Small Molecules of Marine Origin as Potential Anti-Glioma Agents

Prospects of marine-derived compounds as potential therapeutic agents for glioma

CONTEXT

Glioma, the most common primary malignant brain tumour, is a grave health concern associated with high morbidity and mortality. Current treatments, while effective to some extent, are often hindered by factors such as the blood-brain barrier and tumour microenvironment. This underscores the pressing need for exploring new pharmacologically active anti-glioma compounds.

METHODS

This review synthesizes information from major databases, including Chemical Abstracts, Medicinal and Aromatic Plants Abstracts, ScienceDirect, SciFinder, Google Scholar, Scopus, PubMed, Springer Link and relevant books. Publications were selected without date restrictions, using terms such as 'Hymenocrater spp.,' 'phytochemical,' 'pharmacological,' 'extract,' 'essential oil' and 'traditional uses.' General web searches using Google and Yahoo were also performed. Articles related to agriculture, ecology, synthetic work or published in languages other than English or Chinese were excluded.

RESULTS

The marine environment has been identified as a rich source of diverse natural products with potent antitumour properties.

CONCLUSIONS

This paper not only provides a comprehensive review of marine-derived compounds but also unveils their potential in treating glioblastoma multiforme (GBM) based on functional classifications. It encapsulates the latest research progress on the regulatory biological functions and mechanisms of these marine substances in GBM, offering invaluable insights for the development of new glioma treatments.

Chrysomycin A Reshapes Metabolism and Increases Oxidative Stress to Hinder Glioblastoma Progression

Glioblastoma represents the predominant and a highly aggressive primary neoplasm of the central nervous system that has an abnormal metabolism. Our previous study showed that chrysomycin A (Chr-A) curbed glioblastoma progression in vitro and in vivo. However, whether Chr-A could inhibit orthotopic glioblastoma and how it reshapes metabolism are still unclear. In this study, Chr-A markedly suppressed the development of intracranial U87 gliomas. The results from airflow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) indicated that Chr-A improved the abnormal metabolism of mice with glioblastoma. Key enzymes including glutaminase (GLS), glutamate dehydrogenases 1 (GDH1), hexokinase 2 (HK2) and glucose-6-phosphate dehydrogenase (G6PD) were regulated by Chr-A. Chr-A further altered the level of nicotinamide adenine dinucleotide phosphate (NADPH), thus causing oxidative stress with the downregulation of Nrf-2 to inhibit glioblastoma. Our study offers a novel perspective for comprehending the anti-glioma mechanism of Chr-A, highlighting its potential as a promising chemotherapeutic agent for glioblastoma.

Using nanotechnology to progress the utilization of marine natural products in combating multidrug resistance in cancer: A prospective strategy

Achieving targeted, customized, and combination therapies with clarity of the involved molecular pathways is crucial in the treatment as well as overcoming multidrug resistance (MDR) in cancer. Nanotechnology has emerged as an innovative and promising approach to address the problem of drug resistance. Developing nano-formulation-based therapies using therapeutic agents poses a synergistic effect to overcome MDR in cancer. In this review, we aimed to highlight the important pathways involved in the progression of MDR in cancer mediated through nanotechnology-based approaches that have been employed to circumvent them in recent years. Here, we also discussed the potential use of marine metabolites to treat MDR in cancer, utilizing active drug-targeting nanomedicine-based techniques to enhance selective drug accumulation in cancer cells. The discussion also provides future insights for developing complex targeted, multistage responsive nanomedical drug delivery systems for effective cancer treatments. We propose more combinational studies and their validation for the possible marine-based nanoformulations for future development.

Nanoparticles for efficient drug delivery and drug resistance in glioma: New perspectives

Gliomas are the most common primary tumors of the central nervous system, with glioblastoma multiforme (GBM) having the highest incidence, and their therapeutic efficacy depends primarily on the extent of surgical resection and the efficacy of postoperative chemotherapy. The role of the intracranial blood-brain barrier and the occurrence of the drug-resistant gene O6-methylguanine-DNA methyltransferase have greatly limited the efficacy of chemotherapeutic agents in patients with GBM and made it difficult to achieve the expected clinical response. In recent years, the rapid development of nanotechnology has brought new hope for the treatment of tumors. Nanoparticles (NPs) have shown great potential in tumor therapy due to their unique properties such as light, heat, electromagnetic effects, and passive targeting. Furthermore, NPs can effectively load chemotherapeutic drugs, significantly reduce the side effects of chemotherapeutic drugs, and improve chemotherapeutic efficacy, showing great potential in the chemotherapy of glioma. In this article, we reviewed the mechanisms of glioma drug resistance, the physicochemical properties of NPs, and recent advances in NPs in glioma chemotherapy resistance. We aimed to provide new perspectives on the clinical treatment of glioma.

