Growth Of U87MG Cells Research Articles

Iloperidone and Temozolomide Synergistically Inhibit Growth, Migration and Enhance Apoptosis in Glioblastoma Cells.

Glioblastoma (GBM) is a fatal astrocytic glioma with poor prognosis and treatment resistance. Repurposing potential FDA-approved drugs like anti-psychotics can address the concerns in a timely and cost-effective manner. Epidemiological studies have shown that patients with schizophrenic using anti-psychotics have a low incidence of GBM. Therefore, we aimed to investigate the therapeutic potential of atypical anti-psychotic Iloperidone (ILO) alone and in combination with Temozolomide (TMZ) against GBM. The study assessed the growth inhibitory effect of ILO, TMZ, and their combination (ILO + TMZ) on U-87MG and T-98G cell lines using an MTT assay. The drug interaction coefficient (CDI) was determined, and doses with synergistic effects were used for subsequent experiments, including migratory, invasion, and TUNEL assays. The expressions of DRD2, β-catenin, Dvl2, Twist, and Slug were assessed by RTq-PCR, whereas the β-catenin protein expression was also determined by immunocytochemistry. ILO (p < 0.05) and TMZ (p < 0.01) significantly inhibited the growth of U-87MG cells at all tested doses. The combination of 60 µM of both drugs showed synergistic activity with CDI < 1. The inhibition of migration and apoptosis was more pronounced in the case of combination treatment (p < 0.001). Inhibition of the invading cells was also found to be significant in ILO- and combination-treated groups (p < 0.001). ILO and combination treatment also significantly downregulated the expression of DRD2, while TMZ upregulated the expression (p < 0.001). The expressions of β-catenin (p < 0.001), Dvl2 (p < 0.001), Twist (p < 0.001), and Slug (p < 0.001) were also significantly downregulated in all treatment groups as compared to the vehicle control. The data suggest that ILO possesses strong growth inhibitory activity, possibly due to its effect on DRD2 and β-catenin expression and has the potential to be repurposed against GBM.

5-Demethylnobiletin mediates cell cycle arrest and apoptosis via the ERK1/2/AKT/STAT3 signaling pathways in glioblastoma cells.

5-Demethylnobiletin is the active ingredient in citrus polymethoxyflavones that could inhibit the proliferation of several tumor cells. However, the anti-tumor effect of 5-Demethylnobiletin on glioblastoma and the underlying molecular mechanisms are remains unknown. In our study, 5-Demethylnobiletin markedly inhibited the viability, migration and invasion of glioblastoma U87-MG, A172 and U251 cells. Further research revealed that 5-Demethylnobiletin induces cell cycle arrest at the G0/G1 phase in glioblastoma cells by downregulating Cyclin D1 and CDK6 expression levels. Furthermore, 5-Demethylnobiletin significantly induced glioblastoma cells apoptosis by upregulating the protein levels of Bax and downregulating the protein level of Bcl-2, subsequently increasing the expression of cleaved caspase-3 and cleaved caspase-9. Mechanically, 5-Demethylnobiletin trigged G0/G1 phase arrest and apoptosis by inhibiting the ERK1/2, AKT and STAT3 signaling pathway. Furthermore, 5-Demethylnobiletin inhibition of U87-MG cell growth was reproducible in vivo model. Therefore, 5-Demethylnobiletin is a promising bioactive agent that might be used as glioblastoma treatment drug.

Transmembrane Protein TMEM230, a Target of Glioblastoma Therapy.

