Apoptosis In C6 Cells Research Articles

Abstract C049: Aryl hydrocarbon receptor activity promotes cancer progression and drug resistance in castration-resistant prostate cancer cells

Abstract The aryl hydrocarbon receptor (AhR) is a nuclear transcription factor, xenobiotic sensor, and has a role in regulating diet-induced obesity. We report constitutive overexpression and activity of AhR promotes progression to androgen independence, proliferation, and mediates drug resistance in metastatic castration-resistant prostate cancer (CRPC) in vitro models. RNAseq analysis identified differentially expressed genes (DEGS) which may further implicate the role of AhR in prostate cancer progression. Recent evidence demonstrates significant changes in the expression profile of these genes in response to treatment with chemotherapeutics, specifically bromocriptine (Wu et al 2023). We also confirmed AhR inhibits drug-induced apoptosis in C4-2 cells. Further understanding of the molecular mechanisms governing AhR-mediated cancer progression and drug resistance should expand treatment options and improve patient outcomes. Citation Format: Kofi K. Khamit-Kush, Nathan J. Bowen, Jeffrey A. Handy, Joann B. Powell. Aryl hydrocarbon receptor activity promotes cancer progression and drug resistance in castration-resistant prostate cancer cells [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C049.

Extract of Astragali Radix and Solanum nigrum Linne regulates microglia and macrophage polarization and inhibits the growth and infiltration of C6 glioblastoma

Ethnopharmacological relevanceThe polarization of glioma-associated microglia/macrophages (GAMs) affects the growth and infiltration of glioma. Astragali Radix (AR) and Solanum nigrum L. (SN) are traditional antitumor combinations in Chinese herbal medicine, but their roles and mechanisms against glioma are not yet clear. Aim of the studyThe effects of AR and SN compound (ARSN) on the polarization of GAMs and glioma cells in vitro and in vivo were studied, providing new ideas for the treatment of glioma. Materials and methodsThe UPLC-QTOF-MS method was used to examine the quality of ARSN extracts. The effects of ARSN on proliferation, migration and apoptosis of C6 cells were investigated using CCK-8 assay, colony-forming assay, wound healing assay and flow cytometry. The impact of ARSN on the polarization of GAMs was verified by PCR, ELISA, and flow cytometry. In addition, a rat glioma model was established to assess the effects of ARSN on glioma growth, infiltration, and polarization of GAMs. ResultsIn vitro experiments, ARSN can effectively inhibit the proliferation and migration of C6 cells and promote apoptosis. In the rat orthotopic tumor model, ARSN also effectively inhibited tumor growth and infiltration. The SN part of ARSN has strong cytotoxicity. Meanwhile the AR part can effectively inhibit the M2 polarization of GAMs and chemokine production induced by tumor, promote the M1 phenotype of GAMs, and regulate the tumor immune microenvironment to indirectly kill glioma. ConclusionsARSN inhibited glioma growth both in vitro and in vivo. SN takes effect through direct cytotoxicity, while AR works by regulating GAMs polarization. ARSN extracts can be used as a potential agent for glioma treatment.

Retracted: Helicid Improves Lipopolysaccharide-Induced Apoptosis of C6 Cells by Regulating SH2D5 DNA Methylation via the CytC/Caspase9/Caspase3 Signaling Pathway.

[This retracts the article DOI: 10.1155/2022/9242827.].

Coal waste-derived synthesis of yellow oxidized graphene quantum dots with highly specific superoxide dismutase activity: characterization, kinetics, and biological studies.

