Lycorine hydrochloride interferes with energy metabolism to inhibit chemoresistant glioblastoma multiforme cell growth through suppressing PDK3.

Glioblastoma multiforme (GBM) is the highest grade of glioma. Tumours, including GBM, possess reprogrammed metabolism, such as altered aerobic glycolysis and aberrant energy production. Lycorine hydrochloride (LH) was extracted from the bulb of Lycoris radiata. The previous study indicated that LH exerts antiviral, anti-inflammatory and antitumour effects. However, the effect of LH on GBM and the underlying molecular mechanism remain unclear. Our study revealed that LH restrained chemoresistant GBM cells growth by inhibiting PDK3 expression in vitro and in vivo. Functionally, LH inhibited the proliferation and invasive capacity of chemoresistant GBM cells in dose-dependent manner. Metabolomics and cellular energy analyses showed that LH decreased extracellular acidification rates while increased oxidative respiration and ROS levels. Mechanistically, LH inhibits the growth of GBM chemoresistant cells by regulating the expression of apoptosis-related proteins, while overexpression of of PDK3 can reverse the antitumor effect of LH. In conclusion, our study revealed that LH could reprogramme cell energy metabolism, including aerobic glycolysis suppression and oxidative phosphorylation hyperactivation by inhibiting PDK3. PDK3 may be a candidate therapeutic target for chemoresistant GBM treatment with LH.

MiR-218 Inhibited Growth and Metabolism of Human Glioblastoma Cells by Directly Targeting E2F2.

In recent years, microRNA has become a hotspot in research on diseases, especially in the initiation and progression of different types of cancer. In this study, we found that miR-218 could inhibit growth and metabolism in gliomas by directly targeting E2F2. First, we obtained data from the Chinese Glioma Genome Atlas (CGGA) database to analyze miR-218 expression in different grades of gliomas. The effects of miR-218 on cell cycle progression and cell proliferation in U87 and U251 cell lines were investigated by flow cytometry, specifically CCK8 assay and tablet cloning, respectively. Glucose consumption and lactate production of glioma cell lines were measured by correlative test kits. Furthermore, we used Western blot analysis and luciferase reporter assay to identify the direct and functional target of miR-218. Data from the CGGA database and real-time quantitative reverse transcription-PCR demonstrated that miR-218 was obviously reduced in human glioblastoma tissues, as well as in the cell lines. When miR-218 level was elevated in vitro, cell cycle progression was arrested in the G1 phase, and cell proliferation was dramatically inhibited. Both glucose consumption and lactate production of glioma cells were significantly reduced. Western blot analysis and luciferase reporter assay revealed that E2F2 was a direct target of miR-218 in glioma cells. This investigation demonstrated that elevated E2F2 expression could partly weaken the effect of miR-218 in vitro. This study also showed that miR-218 may be a repressor in glioma by directly targeting E2F2, as well as a potential therapeutic target in gliomas.

Loss of SNAIL inhibits cellular growth and metabolism through the miR-128-mediated RPS6KB1/HIF-1α/PKM2 signaling pathway in prostate cancer cells.

SNAIL is a promising target for the treatment of cancer because it is known to promote epithelial-mesenchymal transition. Recent studies suggest that SNAIL also takes part in metabolic reprogramming and chemotherapy resistance in some cancers. In prostate cancer (PCa), SNAIL has been proved to be required for hypoxia-induced invasion and as a potential marker for predicting the recurrence. However, the role of SNAIL in PCa aberrant metabolism is poorly understood. In this study, we identified that SNAIL regulated cellular growth and energy metabolism through the miR-128-mediated ribosomal protein S6 kinase 1 (RPS6KB1)/HIF-1α/PKM2 signaling pathway which played a key role in the reprogramming of cancer metabolism. Using quantitative RT-PCR (qRT-PCR), we found that SNAIL expression was elevated in castration-resistant prostate cancer tissues compared with androgen-dependent prostate cancer tissues and nontumorous tissues. Depletion of SNAIL increased miR-128 expression levels, inhibited cell growth, reduced glucose consumption and lactate production, and repressed the expression of RPS6KB1, HIF-1α, and PKM2 in PCa cells. Luciferase reporter assays showed the SNAIL regulated miR-128 expression at the transcriptional level and miR-128 modulated RPS6KB1 expression at the translational level. Furthermore, down-expression of miR-128 partially restored the effect of si-SNAIL on the suppression of cellular growth, metabolism, and RPS6KB1/HIF-1α/PKM2 signaling pathway. To our knowledge, it is the first time to demonstrate that SNAIL/miR-128/RPS6KB1 pathway plays a critical role in the progression of PCa.