Glioblastomas (GBM) are the most aggressive tumors originating in the brain. Histopathologic features include circuitous, disorganized, and highly permeable blood vessels with intermittent blood flow. These features contribute to the inability to direct therapeutic agents to tumor cells. Known targets for anti-angiogenic therapies provide minimal or no effect in overall survival of 12–15 months following diagnosis. Identification of novel targets therefore remains an important goal for effective treatment of highly vascularized tumors such as GBM. We previously demonstrated in zebrafish that a balanced level of expression of the transmembrane protein TMEM230/C20ORF30 was required to maintain normal blood vessel structural integrity and promote proper vessel network formation. To investigate whether TMEM230 has a role in the pathogenesis of GBM, we analyzed its prognostic value in patient tumor gene expression datasets and performed cell functional analysis. TMEM230 was found necessary for growth of U87-MG cells, a model of human GBM. Downregulation of TMEM230 resulted in loss of U87 migration, substratum adhesion, and re-passaging capacity. Conditioned media from U87 expressing endogenous TMEM230 induced sprouting and tubule-like structure formation of HUVECs. Moreover, TMEM230 promoted vascular mimicry-like behavior of U87 cells. Gene expression analysis of 702 patients identified that TMEM230 expression levels distinguished high from low grade gliomas. Transcriptomic analysis of patients with gliomas revealed molecular pathways consistent with properties observed in U87 cell assays. Within low grade gliomas, elevated TMEM230 expression levels correlated with reduced overall survival independent from tumor subtype. Highest level of TMEM230 correlated with glioblastoma and ATP-dependent microtubule kinesin motor activity, providing a direction for future therapeutic intervention. Our studies support that TMEM230 has both glial tumor and endothelial cell intracellular and extracellular functions. Elevated levels of TMEM230 promote glial tumor cell migration, extracellular scaffold remodeling, and hypervascularization and abnormal formation of blood vessels. Downregulation of TMEM230 expression may inhibit both low grade glioma and glioblastoma tumor progression and promote normalization of abnormally formed blood vessels. TMEM230 therefore is both a promising anticancer and antiangiogenic therapeutic target for inhibiting GBM tumor cells and tumor-driven angiogenesis.

In vitro Activity of Novel Cannabinoids Derived from Tetrahydrocannabinolic Acid on Various Human Tumor Cell Lines

The in vitro study of tetracannabinolic acid (THCA) derivatives ALAM027 and ALAM108 was carried out on the following human tumor cells: T47D (breast, ductal carcinoma), PC-3 (prostate, adenocarcinoma), HT29 (colorectal carcinoma), Caco-2 (colon, adenocarcinoma), A549 (lung, carcinoma), U87MG (human glioblastoma) and U266B1 (multiple myeloma). The in vitro effects of THCA derivatives ALAM027 and ALAM108 on cell growth inhibition and IC50 values were measured using the CellTiter Glo assay. The ALAM027 compound showed good growth inhibition in all cell lines tested with the exception of U87MG cells. The ALAM108 compound also suppressed the growth of U87 MG cells but had little effect on T47D tumor cells. In vitro studies of THCA derivatives ALAM027 and ALAM108 showed antitumor activity in all cell lines tested. The difference in the activity of these compounds in relation to the T47D and U87MG tumor cells may be indicative of different functional mechanisms.

Tumstatin attenuates the promotion effect of IL-17 secreted by Th17 cells on the stemness maintenance of glioma cells

The presence and clinical significance of IL-17 and IL-17-expressing cells have been studied for several cancers, although their correlation with tumor development remains controversial. Peripheral blood was collected from healthy donors and glioma patients to isolate peripheral blood mononuclear cells (PBMCs). The percentage of IL-17-expressing cells and the production of inflammatory cytokines in PBMCs and tissues were measured. Human IL‑17 cDNA was then inserted into the pEGFP‑N1 plasmid and transfected into the glioma U87MG cell line, and tumstatin was used to block the effect of the IL-17 overexpression. Stem cell transcription factors were evaluated in each group using qRT-PCR and western blotting, and proliferation and migration were detected using colony formation and wound-healing assays. The cells were then subcutaneously inoculated into nude mice to evaluate the growth of glioma. Compared with healthy donors, the PBMCs from glioma patients showed a significant accumulation of IL-17-expressing T cells. Th17 cell differentiation-related cytokines (IL-23, TGF-β and IL-6) were increased in the tumor microenvironment. IL‑17 transfection increased the mRNA and protein expression of stem cell transcription factors in U87MG cells in vitro. The proliferation and migration of U87MG cells were also increased. Moreover, the pEGFP‑N1‑IL‑17‑U87MG cells grew more rapidly than other cells. However, tumstatin-treated U87MG cells showed significantly inhibited the effects of IL-17 overexpression. Tumstatin effectively suppressed IL-17-derived U87MG cell growth by downregulating stem cell maintenance factors and inducing proliferation and migration. These findings indicated that IL-17 represents a potential prognostic marker for glioma, while tumstatin has potential in the treatment for glioma.