The disintegration of coal-based precursors for the scalable production of nanozymes relies on the fate of solvothermal pyrolysis. Herein, we report a novel economic and scalable strategy to fabricate yellow luminescent graphene quantum dots (YGQDs) by remediating unburnt coal waste (CW). The YGQDs (size: 7-8 nm; M.W: 3157.9 Da) were produced using in situ "anion-radical" assisted bond cleavage in water (within 8 h; at 121 °C) with yields of ∼87%. The presence of exposed surface and edge groups, such as COOH, C-O-C, and O-H, as structural defects accounted for its high fluorescence with εmax ∼530 nm at pH 7. Besides, these defects also acted as radical stabilizers, demonstrating prominent anti-oxidative activity of ∼4.5-fold higher than standard ascorbic acid (AA). In addition, the YGQDs showed high biocompatibility towards mammalian cells, with 500 μM of treatment dose showing <15% cell death. The YGQDs demonstrated specific superoxide dismutase (SOD) activity wherein 15 μM YGQDs equalled the activity of 1-unit biological SOD (bSOD), measured using the pyrogallol assay. The Km for YGQDs was ∼10-fold higher than that for bSOD. However, the YGQDs retained their SOD activity in harsh conditions like high temperatures or denaturing reactions, where the activity of bSOD is completely lost. The binding affinity of YGQDs for superoxide ions, measured from isothermal calorimetry (ITC) studies, was only 10-fold lower than that of bSOD (Kd of 586 nM vs. 57.3 nM). Further, the pre-treatment of YGQDs (∼10-25 μM) increased the cell survivability to >75-90% in three cell lines during ROS-mediated cell death, with the highest survivability being shown for C6-cells. Next, the ROS-induced apoptosis in C6-cells (model for neurodegenerative diseases study), wherein YGQDs uptake was confirmed by confocal microscopy, showed ∼5-fold apoptosis alleviation with only 5 μM pretreatment. The YGQDs also restored the expression of pro-inflammatory Th1 cytokines (TNF-α, IFN-γ, IL-6) and anti-inflammatory Th2 cytokines (IL-10) to their basal levels, with a net >3-fold change observed. This further explains the molecular mechanism for the antioxidant property of YGQDs. The high specific SOD activity associated with YGQDs may provide the cheapest alternative source for producing large-scale SOD-based nanozymes that can treat various oxidative stress-linked disorders/diseases.

In vitro anti-cancer effects of beauvericin through inhibition of actin polymerization and Src phosphorylation

BackgroundBeauvericin (BEA) is a depsipeptide with antimicrobial, anti-inflammatory, and anti-cancer activities isolated from Beauveria bassiana. However, little is understood on its anti-cancer activities and mechanism. PurposeAim of this study was to explore the anti-cancer activity of BEA and its underlying molecular mechanism to provide a theoretical basis for its role as a candidate natural drug in cancer diseases. Study DesignVarious cancer cells such as C6 glioma, U251, MDA-MB-231, HeLa, HCT-15, LoVo cells, and HEK293T cells were used to the anti-cancer activity of BEA. MethodsTo evaluate the anti-cancer activity of BEA, cell viability test (MTT assay), morphological change check, confocal microscopy, actin polymerization assay, flow cytometry, and Western blotting analysis. To check the target enzyme of BEA, overexpression and site-directed mutagenesis was employed. ResultsBEA inhibited the viability of cancer cells including C6, MDA-MB-231, HeLa, HCT-15, LoVo, and U251 cells. Treatment of BEA in C6 glioma cells induced cell membrane blebbing and apoptosis. Caspase-3 and -9 were dose-dependently activated by BEA, and the mRNA expression of Bcl-2 was inhibited by BEA. According to confocal microscopy, actin polymerization and actin-actin interaction were interrupted by BEA in C6 cells. BEA regulated the apoptosis of C6 cells depending on the protein phosphorylation of Src and Signal transducer and activator of transcription (STAT3). Moreover, c-terminal amino acids in Src directly interacted with BEA in C6 cells, and the binding of Src and BEA suppressed the kinase activity of Src. ConclusionsThese results suggest that BEA may be a critical candidate or substitute drug for cancer treatment via suppression of the Src/STAT3 pathway.

