The effects of melatonin on signaling pathways and molecules involved in glioma

A natural compound melatonin enhances the effects of Nimotuzumab via inhibiting EGFR in glioblastoma

Sleep disorders are prevalent and debilitating symptoms in primary brain tumor patients, notably those receiving radiation therapy. Nevertheless, the relationship between sleep disorders, melatonin - a circadian rhythm regulatory hormone, and gliomas is underexplored. Melatonin exhibits various biological functions, one of them being anti-tumor activity. In the context of gliomas, often overexpressing EGFR, the humanized monoclonal antibody Nimotuzumab targets this marker. Our research discovered that variations in circadian rhythm significantly influence tumor growth in mice through impacting melatonin secretion. Harnessing proteogenomic, we identified that melatonin could inhibit the phosphorylation of EGFR and its downstream effectors, key elements in angiogenesis and tumor progression. Building on structural simulations, we propose that melatonin may amplify Nimotuzumab's anti-glioma efficacy by inhibiting EGFR TK dimerization. This proposition was validated in our in vitro and in vivo studies where melatonin synergistically augmented cytotoxicity and apoptosis in Nimotuzumab-treated glioma cells. Thus, melatonin shows promise as a beneficial addition to Nimotuzumab treatment in glioma patients.

Targeting Drug Chemo-Resistance in Cancer Using Natural Products

Cancer is one of the leading causes of death globally. The development of drug resistance is the main contributor to cancer-related mortality. Cancer cells exploit multiple mechanisms to reduce the therapeutic effects of anticancer drugs, thereby causing chemotherapy failure. Natural products are accessible, inexpensive, and less toxic sources of chemotherapeutic agents. Additionally, they have multiple mechanisms of action to inhibit various targets involved in the development of drug resistance. In this review, we have summarized the basic research and clinical applications of natural products as possible inhibitors for drug resistance in cancer. The molecular targets and the mechanisms of action of each natural product are also explained. Diverse drug resistance biomarkers were sensitive to natural products. P-glycoprotein and breast cancer resistance protein can be targeted by a large number of natural products. On the other hand, protein kinase C and topoisomerases were less sensitive to most of the studied natural products. The studies discussed in this review will provide a solid ground for scientists to explore the possible use of natural products in combination anticancer therapies to overcome drug resistance by targeting multiple drug resistance mechanisms.

Melatonin as a promising modulator of aging related neurodegenerative disorders: Role of microRNAs

One of the host risk factors involved in aging-related diseases is coupled with the reduction of endogenous melatonin (MLT) synthesis in the pineal gland. MLT is considered a well-known pleiotropic regulatory hormone to modulate a multitude of biological processes such as the regulation of circadian rhythm attended by potent anti-oxidant, anti-inflammatory, and anti-cancer properties. It has also been established that the microRNAs family, as non-coding mRNAs regulating post-transcriptional processes, also serve a crucial role to promote MLT-related advantageous effects in both experimental and clinical settings. Moreover, the anti-aging impact of MLT and miRNAs participation jointly are of particular interest, recently. In this review, we aimed to scrutinize recent advances concerning the therapeutic implications of MLT, particularly in the brain tissue in the face of aging. We also assessed the possible interplay between microRNAs and MLT, which could be considered a therapeutic strategy to slow down the aging process in the nervous system.

The role of melatonin in angio-miR-associated inhibition of tumorigenesis and invasion in human glioblastoma tumour spheroids

Micro-RNA (miRNA)-based regulation of hypoxia, angiogenesis and tumour growth provides promising targets for effective therapy in malignant glioblastoma multiforme (GBM). Accumulating evidence suggests a potential role of melatonin in miRNA expression in cancer cells. Despite these findings, the melatonin-miRNA interaction in GBM and the effect of this interaction on GBM tumour development and invasion are not clearly understood. The aim of the present study was to evaluate the effects of melatonin on human GBM tumour spheroid tumorigenesis and invasion in vitro, and to analyse the interaction between 36 angio-miRNAs and the HIF1/VEGF/MMP9 axis, which is known to be associated with the antitumour effect of melatonin. We found that melatonin is able to selectively induce cell death in single-layer U87-MG cells (a GBM cell line) in a dose- and time-dependent manner, as characterized by MTT assay. The use of tumour spheroids and a Matrigel invasion assay revealed that melatonin impairs tumorigenesis, and it significantly reduced both the tumour spheroid area and invasion rate, especially at the 0.5 mM and 1 mM concentrations. This inhibition was accompanied by strong reductions in hypoxia-inducible factor 1-α (HIF1-α) and vascular endothelial growth factor (VEGF) gene expression and protein levels in GBM tumour spheroids. In addition, melatonin significantly reduced the relative gene expression and protein levels of matrix metalloproteinase-9 (MMP-9). This study revealed that six differentially expressed angio-miRs (miR-15b, miR-18a-5p, miR-23a-3p, miR-92a-3p, miR-130a-5p, miR-200b-3p) may play important roles in GBM tumorigenesis and invasion, and all respond to melatonin therapy. Our results suggest that melatonin inhibits tumorigenesis and invasion of human GBM tumour spheroids, possibly by suppressing HIF1-α/VEGF/MMP9 signalling via regulation of angio-miRNAs.