[Expression of peroxisome proliferators-activated receptor in glioma and its effect on the growth of human glioma cells].

OBJECTIVE: To study the expression of peroxisome proliferators-activated receptor (PPAR) in human glioma tissue and its influence on tumor growth. METHODS: Expression of PPAR mRNA in glioma tissue was determined by real-time reverse transcription polymerase chain reaction (RT-PCR). Subsequently, MTT (3-(4, 5)-dimethylthiahiazo(-z-y1)-3, 5-di-phenytetrazoliumromide) assay, flow cytometry, reactive oxygen species assay kit and Western blotting were used to assay U87 cells with agonist activity of PPAR. RESULTS: The data demonstrated that the expression of PPAR in glioma was low and negatively correlated with its pathological grade. Activation of PPAR suppresses tumor cell proliferation, delays the cell cycle at G1 phrase, and induces apoptosis and accumulation of reactive oxygen species (ROS) in U87 cells. CONCLUSION: The expression of PPAR mRNA in human glioma was low. PPAR protein plays a critical role in the progression of glioma via the PPAR signal pathway.

CircSOBP suppresses the progression of glioma by disrupting glycolysis and promoting the MDA5-mediated immune response.

Glioma, an aggressively growing and highly malignant brain tumor, poses substantial therapeutic challenges due to its resistance to radiotherapy and chemotherapy. Recent research has identified circRNAs as pivotal players in glioma formation and development. However, the roles of circRNA in the metabolic and immune regulation of glioma are unclear. In this study, circSOBP expression was significantly downregulated in glioma cells and specimens. Functionally, enhanced circSOBP expression mitigated cell proliferation, invasion, migration, and glycolysis in gliomas. Mechanistically, circSOBP inhibited glycolysis and activated the MDA5-mediated IKKε/TBK1/IRF3 signaling pathway by binding TKFC proteins. Furthermore, the elevated levels of IFN-I induced by the MDA5 pathway increased the number and activity of CD8+ T and NK cells in the immune response of the animal models. In summary, our findings have emphasized the critical role of circSOBP in binding and modulating TKFC protein, offering potential therapeutic avenue for targeting glioma metabolism and immunological reprogramming.

Diffusion tensor imaging reveals microstructural alteration of the trigeminal nerve root in classical trigeminal neuralgia without neurovascular compression and correlation with outcome after internal neurolysis.

OBJECTIVES: Diffusion tensor imaging (DTI) has been used to detect microstructural alteration and effect of surgical treatment of the trigeminal nerve root (TR) in patients with classical trigeminal neuralgia (CTN) underwent microvascular decompression (MVD). Patients with CTN without neurovascular compression (woNVC) is a special population of TN, however, the pathogenesy of CTN woNVC and the mechanism of internal neurolysis (IN) remain unknown. MATERIALS AND METHODS: 21 patients with CTN woNVC who underwent IN and 20 healthy controls were included in this study. The differences in the means, kurtosis and skewness of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) between the affected and unaffected nerves in patients and both nerves in controls were investigated by independent t-test and paired t-test respectively. Longitudinal changes of FA and ADC were correlated with outcome of IN via Spearman correlation coefficient. RESULTS: Significant differences were found in preoperative mean and kurtosis values for both FA and ADC of the affected side TR, compared to the unaffected side and control group respectively. However, these differences remarkably reduced postoperatively. Further, the Spearman correlation coefficient showed a strong negative correlation between decrease of ADC in the affected side and the surgical outcome in BNI total score. CONCLUSION: The changes of diffusive property of TR, especially the FA and ADC, provide alternative radiological evidence for evaluating the mechanism of CTN woNVC. The modification of DTI metrics could be an effective factor for providing potential noninvasive biomarkers for determining the prognosis of patients with CTN woNVC underwent IN.