Preparation of C6 cell membrane-coated doxorubicin conjugated manganese dioxide nanoparticles and its targeted therapy application in glioma

In this study, we prepared a C6 cell membrane-coated doxorubicin conjugated manganese dioxide biomimetic nanomedicine system (MnO2-DOX-C6) for the treatment of glioma. In the glioma microenvironment, manganese dioxide could alleviate tumor hypoxia by promoting the decomposition of hydrogen peroxide (H2O2) to generate oxygen and, through a Fenton-like reaction, increase ROS levels in tumor cells, thus inducing oxidative stress to further kill cancer cells. Doxorubicin and manganese dioxide were connected through a hydrazone bond so that doxorubicin could be released only in the acidic environment of the tumor, which helped to reduce the toxicity and side effects of doxorubicin. Encapsulation of glioma C6 cancer cell membrane in MnO2-DOX-C6 made MnO2-DOX possess the homologous targeting ability and also regulated drug release rate. In vitro release experiments showed that the cumulative release of doxorubicin from MnO2-DOX-C6 at a pH of 5.0 for 48 h was 66.84 ± 3.81%, proving that it had pH sensitivity and a sustained-release effect. Cellular uptake experiments showed that MnO2-DOX-C6 had a good ability to target syngeneic tumor cells. MTT, flow cytometry, Western blot, cell immunofluorescence staining and in vivo antitumor experiments demonstrated that MnO2-DOX-C6 could promote C6 cell apoptosis and inhibit its proliferative ability. These results clearly suggested that MnO2-DOX-C6 may be a promising bionic nanosystem agent for the treatment of glioma.

Pelargonidin inhibits vascularization and metastasis of brain gliomas by blocking the PI3K/AKT/mTOR pathway

Pelargonidin has attracted much attention in many cancers. Whether the growth of glioma inhibited by pelargonidin is related to the PI3K/AKT/mTOR pathway is unknown. To examine this, we performed both in vivo and in vitro studies. Twenty-four hours after inoculation, C6 cells received various treatments: CCK8, transwell, flow cytometry, and Western blot were performed. The cell supernatant was collected in order to pretreat HUVEC cells, and tube formation assay was performed. An in situ glioma rat model was constructed and administrated treatment according to its group. After 14 days, the brains were obtained for TUNEL assay, immunohistochemical staining, and Western blot. In vitro studies demonstrated that pelargonidin inhibited the proliferation, migration, and invasion of C6 cells, and promoted apoptosis of C6 cells. Additionally, pelargonidin could inhibit tube formation of HUVECs. We also detected the proteins in the PI3K/AKT/mTOR pathway, and the results indicated that pelargonidin inhibited the phosphorylation of AKT, PI3K, and mTOR, and downregulated VEGF protein. In vivo glioma models were successfully built, and pelargonidin could increase the survival rate of rat, and pathological staining results indicated that pelargonidin increased TUNELpositive cells and decreased micro-vessel density (MVD) through PI3K/AKT/mTOR. Pelargonidin could reduce the relative expression of MMP2, MMP9, N-cadherin, and VEGF proteins, and inhibit the PI3K/AKT/ mTOR pathway. Pelargonidin inhibited the vascularization and metastasis of glioma by blocking the PI3K/ AKT/mTOR pathway.

The mechanism of formononetin/calycosin compound optimizing the effects of temozolomide on C6 malignant glioma based on metabolomics and network pharmacology

The complex of formononetin and calycosin (FMN/CAL) shows a synergistic effect on temozolomide in the treatment of malignant glioma, however the mechanism is unclear. We investigated the mechanism through means of metabolomics, network pharmacology and molecular biology. FMN/CAL enhanced the inhibition of TMZ on the growth and infiltration of C6 glioma. The metabolomic results showed that the TMZ sensitization of FMN/CAL mainly involved 5 metabolic pathways and 4 metabolites in cells, 1 metabolic pathway and 2 metabolites in tumor tissues, and 7 metabolic pathways and 8 metabolites in serum. Further network pharmacological analysis revealed that NOS2 was a potential target for FMN/CAL to regulate the metabolism in TMZ-treated C6 glioma cells, serums and tissues, and TNF-α was another potential target identified in tissues. FMN/CAL down-regulated the expression of NOS2 in tumor cells and tissues, and reduced the secretion of TNF-α in tumor region. FMN/CAL promoted TMZ-induced C6 cell apoptosis by inhibiting NOS2, but the inhibition of cell vitality and migration was not through NOS2. Our work revealed that FMN/CAL can increase the sensitivity of malignant glioma to TMZ by inhibiting NOS2-dependent cell survival, which provides a basis for the application of this combination in adjuvant treatment of glioma.

