ATM Activation is Key in Vasculogenic Mimicry Formation by Glioma Stem-like Cells

Objective Vasculogenic mimicry(VM)is a novel vasculogenic process integral to glioma stem cells(GSCs)in glioblastoma(GBM).However,the relationship between VM and ataxia-telangiectasia mutated(ATM)serine/threonine kinase activation,which confers chemoradiotherapy resistance,remains unclear.Methods We investigated VM formation and phosphorylated ATM(pATM)levels by CD31/GFAPperiodic acid-Schiff dual staining and immunohistochemical staining in 145 GBM specimens.Glioma stem-like cells(GSLCs)derived from the formatted spheres of U87 and U251 cell lines and their pATM level and VM formation ability were examined using western blot and three-dimensional culture.For the examination of the function of pATM in VM formation by GSLCs,ATM knockdown by shRNAs and deactivated via ATM phosphorylation inhibitor KU55933 were studied.Results VM and high pATM expression occurred in 38.5% and 41.8% of tumors,respectively,and were significantly associated with reduced progression-free and overall survival.Patients with VM-positive GBMs exhibited higher pATM levels(r_(s)=0.425,P=0.01).The multivariate analysis established VM as an independent negative prognostic factor(P=0.002).Furthermore,GSLCs expressed high levels of pATM and formed vascular-like networks in vitro.ATM inactivation or knockdown hindered VM-like network formation concomitant with the downregulation of pVEGFR-2,VE-cadherin,and laminin B2.Conclusion VM may predict a poor GBM prognosis and is associated with pATM expression.We propose that pATM promotes VM through extracellular matrix modulation and VE-Cadherin/pVEGFR-2 activation,thereby highlighting ATM activation as a potential target for enhancing anti-angiogenesis therapies for GBM.

Enhanced MGMT expression contributes to temozolomide resistance in glioma stem-like cells

O6-methylguanine DNA methyltransferase(MGMT) can remove DNA alkylation adducts, thereby repairing damaged DNA and contributing to the drug resistance of gliomas to alkylating agents. In addition, glioma stem-like cells(GSCs) have been demonstrated to be involved in the recurrence and treatment resistance of gliomas. In this study, we aimed to investigate MGMT expression and regulatory mechanisms in GSCs and the association of MGMT with temozolomide(TMZ) sensitivity. GSCs were enriched from one MGMT-positive cell line(SF-767) and 7 MGMT-negative cell lines(U251, SKMG-4, SKMG-1, SF295, U87, MGR1, and MGR2) through serum-free clone culture. GSCs from the U251G, SKMG-4G, SF295G, and SKMG-1G cell lines became MGMT-positive, but those from the U87G, MGR1G, and MGR2G cell lines remained MGMT-negative. However, all the GSCs and their parental glioma cell lines were positive for nuclear factor-κB(NF-κB). In addition, GSCs were more resistant to TMZ than their parental glioma cell lines(P < 0.05). However, there was no significant difference in the 50% inhibition concentration(IC50) of TMZ between MGMT-positive and MGMT-negative GSCs(P > 0.05). When we treated the MGMT-positive GSCs with TMZ plus MG-132(an NF-κB inhibitor), the antitumor activity was significantly enhanced compared to that of GSCs treated with TMZ alone(P < 0.05). Furthermore, we found that MGMT expression decreased through the down-regulation of NF-κB expression by MG-132. Our results show that MG-132 may inhibit NF-κB expression and further decrease MGMT expression, resulting in a synergistic effect on MGMT-positive GSCs. These results indicate that enhanced MGMT expression contributes to TMZ resistance in MGMT-positive GSCs.

Limonin inhibits the stemness of cancer stem-like cells derived from colorectal carcinoma cells potentially via blocking STAT3 signaling