Chromium (VI) detoxification by oxidation and flocculation of exopolysaccharides from Arthrobacter sp. B4.

The exopolysaccharides from Arthrobacter sp. B4 (B4-EPS) exhibited an excellent chromium (VI) (Cr(VI)) removal capability without any pH adjustment, whereby 50mgL(-1) of Cr(VI) could be completely removed by 4gL(-1) of B4-EPS. The kinetics tests revealed that the first-order rate constant was 8.3×10(-5)s(-1) and the optimal reaction time was 720min. However, a low initial concentration of Cr(VI) (5-30mgL(-1)) would accelerate the reaction rate of Cr(VI) removal and shorten reaction time to less than 360min. Meanwhile, the X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible (UV-vis) spectra indicated that Cr(VI) was reduced to Cr(III) by B4-EPS in accordance with the emergence of the green reaction products. Furthermore, the Fourier transform-infrared spectra (FT-IR) and nuclear magnetic resonance (NMR) showed that carboxyl and hydroxyl groups of B4-EPS contributed to Cr(VI) reduction. Additionally, a feasible scheme for Cr(VI) detoxification by oxidation and flocculation of B4-EPS is presented.

MicroRNA-210 overexpression predicts poorer prognosis in glioma patients.

MicroRNA-210 (miR-210) levels are elevated in many tumor types, are frequently associated with hypoxia induction, and are correlated with poor prognosis in many solid tumors. miR-210 regulates cell growth, angiogenesis, invasion, and apoptosis of many human tumors. In this study, we investigated the clinical significance of miR-210 expression in common brain tumors, or human gliomas. Glioma samples and normal brain tissues were analyzed using real-time quantitative reverse transcriptase polymerase chain reaction to characterize the expression patterns of miR-210. The association of miR-210 expression with clinicopathological parameters and prognosis of glioma patients was statistically analyzed. Gliomas were further divided by grade: pilocytic astrocytoma (World Health Organization [WHO] grade I), diffuse astrocytomas (WHO grade II), anaplastic astrocytomas (WHO grade III), and glioblastoma (WHO grade IV). There was a significantly higher expression level of miR-210 amongst the glioma tissues as compared with normal brain tissues (p<0.001). Increased expression of miR-210 in glioma tissues was significantly associated with advanced pathological grade (p<0.001) and low Karnofsky Performance Score (p=0.014). In addition, increased miR-210 levels were also associated with poor progression-free survival (PFS) and overall survival (OS) rates when compared to the normal control (both p<0.001), as calculated by Kaplan-Meier survival and Cox regression analyses. Furthermore, subgroup analyses showed that miR-210 expression was significantly associated with poor PFS and OS of glioma patients with high pathological grades (III-IV: both p<0.001). miR-210 is highly expressed in human gliomas and confers a poor prognosis in glioma patients. These findings may bring the development of novel, tailored pharmacological therapies for glioma patients.

Identification of intrinsic subtype-specific prognostic microRNAs in primary glioblastoma.

BACKGROUND: Glioblastoma multiforme (GBM) is the most malignant type of glioma. Integrated classification based on mRNA expression microarrays and whole-genome methylation subdivides GBM into five subtypes: Classical, Mesenchymal, Neural, Proneural-CpG island methylator phenotype (G-CIMP) and Proneural-non G-CIMP. Biomarkers that can be used to predict prognosis in each subtype have not been systematically investigated. METHODS: In the present study, we used Cox regression and risk-score analysis to construct respective prognostic microRNA (miRNA) signatures in the five intrinsic subtypes of primary glioblastoma in The Cancer Genome Atlas (TCGA) dataset. RESULTS: Patients who had high-risk scores had poor overall survival compared with patients who had low-risk scores. The prognostic miRNA signature for the Mesenchymal subtype (four risky miRNAs: miR-373, miR-296, miR-191, miR-602; one protective miRNA: miR-223) was further validated in an independent cohort containing 41 samples. CONCLUSION: We report novel diagnostic tools for deeper prognostic sub-stratification in GBM intrinsic subtypes based upon miRNA expression profiles and believe that such signature could lead to more individualized therapies to improve survival rates and provide a potential platform for future studies on gene treatment for GBM.