Doramectin inhibits glioblastoma cell survival via regulation of autophagy invitro and invivo.

Glioblastoma (GBM) is one of the most widespread and lethal types of cancer. However, there are currently no drugs or therapeutic strategies that can completely cure GBM. Doramectin (DRM) has a broad range of activities against endoparasites and ectoparasites, and is extensively used in livestock. In the present study, the effect of DRM on the induction of autophagy in U87 and C6 GBM and glioma cell lines, as well as the mechanism of autophagy, were examined. First, transmission electron microscopy, plasmid transfection and western blot analysis demonstrated that DRM could induce autophagy in U87 and C6 cells in vitro. Next, MTT and colony formation assays revealed that DRM-induced autophagy prevented U87 and C6 cell viability and colony formation ratio. In addition, DRM-induced autophagy promoted U87 and C6 cell apoptosis, as indicated by DAPI analysis and flow cytometry. Furthermore, transcriptome analysis demonstrated that DRM modulated a number of genes and pathways involved in autophagy. In a nude mouse xenograft model, immunohistochemical staining and the TUNEL assay demonstrated that the effect of DRM on the tumor was consistent with that in vivo. These data indicated that DRM induced autophagy mainly by blocking the PI3K/AKT/mTOR signaling pathway in GBM cells. DRM-induced autophagy promoted the inhibition of GBM cell proliferation and apoptosis in vitro and in vivo. The present study suggested that DRM may be an effective drug for the treatment of GBM.

RETRACTED ARTICLE: Cirsilineol inhibits cell growth and induces apoptosis in glioma C6 cells via inhibiting MAPK and PI3K/Akt/mTOR signaling pathways

BackgroundGlioma is a major type of brain cancer and responsible for high death rate worldwide due to the delayed diagnosis and chemo-resistance. It is responsible for nearly 16% of all brain cancer incidences with increased prevalence globally.ObjectiveThe present research study deals with discovering the in vitro anticancer potential of cirsilineol on the rat glioma C6 cells through the inhibition of PI3K/Akt/mTOR and MAPK signaling pathways.MethodologyThe in vitro antioxidant potential of cirsilineol was examined by different free radical scavenging analyses. The effects of cirsilineol on the cell viability of C6 and normal Vero cells were investigated by MTT assay. The intracellular ROS production and apoptotic cell death in the cirsilineol-administered C6 cells were scrutinized by fluorescent staining techniques. The contents of TBARS and GSH, SOD and caspase activity were examined using assay kits. The PI3K, mTOR, Akt, ERK1/2, JNK1/2, and p38 expressions in the cirsilineol-supplemented C6 cells were examined by RT-PCR study.ResultsThe cirsilineol treatment appreciably scavenged the DPPH, superoxide, and peroxyl radicals. The cell viability of C6 cells was markedly reduced by the cirsilineol; however, it does not affected the Vero cell viability. The cirsilineol treatment demonstrated the augmented ROS production and apoptosis in the C6 cells. The TBARS level and caspase activity were improved, and GSH level and SOD activity were depleted by the cirsilineol. Cirsilineol effectively inhibited PI3K, mTOR, Akt, ERK1/2, JNK1/2, and p38 expressions in the C6 cells.ConclusionOur findings confirmed that the cirsilineol inhibited cell growth and induced apoptosis in C6 cells by inhibiting the PI3K/Akt/mTOR and MAPK signaling cascades. Hence, it can be a potential candidate to treat the glioma in the future.

Helicid Improves Lipopolysaccharide-Induced Apoptosis of C6 Cells by Regulating SH2D5 DNA Methylation via the CytC/Caspase9/Caspase3 Signaling Pathway.

