Zerumbone, a ginger sesquiterpene, inhibits migration, invasion, and metastatic behavior of human malignant glioblastoma multiforme in vitro

Recent update on anti-tumor mechanisms of valproic acid in glioblastoma multiforme

Glioblastoma multiforme (GBM) is a malignant tumor of the brain that is considered to be incurable. Currently, surgical removal of tumors, chemotherapy with temozolomide, and radiation treatment remain established options for treatment. Nevertheless, the prognosis of those with GBM continues to be poor owing to the inherent characteristics of tumor growth and spread, as well as the resistance to treatment. To effectively deal with the present circumstances, it is vital to do extensive study to understand GBM thoroughly. The following piece provides a concise overview of the most recent advancements in using valproic acid, an antiseizure medication licensed by the FDA, for treating GBM. In this review, we outline the most recent developments of valproic acid in treating GBM, as well as its fundamental mechanisms and practical consequences. Our goal is to provide a greater understanding of the clinical use of valproic acid as a potential therapeutic agent for GBM.

Harnessing the capacity of phytochemicals to enhance immune checkpoint inhibitor therapy of cancers: A focus on brain malignancies

Brain cancers, particularly glioblastoma multiforme (GBM), are challenging health issues with frequent unmet aspects. Today, discovering safe and effective therapeutic modalities for brain tumors is among the top research interests. Immunotherapy is an emerging area of investigation in cancer treatment. Since immune checkpoints play fundamental roles in repressing anti-cancer immunity, diverse immune checkpoint inhibitors (ICIs) have been developed, and some monoclonal antibodies have been approved clinically for particular cancers; nevertheless, there are significant concerns regarding their efficacy and safety in brain tumors. Among the various tools to modify the immune checkpoints, phytochemicals show good effectiveness and excellent safety, making them suitable candidates for developing better ICIs. Phytochemicals regulate multiple immunological checkpoint-related signaling pathways in cancer biology; however, their efficacy for clinical cancer immunotherapy remains to be established. Here, we discussed the involvement of immune checkpoints in cancer pathology and summarized recent advancements in applying phytochemicals in modulating immune checkpoints in brain tumors to highlight the state-of-the-art and give constructive prospects for future research.

A review of natural products and small-molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time-consuming nature of studies to find new anticancer agents makes it necessary to have well-designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi-synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal-oriented studies for drug development against CNS malignancies.

Natural products targeting the MAPK-signaling pathway in cancer: overview

PURPOSE

This article summarizes natural products that target the MAPK-signaling pathway in cancer therapy. The classification, chemical structures, and anti-cancer mechanisms of these natural products are elucidated, and comprehensive information is provided on their potential use in cancer therapy.

METHODS

Using the PubMed database, we searched for keywords, including "tumor", "cancer", "natural product", "phytochemistry", "plant chemical components", and "MAPK-signaling pathway". We also screened for compounds with well-defined structures that targeting the MAPK-signaling pathway and have anti-cancer effects. We used Kingdraw software and Adobe Photoshop software to draw the chemical compound structural diagrams.

RESULTS

A total of 131 papers were searched, from which 85 compounds with well-defined structures were selected. These compounds have clear mechanisms for targeting cancer treatment and are mainly related to the MAPK-signaling pathway. Examples include eupatilin, carvacrol, oridonin, sophoridine, diosgenin, and juglone. These chemical components are classified as flavonoids, phenols, terpenoids, alkaloids, steroidal saponins, and quinones.

CONCLUSIONS

Certain MAPK pathway inhibitors have been used for clinical treatment. However, the clinical feedback has not been promising because of genomic instability, drug resistance, and side effects. Natural products have few side effects, good medicinal efficacy, a wide range of sources, individual heterogeneity of biological activity, and are capable of treating disease from multiple targets. These characteristics make natural products promising drugs for cancer treatment.

Alpha-Lipoic Acid, Auraptene, and Particularly Their Combination Prevent the Metastasis of U87 Human Glioblastoma Cells

Background

The primary malignant brain tumor glioblastoma multiforme (GBM) is most commonly detected in individuals over 60 years old. The standard therapeutic approach for GBM is radiotherapy combined with temozolomide. Recently, herbal products, such as alpha-lipoic acid (ALA) and auraptene (AUR), have shown promising anticancer effects on various cancer cells and animal models. However, it is not well understood how ALA, AUR, and their combination in GBM work to combat cancer. Thus, the purpose of this study was to investigate the antimetastatic effects of the ALA-AUR combination on U87 human glioblastoma cells.

Methods

The inhibitory effects of ALA, AUR, and the ALA/AUR combination on the migration and metastasis of U87 cells were evaluated using a wound healing test and gelatin zymography. The expression levels of matrix metalloproteinase MMP-2 and MMP-9 were assessed at the transcriptional and translational levels using quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting, respectively.

Results

Our findings revealed that combination therapy reduced cell migration and metastasis, which was indicated by the reduction in MMP-2/-9 expression both at mRNA and protein levels, as well as their enzymatic activity in U87 cells.