BACKGROUND Limonin is one of the most abundant active ingredients of Tetradium ruticarpum.It exerts antitumor effects on several kinds of cancer cells.However,whether limonin exerts antitumor effects on colorectal cancer(CRC)cells and cancer stem-like cells(CSCs),a subpopulation responsible for a poor prognosis,is unclear.AIM To evaluate the effects of limonin on CSCs derived from CRC cells.METHODS CSCs were collected by culturing CRC cells in serum-free medium.The cytotoxicity of limonin against CSCs and parental cells(PCs)was determined by cholecystokinin octapeptide-8 assay.The effects of limonin on stemness were detected by measuring stemness hallmarks and sphere formation ability.RESULTS As expected,limonin exerted inhibitory effects on CRC cell behaviors,including cell proliferation,migration,invasion,colony formation and tumor formation in soft agar.A relatively low concentration of limonin decreased the expression stemness hallmarks,including Nanog andβ-catenin,the proportion of aldehyde dehydrogenase 1-positive CSCs,and the sphere formation rate,indicating that limonin inhibits stemness without presenting cytotoxicity.Additionally,limonin treatment inhibited invasion and tumor formation in soft agar and in nude mice.Moreover,limonin treatment significantly inhibited the phosphorylation of STAT3 at Y705 but not S727 and did not affect total STAT3 expression.Inhibition of Nanog andβ-catenin expression and sphere formation by limonin was obviously reversed by pretreatment with 2μmol/L colievlin.CONCLUSION Taken together,these results indicate that limonin is a promising compound that targets CSCs and could be used to combat CRC recurrence and metastasis.

Role of glioma stem cells in promoting tumor chemo- and radioresistance: A systematic review of potential targeted treatments

BACKGROUND Gliomas pose a significant challenge to effective treatment despite advancements in chemotherapy and radiotherapy.Glioma stem cells(GSCs),a subset within tumors,contribute to resistance,tumor heterogeneity,and plasticity.Recent studies reveal GSCs’role in therapeutic resistance,driven by DNA repair mechanisms and dynamic transitions between cellular states.Resistance mechanisms can involve different cellular pathways,most of which have been recently reported in the literature.Despite progress,targeted therapeutic approaches lack consensus due to GSCs’high plasticity.AIM To analyze targeted therapies against GSC-mediated resistance to radio-and chemotherapy in gliomas,focusing on underlying mechanisms.METHODS A systematic search was conducted across major medical databases(PubMed,Embase,and Cochrane Library)up to September 30,2023.The search strategy utilized relevant Medical Subject Heading terms and keywords related to including“glioma stem cells”,“radiotherapy”,“chemotherapy”,“resistance”,and“targeted therapies”.Studies included in this review were publications focusing on targeted therapies against the molecular mechanism of GSC-mediated re-sistance to radiotherapy resistance(RTR).RESULTS In a comprehensive review of 66 studies on stem cell therapies for SCI,452 papers were initially identified,with 203 chosen for full-text analysis.Among them,201 were deemed eligible after excluding 168 for various reasons.The temporal breakdown of studies illustrates this trend:2005-2010(33.3%),2011-2015(36.4%),and 2016-2022(30.3%).Key GSC models,particularly U87(33.3%),U251(15.2%),and T98G(15.2%),emerge as significant in research,reflecting their representativeness of glioma characteristics.Pathway analysis indicates a focus on phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin(mTOR)(27.3%)and Notch(12.1%)pathways,suggesting their crucial roles in resistance development.Targeted molecules with mTOR(18.2%),CHK1/2(15.2%),and ATP binding cassette G2(12.1%)as frequent targets underscore their importance in overcoming GSC-mediated resistance.Various therapeutic agents,notably RNA inhibitor/short hairpin RNA(27.3%),inhibitors(e.g.,LY294002,NVP-BEZ235)(24.2%),and monoclonal antibodies(e.g.,cetuximab)(9.1%),demonstrate versatility in targeted therapies.among 20 studies(60.6%),the most common effect on the chemotherapy resistance response is a reduction in temozolomide resistance(51.5%),followed by reductions in carmustine resistance(9.1%)and doxorubicin resistance(3.0%),while resistance to RTR is reduced in 42.4%of studies.CONCLUSION GSCs play a complex role in mediating radioresistance and chemoresistance,emphasizing the necessity for precision therapies that consider the heterogeneity within the GSC population and the dynamic tumor microenvironment to enhance outcomes for glioblastoma patients.