Hyaluronic acid conjugated albumin nanoparticles for efficient receptor mediated brain targeted delivery of temozolomide

In the present investigation, temozolomide (TMZ) loaded albumin nanoparticles (TNPs) were prepared by desolvation method and optimized by Box-Behnken design. Hyaluronic acid (HA) was used to modify the surface of TNPs to achieve CD44 receptor mediated targeting (HA-TNPs). The developed nanoparticles were characterized and evaluated using various in vitro and in vivo techniques. HA-TNPs were able to cross the blood brain barrier (BBB) as demonstrated in BBB passage study performed on monolayer and co-culture models. Cell viability assay demonstrated superior suppression of growth of U87 MG cells by HA-TNPs as compared to pure drug. HA-TNPs were able to generate reactive oxygen species (ROS) in U87 MG cells and their uptake was both endocytosis mediated (caveolae pathway) and CD44 receptor mediated as confirmed by CD44 receptor blocking study. In vivo results showed improvement in pharmacokinetics of TMZ as significant enhancement in plasma AUC, t1/2 and MRT from HA-TNPs was observed as compared to TMZ alone. Biodistribution results demonstrated higher accumulation of TMZ in brain and significant decrease of drug in other vital organs like liver and lungs by HA-TNPs as compared to pure drug. From all these results, it was concluded that HA-TNPs have potential to target brain tumor more specifically as compared to pure TMZ and may act as a promising targeted delivery platform.

Transcriptomics predicts compound synergy in drug and natural product treated glioblastoma cells.

Pathway analysis is an informative method for comparing and contrasting drug-induced gene expression in cellular systems. Here, we define the effects of the marine natural product fucoxanthin, separately and in combination with the prototypic phosphatidylinositol 3-kinase (PI3K) inhibitor LY-294002, on gene expression in a well-established human glioblastoma cell system, U87MG. Under conditions which inhibit cell proliferation, LY-294002 and fucoxanthin modulate many pathways in common, including the retinoblastoma, DNA damage, DNA replication and cell cycle pathways. In sharp contrast, we see profound differences in the expression of genes characteristic of pathways such as apoptosis and lipid metabolism, contributing to the development of a differentiated and distinctive drug-induced gene expression signature for each compound. Furthermore, in combination, fucoxanthin synergizes with LY-294002 in inhibiting the growth of U87MG cells, suggesting complementarity in their molecular modes of action and pointing to further treatment combinations. The synergy we observe between the dietary nutraceutical fucoxanthin and the synthetic chemical LY-294002 in producing growth arrest in glioblastoma, illustrates the potential of nutri-pharmaceutical combinations in targeting this challenging disease.

Over-expression of miR-187 inhibited cell proliferation and metastasis of glioma via down-regulating SMAD1.

