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1.
Free Radic Biol Med ; 222: 173-186, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38871197

ABSTRACT

Regulation of the redox system by branched-chain amino acid transferase 1 (BCAT1) is of great significance in the occurrence and development of diseases, but the relationship between BCAT1 and subarachnoid hemorrhage (SAH) is still unknown. Ferroptosis, featured by iron-dependent lipid peroxidation accompanied by the depletion of glutathione peroxidase 4 (GPX4), has been implicated in the pathological process of early brain injury after subarachnoid hemorrhage. This study established SAH model by endovascular perforation and adding oxyhemoglobin (Hb) to HT22 cells and delved into the mechanism of BCAT1 in SAH-induced ferroptotic neuronal cell death. It was found that SAH-induced neuronal ferroptosis could be inhibited by BCAT1 overexpression (OE) in rats and HT22 cells, and BCAT1 OE alleviated neurological deficits and cognitive dysfunction in rats after SAH. In addition, the effect of BCAT1 could be reversed by the Ly294002, a specific inhibitor of the PI3K pathway. In summary, our present study indicated that BCAT1 OE alleviated early brain injury EBI after SAH by inhibiting neuron ferroptosis via activation of PI3K/AKT/mTOR pathway and the elevation of GPX4. These results suggested that BCAT1 was a promising therapeutic target for subarachnoid hemorrhage.

2.
Free Radic Biol Med ; 208: 555-570, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37717795

ABSTRACT

Ferroptosis is a novel form of cell death that plays a critical role in the pathological and physiological processes of early brain injury following subarachnoid hemorrhage. Melatonin, as the most potent endogenous antioxidant, has shown strong protective effects against pathological changes following subarachnoid hemorrhage, but its impact on ferroptosis induced by subarachnoid hemorrhage remains unexplored. In our study, we established a subarachnoid hemorrhage model in male SD rats. We found that subarachnoid hemorrhage induced changes in ferroptosis-related indicators such as lipid peroxidation and iron metabolism, while intraperitoneal injection of melatonin (40 mg/kg) effectively ameliorated these changes to a certain degree. Moreover, in a subset of rats with subarachnoid hemorrhage who received pre-treatment via intravenous injection of the melatonin receptor antagonist Luzindole (1 mg/kg) and 4P-PDOT (1 mg/kg), we found that the protective effect of melatonin against subarachnoid hemorrhage includes inhibition of lipid peroxidation and reduction of iron accumulation depended on melatonin receptor 1B (MT2). Furthermore, our study demonstrated that melatonin inhibited neuronal ferroptosis by activating the NRF2 signaling pathway, as evidenced by in vivo inhibition of NRF2. In summary, melatonin acts through MT2 and activates NRF2 and downstream genes such as HO-1/NQO1 to inhibit ferroptosis in subarachnoid hemorrhage-induced neuronal injury, thereby improving neurological function in rats. These results suggest that melatonin is a promising therapeutic target for subarachnoid hemorrhage.


Subject(s)
Brain Injuries , Ferroptosis , Melatonin , Subarachnoid Hemorrhage , Rats , Male , Animals , Melatonin/pharmacology , Melatonin/therapeutic use , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Rats, Sprague-Dawley , Receptors, Melatonin , Subarachnoid Hemorrhage/drug therapy , Subarachnoid Hemorrhage/genetics , Subarachnoid Hemorrhage/pathology , Brain Injuries/metabolism , Iron/therapeutic use
4.
Cell Death Discov ; 8(1): 193, 2022 Apr 11.
Article in English | MEDLINE | ID: mdl-35410993

ABSTRACT

Immunosuppressive tumor microenvironment is a crucial factor that impedes the success of tumor immunotherapy, and tumor-associated macrophages (TAMs) are essential for the formation of tumor immunosuppressive microenvironment. Hyaluronic acid (HA) is highly important brick for glioblastoma microenvironment, but whether it contributes to TAM polarization and glioblastoma immunosuppressive microenvironment is less well known. In our study, we observed that disrupting glioblastoma HA synthesis or blocking HA binding to its receptor CD44 on macrophages increased the proportion of M1 macrophages by upregulating SIRPα in macrophages, the underlying mechanism was elevated SIRPα enhanced STAT1 phosphorylation and suppressed STAT3 phosphorylation in macrophages. Subsequently, the induced macrophages could inhibit glioblastoma growth via a feedback effect. In addition, 4-methylumbelliferone (4MU), a cholecystitis drug, can disrupt the CD47/SIRPα axis by disturbing glioblastoma HA synthesis. Collectively, these findings indicated that HA plays a crucial role in macrophages polarization and CD47/SIRPα signaling between glioblastoma cells and macrophages, and suppressing the HA pathway may be a new immunotherapeutic approach for glioblastoma.