Sox2 enhances the tumorigenicity and chemoresistance of cancer stem-like cells derived from gastric cancer

Gastric cancer stem-like cells（GCSCs） have been identified to possess the ability of self-renewal and tumor initi-ation.However,the mechanisms involved remain largely unknown.Here,we isolated and characterized the GCSCs by side population（SP） sorting procedure and cultured sphere cells（SC） from human gastric cancer cell lines SGC-7901,BGC-823,MGC-803,HGC-27 and MKN-28.The sorting and culture assay revealed that SP cells proliferated in an asymmetric division manner.In addition,SP cells exhibited a higher potential of spheroid colony formation and greater drug resistance than non-SP cells（NSP）.Moreover,the SC were found with enhanced capabilities of drug resistance in vitro and tumorigenicity in vivo.Sox2 mRNA and protein was highly and significantly overex-pressed in the SP cells and SC.Importantly,downregulation of Sox2 with siRNA obviously reduced spheroid colony formation and doxorubicin efflux,as well as increased apoptosis rate in sphere cells in vitro and suppressed tumori-genicity in vivo.These results suggest that both SP cells and cultured SC enrich with GCSCs and that Sox2 plays a pivotal role in sustaining stem cell properties and might be a potential target for gastric cancer therapy.

Cancer stem-like cells directly participate in vasculogenic mimicry channels in triple-negative breast cancer

Objective: Vasculogenic mimicry(VM) channels that are lined by tumor cells are a functional blood supply in malignant tumors.However, the role of VM-initiating cells remains poorly understood. Cancer stem-like cells(CSCs) are positively correlated with VM. In this study, triple-negative breast cancer(TNBC) enriched with CSCs was used to investigate the relationship between VM and CSCs.Methods: The expression of several CSC markers was detected by immunohistochemistry in 100 human breast cancer samples.The clinical significance of CSC markers and the relationship between VM, CSCs, breast cancer subtypes, and VM-associated proteins were analyzed. CD133+ and ALDH+ human and mouse TNBC cells were isolated by FACS to examine the ability of VM formation and the spatial relationship between VM and CSCs.Results: CSCs were associated with TNBC subtype and VM in human invasive breast cancer. CSCs in TNBC MDA-MB-231 cells formed more VM channels and expressed more molecules promoting VM than the non-TNBC MCF-7 cells in vitro. MDA-MB-231 cells that encircled VM channels on Matrigel expressed CD133. Moreover, CSCs were located near VM channels in the 3D reconstructed blood supply system in human TNBC grafts. The CD133+ and ALDH+ cells isolated from TA2 mouse breast cancer formed more VM channels in vivo.Conclusions: CSCs line VM channels directly. Additionally, CSCs provide more VM-related molecules to synergize VM formation. The signaling pathways that control CSC differentiation may also be potential treatment targets for TNBC.

Xiaotan Sanjie decoction attenuates tumor angiogenesis by manipulating Notch-1-regulated proliferation of gastric cancer stem-like cells

AIM: To determine the underlying mechanisms of action and influence of Xiaotan Sanjie (XTSJ) decoction on gastric cancer stem-like cells (GCSCs).

Hallmarks in colorectal cancer:Angiogenesis and cancer stem-like cells

Carcinogenesis is a multistep process that requires the accumulation of various genetic and epigenetic aberrations to drive the progressive malignant transformation of normal human cells.Two major hallmarks of carcinogenesis that have been described are angiogenesis and the stem cell characteristic of limitless replicative potential.These properties have been targeted over the past decade in the development of therapeutic treatments for colorectal cancer(CRC),one of the most commonly diagnosed and lethal cancers worldwide.The treatment of solid tumor cancers such as CRC has been challenging due to the heterogeneity of the tumor itself and the chemoresistance of the malignant cells.Furthermore,the same microenvironment that maintains the pool of intestinal stem cells that contribute to the continuous renewal of the intestinal epithelia also provides the necessary conditions for proliferative growth of cancer stem-like cells.These cancer stem-like cells are responsible for the resistance to therapy and cancer recurrence,though they represent less than 2.5%of the tumor mass.The stromal environment surrounding the tumor cells,referred to as the tumor niche,also supports angiogenesis,which supplies the oxygen and nutrients needed for tumor development.Anti-angiogenic therapy,such as with bevacizumab,a monoclonal antibody against vascular-endothelial growth factor,significantly prolongs the survival of metastatic CRC patients.However,such treatments are not completely curative,and a large proportion of patient tumors retain chemoresistance or show recurrence.This article reviews the current knowledge regarding the molecular phenotype of CRC cancer cells,as well as discusses the mechanisms contributing to their maintenance.Future personalized therapeutic approaches that are based on the interaction of the carcinogenic hallmarks,namely angiogenic and proliferative attributes,could improve survival and decrease adverse effects induced by unnecessary chemotherapy.