Shikimate-Derived Meroterpenoids from the Ascidian-Derived Fungus Amphichorda felina SYSU-MS7908 and Their Anti-Glioma Activity

Glioma is a clinically heterogeneous type of brain tumor with a poor prognosis. Current treatment approaches have limited effectiveness in treating glioma, highlighting the need for novel drugs. One approach is to explore marine natural products for their therapeutic potential. In this study, we isolated nine shikimate-derived diisoprenyl-cyclohexene/ane-type meroterpenoids (1-9), including four new ones, amphicordins A-D (1-4) from the ascidian-derived fungus Amphichorda felina SYSU-MS7908, and further semisynthesized four derivatives (10-13). Their structures were extensively characterized using 1D and 2D NMR, modified Mosher's method, HR-ESIMS, NMR and ECD calculations, and X-ray crystallography. Notably, amphicordin C (3) possesses a unique benzo[g]chromene (6/6/6) skeleton in this meroterpenoid family. In an anti-glioma assay, oxirapentyn A (7) effectively inhibited the proliferation, migration, and invasion of glioma cells and induced their apoptosis. Furthermore, an in silico analysis suggested that oxirapentyn A has the potential to penetrate the blood-brain barrier. These findings highlight the potential of oxirapentyn A as a candidate for the development of novel anti-glioma drugs.

Cellular Components of the Tumor Environment in Gliomas-What Do We Know Today?

A generation ago, the molecular properties of tumor cells were the focus of scientific interest in oncology research. Since then, it has become increasingly apparent that the tumor environment (TEM), whose major components are non-neoplastic cell types, is also of utmost importance for our understanding of tumor growth, maintenance and resistance. In this review, we present the current knowledge concerning all cellular components within the TEM in gliomas, focusing on their molecular properties, expression patterns and influence on the biological behavior of gliomas. Insight into the TEM of gliomas has expanded considerably in recent years, including many aspects that previously received only marginal attention, such as the phenomenon of phagocytosis of glioma cells by macrophages and the role of the thyroid-stimulating hormone on glioma growth. We also discuss other topics such as the migration of lymphocytes into the tumor, phenotypic similarities between chemoresistant glioma cells and stem cells, and new clinical approaches with immunotherapies involving the cells of TEM.

EGFR-Targeted Pentacyclic Triterpene Analogues for Glioma Therapy

Glioma, particularly its most malignant form, glioblastoma multiforme (GBM), is the most common and aggressive malignant central nervous system tumor. The drawbacks of the current chemotherapy for GBM have aroused curiosity in the search for targeted therapies. Aberrantly overexpressed epidermal growth factor receptor (EGFR) in GBM results in poor prognosis, low survival rates, poor responses to therapy and recurrence, and therefore EGFR-targeted therapy stands out as a promising approach for the treatment of gliomas. In this context, a series of pentacyclic triterpene analogues were subjected to in vitro and in silico assays, which were conducted to assess their potency as EGFR-targeted anti-glioma agents. In particular, compound 10 was the most potent anti-glioma agent with an IC₅₀ value of 5.82 µM towards U251 human glioblastoma cells. Taking into account its low cytotoxicity to peripheral blood mononuclear cells (PBMCs), compound 10 exerts selective antitumor action towards Jurkat human leukemic T-cells. This compound also induced apoptosis and inhibited EGFR with an IC₅₀ value of 9.43 µM compared to erlotinib (IC₅₀ = 0.06 µM). Based on in vitro and in silico data, compound 10 stands out as a potential orally bioavailable EGFR-targeted anti-glioma agent endowed with the ability to cross the blood–brain barrier (BBB).