5.
Am J Cancer Res ; 11(4): 1185-1205, 2021.
Article in English | MEDLINE | ID: mdl-33948353

ABSTRACT

This study aimed to investigate the interaction of A-kinase-interacting protein 1 (AKIP1) with C-X-C motif chemokine ligand (CXCL)1, CXCL2, CXCL8, and their effects on regulating glioblastoma multiforme (GBM) malignant behaviors. AKIP1 expression was modified by pcDNA and pGPH1 vectors in U-87 MG and U-251 MG cells. Subsequently, multiple compensative experiments were conducted via adding CXCL1, CXCL2 and CXCL8 in the pGPH1-AKIP1 (AKIP1 knockdown) transfected U-87 MG and U-251 MG cells, respectively. Furthermore, AKIP1, CXCL1/2/8 expressions in 10 GBM and 10 low-grade glioma (LGG) tumor samples were detected. AKIP1 was elevated in various GBM cell lines compared to normal human astrocytes. AKIP1 overexpression promoted U-87 MG and U-251 MG cell proliferation and invasion while inhibited apoptosis; and it enhanced chemoresistance to temozolomide (but not cisplatin) and radiation resistance; then AKIP1 knockdown showed the opposite effects. Meanwhile, AKIP1 positively regulated CXCL1/2/8, NF-κB pathway, AKT pathway and PD-L1 expression. Further multiple compensative experiments uncovered that CXCL1 and CXCL8 promoted proliferation, invasion, chemoradiation resistance, NF-κB pathway, AKT pathway and PD-L1 expression in U-87 MG and U-251 MG cells, also in pGPH1-AKIP1 (AKIP1 knockdown) transfected U-87 MG and U-251 MG cells; although CXCL2 exhibited similar treads, but its effect was much weaker. Besides, NF-κB pathway inhibitor and AKT pathway inhibitor attenuated the effect of CXCL1&CXCL8 on promoting GBM cell malignant behaviors. Clinically AKIP1 and CXCL1/8 were elevated in GBM compared to LGG tumor samples, and they were inter-correlated. AKIP1 promotes GBM viability, mobility and chemoradiation resistance via regulating CXCL1 and CXCL8 mediated NF-κB and AKT pathways.

6.
Cell Death Dis ; 12(5): 486, 2021 05 13.
Article in English | MEDLINE | ID: mdl-33986244

ABSTRACT

The tumor microenvironment plays an important role in tumor progression. Hyaluronic acid (HA), an important component of the extracellular matrix in the tumor microenvironment, abnormally accumulates in a variety of tumors. However, the role of abnormal HA accumulation in glioma remains unclear. The present study indicated that HA, hyaluronic acid synthase 3 (HAS3), and a receptor of HA named CD44 were expressed at high levels in human glioma tissues and negatively correlated with the prognosis of patients with glioma. Silencing HAS3 expression or blocking CD44 inhibited glioma cell proliferation in vitro and in vivo. The underlying mechanism was attributed to the inhibition of autophagy flux and maintaining glioma cell cycle arrest in G1 phase. More importantly, 4-methylumbelliferone (4-MU), a small competitive inhibitor of Uridine diphosphate (UDP) with the ability to penetrate the blood-brain barrier (BBB), also inhibited glioma cell proliferation in vitro and in vivo. Thus, approaches that interfere with HA metabolism by altering the expression of HAS3 and CD44 and the administration of 4-MU potentially represent effective strategies for glioma treatment.


Subject(s)
Genomics/methods , Glioma/genetics , Hyaluronic Acid/metabolism , Animals , Autophagy , Cell Line, Tumor , Cell Proliferation , Humans , Mice , Mice, Nude , Transfection , Tumor Microenvironment
7.
Chin Neurosurg J ; 6: 22, 2020.
Article in English | MEDLINE | ID: mdl-32922951

