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.

Lipid-albumin nanoassemblies co-loaded with borneol and paclitaxel for intracellular drug delivery to C6 glioma cells with P-gp inhibition and its tumor targeting

Successful chemotherapy with paclitaxel(PTX)is impeded by multidrug resistance(MDR)in tumor cells.In this study,lipid-albumin nanoassemblies co-loaded with borneol and paclitaxel(BOR/PTX LANs)were prepared to circumvent MDR in C6 glioma cells.The physiochemical properties including particle size,encapsulation efficiency and morphology were evaluated in vitro.Quantitative and qualitative investigations of cellular uptake were carried out in C6 glioma cells.The cytotoxicity of the BOR/PTX LANs was determined by MTT assay.After that,the tumor targeting was also evaluated in C6 glioma bearing mice by in vivo imaging analysis.BOR/PTX LANs have a higher entrapment efficiency(90.4±1.2%),small particle size(107.5±3.2 nm),narrow distribution(P.I.=0.171±0.02).The cellular uptake of PTX was significantly increased by BOR/PTX LANs compared with paclitaxel loaded lipidalbumin nanoassemblies(PTX LANs)in quantitative research.The result was further confirmed by confocal laser scanning microscopy qualitatively.The cellular uptake was energy-,timeand concentration-dependent,and clathrin-and endosome/lysosome-associated pathways were involved.The BOR/PTX LANs displayed a higher cytotoxicity agaist C6 glioma cells in comparion with PTX LANs and Taxol.Moreover,the encapsulation of BOR in LANs obviously increased the accumulation of the drug in tumor tissues,demonstrating the tumor targeted ability of BOR/PTX LANs.These results indicated that BOR/PTX LANs could overcome MDR by combination of drug delivery systems and P-gp inhibition,and shown the potential for treatment of gliomas.

Effects of antigliomatin from the scorpion venom of Buthus martensii Karsch on chloride channels on C6 glioma cells

Using whole-cell patch-clamp recordings, the effects of antigliomatin were observed on chloride channels on C6 glioma cells cultured in vitro. Antigliomatin was extracted from the venom of the scorpion Buthus martensii Karsch. Chloride channels are closed under normal osmotic pressure. When osmotic pressure was reduced to 120, 110 and 100 mV, the cell volume enlarged, chloride channels opened, and the chloride channel current increased. Three minutes after antigliomatin treatment, the chloride channel current decreased in a dose-dependent manner. These results show that antigliomatin extracted from the venom of the scorpion Buthus martensii Karsch diminishes chloride channel currents on C6 glioma cells.

Expression of the B7 - related molecule B7 - H1 by glioma cells: a potential mechanism of immune paralysis

Human glioblastoma is a highly lethal tumor that is known for its immune inhibitory capabilities.B7-homologue l(B7-H 1),a recently identified homologue of B7.1/2(CD80/86),has been described to exert costimulatoryand immune regulatory functions.We investigated the expression and the functional activity of B7-H 1 in humanglioma cells in vitro and in vivo.Although lacking B7.1/2(CD80/86),all 12 glioma cel1 1ines constitutivelyexpressed B7-H1 mRNA and protein.Exposure to IFN-gamma strongly enhanced B7-H 1 expression.Im-

Inhibition of epidermal growth factor receptor signaling protects human malignant glioma cells from hypoxia - induced cell death

Epidermal growth factor receptor(EGFR)signaling has become an importanttarget for drug development becauseEGFR signaling enhances tumor cell proliferation,migration,and invasion and inhibits apoptosis.However,theresults of clinical trials using EGFR inhibitors in patients with solid tumors have been disappointing.Here,wereport a protective effect of the EGFR inhibitors AG1478 and PD153035 against cell death induced by acute hy-poxia,which contrasts with their proapoptotic effects under normoxia.Under hypoxic conditions,both agents re-

Exogenous p16 gene therapy combined with X-ray irradiation suppresses the growth of human glioma cells

In this study, we infected human glioma U251 cells with a replication-defective recombinant adenovirus carrying the p16 gene. This adenovirus constructed was able to transfect exogenous p16 into the human glioma cells efficiently, and direct a high level of p16 protein expression. Tumor-inhibition experiments demonstrated that treatment with the adenovirus-p16 significantly inhibited the growth of glioma cells in vitro as well as the in vivo development of tumors in nude mice bearing a brain glioma. The combination of adenovirus-p16 gene treatment and X-ray irradiation resulted in a greater inhibition of tumor growth. Adenovirus-mediated p16 gene therapy conferred a significant antitumor effect against human glioma cells both in vitro and in vivo, and that there was a synergistic effect when X-ray irradiation was also used.