Conclusion

This study demonstrated that the combination of ALA and AUR effectively inhibited the migration and metastasis of U87 cells. Thus, given their safety and favorable specifications, the combination of these drugs can be a promising candidate for GBM treatment as primary or adjuvant therapy.

4-Methylumbelliferone enhances the effects of chemotherapy on both temozolomide-sensitive and resistant glioblastoma cells

Glioblastoma (GBM) is the most frequent malignant primary tumor of the CNS in adults, with a median survival of 14.6 months after diagnosis. The effectiveness of GBM therapies remains poor, highlighting the need for new therapeutic alternatives. In this work, we evaluated the effect of 4-methylumbelliferone (4MU), a coumarin derivative without adverse effects reported, in combination with temozolomide (TMZ) or vincristine (VCR) on U251, LN229, U251-TMZ resistant (U251-R) and LN229-TMZ resistant (LN229-R) human GBM cells. We determined cell proliferation by BrdU incorporation, migration through wound healing assay, metabolic and MMP activity by XTT and zymography assays, respectively, and cell death by PI staining and flow cytometry. 4MU sensitizes GBM cell lines to the effect of TMZ and VCR and inhibits metabolic activity and cell proliferation on U251-R cells. Interestingly, the lowest doses of TMZ enhance U251-R and LN229-R cell proliferation, while 4MU reverts this and even sensitizes both cell lines to TMZ and VCR effects. We showed a marked antitumor effect of 4MU on GBM cells alone and in combination with chemotherapy and proved, for the first time, the effect of 4MU on TMZ-resistant models, demonstrating that 4MU would be a potential therapeutic alternative for improving GBM therapy even on TMZ-refractory patients.

Urolithin B loaded in cerium oxide nanoparticles enhances the anti-glioblastoma effects of free urolithin B in vitro

Glioblastoma multiforme (GBM) is the most aggressive kind of malignant primary brain tumor in humans. Given the limitation of Conventional therapeutic strategy, the development of nanotechnology and natural product therapy seems to be an effective method enhancing the prognosis of GBM patients. In this research, cell viability, mRNA expressions of various apoptosis-related genes apoptosis, and generation of reactive oxygen species (ROS) in human U-87 malignant GBM cell line (U87) treated with Urolithin B (UB) and CeO₂-UB. Unlike CeO₂-NPs, both UB and CeO₂-UB caused a dose-dependent decrease in the viability of U87 cells. The half-maximal inhibitory concentration values of UB and CeO₂-UB were 315 and 250 μM after 24 h, respectively. Moreover, CeO₂-UB exerted significantly higher effects on U87 viability, P53 expression, and ROS generation. Furthermore, UB and CeO2-UB increased the accumulation of U87 cells in the SUB-G1 population, decreased the expression of cyclin D1, and increased the Bax/Bcl2 ratio expression. Collectively, these data indicate that CeO₂-UB exhibited more substantial anti-GBM effects than UB. Although further in vivo investigations are needed, these results proposed that CeO₂-NPs could be utilized as a potential novel anti-GBM agent after further studies.

Psidium guajava induces cytotoxicity in human malignant glioblastoma cell line: Role of reactive oxygen species

One of the deadliest types of CNS primary brain cancers is glioblastoma multiforme (GBM), and the survival rate of patients is about 7.2%. The standard treatment for GBM is surgical interventions followed by temozolomide. We investigated for the first time, the cytotoxic impacts of Psidium guajava (P. guajava) on the U87 GBM cell line. We measured cell toxicity through the MTT test following 24 h, 48 h, and 72 h treatment with different concentrations of fruit and seed hydroalcoholic extracts of P. guajava (25-400 μg/ml). Lipid peroxidation assay, reactive oxygen species (ROS) production, and apoptosis rate were evaluated 24 h after treatment by extracts of P. guajava. Moreover, to determine the Bax/Bcl-2 and NF-κB genes expression, we performed a real-time polymerase chain reaction (RT-PCR). Our finding demonstrated that 50-400 μg/ml of P. guajava extracts dose-dependently decreased the viability of U87 cells. Also, treatment by extracts increased lipid peroxidation, ROS production, and apoptosis in a dose-dependent manner. Moreover, the RT-PCR demonstrated an up-regulation in Bax\Bcl-2 and NF-κB. Thus, P. guajava inhibited the proliferation of U87 GBM cells and increased apoptosis probably through Bax/Bcl-2 and NF-κB regulation.