ABSTRACT

Our study aimed to determine the effect of the neutrophil-lymphocyte ratio on the prognosis of adult patients with acute stroke. We searched the Web of Science, PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure databases and selected all of the potentially eligible studies. From the included studies, we extracted characteristics such as the stroke type and acquisition time until routine blood collection and the odds ratios across studies. The 95% confidence intervals and odds ratios were pooled to calculate the effect size for the neutrophil-lymphocyte ratio in acute stroke patients. We defined poor function outcomes according to the modified Rankin Scale ≥ 3 or Glasgow Outcome Scale< 3.Thirteen studies with 4443 patients were included in our analysis, including 7 ischemic and 6 hemorrhagic stroke studies. The pooled odds ratios for poor functional outcome at 3 months with a higher neutrophil-lymphocyte ratio in acute ischemic and hemorrhagic patients were 1.689 (95% CI = 1.184-2.409, p < 0.001) and 1.125 (95% CI = 1.022-1.239, p < 0.001), respectively, and the overall pooled odds ratio for poor functional outcome following stroke was 1.257 (95% CI = 1.146-1.379, p < 0.001). At the same time, the overall combined odds ratio for death at 3 months was 1.632 (95% CI = 1.155-2.306, p < 0.001).The neutrophil-lymphocyte ratio, an easily calculated marker, plays a predictive role in the short-term outcomes of adult patients (mean age ≥ 50 years) following acute ischemic and hemorrhagic stroke.

8.
Int Immunopharmacol ; 75: 105771, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31352322

ABSTRACT

OBJECTIVE: Intracerebral hemorrhage (ICH) is acknowledged as a serious clinical problem lacking effective treatments. And caspase-1-mediated inflammatory response happened during the progression of ICH. Therefore, we aimed to investigate the effects of caspase-1 inhibitor Ac-YVAD-cmk on ICH. MATERIALS AND METHODS: Microglia cells were isolated and activated by thrombin for 24 h. Then the transcript and protein expressions of NLRP3 and inflammatory factors were assessed by RT-PCR and western blotting. Moreover, Ac-YVAD-cmk was injected into the ICH model. The mNSS and brain water content were tested at 24 h post-ICH. Finally, the pathological changes of microglia activation following ICH were discovered by the immunohistochemical and HE staining ways. RESULTS: Ac-YVAD-cmk inhibited the activation of pro-caspase-1 and decreased brain edema, in association with decreasing activated microglia and the expression of inflammation-related factors at 24 h post-ICH. Consequently, Ac-YVAD-cmk reduced the release of mature IL-1ß/IL-18 in perihematoma, improved the behavioral performance, and alleviated microglia in perihematoma region in ICH rats. CONCLUSIONS: These results indicate that caspase-1 could amplify the plural inflammatory responses in the ICH. Administration of Ac-YVAD-cmk has the potential to be a novel therapeutic strategy for ICH.


Subject(s)
Amino Acid Chloromethyl Ketones/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Caspase 1/immunology , Caspase Inhibitors/therapeutic use , Cerebral Hemorrhage/drug therapy , Neuroprotective Agents/therapeutic use , Amino Acid Chloromethyl Ketones/pharmacology , Animals , Anti-Inflammatory Agents/pharmacology , Behavior, Animal/drug effects , Brain/drug effects , Brain/pathology , Caspase Inhibitors/pharmacology , Cells, Cultured , Cerebral Hemorrhage/immunology , Cerebral Hemorrhage/pathology , Interleukin-18/genetics , Interleukin-18/immunology , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Male , Microglia , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Neuroprotective Agents/pharmacology , Rats, Sprague-Dawley
9.
Cancer Lett ; 454: 146-157, 2019 07 10.
Article in English | MEDLINE | ID: mdl-30978442

ABSTRACT

Metabolic abnormality is one of the hallmarks of cancer cells, and limiting material supply is a potential breakthrough approach for cancer treatment. Increasing researchers have been involved in the study of glioma cell metabolism reprogramming since the significance of IDH1 was confirmed in glioma. However, the molecular mechanisms underlying metabolic reprogramming induced by methionine deprivation regulates glioma cell proliferation remain unclear. Here we demonstrated that methionine deprivation inhibited glioma cell proliferation via downregulating interleukin 1 receptor antagonist (IL1RN) both in vitro and in vivo, methionine deprivation or knocking down IL1RN induced glioma cell cycle arrest. Moreover, we confirmed that IL1RN is a tumor associated gene and its expression is negatively correlated with the survival time of glioma patients. Altogether these results demonstrate a strong rationale insight that targeting amino acid metabolism such as methionine deprivation/IL1RN related gene therapy may offer novel direction for glioma treatment.


