Modulation of Antioxidant Potential with Coenzyme Q10 Suppressed Invasion of Temozolomide-Resistant Rat Glioma In Vitro and In Vivo

Drug screening approaches for small-molecule compounds in cancer-targeted therapy

Small-molecule compounds exhibit distinct pharmacological properties and clinical effectiveness. Over the past decade, advances in covalent drug discovery have led to successful small-molecule drugs, such as EGFR, BTK, and KRAS (G12C) inhibitors, for cancer therapy. Researchers are paying more attention to refining drug screening methods aiming for high throughput, fast speed, high specificity, and accuracy. Therefore, the discovery and development of small-molecule drugs has been facilitated by significantly reducing screening time and financial resources, and increasing promising lead compounds compared with traditional methods. This review aims to introduce classical and emerging methods for screening small-molecule compounds in targeted cancer therapy. It includes classification, principles, advantages, disadvantages, and successful applications, serving as valuable references for subsequent researchers.

Preventive effect of MitoQ supplementation and endurance training on glioblastoma and its consequences: TLR4/CREB/ NF-κβ /IL-1β pathway and behaviors

OBJECTIVE

The present study investigated the preventive effect of MitoQ supplementation and endurance training (ET) on the TLR4/CREB/ NF-κβ signaling pathway, antioxidant indices, and behaviors in C6-induced glioblastoma (GBM) in rats.

METHODS

60 male Wistar rats were randomly divided into five groups (n = 12); Sham, Tumor, MitoQ, ET, and MitoQ + ET. Rats in the training groups performed endurance training (5 days per week), and MitoQ at the dose of 250 µM/L daily was administered in drinking water for 8 weeks. At the end of the protocol, all groups except the sham group received 1*106 tumor cells /10 µl culture medium. Two weeks after tumor induction, behavioral tests were performed, and then brain tissue was collected for the histopathology, measurement of antioxidant and inflammatory factors, TLR4, NF-κB proteins, and TLR4, NF-κβ, CREB, IL-1ß, TNF-a, IL-10, Bax, Bcl-2, and Caspase-3 gene expression.

RESULTS

The increased level of TLR4 and NF-κβ protein expression in GBM rats decreased in the treatment groups. Gene expression of TLR4, NF-κβ, CREB, TNF-a, IL-10, and Bcl-2 increased in the tumor groups, and treatment groups decreased TLR4, NF-κB, Bcl-2, and CREB. In addition, social behaviors, balance, and memory were impaired in the tumor group, which combination group could improve these behaviors.

CONCLUSION

In sum, the preventive effects of MitoQ as a beneficial immune reactive agent and exercise training in rats with C6-induced glioblastoma may be mediated via modulating oxidative stress, inflammatory factors, and down-regulation of the expression of TLR4.

The role of coenzyme Q10 as a preventive and therapeutic agent for the treatment of cancers

Currently, several options are available for the prevention and treatment of cancers; however, many limitations remain with these approaches. Recently, antioxidants have become important preventive and therapeutic alternatives with few adverse events and minimum cost. Coenzyme Q10 (CoQ10) is a naturally occurring component that performs an anticancer function by reducing oxidative stress. CoQ10 supplementation as an adjuvant therapy offers more progress in the elimination and development of cancers. This review aimed to critically assess and summarize the implication of CoQ10 in cancers, highlighting possible mechanisms, and future directions of research for the standardization of the current regimen for cancer prevention and treatment.

ROS regulation in gliomas: implications for treatment strategies

Gliomas are one of the most common primary malignant tumours of the central nervous system (CNS), of which glioblastomas (GBMs) are the most common and destructive type. The glioma tumour microenvironment (TME) has unique characteristics, such as hypoxia, the blood-brain barrier (BBB), reactive oxygen species (ROS) and tumour neovascularization. Therefore, the traditional treatment effect is limited. As cellular oxidative metabolites, ROS not only promote the occurrence and development of gliomas but also affect immune cells in the immune microenvironment. In contrast, either too high or too low ROS levels are detrimental to the survival of glioma cells, which indicates the threshold of ROS. Therefore, an in-depth understanding of the mechanisms of ROS production and scavenging, the threshold of ROS, and the role of ROS in the glioma TME can provide new methods and strategies for glioma treatment. Current methods to increase ROS include photodynamic therapy (PDT), sonodynamic therapy (SDT), and chemodynamic therapy (CDT), etc., and methods to eliminate ROS include the ingestion of antioxidants. Increasing/scavenging ROS is potentially applicable treatment, and further studies will help to provide more effective strategies for glioma treatment.