Melatonin in Cancer Treatment: Current Knowledge and Future Opportunities

Melatonin is a pleotropic molecule with numerous biological activities. Epidemiological and experimental studies have documented that melatonin could inhibit different types of cancer in vitro and in vivo. Results showed the involvement of melatonin in different anticancer mechanisms including apoptosis induction, cell proliferation inhibition, reduction in tumor growth and metastases, reduction in the side effects associated with chemotherapy and radiotherapy, decreasing drug resistance in cancer therapy, and augmentation of the therapeutic effects of conventional anticancer therapies. Clinical trials revealed that melatonin is an effective adjuvant drug to all conventional therapies. This review summarized melatonin biosynthesis, availability from natural sources, metabolism, bioavailability, anticancer mechanisms of melatonin, its use in clinical trials, and pharmaceutical formulation. Studies discussed in this review will provide a solid foundation for researchers and physicians to design and develop new therapies to treat and prevent cancer using melatonin.

Bioinformatics analysis of immune infiltration in glioblastoma multiforme based on data using a methylation chip in the GEO database

Background

Glioblastoma multiforme (GBM) is the most aggressive and malignant tumor of the central nervous system. The study was to obtain the data of immune cell infiltration based on the data of a methylation chip in the GEO, and to clarify its prognostic significance for GBM.

Methods

The methylation data of glioblastoma was obtained by using the Illumina human methylation 450k BeadChip. The corrected expression was obtained by using edge R. Limma was used to correct the expression amount of the samples, and EpiDISH was used to translate the methylation expression data, so that the expression amount was transformed into the expression matrix of immune cells. The immune cells were then co-expressed, and the proportion and correlation of related immune cells was determined. The results of the cells in each of two groups were analyzed by enrichment and PCA mapping to establish the relevant differences.

Results

The data of GBM patients were obtained from the methylation chip of the GEO database. Patients were divided into a long-term (SNU-LTS) (21 cases), and short-term survival group (SNU-STS) (12 cases). There were 73 genes with significant individual differences between the two groups (P<0.05). EpiDISH was used to translate the methylation expression data into the expression matrix of immune cells, which showed that the highest proportion of cells in groups were mono cells, while Gran cells and CD8T appeared in a very small number of samples. The positive correlation between mono and B cells was the strongest, while the negative correlation between mono and Gran cells was the strongest. A violin chart shows that there was no significant difference in the infiltration degree of six kinds of immune cells between the two groups. Principal component analysis (PCA) showed that there was individual difference between the two groups, but the overall consistency was high.

Conclusions

Data on tumor immune cell infiltration can be obtained by using a methylation chip in the GEO database. This not only extends the application abilities of methylation chips but provides obvious individual differences. The study of tumor immune infiltrating cells may pave the way for targeted therapy in the treatment of GBM.

Long Noncoding RNA FGD5-AS1 Promotes Glioma Cell Proliferation, Migration and Invasion by Regulating wnt/β-Catenin Pathway

Purpose

To investigate the specific function of long noncoding RNA FGD5 antisense RNA 1 (lncRNA FGD5-AS1) in glioma.

Materials and Methods

The level of FGD5-AS1 was detected in clinical samples and cell lines by qRT-PCR. Small interfering RNA (siRNA) of FGD5-AS1 or scramble siRNA was transfected into U87 cell lines to examine the role of FGD5-AS1 on glioma development. The proliferation of glioma cells was tested by Cell Counting Kit-8 (CCK-8), the migration and invasion of glioma cells were tested by transwell assay without matrigel or with matrigel. Western blot was used to detect the protein expression, and XAV-939 was used to inhibit wnt/β-catenin pathway. The effect of FGD5-AS1 on tumorigenesis of glioma was confirmed by xenograft nude mice model.

Results

FGD5-AS1 was significantly increased in glioma tissues and cells. Loss of FGD5-AS1 inhibited the proliferation, migration and invasion of U87 cells. Furthermore, overexpression of FGD5-AS1 increased the mRNA and protein levels of β-catenin and cyclin D1. Blocking of wnt/β-catenin using XAV-939 reversed the promotion role of FGD3-AS1 on glioma cells’ migration and invasion. The in vivo tumor growth assay showed that FGD3-AS1 accelerated glioma tumorigenesis with activating wnt/β-catenin pathway.

Conclusion

Our research emphasized FGD5-AS1 acting as an oncogene by regulating wnt/β-catenin signaling pathway, thus providing some novel experimental basis for clinical treatment of glioma.

Melatonin's Antineoplastic Potential Against Glioblastoma

Glioblastoma (GBM) is one of the most intransigent and aggressive brain tumors, and its treatment is extremely challenging and ineffective. To improve patients’ expectancy and quality of life, new therapeutic approaches were investigated. Melatonin is an endogenous indoleamine with an incredible variety of properties. Due to evidence demonstrating melatonin’s activity against several cancer hallmarks, there is growing interest in its use for preventing and treating cancer. In this review, we report on the potential effects of melatonin, alone or in combination with anticancer drugs, against GBM. We also summarize melatonin targets and/or the intracellular pathways involved. Moreover, we describe melatonin’s epigenetic activity responsible for its antineoplastic effects. To date, there are too few clinical studies (involving a small number of patients) investigating the antineoplastic effects of melatonin against GBM. Nevertheless, these studies described improvement of GBM patients’ quality of life and did not show significant adverse effects. In this review, we also report on studies regarding melatonin-like molecules with the tumor-suppressive properties of melatonin together with implemented pharmacokinetics. Melatonin effects and mechanisms of action against GBM require more research attention due to the unquestionably high potential of this multitasking indoleamine in clinical practice.