Subject(s)
Brain Neoplasms/metabolism , Glioma/metabolism , Interleukin 1 Receptor Antagonist Protein/biosynthesis , Methionine/deficiency , Animals , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/physiology , Down-Regulation , Glioma/pathology , Heterografts , Humans , Interleukin 1 Receptor Antagonist Protein/genetics , Mice , Mice, Inbred BALB C , Mice, Nude , RNA, Messenger/genetics , RNA, Messenger/metabolism , Transfection
10.
Cancer Sci ; 110(1): 107-117, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30387548

ABSTRACT

Gliomas are the most common central nervous system tumors. They show malignant characteristics indicating rapid proliferation and a high invasive capacity and are associated with a poor prognosis. In our previous study, p68 was overexpressed in glioma cells and correlated with both the degree of glioma differentiation and poor overall survival. Downregulating p68 significantly suppressed proliferation in glioma cells. Moreover, we found that the p68 gene promoted glioma cell growth by activating the nuclear factor-κB signaling pathway by a downstream molecular mechanism that remains incompletely understood. In this study, we found that dual specificity phosphatase 5 (DUSP5) is a downstream target of p68, using microarray analysis, and that p68 negatively regulates DUSP5. Upregulating DUSP5 in stably expressing cell lines (U87 and LN-229) suppressed proliferation, invasion, and migration in glioma cells in vitro, consistent with the downregulation of p68. Furthermore, upregulating DUSP5 inhibited ERK phosphorylation, whereas downregulating DUSP5 rescued the level of ERK phosphorylation, indicating that DUSP5 might negatively regulate ERK signaling. Additionally, we show that DUSP5 levels were lower in high-grade glioma than in low-grade glioma. These results suggest that the p68-induced negative regulation of DUSP5 promoted invasion by glioma cells and mediated the activation of the ERK signaling pathway.


Subject(s)
Brain Neoplasms/genetics , DEAD-box RNA Helicases/genetics , Dual-Specificity Phosphatases/genetics , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Glioma/genetics , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , DEAD-box RNA Helicases/metabolism , Dual-Specificity Phosphatases/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Glioma/metabolism , Glioma/pathology , Humans , MAP Kinase Signaling System/genetics , Neoplasm Invasiveness , Phosphorylation , RNA Interference
11.
Cell Death Dis ; 9(10): 1032, 2018 10 09.
Article in English | MEDLINE | ID: mdl-30302016

ABSTRACT

Glioblastoma is the most common and aggressive primary brain tumor in adults. New drug design and development is still a major challenge for glioma treatment. Increasing evidence has shown that nitazoxanide, an antiprotozoal drug, has a novel antitumor role in various tumors and exhibits multiple molecular functions, especially autophagic regulation. However, whether nitazoxanide-associated autophagy has an antineoplastic effect in glioma remains unclear. Here, we aimed to explore the underlying molecular mechanism of nitazoxanide in glioblastoma. Our results showed that nitazoxanide suppressed cell growth and induced cell cycle arrest in glioblastoma by upregulating ING1 expression with a favorable toxicity profile. Nitazoxanide inhibited autophagy through blockage of late-stage lysosome acidification, resulting in decreased cleavage of ING1. A combination with chloroquine or Torin1 enhanced or impaired the chemotherapeutic effect of nitazoxanide in glioblastoma cells. Taken together, these findings indicate that nitazoxanide as an autophagy inhibitor induces cell cycle arrest in glioblastoma via upregulated ING1 due to increased transcription and decreased post-translational degradation by late-stage autophagic inhibition.


Subject(s)
Antiprotozoal Agents/pharmacology , Autophagy/drug effects , Cell Cycle Checkpoints/drug effects , Glioblastoma/drug therapy , Glioblastoma/metabolism , Inhibitor of Growth Protein 1/metabolism , Thiazoles/pharmacology , Animals , Apoptosis/drug effects , Brain Neoplasms/drug therapy , Brain Neoplasms/metabolism , Cell Line , Cell Line, Tumor , Cell Proliferation/drug effects , Chloroquine/pharmacology , Glioma/drug therapy , Glioma/metabolism , Human Umbilical Vein Endothelial Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Naphthyridines/pharmacology , Nitro Compounds , Protein Processing, Post-Translational/drug effects , Transcription, Genetic/drug effects , Up-Regulation/drug effects
12.
Cell Physiol Biochem ; 44(4): 1381-1395, 2017.
Article in English | MEDLINE | ID: mdl-29186708