MiR-210 expression reverses radioresistance of stem-like cells of oesophageal squamous cell carcinoma

AIM: To investigate the expression of miR-210 and the role it plays in the cell cycle to regulate radioresistance in oesophageal squamous cell carcinoma(ESCC). METHODS: Mi R-210 expression was evaluated in 37 pairs of ESCC tissues and matched para-tumorous normal oesophageal tissues from surgical patients who had not received neoadjuvant therapy, and in the cells of two novel radioresistant cell lines, TE-1R and Eca-109 R, using quantitative reverse transcription-polymerase chain reaction(q RT-PCR). The transient up-regulation of mi R-210 expression in TE-1R and Eca-109 R cells was studied using liposomes and was confirmed using qR T-PCR. The rate of cell survival after a series of radio-treatment doses was evaluated using the cloneformation assay. Flow cytometry was used to detect the changes to the cell cycle patterns due to radiation treatment. RT-PCR and Western blot were used to detect the expression of ataxia telangiectasia mutated(ATM) and DNA dependent protein kinase(DNA-PKcs) after irradiation, and the cell sphere formation assay was used to evaluate the proliferative ability of the cancer stem-like cells.RESULTS: The level of mi R-210 expression was significantly decreased, by 21.3% to 97.2%, with the average being 39.2% ± 16.1%, in the ESCC tissues of most patients(81.1%, 30 of 37 vs patients with high mi R-210 expression, P < 0.05). A low level of expression of miR-210 was correlated with a poorly differentiated pathological type(P < 0.01) but was not correlated with the T-stage or lymph node infiltration(both P > 0.05). Early local recurrences(< 18 mo, n = 19) after radiotherapy were significantly related with low miR-210 expression(n = 13, P < 0.05). The level of mi R-210 was decreased by approximately 73%(vs TE-1, 0.27 ± 0.10, P < 0.01) in the established radioresistant TE-IR cell line and by 52%(vs Eca-109, 0.48 ± 0.17, P < 0.05) in the corresponding Eca-109 R line. Transient transfection with a mi R-210 precursor increased the level of mi R-210 expression, leading to a significant increase in cell survival after radiotherapy(P < 0.05). Twenty-four hours after radiation, the proportion of pmiR-210 cells in S phase was increased(vs control cells, 30.4% ± 0.4%, and vs untreated TE-1R cells, 23.3% ± 0.7%, P < 0.05 for both). The levels of DNA-PKcs(0.21 ± 0.07) and ATM(0.12 ± 0.03, P < 0.05) proteins were significantly lower in the PmiR-210 cells than in control cells, but no differences were found in the levels of the corresponding mR NAs in the two cell types(P > 0.05 for all). Exogenous mi R-210 expression decreased the diameter of pmi R-210 cell spheres(vs control cells, 0.60 ± 0.14, P < 0.05).CONCLUSION: Mi R-210 expression is negatively correlated with the pathological type and the local survivalrate after radiotherapy, and high expression of miR-210 may reverse the radioresistance of ESCC stem-like cells.

Brain tumors:Cancer stem-like cells interact with tumor microenvironment

Cancer stem-like cells(CSCs)with potential of self-renewal drive tumorigenesis.Brain tumor microenvironment(TME)has been identified as a critical regulator of malignancy progression.Many researchers are searching new ways to characterize tumors with the goal of predicting how they respond to treatment.Here,we describe the striking parallels between normal stem cells and CSCs.We review the microenvironmental aspects of brain tumors,in particular composition and vital roles of immune cells infiltrating glioma and medulloblastoma.By highlighting that CSCs cooperate with TME via various cellular communication approaches,we discuss the recent advances in therapeutic strategies targeting the components of TME.Identification of the complex and interconnected factors can facilitate the development of promising treatments for these deadly malignancies.

Effect of Octadecadienoic Acid on Proliferation and Apoptosis of Glioma Cells and Its Mechanism