MicroRNAs (miRNAs) have been identified to participate in the tumorigenesis and progression of glioma. However, the expression and function of miR-187 have not been fully elucidated in glioma so far. Therefore, the aim of this study was to investigate the role of miR-187 in glioma and to explore the possible underlying mechanism. The expression levels of miR-187 in 67 glioma tissues and 21 normal brain tissues, as well as 4 glioma-derived cell lines were measured using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). MiR-187 was overexpressed or inhibited in U251 or U87MG cells using miR-187 mimics or inhibitor transfection, respectively. Colony formation assay and Cell Counting Kit-8 (CCK-8) assay were employed to detect the proliferation ability of cells. Meanwhile, transwell assay and wound-healing assay were applied to evaluate the invasion and migration capacities of cells. Furthermore, Dual-Luciferase assay and Western blot analysis were used to verify the downstream target gene of miR-187 in glioma. MiR-187 expression was significantly lower in glioma tissues and cells when compared with normal brain tissues and cell lines. Up-regulation of miR-187 markedly reduced the proliferation, migration and invasion of U251 cells compared with the negative control group. However, down-regulation of miR-187 remarkably accelerated U87MG cell growth and metastasis compared with inhibitor negative control group. Furthermore, SMAD1 was identified as a direct target for miR-187 in glioma, which could be repressed by miR-187. In addition, over-expression of SMAD1 restored the influence of miR-187 mimics in glioma cells. MiR-187 was lowly expressed in glioma tissues and cell lines. Acting as a tumor suppressor, miR-187 inhibited cell growth, invasion, and migration in glioma via repressing SMAD1 expression. Our findings might provide a novel insight into the biological diagnosis and treatment in glioma.

Abstract 256: Repurposing neuroleptic drug for brain tumor therapy

Abstract Brain tumor is considered as one of the most aggressive and incurable form of cancer. Majority of the brain tumors have a median survival rate of only 12%. Even though advanced treatments such as surgical removal, chemotherapy and radiotherapy are available, brain tumor persists to be lethal. Temozolomide (TMZ) is the main therapy for brain tumor but resistance to TMZ is the major cause of treatment failure. This resistance in tumor cells has frequently been linked to the expression of O6-methylguanine-DNA methyltransferase (MGMT). Pimozide (PMZ) is a neuroleptic drug used for the treatment of schizophrenia and chronic psychosis. In our study, we observed that pimozide significantly reduced the viability of U87MG, U251MG, DAOY and GBM28 cell lines with an IC50 ranging from 11µM to 20µM after 24 h of treatment. Pimozide induced apoptosis in these cell lines as evaluated by FITC/Annexin assay and further validated by the cleavage of caspase 3 as well as PARP. Western blot analysis resulted in the concentration dependent decrease in the expression of STAT3 signaling mainly targeting the anti-apoptotic markers BCl-XL, BCl-2 and Survivin etc in U87MG, U251MG, DAOY and GBM28 brain cancer cell lines. PMZ alone suppressed the growth of U87MG cells with an IC50 of 10µM, after 96 hours of treatment. On the other hand, treatment of U87MG cells with 750 µM of TMZ in combination with 10µM PMZ for 96 hours increased the killing of U87MG cells by 50% as compared to 10% when treated with TMZ. In addition, PMZ treatment reduced the survival of TMZ resistant U251R cells with an IC50 ranging from 15-20 µM after 24 h of treatment. Our results further demonstrated that oral administration of PMZ (25mg/kg) significantly inhibits the growth of brain tumors in an intracranial tumor model without any apparent signs of toxicity. It is important to note that PMZ is an FDA approved drug with no considerable toxicity. Overall, this study depicts that PMZ is a potential candidate to target brain tumors. Citation Format: Iti S. Kaushik, Alok Ranjan, Blake Schwettmann, Sanjay Srivastava. Repurposing neuroleptic drug for brain tumor therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 256.

NFBTA: A Potent Cytotoxic Agent against Glioblastoma.