Recent advances in ferroptosis and therapeutic strategies for glioblastoma

Ferroptosis is an emerging form of cell death characterized by the over-accumulation of iron-dependent lipid peroxidation. Ferroptosis directly or indirectly disturbs glutathione peroxidases cycle through diverse pathways, impacting the cellular antioxidant capacities, aggravating accumulation of reactive oxygen species in lipid, and it finally causes oxidative overload and cell death. Ferroptosis plays a significant role in the pathophysiological processes of many diseases. Glioblastoma is one of the most common primary malignant brain tumors in the central nervous system in adults. Although there are many treatment plans for it, such as surgical resection, radiotherapy, and chemotherapy, they are currently ineffective and the recurrent rate is almost up to 100%. The therapies abovementioned have a strong relationship with ferroptosis at the cellular and molecular level according to the results reported by numerous researchers. The regulation of ferroptosis can significantly determine the outcome of the cells of glioblastoma. Thus ferroptosis, as a regulated form of programed cell death, has the possibility for treating glioblastoma.

Antioxidants in brain tumors: current therapeutic significance and future prospects

Brain cancer is regarded among the deadliest forms of cancer worldwide. The distinct tumor microenvironment and inherent characteristics of brain tumor cells virtually render them resistant to the majority of conventional and advanced therapies. Oxidative stress (OS) is a key disruptor of normal brain homeostasis and is involved in carcinogenesis of different forms of brain cancers. Thus, antioxidants may inhibit tumorigenesis by preventing OS induced by various oncogenic factors. Antioxidants are hypothesized to inhibit cancer initiation by endorsing DNA repair and suppressing cancer progression by creating an energy crisis for preneoplastic cells, resulting in antiproliferative effects. These effects are referred to as chemopreventive effects mediated by an antioxidant mechanism. In addition, antioxidants minimize chemotherapy-induced nonspecific organ toxicity and prolong survival. Antioxidants also support the prooxidant chemistry that demonstrate chemotherapeutic potential, particularly at high or pharmacological doses and trigger OS by promoting free radical production, which is essential for activating cell death pathways. A growing body of evidence also revealed the roles of exogenous antioxidants as adjuvants and their ability to reverse chemoresistance. In this review, we explain the influences of different exogenous and endogenous antioxidants on brain cancers with reference to their chemopreventive and chemotherapeutic roles. The role of antioxidants on metabolic reprogramming and their influence on downstream signaling events induced by tumor suppressor gene mutations are critically discussed. Finally, the review hypothesized that both pro- and antioxidant roles are involved in the anticancer mechanisms of the antioxidant molecules by killing neoplastic cells and inhibiting tumor recurrence followed by conventional cancer treatments. The requirements of pro- and antioxidant effects of exogenous antioxidants in brain tumor treatment under different conditions are critically discussed along with the reasons behind the conflicting outcomes in different reports. Finally, we also mention the influencing factors that regulate the pharmacology of the exogenous antioxidants in brain cancer treatment. In conclusion, to achieve consistent clinical outcomes with antioxidant treatments in brain cancers, rigorous mechanistic studies are required with respect to the types, forms, and stages of brain tumors. The concomitant treatment regimens also need adequate consideration.

Combination therapy with interferon-gamma as a potential therapeutic medicine in rat's glioblastoma: A multi-mechanism evaluation

BACKGROUND

This study assessed the effects of single or combined administration of temozolomide (TMZ) and interferon-gamma (IFN-ᵞ) on anxiety-like behaviors, balance disorders, learning and memory, TNF-α, IL-10, some oxidant and antioxidants factors with investigating the toll-like receptor-4 (TLR4) and p-CREB signaling pathway in C6-induced glioblastoma of rats.