DNA methylation is reportedly associated with stress responses and depression. Treatment with antidepressants can regulate DNA methylation and, subsequently, gene expression in the hippocampus. Hence, DNA methylation is a potential target for treatment of depression. Screening of high-throughput data of a rat model of chronic unpredictable mild stress revealed relatively low expression of SH2 domain-containing 5 (SH2D5). SH2D5 can be overexpressed by treatment with helicid. Therefore, in order to further explore the role of SH2D5 in depression and whether helicid mediates the DNA methylation of SH2D5 as a potential antidepressant role, SH2D5 was overexpressed in C6 cells as a lipopolysaccharides (LPS)-induced model of depression. The expression levels of Bax, Bcl-2, Bad, and Daxx, and changes to the CytC/caspase9/caspase3 signal pathway were detected by qRT-PCR and Western blot analyses. After treatment with helicid or silencing of SH2D5, the above indices were detected. The results showed that helicid regulated the CytC/caspase9/caspase3 signaling pathway and improved the apoptosis indices of C6 cells through the overexpression of SH2D5. Interestingly, silencing of SH2D5 reversed the effects of helicid on the above indices. Then, in order to study the underlying mechanism, the cells were administered to helicid or 5-aza-2′-deoxycytidine (5-AzaD) and expression of SH2D5 was detected by qRT-PCR and Western blot analyses, while to assess the DNA methylation level of SH2D5 using bisulfite sequencing/PCR. The results showed that SH2D5 was hypermethylated with low expression in LPS-induced C6 cells, which was reversed by helicid and 5-AzaD. These results suggest that helicid may affect the CytC/caspase9/caspase3 apoptosis signaling pathway and improve the apoptosis indices by mediating DNA methylation of SH2D5.

Neuroimmunomodulatory Properties of Flavonoids and Derivates: A Potential Action as Adjuvants for the Treatment of Glioblastoma.

Glioblastomas (GBMs) are tumors that have a high ability to migrate, invade and proliferate in the healthy tissue, what greatly impairs their treatment. These characteristics are associated with the complex microenvironment, formed by the perivascular niche, which is also composed of several stromal cells including astrocytes, microglia, fibroblasts, pericytes and endothelial cells, supporting tumor progression. Further microglia and macrophages associated with GBMs infiltrate the tumor. These innate immune cells are meant to participate in tumor surveillance and eradication, but they become compromised by GBM cells and exploited in the process. In this review we discuss the context of the GBM microenvironment together with the actions of flavonoids, which have attracted scientific attention due to their pharmacological properties as possible anti-tumor agents. Flavonoids act on a variety of signaling pathways, counteracting the invasion process. Luteolin and rutin inhibit NFκB activation, reducing IL-6 production. Fisetin promotes tumor apoptosis, while inhibiting ADAM expression, reducing invasion. Naringenin reduces tumor invasion by down-regulating metalloproteinases expression. Apigenin and rutin induce apoptosis in C6 cells increasing TNFα, while decreasing IL-10 production, denoting a shift from the immunosuppressive Th2 to the Th1 profile. Overall, flavonoids should be further exploited for glioma therapy.

Ethanolic Leaf Extract of C. angustifolia Instigates ROS Mediated Apoptosis within Glioblastoma C6 Cells.

Glioblastoma multiforme or GBM is a destructive malignancy of the central nervous system and is accountable for leading cause of cancer related mortality. Inadequate success rate of surgical interventions and development of resistance towards the current therapeutical regime provides impetus for exploring novel therapeutical interventions against the disease. Recently, several epidemiological studies have explored the plausible utility of natural, dietary compounds in influencing the development, progression, and cancer metastasis. Recently, different phytoconstituents of Cassia angustifolia were found to be associated with anti-microbial, anti-cancer and anti-inflammatory effects. Therefore, the aim of the present study was to evaluate the anti-proliferative efficacy of ethanolic leaf extract of C. angustifolia (LCaEt-OH) against rat derived glioblastoma C6 cells. Briefly, the anti-proliferative potential of LCaEt-OH was assessed using MTT assay, quantitative estimation of ROS, and evaluation of mitochondrial membrane potential (ΔΨm). Moreover, the activity of caspases involved in intrinsic apoptotic pathways was also investigated using colorimetric kit followed by quantitative RT-PCR evaluation of modulation in gene expressions triggered due to LCaEt-OH treatment. Treatment of LCaEt-OH on C6 cells elucidated substantial dose-dependent decline in cellular viability. Furthermore, LCaEt-OH showed its efficacy in substantially enhancing intracellular ROS. LCaEt-OH also incited apoptosis in C6 cells by instigating nuclear condensation and dissipation of ΔΨm. In addition, LCaEt-OH mediated instigation of apoptosis was directly influenced by increased activity of caspases indispensable for intrinsic apoptotic pathway. These conclusive evidences indicate towards anticancer efficacy of LCaEt-OH against C6 cells.