Piplartine (PPL), also known as piperlongumine, is a biologically active alkaloid extracted from the Piper genus which has been found to have highly effective anticancer activity against several tumor cell lines. This study investigates in detail the antitumoral potential of a PPL analogue; (E)-N-(4-fluorobenzyl)-3-(3,4,5-trimethoxyphenyl) acrylamide (NFBTA). The anticancer potential of NFBTA on the glioblastoma multiforme (GBM) cell line (U87MG) was determined by 3-(4,5-dimethyl-2-thia-zolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT), and lactate dehydrogenase (LDH) release analysis, and the selectivity index (SI) was calculated. To detect cell apoptosis, fluorescent staining via flow cytometry and Hoechst 33258 staining were performed. Oxidative alterations were assessed via colorimetric measurement methods. Alterations in expressions of key genes related to carcinogenesis were determined. Additionally, in terms of NFBTA cytotoxic, oxidative, and genotoxic damage potential, the biosafety of this novel agent was evaluated in cultured human whole blood cells. Cell viability analyses revealed that NFBTA exhibited strong cytotoxic activity in cultured U87MG cells, with high selectivity and inhibitory activity in apoptotic processes, as well as potential for altering the principal molecular genetic responses in U87MG cell growth. Molecular docking studies strongly suggested a plausible anti-proliferative mechanism for NBFTA. The results of the experimental in vitro human glioblastoma model and computational approach revealed promising cytotoxic activity for NFBTA, helping to orient further studies evaluating its antitumor profile for safe and effective therapeutic applications.

NOS2 inhibitor 1400W Induces Autophagic Flux and Influences Extracellular Vesicle Profile in Human Glioblastoma U87MG Cell Line.

The relevance of nitric oxide synthase 2 (NOS2) as a prognostic factor in Glioblastoma Multiforme (GBM) malignancy is emerging. We analyzed the effect of NOS2 inhibitor 1400W on the autophagic flux and extracellular vesicle (EV) secretion in U87MG glioma cells. The effects of glioma stem cells (GSC)-derived EVs on adherent U87MG were evaluated. Cell proliferation and migration were examined while using Cell Counting Kit-8 assay (CCK-8) and scratch wound healing assay. Cell cycle profile and apoptosis were analyzed by flow cytometry. Autophagy-associated acidic vesicular organelles were detected and quantified by acridine orange staining. The number and size of EVs were assessed by nanoparticle tracking analysis. EV ultrastructure was verified by transmission electron microscopy (TEM). WB was used to analyze protein expression and acid sphingomyelinase was determined through ceramide levels. 1400W induced autophagy and EV secretion in both adherent U87MG and GSCs. EVs secreted by 1400W-treated GSC, but not those from untreated cells, were able to inhibit adherent U87MG cell growth and migration while also inducing a relevant level of autophagy. The hypothesis of NOS2 expression as GBM profile marker or interesting therapeutic target is supported by our findings. Autophagy and EV release following treatment with the NOS2 inhibitor could represent useful elements to better understand the complex biomolecular frame of GBM.

Repurposing neuroleptic drug for brain tumor therapy

Brain tumor is considered as one of the most aggressive and incurable form of cancer. Majority of the brain tumors have a median survival rate of only 12%. Even though advanced treatments such as surgical removal, chemotherapy and radiotherapy are available, brain tumor persists to be lethal. Temozolomide (TMZ) is the main therapy for brain tumor but resistance to TMZ is the major cause of treatment failure. This resistance in tumor cells has frequently been linked to the expression of O6‐methylguanine‐DNA methyltransferase (MGMT). Pimozide (PMZ) is a neuroleptic drug used for the treatment of schizophrenia and chronic psychosis. In our study, we observed that pimozide significantly reduced the viability of U87MG, U251MG, DAOY and GBM28 cell lines with an IC50 ranging from 11μM to 20μM after 24 h of treatment. Pimozide induced apoptosis in these cell lines as evaluated by FITC/Annexin assay and further validated by the cleavage of caspase 3 as well as PARP. Western blot analysis resulted in the concentration dependent decrease in the expression of STAT3 signaling mainly targeting the anti‐apoptotic markers BCl‐XL, BCl‐2 and Survivin etc in U87MG, U251MG, DAOY and GBM28 brain cancer cell lines. PMZ alone suppressed the growth of U87MG cells with an IC50 of 10μM, after 96 hours of treatment. On the other hand, treatment of U87MG cells with 750 μM of TMZ in combination with 10μM PMZ for 96 hours increased the killing of U87MG cells by 50% as compared to 10% when treated with TMZ. In addition, PMZ treatment reduced the survival of TMZ resistant U251R cells with an IC50 ranging from 15–20 μM after 24 h of treatment. Our results further demonstrated that oral administration of PMZ (25mg/kg) significantly inhibits the growth of brain tumors in an intracranial tumor model without any apparent signs of toxicity. It is important to note that PMZ is an FDA approved drug with no considerable toxicity. Overall, this study depicts that PMZ is a potential candidate to target brain tumors.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Shikonin inhibits proliferation and induces apoptosis in glioma cells via downregulation of CD147.