METHODS

40 male Sprague-Dawley rats bearing intra-caudate nucleus (CN) culture medium or C6 inoculation were randomly divided into five groups as follows: Sham, Tumor, TMZ, IFN-ᵞ and a TMZ + IFN-ᵞ combination. The open-field test (OFT), elevated plus maze (EPM), rotarod, and passive avoidance test (PAT) were done on days 14-17. On day 17 after tumor implantation, brain tissues were extracted for histopathological evaluation. TNF-α, IL-10, SOD, GPX, TAC, MDA, the protein level of TLR4 and p-CREB was measured.

RESULTS

Combination therapy inhibited the growth of the tumor. Treatment groups alleviated tumor-induced anxiety-like behaviors and improved imbalance and memory impairment. SOD, GPX, and TAC decreased in the tumor group. The combination group augmented GPX and TAC. MDA decreased in treatment groups. TMZ, IFN-ᵞ reduced tumor-increased TNF-α and IL-10 level. The combination group declined TNF-α level in serum and IL-10 level in serum and brain. Glioblastoma induced significant upregulation of TLR4 and p-CREB in the brain which inhibited by IFN-ᵞ and TMZ+ IFN-ᵞ.

CONCLUSION

The beneficial effects of TMZ, IFN-ᵞ, and TMZ+ IFN-ᵞ on neurocognitive functioning of rats with C6-induced glioblastoma may be mediated via modulating oxidative stress, reduced cytokines, and the downregulation of expression of TLR4 and p-CREB. Combination treatment appears to be more effective than single treatment.

The Role of the Thioredoxin Detoxification System in Cancer Progression and Resistance

The intracellular redox homeostasis is a dynamic balancing system between the levels of free radical species and antioxidant enzymes and small molecules at the core of cellular defense mechanisms. The thioredoxin (Trx) system is an important detoxification system regulating the redox milieu. This system is one of the key regulators of cells’ proliferative potential as well, through the reduction of key proteins. Increased oxidative stress characterizes highly proliferative, metabolically hyperactive cancer cells, which are forced to mobilize antioxidant enzymes to balance the increase in free radical concentration and prevent irreversible damage and cell death. Components of the Trx system are involved in high-rate proliferation and activation of pro-survival mechanisms in cancer cells, particularly those facing increased oxidative stress. This review addresses the importance of the targetable redox-regulating Trx system in tumor progression, as well as in detoxification and protection of cancer cells from oxidative stress and drug-induced cytotoxicity. It also discusses the cancer cells’ counteracting mechanisms to the Trx system inhibition and presents several inhibitors of the Trx system as prospective candidates for cytostatics’ adjuvants. This manuscript further emphasizes the importance of developing novel multitarget therapies encompassing the Trx system inhibition to overcome cancer treatment limitations.

The Advances in Glioblastoma On-a-Chip for Therapy Approaches

Simple Summary

This systematic review showed different therapeutic approaches to glioblastoma on-a-chip with varying levels of complexity, answering, from the simplest question to the most sophisticated questions, in a biological system integrated in an efficient way. With advances in manufacturing protocols, soft lithography in PDMS material was the most used in the studies, applying different strategy geometrics in device construction. The microenvironment showed the relevant elaborations in co-culture between mainly human tumor cells and support cells involved in the collagen type I matrix; remaining an adequate way to assess the therapeutic approach. The most complex devices showed efficient intersection between different systems, allowing in vitro studies with major human genetic similarity, reproducibility, and low cost, on a highly customizable platform.