ABSTRACT

BACKGROUND/AIMS: Glioma is the most devastating cancer in the brain and has a poor prognosis in adults. Therefore, there is a critical need for novel therapeutic strategies for the management of glioma patients. Isogambogenic acid, an active compound extracted from the Chinese herb Garcinia hanburyi, induces autophagic cell death. METHODS: Cell viability was detected with MTT assays. Cell proliferation was assessed using the colony formation assay. Morphological changes associated with autophagy and apoptosis were tested by TEM and Hoechst staining, respectively. The apoptosis rate was measured by flow cytometry. Western blot, immunofluorescence and immunohistochemical analyses were used to detect protein expression. U87-derived xenografts were established for the examination of the effect of isogambogenic acid on glioma growth in vivo. RESULTS: Isogambogenic acid induced autophagic death in U87 and U251 cells, and blocking late-stage autophagy markedly enhanced the antiproliferative activities of isogambogenic acid. Moreover, we observed the activation of AMPK-mTOR signalling in isogambogenic acid-treated glioma cells. Furthermore, the activation of AMPK or the inhibition of mTOR augmented isogambogenic acid-induced autophagy. Inhibition of autophagy attenuated apoptosis in isogambogenic acid-treated glioma cells. Finally, isogambogenic acid inhibited the growth of U87 glioma in vivo. CONCLUSION: Isogambogenic acid inhibits the growth of glioma via activation of the AMPK-mTOR signalling pathway, which may provide evidence for future clinical applications in glioma therapy.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Antineoplastic Agents/toxicity , Cell Proliferation/drug effects , TOR Serine-Threonine Kinases/metabolism , Xanthones/toxicity , Adenine/analogs & derivatives , Adenine/pharmacology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Autophagy/drug effects , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Glioma/drug therapy , Glioma/pathology , Humans , Immunohistochemistry , Mice , Mice, Inbred BALB C , Mice, Nude , Signal Transduction/drug effects , Transplantation, Heterologous , Xanthones/chemistry , Xanthones/therapeutic use
13.
Mol Neurobiol ; 54(4): 2595-2610, 2017 05.
Article in English | MEDLINE | ID: mdl-26993299

ABSTRACT

Chronic brain hypoperfusion (CBH) induces the accumulation of abnormal cellular proteins, accompanied by cognitive decline, and the autophagic-lysosomal system is abnormal in dementia. Whether CBH accounts for autophagic-lysosomal neuropathology remains unknown. Here, we show that CBH significantly increased the number of autophagic vacuoles (AVs) with high LC3-II levels, but decreased SQSTM1 and cathepsin D levels in the hippocampi of rats following bilateral common carotid artery occlusion (2VO) for 2 weeks. Further studies showed that microRNA-27a (Mir27a) was upregulated at 2 weeks compared with the sham group. Additionally, LAMP-2 proteins were downregulated by Mir27a overexpression, upregulated by Mir27a inhibition, and unchanged by binding-site mutations or miR-masks, indicating that lamp-2 is the target of Mir27a. Knockdown of endogenous Mir27a prevented the reduction of LAMP-2 protein expression as well as the accumulation of AVs in the hippocampi of 2VO rats. Overexpression of Mir27a induced, while the knockdown of Mir27a reduced, the accumulation of AVs and the LC3-II level in cultured neonatal rat neurons. The results revealed that CBH in rats at 2 weeks could induce inefficient lysosomal clearance, which is regulated by the Mir27a-mediated downregulation of LAMP-2 protein expression. These findings provide an insight into a novel molecular mechanism of autophagy at the miRNA level.


Subject(s)
Brain Ischemia/metabolism , Hippocampus/metabolism , Lysosomes/metabolism , MicroRNAs/metabolism , Animals , Autophagy/genetics , Base Sequence , Brain Ischemia/pathology , Chronic Disease , Down-Regulation/genetics , Hippocampus/ultrastructure , Lysosomal-Associated Membrane Protein 2/metabolism , Lysosomes/ultrastructure , Male , MicroRNAs/genetics , Microtubule-Associated Proteins/metabolism , Phagosomes/metabolism , Phagosomes/ultrastructure , Rats, Sprague-Dawley , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Sequestosome-1 Protein/metabolism , Vacuoles/metabolism , Vacuoles/ultrastructure
14.
Oncotarget ; 7(12): 15200-14, 2016 Mar 22.
Article in English | MEDLINE | ID: mdl-26934654