Shikonin, a traditional Chinese medicine, has been identified as being capable of inducing apoptosis in various tumors, including glioma, and is thus considered to be a promising therapeutic agent for tumor therapy. However, little is known about the molecular mechanism of shikonin in glioma. The present study investigated the influence of shikonin on the proliferation and apoptosis of glioma cells U251 and U87MG and explored the potential molecular mechanisms. It was identified that shikonin was able to induce apoptosis in human glioma cells in a time- and dose-dependent manner, and a decreased expression level of cluster of differentiation (CD)147 was observed in shikonin-treated U251 and U87MG cells. Knockdown of CD147 inhibited U251 and U87MG cell growth, whereas CD147 overexpression enhanced cell growth and decreased shikonin-induced apoptosis. Additionally, an increased expression level of CD147 suppressed the elevated production of reactive oxygen species and mitochondrial membrane potential levels induced by shikonin. The data indicated that shikonin-induced apoptosis in glioma cells was associated with the downregulation of CD147 and the upregulation of oxidative stress. CD147 may be an optional target of shikonin-induced cell apoptosis in glioma cells.

Nutraceutical phycocyanin nanoformulation for efficient drug delivery of paclitaxel in human glioblastoma U87MG cell line

To enhance the therapeutic efficacy of chemotherapy on glioblastoma U87MG cell line, paclitaxel-loaded phycocyanin nanoparticles (PTX-PcNPs) were prepared by modified desolvation process. PTX-PcNPs were characterised in terms of size, zeta potential, drug loading efficiency and drug release. Confocal laser scanning microscopy showed PTX-PcNPs could be internalised by U87MG cells. The anti-cancer activity was investigated in vitro by 3-(4,5-dimethylthizol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with and without photodynamic therapy. It was observed that formulation could significantly inhibit growth of U87MG cells as compared to PTX alone and also induced apoptosis, which was evidenced by presence of apoptotic bodies and nuclear fragmentation in treated cells. The present study suggests that PTX-PcNPs can act as a promising drug delivery system for cancer treatment.

219. Investigation of the Role of Decorin Gene (DCN) in Glioblastoma and Cancer Stem Cells (CSCs)

Glioblastoma multiforme (GBM) is the most malignant cancer in the central nervous system with poor clinical prognosis. In this study, we investigated the therapeutic effect of an anti-cancer protein, decorin, by delivering it into a xenograft U87MG glioma tumor in the brain of nude mice through an adeno-associated viral (AAV2) gene delivery system. Decorin expression from the AAV vector in vitro inhibited cultured U87MG cell growth by induction of cell differentiation. Intracranial injection of AAV-decorin vector to the glioma-bearing nude mice in vivo significantly suppressed brain tumor growth and prolonged survival when compared to control non-treated mice bearing the same U87MG tumors. Proteomics analysis on protein expression profiles in the U87MG glioma cells after AAV-mediated decorin gene transfer revealed up- and down-regulation of important proteins. Differentially expressed proteins between control and AAV-decorin-transduced cells were identified through MALDI-TOF MS and database mining. We found that a number of important proteins that are involved in apoptosis, transcription, chemotherapy resistance, mitosis, and fatty acid metabolism have been altered as a result of decorin overexpression. These findings offer valuable insight into the mechanisms of the anti-glioblastoma effects of decorin. In addition, AAV-mediated decorin gene delivery warrants further investigation as a potential therapeutic approach for brain tumors.