[Objectives] To explore the inhibitory effect of octadecadienoic acid (ODA) on proliferation and apoptosis of glioma cells and its mechanism. [Methods] Cultured human glioma cells (cell density 2×10^(6) cells/L) were divided into three groups: solvent control group (DMSO, 30 μL/L), 5-FU group (10 mg/L) and octadecadienoic acid group (0.3, 0.6, 1.2 mg/L). The toxic effects of ODA on glioma cells were detected by trypan blue and thiazolium blue (MTT). The expression of P53, PI3K, P21, PKB/Akt and caspase-9 protein in glioma cells were detected by enzyme-linked immunosorbent assay (ELISA). [Results] The cell count under optical microscope showed that the inhibition rate of cell proliferation in low, medium and high dose ODA groups and 5-FU group was significantly higher than that in solvent control group ( P <0.01), but there was no significant difference compared with 5-FU group ( P >0.05). The results of MTT showed that compared with the solvent control group, the inhibition rate of cell proliferation in low, medium and high dose ODA groups and 5-FU group significantly increased ( P <0.01);compared with 5-FU group, the inhibition rate of cell proliferation in high dose ODA group significantly increased ( P <0.01). The results of flow cytometry showed that compared with the solvent control group, the number of cells in G_(0)/G_(1) phase increased significantly ( P <0.05, P <0.01), the number of cells in G_(2)/M phase decreased significantly ( P <0.01) and the apoptosis rate increased significantly ( P <0.01) in the low, medium and high dose ODA groups and 5-FU group;compared with 5-FU group, the number of cells in G_(2)/M phase decreased significantly ( P <0.01) and the apoptosis rate increased significantly ( P <0.01) in ODA group. ELISA testing results showed that the expression levels of P53, P13K and PKB/Akt in low, medium and high dose ODA groups and 5-FU group were significantly lower than those in solvent control group ( P <0.01), and only the expression level of protein in high dose ODA group was significantly lower than that in 5-FU group ( P <0.01);the expression levels of P21 and caspase-9 in low, medium and high dose ODA groups and 5-FU group were significantly higher than those in solvent control group ( P <0.05, P <0.01), but the expression level of protein in high dose ODA group was significantly higher than that in 5-FU group ( P <0.01). [Conclusions] ODA can obviously inhibit the proliferation of glioma cells and induce apoptosis. The mechanism is related to up-regulation of P21, caspase-9, down-regulation of P53, PI3K, PKB/Akt, inhibition of cell division cycle and decrease of PI3K-Akt signal transduction pathway.

Sphere-forming-like cells(squamospheres) with cancer stem-like cell traits from VX2 rabbit buccal squamous cell carcinoma

Previous studies have demonstrated that spheroid type cells grown under suspension culture conditions have cancer stem cell（CSC） traits in a number of cancers, but this phenomenon has not yet been reported in the VX2 rabbit oral cancer model. Hence, this study aimed to study the spheroid cells from VX2 rabbit buccal squamous cell carcinomas（SCCs） and assess their CSC characteristics. Five adult male New Zealand white outbred rabbits were used to generate VX2 rabbit buccal SCC. Sphere-forming cell culture was performed for the VX2 rabbit buccal SCC specimens. The self-renewal capability; cluster of designation（CD） 44, CD133, acetaldehyde dehydrogenase 1（ALDH1）, B cell-specific Moloney murine leukemia virus integration site 1（Bmi-1）, Nestin, octamer-binding transcription factor 4（Oct4）and reduced expression protein-1（Rex-1） expression with reverse transcription-polymerase chain reaction（RT-PCR）; chemoresistance to cisplatin and 5-fluorouracil; and in vivo tumorigenicity of spheroid cell transplantation in nude mice were evaluated to determine the CSC characteristics of the resulting spheroid cells. We successfully obtained spheroid cells from the VX2 rabbit OSCC tissues. The spheroid cells exhibited CSC traits, including the expression of CSC and stem cell markers（CD44, Bmi-1, Nestin, Oct4 and Rex-1）, capacity to generate new spheroid colonies within 1 week of reseeding from single-dissociated spheroid cells, chemoresistance capacity and generation of tumour xenografts（with histological features resembling those of the original VX2 rabbit buccal SCC） from the transplantation of 103 undifferentiated spheroid cells into nude mice. In summary, we demonstrated that spheroid cells with CSC cell traits can be derived from VX2 rabbit buccal SCCs, indicating that this animal cancer model is applicable for studying CSCs in human oral cancers.

Stem cells tropism for malignant gliomas

Various studies have demonstrated the tremendous tropism of stem cells for malignant gliomas,making these cells a potential vehicle for delivery of therapeutic genes to disseminated glioma cells.However,little is known about the mechanisms underlying the glioma-induced tropism of stem cells.Soluble factors including chemokines or growth factors released and expressed by glioma cells at least mediate the tropism of stem cells for gliomas.Here we review the possible mechanisms of stem cells tropism for malignant gliomas.