ABSTRACT

Metabolomics has shown significant potential in identifying small molecules specific to tumor phenotypes. In this study we analyzed resected tissue metabolites using capillary electrophoresis-mass spectrometry and found that tissue hypotaurine levels strongly and positively correlated with glioma grade. In vitro studies were conducted to show that hypotaurine activates hypoxia signaling through the competitive inhibition of prolyl hydroxylase domain-2. This leads to the activation of hypoxia signaling as well as to the enhancement of glioma cell proliferation and invasion. In contrast, taurine, the oxidation metabolite of hypotaurine, decreased intracellular hypotaurine and resulted in glioma cell growth arrest. Lastly, a glioblastoma xenograft mice model was supplemented with taurine feed and exhibited impaired tumor growth. Taken together, these findings suggest that hypotaurine is an aberrantly produced oncometabolite, mediating tumor molecular pathophysiology and progression. The hypotaurine metabolic pathway may provide a potentially new target for glioblastoma diagnosis and therapy.


Subject(s)
Brain/pathology , Glioma/pathology , Hypoxia/physiopathology , Metabolomics , Signal Transduction , Taurine/analogs & derivatives , Animals , Apoptosis , Brain/metabolism , Case-Control Studies , Cell Cycle , Cell Proliferation , Follow-Up Studies , Glioma/metabolism , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Phenotype , Prognosis , Taurine/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
15.
Tumour Biol ; 37(3): 3549-60, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26454746

ABSTRACT

Glioma is the most common primary brain tumor in the central nervous system (CNS) with high morbidity and mortality in adults. Although standardized comprehensive therapy has been adapted, the prognosis of glioma patients is still frustrating and thus novel therapeutic strategies are urgently in need. Quercetin (Quer), an important flavonoid compound found in many herbs, is shown to be effective in some tumor models including glioma. Recently, it is reported that adequate regulation of autophagy can strengthen cytotoxic effect of anticancer drugs. However, it is not yet fully clear how we should modulate autophagy to achieve a satisfactory therapeutic effect. 3-Methyladenine (3-MA) and Beclin1 short hairpin RNA (shRNA) were used to inhibit the early stage of autophage while chloroquine (CQ) to inhibit the late stage. MTT assay was implemented to determine cell viability. Transmission electron microscopy, western blot, and immunohistochemistry were adopted to evaluate autophagy. Western blot, flow cytometry, and immunohistochemistry were used to detect apoptosis. C6 glioma xenograft models were established to assess the therapeutic effect (the body weight change, the median survival time, and tumor volume) in vivo. Quercetin can inhibit cell viability and induce autophagy of U87 and U251 glioma cells in a dose-dependent manner. Inhibition of early-stage autophagy by 3-MA or shRNA against Beclin1 attenuated the quercetin-induced cytotoxicity. In contrast, suppression of autophagy at a late stage by CQ enhanced the anti-glioma efficiency of quercetin. Therapeutic effect of quercetin for malignant glioma can be strengthened by inhibition of autophagy at a late stage, not initial stage, which may provide a novel opportunity for glioma therapy.


Subject(s)
Autophagy/drug effects , Brain Neoplasms/drug therapy , Glioma/drug therapy , Quercetin/pharmacology , Adenine/analogs & derivatives , Adenine/pharmacology , Animals , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Chloroquine/pharmacology , Glioma/mortality , Glioma/pathology , Humans , Male , Neoplasm Staging , Rats , Rats, Sprague-Dawley
16.
Neuroreport ; 27(3): 136-44, 2016 Feb 10.
Article in English | MEDLINE | ID: mdl-26716385

ABSTRACT

Cancer cells preferentially use aerobic glycolysis to support growth, a metabolic alteration commonly referred to as the 'Warburg effect.' Here, we show that the tumor necrosis factor receptor-associated protein 1 (TRAP1) is crucial for the Warburg effect in human glioblastoma multiforme (GBM). In contrast to normal brain, GBMs show increased TRAP1 expression. We used both GBM cell lines and neurospheres derived from human GBM specimens to examine the effects of Knockdown of TRAP1 on GBM cell lines and glioma stem cells. We also used a neurosphere recovery assay that measured neurosphere formation at three time points to assess the capacity of the culture to repopulate after knockdown of TRAP1. Our results showed that knockdown of TRAP1 strongly decreased GBM cell proliferation and migration, inhibited neurosphere recovery, secondary neurosphere formation, and enhanced the therapeutic effect of temozolomide in neurosphere cultures. In GBM, knockdown of TRAP1 appeared to inhibit tumor growth and migration through its regulatory effects on metabolic reprogramming.