ER-α36, a novel variant of ERα, is involved in the regulation of Tamoxifen-sensitivity of glioblastoma cells

Although accumulating evidence has confirmed that adjuvant Tamoxifen (TAM) treatment is able to sensitize glioblastoma cells to radiotherapy and inhibit their proliferation, TAM is not a suitable treatment for all types of glioblastoma cells; furthermore, long-term TAM usage may lead to TAM resistance. Therefore, understanding the underlying molecular mechanism of TAM resistance is necessary in order to improve TAM clinical therapy and the quality of life of patients suffering from glioblastomas. In this study, the significance of ER-α36 to TAM resistance in glioblastoma cells was examined. First, an analysis of ER-α36 expression in two glioblastoma cell lines U87-MG and U251, showed that ER-α36 was anchored to the cytoplasmic membrane of these cells via Caveolin-1. Subsequent experiments investigating the mechanism of TAM-induced inhibition of U87-MG cell growth showed that TAM exerts its effect by inducing apoptosis via a down-regulation of Survivin expression and an up-regulation of Caspase-3 expression. Furthermore, TAM also arrested the cell cycle at S-phase. However, when U87-MG cells were preconditioned with an ER-α36-specific agonist, IC162, this neutralized TAM-induced inhibition of cell growth. This contrasted with the effect of ER-α36 depletion by RNAi, which enhanced TAM-induced inhibition of cell growth. These findings suggest that resistance to TAM involves ER-α36, which probably acts as a negative regulator of TAM-induced inhibition of glioblastoma cell growth. These findings provide a novel insight into the basis of TAM resistance during glioblastoma therapy and a further study is underway to reveal more about the specific molecular mechanisms associated with ER-α36-mediated TAM resistance.

Nanostructured lipid carriers based temozolomide and gene co-encapsulated nanomedicine for gliomatosis cerebri combination therapy

Background: Co-delivery of gene and anticancer drug into the same cancer cells or tissues by multifunctional nanocarriers may provide a new paradigm in cancer treatment. In this study, nanostructured lipid carriers (NLCs) were constructed as multifunctional nanomedicine for co-delivery of enhanced green fluorescence protein plasmid (DNA) and temozolomide (TMZ).Methods: TMZ- and DNA-loaded NLCs (TMZ/DNA-NLCs) were prepared. Their particle size, zeta potential, gene-loading capacity (GL) and drug encapsulation efficiency (EE) were evaluated. In vitro cytotoxicity study TMZ/DNA-NLCs was tested in U87 malignant glioma cells (U87 MG cells). In vivo gene transfection and anti-tumor efficacy of the carriers were evaluated on mice bearing malignant glioma model.Results: The optimum TMZ/DNA-NLCs formulations with the particle size of 179 nm and with a +23 mV surface charge; got 91% of GL and 83% of EE. The growth of U87 MG cells in vitro was obviously inhibited. TMZ/DNA-NLCs also displayed the highest gene transfection efficiency and the best antitumor activity than other formulations in vivo.Conclusion: The results demonstrated that TMZ/DNA-NLCs were efficient in selective delivery to malignant glioma cells. Also TMZ/DNA-NLCs transfer both drug and gene to the gliomatosis cerebri, enhance the antitumor capacity and gene transfection efficacy. Thus, TMZ/DNA-NLCs could prove to be a superior co-delivery nanomedicine to achieve therapeutic efficacy and this report could be a new promising strategy for treatment in malignant gliomatosis cerebri.

Fatsioside A inhibits the growth of glioma cells via the induction of endoplasmic reticulum stress-mediated apoptosis.