Platelet-Tumor Cell Hybrid Membrane-Camouflaged Nanoparticles for Enhancing Therapy Efficacy in Glioma.

PurposeCell membrane-camouflaged nanoparticles (NPs) are drawing increasing attention because their surfaces acquire some characteristics of the cell membranes, making them a unique class of biomimetic materials for diverse applications. Modification of cell membrane or combination of different types of membranes can enhance their functionality.MethodsWe prepared platelet and tumor cell membrane camouflaged β-mangostin-loaded NPs, which were synthesized with platelet–C6 hybrid biomimetic coating, poly(lactic-co-glycolic acid), and β-mangostin (β-PCNPs). Then, we evaluated their targeting ability and anticancer activity against glioma in vitro and in vivo.ResultsBiomimetic coating enhanced active drug targeting and immune escape properties of nanocarrier in C6 and THP-1 cells, respectively, which improved their cytotoxicity. β-PCNPs were characterized to study the inherent properties of both source cells. Compared with bare β-NPs, β-PCNPs exhibited high tumor-targeting capability and induced apoptosis of C6 cells in vitro. Similarly, intravenous administration of drug through β-PCNPs resulted in enhanced tumor-targeting and exhibited excellent rate of inhibition of glioma tumor growth in mice. Moreover, the blood circulation time of drug in mice in the β-PCNP group was markedly prolonged and these mice exhibited better outcome than those in the β-NP group.ConclusionThese results provide a new strategy of utilizing PCNPs as carriers for drug delivery, which improves the targeting efficiency and therapeutic efficacy of chemotherapeutic agents for glioma therapy.

Systems Pharmacology-Based Dissection of Anti-Cancer Mechanism of Traditional Chinese Herb Saussurea involucrata.

Cancer has the highest mortality in humans worldwide, and the development of effective drugs remains a key issue. Traditional Chinese medicine Saussurea involucrata (SI) exhibits a series of effects, such as anti-cancer, but the action mechanisms are still unclear. Here, systems pharmacology was applied to reveal its anti-cancer mechanism. First, we screened the active compounds of SI. Then, the compound–target network, target–disease network, and target–pathway network were constructed. DAVID was applied for GOBP analysis and KEGG pathway enrichment analysis on cancer-related targets. Seven potential compounds and 187 targets were identified. The target–disease classification network showed that compounds mainly regulated proteins related to cancer, nervous system diseases, and cardiovascular system diseases. Also, SI anti-tumor effect mainly associated with the regulation of NO production, angiogenesis, MAPK, and PKB from GOBP enrichment. Additionally, KEGG pathway enrichment indicated that targets involved in anti-inflammatory action, inhibiting angiogenesis and anti-proliferation or inducing apoptosis. Experimental validation showed that four active compounds could inhibit cell proliferation and promote apoptosis in A549 (except for kaempferol), PC-3, and C6 cells. This study not only provides experimental evidence for further research on SI in cancer treatment but also promotes the development of potential drugs of SI in modern medicine.

Xanthohumol-Induced Rat Glioma C6 Cells Death by Triggering Mitochondrial Stress.

