These findings suggest that ND-17 could be a promising JAK2 inhibitor for the treatment of T-ALL.

Curcumin in Combination with Other Adjunct Therapies for Brain Tumor Treatment: Existing Knowledge and Blueprint for Future Research

Malignant brain tumors proliferate aggressively and have a debilitating outcome. Surgery followed by chemo-radiotherapy has been the standard procedure of care since 2005 but issues of therapeutic toxicity and relapse still remain unaddressed. Repurposing of drugs to develop novel combinations that can augment existing treatment regimens for brain tumors is the need of the hour. Herein, we discuss studies documenting the use of curcumin as an adjuvant to conventional and alternative therapies for brain tumors. Comprehensive analysis of data suggests that curcumin together with available therapies can generate a synergistic action achieved through multiple molecular targeting, which results in simultaneous inhibition of tumor growth, and reduced treatment-induced toxicity as well as resistance. The review also highlights approaches to increase bioavailability and bioaccumulation of drugs when co-delivered with curcumin using nano-cargos. Despite substantial preclinical work on radio-chemo sensitizing effects of curcumin, to date, there is only a single clinical report on brain tumors. Based on available lab evidence, it is proposed that antibody-conjugated nano-curcumin in combination with sub-toxic doses of conventional or repurposed therapeutics should be designed and tested in clinical studies. This will increase tumor targeting, the bioavailability of the drug combination, reduce therapy resistance, and tumor recurrence through modulation of aberrant signaling cascades; thus improving clinical outcomes in brain malignancies.

Rutaecarpine Inhibits U87 Glioblastoma Cell Migration by Activating the Aryl Hydrocarbon Receptor Signaling Pathway

Glioblastoma is the most frequent and aggressive primary astrocytoma in adults. The high migration ability of the tumor cells is an important reason for the high recurrence rate and poor prognosis of glioblastoma. Recently, emerging evidence has shown that the migration ability of glioblastoma cells was inhibited upon the activation of aryl hydrocarbon receptor (AhR), suggesting potential anti-tumor effects of AhR agonists. Rutaecarpine is a natural compound with potential tumor therapeutic effects which can possibly bind to AhR. However, its effect on the migration of glioblastoma is unclear. Therefore, we aim to explore the effects of rutaecarpine on the migration of human glioblastoma cells U87 and the involvement of the AhR signaling pathway. The results showed that: (i) compared with other structural related alkaloids, like evodiamine and dehydroevodiamine, rutaecarpine was a more potent AhR activator, and has a stronger inhibitory effect on the glioblastoma cell migration; (ii) rutaecarpine decreased the migration ability of U87 cells in an AhR-dependent manner; (iii) AhR mediated the expression of a tumor suppressor interleukin 24 (IL24) induced by rutaecarpine, and AhR-IL24 axis was involved in the anti-migratory effects of rutaecarpine on the glioblastoma. Besides IL24, other candidates AhR downstream genes both associated with cancer and migration were proposed to participate in the migration regulation of rutaecarpine by RNA-Seq and bioinformatic analysis. These data indicate that rutaecarpine is a naturally-derived AhR agonist that could inhibit the migration of U87 human glioblastoma cells mostly via the AhR-IL24 axis.

The multifaceted NF-kB: are there still prospects of its inhibition for clinical intervention in pediatric central nervous system tumors?

Despite advances in the understanding of the molecular mechanisms underlying the basic biology and pathogenesis of pediatric central nervous system (CNS) malignancies, patients still have an extremely unfavorable prognosis. Over the years, a plethora of natural and synthetic compounds has emerged for the pharmacologic intervention of the NF-kB pathway, one of the most frequently dysregulated signaling cascades in human cancer with key roles in cell growth, survival, and therapy resistance. Here, we provide a review about the state-of-the-art concerning the dysregulation of this hub transcription factor in the most prevalent pediatric CNS tumors: glioma, medulloblastoma, and ependymoma. Moreover, we compile the available literature on the anti-proliferative effects of varied NF-kB inhibitors acting alone or in combination with other therapies in vitro, in vivo, and clinical trials. As the wealth of basic research data continues to accumulate, recognizing NF-kB as a therapeutic target may provide important insights to treat these diseases, hopefully contributing to increase cure rates and lower side effects related to therapy.

Human astrocytes and astrocytoma respond differently to resveratrol

A fundamental problem in oncology is that anticancer chemotherapeutics kill both cancer and healthy cells in the surrounding tissues. Resveratrol is a natural antioxidant with intriguing and opposing biological properties: it reduces viability of some cancer cells but not of non-transformed ones (in equimolar concentrations). Therefore, we examined resveratrol in human non-transformed primary astrocytes and astrocytoma. Resveratrol reduced reactive oxygen species in astrocytes, but not in astrocytoma. Such cell-type dependent response is particularly evident with analyses at the single cell level showing clear population difference in high and low glutathione levels. Due to resveratrol's poor aqueous solubility that limits its use in clinics, we incorporated it into stimulus-responsive micelles assembled from miktoarm polymers. This could be an attractive chemotherapeutic delivery strategy in nano-oncology. As a proof of principle, we show that these formulations containing resveratrol markedly decrease astrocytoma viability, particularly in combination with temozolomide, a first line chemotherapeutic for astrocytoma.

Therapeutic potentials of resveratrol in combination with radiotherapy and chemotherapy during glioblastoma treatment: a mechanistic review

Glioblastoma, WHO grade IV astrocytoma, is the most aggressive type of brain tumors. These cancerous cells have a rapid growth rate, tendency to penetrate vital brain structures, molecular heterogeneity, etc. and this cancer is associated with a poor prognosis and low survival rate. Due to the resistance of glioblastoma cells to conventional therapeutic modalities (such as radiation therapy and chemotherapy) as well as the adverse effects of these modalities, the researchers have attempted to discover an appropriate alternative or adjuvant treatment for glioblastoma. Resveratrol, as an herbal and natural polyphenolic compound, has anti-tumoral property and has shown to be effective in GBM treatment. Resveratrol exerts its anti-tumoral effect through various mechanisms such as regulation of cell cycle progression and cell proliferation, autophagy, oxidant system, apoptosis pathways, and so on. Resveratrol in combination with radiation therapy and chemotherapy has also been used. In the present study, we summarized the current findings on therapeutic potentials of resveratrol in glioblastoma radiotherapy and chemotherapy.

Challenges and Perspectives of Standard Therapy and Drug Development in High-Grade Gliomas

Despite their low incidence rate globally, high-grade gliomas (HGG) remain a fatal primary brain tumor. The recommended therapy often is incapable of resecting the tumor entirely and exclusively targeting the tumor leads to tumor recurrence and dismal prognosis. Additionally, many HGG patients are not well suited for standard therapy and instead, subjected to a palliative approach. HGG tumors are highly infiltrative and the complex tumor microenvironment as well as high tumor heterogeneity often poses the main challenges towards the standard treatment. Therefore, a one-fit-approach may not be suitable for HGG management. Thus, a multimodal approach of standard therapy with immunotherapy, nanomedicine, repurposing of older drugs, use of phytochemicals, and precision medicine may be more advantageous than a single treatment model. This multimodal approach considers the environmental and genetic factors which could affect the patient's response to therapy, thus improving their outcome. This review discusses the current views and advances in potential HGG therapeutic approaches and, aims to bridge the existing knowledge gap that will assist in overcoming challenges in HGG.