Subject(s)
Antineoplastic Agents, Alkylating/pharmacology , Dacarbazine/analogs & derivatives , Glioblastoma/metabolism , HSP90 Heat-Shock Proteins/physiology , Cell Line, Tumor/drug effects , Cell Line, Tumor/metabolism , Dacarbazine/pharmacology , Down-Regulation , Glioblastoma/drug therapy , HSP90 Heat-Shock Proteins/metabolism , Humans , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Neural Stem Cells/drug effects , Neural Stem Cells/metabolism , Temozolomide
17.
Mol Carcinog ; 55(5): 575-85, 2016 May.
Article in English | MEDLINE | ID: mdl-25764520

ABSTRACT

microRNAs (miRNAs) are commonly altered in glioblastoma. Publicly available algorithms suggest the Wnt pathway is a potential target of miR-577 and the Wnt pathway is commonly altered in glioblastoma. Glioblastoma has not been previously evaluated for miR-577 expression. Glioblastoma tumors and cell lines were evaluated for their expression of miR-577. Cell lines were transfected with miR-577, miR-577-mutant, or control mimics to evaluate the effect of miR-577 expression on cell proliferation in vitro and in an animal model. Wnt pathway markers were also evaluated for their association with miR-577 expression. miR-577 expression was decreased in 33 of 40 (82.5%) glioblastoma tumors and 5 of 6 glioblastoma cell lines. miR-577 expression correlated negatively with cell growth and cell viability. miR-577 down-regulation was associated with increased expression of the Wnt signaling pathway genes lipoprotein receptor-related protein (LRP) 6 (LRP6) and ß-catenin. Western blot analysis confirmed decreased expression of the Wnt signaling pathway genes Axin2, c-myc, and cyclin D1 in miR-577 transfected cells. miR-577 expression is down-regulated in glioblastoma. miR-577 directly targets Wnt signaling pathway components LRP6 and ß-catenin. miR-577 suppresses glioblastoma multiforme (GBM) growth by regulating the Wnt signaling pathway.


Subject(s)
Brain Neoplasms/pathology , Glioblastoma/pathology , MicroRNAs/genetics , MicroRNAs/metabolism , Wnt Signaling Pathway , Animals , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation , Cell Survival , Down-Regulation , Gene Expression Regulation, Neoplastic , Glioblastoma/genetics , Glioblastoma/metabolism , Humans , Low Density Lipoprotein Receptor-Related Protein-6/genetics , Male , Mice , Neoplasm Transplantation , beta Catenin/genetics
18.
J Neurooncol ; 126(3): 455-62, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26680227

ABSTRACT

Glioma cells rely on glycolysis to obtain energy and sustain their survival under microenvironmental stress in vivo. The mechanisms of regulation of glycolysis in glioma cells are unclear. Signaling pathway mediated by the transcription factor X box-binding protein 1 (XBP1) is one of the most important pathways of unfolded protein response which is comprehensively activated in cancer cells upon the microenvironmental stress. Here we showed that XBP1 was significantly activated in glioma tissues in vivo. XBP1 silencing resulted in decreasing of glioma cell viability and ATP/lactate production under hypoxia, which is possibly mediated by inhibition of Hexokinase II (HK2)'s expression. More importantly, XBP1 silenced glioma cells showed the decrease of tumor formation capacity. Our results revealed that XBP1s activation was involved in glioma glycolysis regulation and might be a potential molecular target for glioma treatment.


Subject(s)
Apoptosis , DNA-Binding Proteins/antagonists & inhibitors , Gene Silencing , Glycolysis , Hexokinase/antagonists & inhibitors , RNA, Small Interfering/genetics , Transcription Factors/antagonists & inhibitors , Adenosine Triphosphate/metabolism , Animals , Cell Proliferation , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Female , Glioma , Hexokinase/genetics , Hexokinase/metabolism , Humans , Hypoxia/physiopathology , Lactic Acid/metabolism , Mice , Mice, Inbred BALB C , Mice, Nude , Oxygen Consumption , Rats, Wistar , Regulatory Factor X Transcription Factors , Signal Transduction , Transcription Factors/genetics , Transcription Factors/metabolism , Tumor Cells, Cultured , X-Box Binding Protein 1 , Xenograft Model Antitumor Assays
19.
Mol Neurodegener ; 10: 36, 2015 Aug 11.
Article in English | MEDLINE | ID: mdl-26259688