Brain stem cells as the cell of origin in glioma

Glioma incidence rates in the United States are near 20000 new cases per year, with a median survival time of 14.6 mo for high-grade gliomas due to limited therapeutic options. The origins of these tumors and their many subtypes remain a matter of investigation. Evidence from mouse models of glioma and human clinical data have provided clues about the cell types and initiating oncogenic mutations that drive gliomagenesis, a topic we review here. There has been mixed evidence as to whether or not the cells of origin are neural stem cells, progenitor cells or differentiated progeny. Many of the existing murine models target cell populations defined by lineage-specific promoters or employ lineagetracing methods to track the potential cells of origin. Our ability to target specific cell populations will likely increase concurrently with the knowledge gleaned from an understanding of neurogenesis in the adult brain. The cell of origin is one variable in tumorigenesis, as oncogenes or tumor suppressor genes may differentially transform the neuroglial cell types. Knowledge of key driver mutations and susceptible cell types will allow us to understand cancer biology from a developmental standpoint and enable early interventional strategies and biomarker discovery.

MiR-181b suppresses proliferation of and reduces chemoresistance to temozolomide in U87 glioma stem cells

MicroRNAs regulate self renewal and differentiation of cancer stem cells.There,we sought to identify the expression of miR-181b in glioma stem cells and investigate the biological effect of miR-181b on glioma stem cells in this study.MiR-181b expression was measured by real-time PCR in glioma stem cells isolated from U87 cells by FACS sorting.After miR-181b was overexpressed in U87 glioma stem cells by miR-181b lentiviral expression vector and/or treatment of temozolomide,secondary neurosphere assay,soft agar colony assay and MTT assay were performed.Compared with U87 cells,the expression of miR-181b was significantly decreased in U87 glioma stem cells.Overexpression of miR-181b decreased neurosphere formation by U87 glioma stem cells in vitro and suppressed colony formation in soft agar,and the cell growth inhibition rates increased in a time-dependent manner in U87 glioma stem cells infected with miR-181b lentivirus.Furthermore,miR-181b had a synergistic effect on temozolomide-induced inhibition of secondary neurosphere and soft agar colony,and on cell growth inhibition rates.MiR-181b functions as a tumor suppressor that suppresses proliferation and reduces chemoresistance to temozolomide in glioma stem cells.

MicroRNA-184 promotes proliferation ability of glioma cells by regulating FOXO3

Objective:To investigate the effect of microRNA(miR-184)on regulating the genesis.development and prolifration of glioma cells.Methods:Lipidosome was used to transfect miR-184 mimic and inhibitor to glioma cell ling,and the cell proliferation ability changes were determined by MTT and plate cloning experiment after the transfection.WB test was used to measure the levels of cyclinD1,p27 and FOXO3.Meanwhile.QPCR was used to detect miR-184expression in glioma cell line.glioma tissues and adjacent tissues.Luciferase experiment was used to test 3'UTR gene targeting regulation of miR-184 and FOXO3.Results:QPCR results showed a significaat lower miR-184 expression level in glioma cell line and glioma tissues than that in juxtacancerous tissue.MTT and plate cloning experiments have shown that after overexpressing of miR-184,the cell proliferation capacity of glioma U87 and T98G was signifieantly increased,which was significantly inhibited after the inhibition of miN-184.WB results showed a lower expression level of p27 in U87 and T98G cells,and a higher expression level of cyclind1after over-expressing of miR-184 wss observed.However.a lower expression level of eyelinD1and a higher expression level of p27 after the inhibition of miR-184.The luciferase activity was inhibited after the over-expressing of miR-184.Conclusions:MiR-184 can affect the proliferation abilities of glioma cells and regulate the cell cycle related protein.It plays an important role in the occurrence and development of gliomas.