AIM: To investigate the underlying mechanisms of xanthohumol (XN) on the proliferation inhibition and death of C6 glioma cells. METHODS: To determine the effects of XN on C6 cells, cell proliferation and mortality after XN treatment were assessed by SRB assay and trypan blue assay respectively. Apoptotic rates were evaluated by flowcytometry after Annexin V-FITC/PI double staining. The influence of XN on the activity of caspase-3 was determined by Western blot (WB); and nuclear transposition of apoptosis-inducing factor (AIF) was tested by immunocytochemistry and WB. By MitoSOXTM staining, the mitochondrial ROS were detected. Mitochondrial function was also tested by MTT assay (content of succinic dehydrogenase), flow cytometry (mitochondrial membrane potential (MMP)—JC-1 staining; mitochondrial abundance—mito-Tracker green), immunofluorescence (MMP—JC-1 staining; mitochondrial morphology—mito-Tracker green), WB (mitochondrial fusion-fission protein—OPA1, mfn2, and DRP1; mitophagy-related proteins—Pink1, Parkin, LC3B, and P62), and high-performance liquid chromatography (HPLC) (energy charge). Finally, mitochondrial protein homeostasis of C6 cells after XN treatment with and without LONP1 inhibitor bortezomib was investigated by trypan blue assay (proliferative activity and mortality) and WB (mitochondrial protease LONP1). All cell morphology images were taken by a Leica Microsystems microscope. RESULTS: XN could lead to proliferation inhibition and death of C6 cells in a time- and dose-dependent manner and induce apoptosis of C6 cells through the AIF pathway. After long incubation of XN, mitochondria of C6 cells were seriously impaired, and mitochondria had a diffuse morphology and mitochondrial ROS were increased. The content of succinic dehydrogenase per cell was significantly decreased after XN insults of 24, 48, and 72 h. The energy charge was weakened after XN insult of 24 h. Furthermore, the MMP and mitochondrial abundance were significantly decreased; the protein expression levels of OPA1, mfn2, and DRP1 were down-regulated; and the protein expression levels of Pink1, Parkin, LC3B-II/LC3B-I, and p62 were up-regulated in long XN incubation times (24, 48, and 72 h). XN incubation with bortezomib for 48 h resulted in lower proliferative activity and higher mortality of C6 cells and caused the cell to have visible vacuoles. Moreover, the protein expression levels of LONP1 was up-regulated gradually as XN treatment time increased. CONCLUSION: These data supported that XN could induce AIF pathway apoptosis of the rat glioma C6 cells by affecting the mitochondria.

Hyaluronic Acid-Conjugated Nanoparticles for the Targeted Delivery of Cabazitaxel to CD44-Overexpressing Glioblastoma Cells.

In decades, the efficiency of glioma therapy is far from satisfaction due to the inability of most therapeutics to accumulate at the glioblastoma (GBM) site. Therefore, it is urgent to develop novel tumor-targeted delivery systems for more optimized and effective glioma treatment. In this study, hyaluronic acid modified MPEG-PDLLA polymer (HAML) nanoparticles were used to encapsulate the cabazitaxel (Cab), creating Cab loaded HAML nanoparticles (Cab/HAML NPs) for glioma therapy both in vitro and in vivo. MTT assay and apoptotic study indicated Cab/HAML NPs induced a significant cell growth inhibition and more apoptosis of C6 cells than free Cab in vitro. In vivo study showed that Cab/HAML NPs could significantly improve chemotherapeutic effect to C6 tumor-bearing rats compared with free Cab. The median survival rate of Cab/HAML NPs-treated groups (30 days) was remarkably longer than the other groups treated with control (20 days), free Cab (19 days) and Cab/ML NPs (26 days). Immunohistochemical analysis revealed that Cab/HAML NPs improved Cab's anti-tumor effect via improvement of tumor cell apoptosis, inhibition of tumor cell proliferation and a significant decrease in tumor angiogenesis. Together, our study suggested that Cab/HAML NPs might show promise for application to glioma therapy.