ABSTRACT

BACKGROUND: Previous studies have demonstrated that the trafficking defects of Nav1.1/Nav1.2 are involved in the dementia pathophysiology. However, the detailed mechanisms are not fully understood. Moreover, whether the impaired miRNAs regulation linked to dementia is a key player in sodium channel trafficking disturbance remains unclear. The cognitive impairment induced by chronic cerebral ischemia through chronic brain hypoperfusion (CBH) is likely reason to precede dementia. Therefore, our goal in the present study was to examine the role of microRNA-9 (miR-9) in regulating Nav1.1/Nav1.2 trafficking under CBH generated by bilateral common carotid artery occlusion (2VO). RESULTS: The impairment of Nav1.1/Nav1.2 trafficking and decreased expression of Navß2 were found in the hippocampi and cortices of rats following CBH generated by bilateral 2VO. MiR-9 was increased in both the hippocampi and cortices of rats following CBH by qRT-PCR. Intriguingly, miR-9 suppressed, while AMO-miR-9 enhanced, the trafficking of Nav1.1/Nav1.2 from cytoplasm to cell membrane. Further study showed that overexpression of miR-9 inhibited the Navß2 expression by targeting on its coding sequence (CDS) domain by dual luciferase assay. However, binding-site mutation or miR-masks failed to influence Navß2 expression as well as Nav1.1/Nav1.2 trafficking process, indicating that Navß2 is a potential target for miR-9. Lentivirus-mediated miR-9 overexpression also inhibited Navß2 expression and elicited translocation deficits to cell membrane of Nav1.1/Nav1.2 in rats, whereas injection of lentivirus-mediated miR-9 knockdown could reverse the impaired trafficking of Nav1.1/Nav1.2 triggered by 2VO. CONCLUSIONS: We conclude that miR-9 may play a key role in regulating the process of Nav1.1/Nav1.2 trafficking via targeting on Navß2 protein in 2VO rats at post-transcriptional level, and inhibition of miR-9 may be a potentially valuable approach to prevent Nav1.1/Nav1.2 trafficking disturbance induced by CBH.


Subject(s)
Brain Ischemia/metabolism , MicroRNAs/pharmacology , NAV1.1 Voltage-Gated Sodium Channel/metabolism , NAV1.2 Voltage-Gated Sodium Channel/metabolism , Nerve Tissue Proteins/metabolism , Protein Transport/genetics , Voltage-Gated Sodium Channel Blockers , Animals , Brain Ischemia/genetics , Carotid Artery, Common , Cerebral Cortex/metabolism , Chronic Disease , Gene Expression Regulation , Gene Knockdown Techniques , Genetic Vectors/pharmacology , Hippocampus/metabolism , Lentivirus/genetics , Ligation , Male , MicroRNAs/genetics , NAV1.1 Voltage-Gated Sodium Channel/genetics , NAV1.2 Voltage-Gated Sodium Channel/genetics , Nerve Tissue Proteins/genetics , Oligonucleotides, Antisense/pharmacology , Protein Structure, Tertiary , Rats , Rats, Sprague-Dawley , Sodium/metabolism , Voltage-Gated Sodium Channel beta-2 Subunit/biosynthesis , Voltage-Gated Sodium Channel beta-2 Subunit/genetics
20.
Sci Rep ; 5: 9065, 2015 Mar 12.
Article in English | MEDLINE | ID: mdl-25761777

ABSTRACT

Glioma relies on glycolysis to obtain energy and sustain its survival under low glucose microenvironment in vivo. The mechanisms on glioma cell glycolysis regulation are still unclear. Signaling mediated by Double-stranded RNA-activated protein kinase (PKR) - like ER kinase (PERK) is one of the important pathways of unfolded protein response (UPR) which is comprehensively activated in cancer cells upon the hypoxic and low glucose stress. Here we show that PERK is significantly activated in human glioma tissues. PERK silencing results in decreased glioma cell viability and ATP/lactate production upon low glucose stress, which is mediated by partially blocked AKT activation and subsequent inhibition of Hexokinase II (HK2)'s mitochondria translocation. More importantly, PERK silenced glioma cells show decreased tumor formation capacity. Our results reveal that PERK activation is involved in glioma glycolysis regulation and may be a potential molecular target for glioma treatment.


Subject(s)
Gene Silencing , Glioma/genetics , Glioma/metabolism , Glucose/metabolism , Hexokinase/metabolism , Mitochondria/metabolism , Proto-Oncogene Proteins c-akt/metabolism , eIF-2 Kinase/genetics , Animals , Apoptosis/genetics , Cell Line, Tumor , Cell Survival/genetics , Disease Models, Animal , Glioma/mortality , Heterografts , Humans , Protein Transport , Rats , Stress, Physiological
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