Abstract

This systematic review aimed to verify the use of microfluidic devices in the process of implementing and evaluating the effectiveness of therapeutic approaches in glioblastoma on-a-chip, providing a broad view of advances to date in the use of this technology and their perspectives. We searched studies with the variations of the keywords “Glioblastoma”, “microfluidic devices”, “organ-on-a-chip” and “therapy” of the last ten years in PubMed and Scopus databases. Of 446 articles identified, only 22 articles were selected for analysis according to the inclusion and exclusion criteria. The microfluidic devices were mainly produced by soft lithography technology, using the PDMS material (72%). In the microenvironment, the main extracellular matrix used was collagen type I. Most studies used U87-MG glioblastoma cells from humans and 31.8% were co-cultivated with HUVEC, hCMEC/D3, and astrocytes. Chemotherapy was the majority of therapeutic approaches, assessing mainly the cellular viability and proliferation. Furthermore, some alternative therapies were reported in a few studies (22.6%). This study identified a diversity of glioblastoma on-a-chip to assess therapeutic approaches, often using intermediate levels of complexity. The most advanced level implemented the intersection between different biological systems (liver–brain or intestine–liver–brain), BBB model, allowing in vitro studies with greater human genetic similarity, reproducibility, and low cost, in a highly customizable platform.

Protective effect of Coenzyme Q10 on oxidative ovarian and uterine damage induced by methotrexate in rats

Methotrexate (MTX) has toxic effects on the uterus and ovaries via oxidative stress. Coenzyme Q10 (CoQ10) is an important component in electron transport in the mitochondria and an antioxidant in cellular metabolism through the inhibition of lipid peroxidation. The aim of this study was to investigate the preventive effects of CoQ10 on MTX-induced utero-ovarian damage and oxidative stress in rats.In this experimental study, 30 albino Wistar female rats were divided randomly into three groups. Once a day for a month, 10 mg/kg of CoQ10 was orally administered to the rats in the MTX+CoQ10 group, while the same volume of olive oil was administered orally to the other two groups. One hour thereafter, 20 mg/kg of MTX was injected intraperitoneally into the rats in the MTX and MTX+CoQ10 groups; the remaining group was the control. At the end of the month, biochemical and histopathologic examinations were performed on the extracted uteri and ovaries. In the uterine ovarian tissues of the animals in the MTX group, there was an increase in oxidative stress mediators and a decrease in antioxidant and anti-inflammatory mediators, but these trends were reversed in the MTX+CoQ10 group, demonstrating the antioxidant effects of CoQ10. MTX leads to oxidative stress-related ovarian and uterine injury, and CoQ10 may be useful for protecting ovarian and uterine tissue from such injury.

Emerging role of NRF2 in ROS-mediated tumor chemoresistance

Chemoresistance is a central cause for the tumor management failure. Cancer cells disrupt the redox homeostasis through reactive oxygen species (ROS) regulatory mechanisms, leading to tumor progression and chemoresistance. The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is a master regulator of neutralizing cellular ROS and restoring redox balance. Understanding the role of NRF2 in ROS-mediated chemoresistance can be helpful in the development of chemotherapy strategies with better efficiency. In this review, we sum up the roles of ROS in the development of chemoresistance to classical chemotherapy agents including cisplatin, 5-fluorouracil, gemcitabine, oxaliplatin, paclitaxel, and doxorubicin, and how to overcome ROS-mediated tumor chemoresistance by targeting NRF2. Finally, we propose that targeting NRF2 might be a promising strategy to resist ROS-driven chemoresistance and acquire better efficacy in cancer treatment.

A novel hypoxic tumor microenvironment signature for predicting the survival, progression, immune responsiveness and chemoresistance of glioblastoma: a multi-omic study