Effect of TRPV1 combined with lidocaine on cell state and apoptosis of U87-MG glioma cell lines

Objective:To study the effects of Transient receptor potential cation channel,subfamily V,member 1(TRPV1) combined with lidocaine on status and apoptosis of U87-MG glioma cell line,and explore whether local anesthetic produces neurotoxicity by TRPVI.Methods:U87-MG cells were divided into control group,gene silencing group,empty vector group and TRPV gene up-rcgulation group.For cells in each group,flow cytometry was employed to detect the intracellular calcium ion concentration and mitochondrial membrane potential at different lime point from cellular perspective.Cell apoptosis of U87-MG was assayed by flow cytometry and MTT from a holistic perspective.Results:Calcium ion concentration increased along with time.The concentration in TRPV1 gene up-regulation group was significantly higher than those in other groups at each time point(P<0.05).After adding lidocaine.mitochondrial membrane potential in U87-MG significantly increased(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05).while in TRPV1 gene silencing group,the trend significantly decreased(P<0.05).Flow cytometry result and MTT result both showed that cell apoptosis in each group significantly increased after lidocaine was added(P<0.05).This increasing trend in TRPV1 gene up-regulation group was more significant than other groups(P<0.05),while in TRPV1 gene silencing group,the trend significandy decreased(P<0.05).Moreover,apoptosis was more severe along with the increasing concentration of lidocaine(P<0.05).Conclusions:In this study,it was proved that lidocaine could dose-dependently induce the increase of intracellular calcium ion concentration,mitochondrial membrane potential and apoptosis in U87-MG glioma cell line.The up-regulation of TRPV1 enhanced cytotoxicity of lidocaine,which revealed the correlations between mem.Lidocaine might have increased intracellular calcium ion concentration by activating TRPVI gene and induced apoptosis of U87-GM glioma cell line by up-regulating mitochondrial membrane potential.

Dendritic cell-based immunotherapy for malignant glioma

The immunotherapy for malignant glioma faces unique difficult, due to some anatomical and immunological characteristics including the existence of blood brain barrier, the absence of lymphatic tissues and dendritic cells （DCs） in the central nervous system （CNS） parenchyma, and the presence of an immunosuppressive microenvironment. Therefore, immunothera-peutic approaches will not be beneficial unless the compromised immune status in malignant glioma patients is overcome. DC-based immunotherapy, vaccinating cancer patients with DCs pulsed with various tumor antigens, is one of the most promising immunotherapeutic approaches for treatment of malignantglioma because it seems able to overcome, at least partially, the immunosuppressive state associated with primary malignancies. The preparation of DCs, choice of antigen, and route and schedule of administration are improving and optimizing with rapid development of molecular biology and gene engineering technology. DC vaccination in humans, after a number of pre-clinical models and clinical trials, would increase the clinical benefits for malignant glioma immunotherapy.

Migration capacity of human umbilical cord mesenchymal stem cells towards glioma in vivo

High-grade glioma is the most common malignant primary brain tumor in adults. The poor prognosis of glioma, combined with a resistance tQ currently available treatments, necessitates the develop- ment of more effective tumor-selective therapies. Stem cell-based therapies are emerging as novel cell-based delivery vehicle for therapeutic agents. In the present study, we successfully isolated human umbilical cord mesenchymal stem cells by expiant culture. The human umbilical cord mes- enchymal stem cells were adherent to plastic surfaces, expressed specific surface phenotypes of mesenchymal stem cells as demonstrated by flow cytometry, and possessed multi-differentiation potentials in permissive induction media in vitro. Furthermore, human umbilical cord mesenchymal stem cells demonstrated excellent glioma-specific targeting capacity in established rat glioma models after intratumoral injection or contralateral ventricular administration in vivo. The excellent glioma-specific targeting ability and extensive intratumoral distribution of human umbilical cord mesenchymal stem cells indicate that they may serve as a novel cellular vehicle for delivering therapeutic molecules in glioma therapy.

Apoptosis in glioma-bearing rats after neural stem cell transplantation

Abnormal activation of the Ras/Raf/Mek/Erk signaling cascade plays an important role in glioma. Inhibition of this aberrant activity could effectively hinder glioma cell proliferation and promote cell apoptosis. To investigate the mechanism of gJioblastoma treatment by neural stem ceiJ trans- plantation with respect to the Ras/Raf/Mek/Erk pathway, C6 glioma cells were prepared in sus- pension and then infused into the rat brain to establish a glioblastoma model. Neural stem cells isolated from fetal rats were then injected into the brain of this glioblastoma model. Results showed that Raf-1, Erk and Bcl-2 protein expression significantly increased, while Caspase-3 protein expression decreased. After transplantation of neural stem cells, Raf-1, Erk and Bcl-2 protein expression significantly decreased, while Caspase-3 protein expression significantly in-creased. Our findings indicate that transplantation of neural stem cells may promote apoptosis of glioma cells by inhibiting Ras/Raf/Mek/Erk signaling, and thus may represent a novel treatment approach for glioblastoma.