An axis involving SNAI1, microRNA-128 and SP1 modulates glioma progression.

BACKGROUND: Glioblastoma is an extraordinarily aggressive disease that requires more effective therapeutic options. Snail family zinc finger 1, dysregulated in many neoplasms, has been reported to be involved in gliomas. However, the biological mechanisms underlying SNAI1 function in gliomas need further investigation. METHODS: Quantitative real-time PCR was used to measure microRNA-128 (miR-128) expression level and western blot was performed to detect protein expression in U87 and U251 cells and human brain tissues. Cell cycle, CCK-8, transwell and wound-healing assays were performed. Dual-luciferase reporter assay was used for identifying the mechanism of SNAI1 and miR-128b regulation. The mechanism of miR-128 targeting SP1 was also tested by luciferase reporter assay. Immunohistochemistry and in situ hybridisation staining were used for quantifying SNAI1, SP1 and miR-128 expression levels in human glioma samples. RESULTS: The Chinese Glioma Genome Atlas (CGGA) data revealed that SNAI1 was up-regulated in glioma and we confirmed the findings in normal and glioma tissues. SNAI1 depletion by shRNA retarded the cell cycle and suppressed proliferation and invasion in glioma cell lines. The CGGA data showed that the Pearson correlation index between SNAI1 and miR-128 was negatively correlated. SNAI1 suppressed miR-128b expression by binding to the miR-128b specific promoter motif, and miR-128 targeted SP1 via binding to the 3'-untranslated region of SP1. Moreover, introduction of miR-128 anti-sense oligonucleotide alleviated the cell cycle retardation, proliferation and invasion inhibition induced by SNAI1 shRNA. Immunohistochemistry and in situ hybridisation analysis of SNAI1, SP1 and miR-128 unraveled their expression levels and correlations in glioma samples. CONCLUSIONS: We propose that the SNAI1/miR-128/SP1 axis, which plays a vital role in glioma progression, may come to be a clinically relevant therapeutic target.

MicroRNA-377 inhibited proliferation and invasion of human glioblastoma cells by directly targeting specificity protein 1.

BACKGROUND: Increasing evidence has indicated that microRNAs (miRNAs) are strongly implicated in the initiation and progression of glioblastoma multiforme (GBM). Here, we identified a novel tumor suppressive miRNA, miR-377, and investigated its role and therapeutic effect for GBM. METHODS: MiRNA global screening was performed on GBM patient samples and adjacent nontumor brain tissues. The expression of miR-377 was detected by real-time reverse-transcription PCR. The effects of miR-377 on GBM cell proliferation, cell cycle progression, invasion, and orthotopic tumorigenicity were investigated The therapeutic effect of miR-377 mimic was explored in a subcutaneous GBM model. Western blot and luciferase reporter assay were used to identify the direct and functional target of miR-377. RESULTS: MiR-377 was markedly downregulated in human GBM tissues and cell lines. Overexpression of miR-377 dramatically inhibited cell growth both in culture and in orthotopic xenograft tumor models, blocked G1/S transition, and suppressed cell invasion in GBM cells. Importantly, introduction of miR-377 could strongly inhibit tumor growth in a subcutaneous GBM model. Subsequent investigation revealed that specificity protein 1 (Sp1) was a direct and functional target of miR-377 in GBM cells. Silencing of Sp1 recapitulated the antiproliferative and anti-invasive effects of miR-377, whereas restoring the Sp1 expression antagonized the tumor-suppressive function of miR-377. Finally, analysis of miR-377 and Sp1 levels in human GBM tissues revealed that miR-377 is inversely correlated with Sp1 expression. CONCLUSION: These findings reveal that miR-377/Sp1 signaling that may be required for GBM development and may consequently serve as a therapeutic target for the treatment of GBM.