The hypoxic tumor microenvironment (TME) was reported to promote the aggressive phenotype, progression, recurrence, and chemoresistance of glioblastoma (GBM). We developed and validated a hypoxia gene signature for individualized prognostic prediction in GBM patients. In total, 259 GBM-specific hypoxia-related genes (HRGs) were obtained in hypoxic cultured GBM cells compared with normoxic cells. By applying the k-means algorithm, TCGA GBM patients were divided into two subgroups, and the patients in Cluster 1 exhibited high HRG expression patterns, older age, and poor prognosis, which was validated in the CGGA cohort. Cox regression analyses were performed to generate an HRG-based risk score model consisting of five HRGs, which could reliably discriminate the overall survival (OS) and progression-free survival (PFS) of high- and low-risk patients in both the TCGA training and CGGA validation cohorts. Then, nomograms with the hypoxia signature for OS and PFS prediction were constructed for individualized survival prediction, better treatment decision-making, and follow-up scheduling. Finally, functional enrichment, immune infiltration, immunotherapy response prediction and chemotherapy resistance analyses demonstrated the vital roles of the hypoxic TME in the development, progression, multitherpy resistance of GBM. The hypoxia gene signature could serve as a promising prognostic predictor and potential therapeutic target to combat chemoresistant GBM.

Sp1 Mediates the Constitutive Expression and Repression of the PDSS2 Gene in Lung Cancer Cells

Prenyl diphosphate synthase subunit 2 (PDSS2) is the first key enzyme in the CoQ10 biosynthesis pathway, and contributes to various metabolic and nephritic diseases. It has been reported that PDSS2 is downregulated in several types of tumors and acts as a potential tumor suppressor gene to inhibit the proliferation and migration of cancer cells. However, the regulatory mechanism of PDSS2 expression remains elusive. In the present study, we first identified and characterized the PDSS2 promoter region. We established four different luciferase reporter constructs which mainly cover the 2 kb region upstream of the PDSS2 gene transcription initiation site. Series luciferase reporter assay demonstrated that all four constructs have prominent promoter activity, and the core promoter of PDSS2 is mainly located within the 202 bp region near its transcription initiation site. Transcription factor binding site analysis revealed that the PDSS2 promoter contains binding sites for canonical transcription factors such as Sp1 and GATA-1. Overexpression of Sp1 significantly inhibited PDSS2 promoter activity, as well as its endogenous expression, at both mRNA and protein levels in lung cancer cells. Site-directed mutagenesis assay further confirmed that the Sp1 binding sites are essential for proximal prompter activity of PDSS2. Consistently, a selective Sp1 inhibitor, mithramycin A, treatment repressed the PDSS2 promoter activity, as well as its endogenous expression. Chromatin immunoprecipitation (ChIP) assay revealed that Sp1 binds to the PDSS2 promoter in vivo. Of note, the expression of Sp1 and PDSS2 are negatively correlated, and higher Sp1 expression with low PDSS2 expression is significantly associated with poor prognosis in lung cancer. Taken together, our results strongly suggest the essential role of Sp1 in maintaining the basic constitutive expression of PDSS2, and the pathogenic implication of Sp1-mediated PDSS2 transcriptional repression in lung cancer cells.

The long noncoding RNA ZFAS1 promotes the progression of glioma by regulating the miR-150-5p/PLP2 axis

Numerous studies have reported that long noncoding RNA (lncRNA) dysregulation is involved in the progression of many malignant tumors, including glioma. The lncRNA ZNFX1 antisense RNA 1 (ZFAS1) plays an oncogenic role in various malignant tumors, such as gastric cancer and hepatocellular carcinoma. However, the underlying molecular mechanism of ZFAS1 in glioma has not been fully clarified. In this study, we found that the expression of ZFAS1 was upregulated in both glioma tissues and cell lines. Functional experiments revealed that ZFAS1 promoted glioma proliferation, migration and invasion, and increased resistance to temozolomide in vitro. By using online databases, RNA pull-down assays and luciferase reporter assays, ZFAS1 was demonstrated to act as a sponge of miR-150-5p. Furthermore, proteolipid protein 2 (PLP2) was shown to be the functional target of miR-150-5p. Rescue experiments revealed that ZFAS1 regulated the expression of PLP2 by sponging miR-150-5p. Finally, a xenograft tumor assay demonstrated that ZFAS1 promoted glioma growth in vivo. Our results showed that ZFAS1 promoted glioma malignant progression by regulating the miR-150-5p/PLP2 axis, which may provide a potential therapeutic target for the treatment of glioma.