Inhibition of glioblastoma proliferation, invasion, and migration by Urolithin B through inducing G0/G1 arrest and targeting MMP-2/-9 expression and activity

One kind of brain cancer with a dismal prognosis is called glioblastoma multiforme (GBM) due to its high growth rate and widespread tumor cell invasion into various areas of the brain. To improve therapeutic approaches, the objective of this research investigates the cytotoxic, anti-metastatic, and apoptotic effect of urolithin-B (UB) as a bioactive metabolite of ellagitannins (ETs) on GBM U87 cells. The malignant GBM cell line (U87) was examined for apoptosis rate, cell cycle analysis, cell viability, mRNA expressions of several apoptotic and metastasis-associated genes, production of reactive oxygen species (ROS), MMP-2, and MMP-9 activity and protein expression, and migration ability. The findings revealed that UB decreased U87 GBM viability in a dose-dependent manner and NIH/3T3 normal cells with the IC₅₀ value of 30 and 55 μM after 24 h, respectively. UB also induces necrosis and G0/G1 cell cycle arrest in U87 cells. UB also increases ROS production and caused down-regulation of Bcl2 and up-regulation of Bax apoptotic genes. Additionally, treatment of UB reduced the migration of U87 cells. The protein levels, mRNA expression, and the MMP-2 and MMP-9 enzyme activities also decreased concentration-dependently. So, due to the non-toxic nature of UB and its ability to induce apoptosis and reduce the U87 GBM cell invasion and migration, after more research, it can be regarded as a promising new anti-GBM compound.

Recent advances in glioblastoma multiforme therapy: A focus on autophagy regulation

Despite conventional treatment options including chemoradiation, patients with the most aggressive primary brain tumor, glioblastoma multiforme (GBM), experience an average survival time of less than 15 months. Regarding the malignant nature of GBM, extensive research and discovery of novel treatments are urgently required to improve the patients' prognosis. Autophagy, a crucial physiological pathway for the degradation and recycling of cell components, is one of the exciting targets of GBM studies. Interventions aimed at autophagy activation or inhibition have been explored as potential GBM therapeutics. This review, which delves into therapeutic techniques to block or activate autophagy in preclinical and clinical research, aims to expand our understanding of available therapies battling GBM.

Tumor-Inhibitory Effects of Zerumbone Against HT-29 Human Colorectal Cancer Cells

Colorectal cancer (CRC) is the second cause of cancer-associated death globally. Recently, herbal medicinal products and, in particular, zerumbone have been widely studied and used for cancer treatment as they induce significant anti-cancer effects. However, there is limited information about the anti-cancer effects of zerumbone in CRC. Therefore, we aimed to investigate the in vitro anti-cancer effects of the zerumbone in CRC, focusing on cell apoptosis and migration. Anti-proliferative and anti-migratory effects of zerumbone on HT-29 cells were evaluated using MTT and scratch wound healing assay, respectively. Quantitative real-time PCR (qRT-PCR) was performed to determine the mRNA expression levels of migration and apoptosis-related genes. Apoptosis and cell cycle distribution were evaluated by flow cytometry. The intracellular level of reactive oxygen species (ROS) was measured using a ROS assay kit. Additionally, matrix metalloproteinase-2/-9 (MMP-2/-9) activity was determined using gelatin zymography. Zerumbone suppressed the viability of the HT-29 cells dose-dependently while having less cytotoxicity on normal NIH/3T3 cells. Zerumbone induced apoptosis in HT-29 cells and arrested the cell cycle in the G2/M phase. These effects were associated with alteration in the expression of apoptosis-related genes (up-regulation of Bax and down-regulation of Bcl-2 genes). Zerumbone also enhanced the generation of ROS in HT-29 cells. Furthermore, zerumbone significantly inhibited the migration of HT-29 cells and decreased MMP-2/-9 mRNA expression and activity. Our findings provide a potential use for zerumbone to induce apoptosis and suppress metastasis in HT-29 cells; thus, it could be developed as a promising natural agent for future CRC therapy.

How do phosphodiesterase-5 inhibitors affect cancer? A focus on glioblastoma multiforme

Since the discovery of phosphodiesterase-5 (PDE5) enzyme overexpression in the central nervous system (CNS) malignancies, investigations have explored the potential capacity of current PDE5 inhibitor drugs for repositioning in the treatment of brain tumors, notably glioblastoma multiforme (GBM). It has now been recognized that these drugs increase brain tumors permeability and enhance standard chemotherapeutics effectiveness. More importantly, studies have highlighted the promising antitumor functions of PDE5 inhibitors, e.g., triggering apoptosis, suppressing tumor cell growth and invasion, and reversing tumor microenvironment (TME) immunosuppression in the brain. However, contradictory reports have suggested a pro-oncogenic role for neuronal cyclic guanosine monophosphate (cGMP), indicating the beneficial function of PDE5 in the brain of GBM patients. Unfortunately, due to the inconsistent preclinical findings, only a few clinical trials are evaluating the therapeutic value of PDE5 inhibitors in GBM treatment. Accordingly, additional studies should be conducted to shed light on the precise effect of PDE5 inhibitors in GBM biology regarding the existing molecular heterogeneities among individuals. Here, we highlighted and discussed the previously investigated mechanisms underlying the impacts of PDE5 inhibitors in cancers, focusing on GBM to provide an overview of current knowledge necessary for future studies.