Angiopep-2 modified lipid-coated mesoporous silica nanoparticles for glioma targeting therapy overcoming BBB

Glioma is the most typical malignant brain tumor, and the chemotherapy to glioma is limited by poor permeability for crossing blood-brain-barrier (BBB) and insufficient availability. In this study, angiopep-2 modified lipid-coated mesoporous silica nanoparticle loading paclitaxel (ANG-LP-MSN-PTX) was developed to transport paclitaxel (PTX) across BBB mediated by low-density lipoprotein receptor-related protein 1 (LRP1), which is over-expressed on both BBB and glioma cells. ANG-LP-MSN-PTX was characterized with homogeneous hydrodynamic size, high drug loading capacity (11.08%) and a sustained release. In vitro experiments demonstrated that the targeting efficiency of PTX was enhanced by ANG-LP-MSN-PTX with higher penetration ability (10.74%) and causing more C6 cell apoptosis. ANG-LP-MSN-PTX (20.6%) revealed higher targeting efficiency compared with LP-MSN-PTX (10.6%) via blood and intracerebral microdialysis method in the pharmacokinetic study. The therapy of intracranial C6 glioma bearing rats was increasingly efficient, and ANG-LP-MSN-PTX could prolong the survival time of model rats. Taken together, ANG-LP-MSN-PTX might hold great promise as a targeting delivery system for glioma treatment.

Synergetic therapy of glioma mediated by a dual delivery system loading \u03b1-mangostin and doxorubicin through cell cycle arrest and apoptotic pathways

Two of the biggest hurdles in the deployment of chemotherapeutics against glioma is a poor drug concentration at the tumor site and serious side effects to normal tissues. Nanocarriers delivering different drugs are considered to be one of the most promising alternatives. In this study, a dual delivery system (methoxy poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL)) loaded with α-mangostin (α-m) and doxorubicin (Dox) was decorated and constructed by self-assembly to determine its ability to treat glioma. Molecular dynamics simulations showed that MPEG-PCL could provide ideal interaction positions for both α-m and Dox, indicating that the two drugs could be loaded into MPEG-PCL. Based on the in vitro results, MPEG-PCL loaded with α-m and Dox (α-m-Dox/M) with a size of 25.68 nm and a potential of −1.51 mV was demonstrated to significantly inhibit the growth and promote apoptosis in Gl261, C6 and U87 cells, and the effects of the combination were better than each compound alone. The mechanisms involved in the suppression of glioma cell growth were blockage of the cell cycle in S phase by inhibition of CDK2/cyclin E1 and promotion of apoptosis through the Bcl-2/Bax pathway. The synergetic effects of α-m-Dox/M effectively inhibited tumor growth and prolonged survival time without toxicity in mouse glioma models by inducing glioma apoptosis, inhibiting glioma proliferation and limiting tumor angiogenesis. In conclusion, a codelivery system was synthesized to deliver α-m and Dox to the glioma, thereby suppressing the development of glioma by the mechanisms of cell cycle arrest and cellular apoptosis, which demonstrated the potential of this system to improve the chemotherapy response of glioma.

Neuro-protective roles of long non-coding RNA MALAT1 in Alzheimer's disease with the involvement of the microRNA-30b/CNR1 network and the following PI3K/AKT activation

Long non-coding RNAs (lncRNAs) have been increasingly found to fulfill key functions in neurodegenerative diseases. This study aimed to probe the function of lncRNA MALAT1 in neuronal recovery in Alzheimer's disease (AD). Aβ25-35 was used to induce AD in a rat model and neuronal injury in PC12 and C6 cells. Aberrantly expressed lncRNAs/microRNAs (miRNAs) in AD rats were screened out by microarray analyses. Altered expression of MALAT1, miR-30b and CNR1 was performed to explore their roles in neuronal recovery in rat and cell models. Consequently, LncRNA MALAT1 and CNR1 were poorly expressed while miR-30b was highly expressed in Aβ25-35-induced rat models and cells. Overexpression of MALAT1 or CNR1 reduced neuronal injury in rat hippocampus. It increased viability and decreased apoptosis in injured PC12 and C6 cells, and decreased the secretion of pro-inflammatory factor IL-6 and TNF-α but increased IL-10 production. However, overexpression of miR-30b reversed these trends. MALAT1 could served as a sponge for mR-30b to up-regulate CNR1 expression. The phosphorylation of PI3K and AKT was stimulated when MALAT1 or CNR1 was overexpressed. To sum up, we found MALAT1 could promote neuronal recovery following AD through the miR-30b/CNR1 network and the PI3K/AKT signaling activation.