Malignant gliomas are a common type of primary tumor of the central nervous system. In spite of current intensive therapy, the prognosis of patients with malignant glioma remains poor, hence the development of novel therapeutic modalities is necessary. Cell apoptosis is a frequent target in the development of anti‑cancer drugs. Fatsioside A, a novel baccharane‑type triterpenoid glycoside, is extracted from the fruits of Fatsia japonica. Previous studies have shown that Fatsioside A induces growth inhibition, cell cycle arrest and apoptosis in C6 rat glioma cells and U251 human glioma cells. However, to the best of our knowledge, no detailed studies have reported its effect on U87MG glioma cells and its exact mechanisms remain unknown. In the current study, the growth inhibitory effect of Fatsioside A on U87MG cells was evaluated and the underlying molecular mechanisms were explored. Through the use of flow cytometry and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, it was determined that Fatsioside A markedly inhibits the growth of U87MG cells. Mechanistic studies demonstrated that Fatsioside A induces growth inhibition of U87MG cells via the induction of endoplasmic reticulum (ER) stress, which was supported by the upregulation of ER stress markers, including elevated levels of phosphorylation of PERK and eIF2α, the increased expression levels of CHOP and the accelerated cleavage of caspase‑4. The downregulation of CHOP via CHOP‑specific siRNA reduced the growth‑inhibitive effect of Fatsioside A on U87MG cells, further confirming the role of the ER stress response in mediating Fatsioside A‑induced growth inhibition. In conclusion, Fatsioside A inhibits glioma cell growth via the induction of ER stress‑mediated apoptosis. This may provide a molecular basis for the development of Fatsioside A into a drug candidate for the treatment of malignant glioma.

Targeting delivery of etoposide to inhibit the growth of human glioblastoma multiforme using lactoferrin- and folic acid-grafted poly(lactide-co-glycolide) nanoparticles

Lactoferrin (Lf) and folic acid (FA) were crosslinked on poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) for transporting etoposide across the blood–brain barrier (BBB) and treating human brain malignant glioblastoma. Lf- and FA-grafted PLGA NPs (Lf/FA/PLGA NPs) were employed to permeate the monolayer of human brain-microvascular endothelial cells (HBMECs) regulated by human astrocytes and to inhibit the multiplication of U87MG cells. Lf/FA/PLGA NPs showed a satisfactory entrapment efficiency of etoposide and characteristics of sustained drug release. When compared with PLGA NPs, the permeability coefficient for etoposide across the BBB using Lf/FA/PLGA NPs increased about twofold. The antiproliferative efficacy against the growth of U87MG cells was in the following order: Lf/FA/PLGA NPs>FA/PLGA NPs>PLGA NPs>free etoposide solution. In addition, the targeting ability of Lf/FA/PLGA NPs was evidenced by immunostaining of Lf receptor on HBMECs and folate receptor on U87MG cells during endocytosis. Lf/FA/PLGA NPs with loaded etoposide can be a promising anticancer pharmacotherapy to enhance the delivery of etoposide to malignant brain tumors for preclinical trials.

NIR photoregulated chemo- and photodynamic cancer therapy based on conjugated polyelectrolyte-drug conjugate encapsulated upconversion nanoparticles.

The design of nanoplatforms with target recognition and near-infrared (NIR) laser photoregulated chemo- and photodynamic therapy is highly desirable but remains challenging. In this work, we have developed such a system by taking advantage of a conjugated polyelectrolyte (CPE)-drug conjugate and upconversion nanoparticles (UCNPs). The poly(ethylene glycol) (PEG) grafted CPE not only serves as a polymer matrix for UCNP encapsulation, but also as a fluorescent imaging agent, a photosensitizer as well as a carrier for chemotherapeutic drug doxorubicin (DOX) through a UV-cleavable ortho-nitrobenzyl (NB) linker. Upon 980 nm laser irradiation, the UCNPs emit UV and visible light. The up-converted UV light is utilized for controlled drug release through the photocleavage of the ortho-nitrobenzyl linker, while the up-converted visible light is used to initiate the polymer photosensitizer to produce reactive oxygen species (ROS) for photodynamic therapy. The NIR photo-regulated UCNP@CPE-DOX showed high efficiency of ROS generation and controlled drug release in cancer cells upon single laser irradiation. In addition, the combination therapy showed enhanced inhibition of U87-MG cell growth as compared to sole treatments. As two light sources with different wavelengths are always needed for traditional photodynamic therapy and photoregulated drug release, the adoption of UCNPs as an NIR light switch is highly beneficial to combined chemo- and photodynamic therapy with enhanced therapeutic effects.