Transient axonal glycoprotein-1 induces apoptosisrelated gene expression without triggering apoptosis in U251 glioma cells

Previous studies show that transient axonal glycoprotein-1, a ligand of amyloid precursor pro- tein, increases the secretion of amyloid precursor protein intracellular domain and is involved in apoptosis in Alzheimer＇s disease. In this study, we examined the effects of transient axonal glyco- protein-1 on U251 glioma cells. 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide assay showed that transient axonal glycoprotein-1 did not inhibit the proliferation of U251 cells, but promoted cell viability. The terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that transient axonal glycoprotein-1 did not induce U251 cell apoptosis. Real-time PCR revealed that transient axonal glycoprotein-1 substantially upregulated levels of amyloid precursor protein intracellular C-terminal domain, and p53 and epidermal growth factor recep- tor mRNA expression. Thus, transient axonal glycoprotein-1 increased apoptosis-related gene expression in U251 cells without inducing apoptosis. Instead, transient axonal glycoprotein-1 promoted the proliferation of these glioma cells.

THE EFFECT OF TRANSFECTED CX43 GENE ON THE GJIC AND PROLIFERATION OF GLIOMA CELLS

Objective: To evaluate the effect of Cx43 gene on gap junction intercellular communication (GJIC) and proliferation of glioma cells. Methods: Cx43 cDNA was transfected into TJ905 human glioblastoma cells using lipofectamine. The expression of Cx43 was identified by Northern blot analyses, in situ hybridization and immunohistochemistry. MTT assay and average number of AgNORs (Argyrophlic nuclear organizer regions) were used to determine the cell proliferation. TUNEL method was used for detection of cell apoptosis, and scrape loading and dye tranfer method for examination of GJIC. Results: The Cx43 expression was greatly upregulated when Cx43 gene was transfected into TJ905 glioma cells. The cell proliferation was inhibited while the cell apoptosis was not increased and GJIC was significantly restored in the glioma cells transfected with Cx43 gene. Conclusion: Cx43 gene has an inhibitory effect on the glioma cell proliferation, but no effect on induction of cell apoptosis. The restoration of GJIC may be the major mechanism involved in its effect. Cx43 gene can be the candidate for gene therapy of gliomas.

THE EFFECT OF ANTISENSE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) RNA ON THE PROLIFERATION OF HUMAN GLIOMA CELLS AND INDUCTION OF CELL APOPTOSIS

Objective: To study the effect of antisense EGFR RNA on the growth of human glioma cells in vitro and evaluate the feasibility of targeting EGFR gene for gene therapy of gliomas. Methods: Southern and Northern blot analysis, in situ hybridization and immunohistochemical staining were used to detect the integration and expression of antisense EGFR constructs. MTT assay and the average number of AgNOR for evaluation of cell proliferation, and the TUNEL method and ultrastructural change for observation of cell apoptosis. Results: Exogenous antisense EGFR cDNA was integrated into the genome of glioma cells and highly expressed, which resulted in a dramatic decrease of endogenous EGFR mRNA and GEPR protein levels. Clones with high expression of the antisense construct showed a lower proliferation activity and the induction of apoptosis in vitro. Conclusion: This study suggests that EGFR plays an important role in the genesis of gliomas; it may be used as a target for antisense gene therapy of gliomas.

THE STUDIES ON MONOCLONAL ANTIBODY SZ-39 AGAINST HUMAN GLIOMA CELLS

A hybridoma cell line SZ-39 secreting monoclonal antibody against the human glioma cell has been established by a fusion between NS-1 myeloma cells and spleen cells from mice immunized with human glioma cell lines. Monoclonal antibody (McAb) SZ-39 was analyzed by ELISA, quantitative absorption, indirect immunofluorescence and ABC immunohistology. McAb SZ-39 strongly bound to 9/10 glioma cell lines, 17/20 glioma tissues, weakly bound to one liver cancer cell line and 1/2 lung cancer line, but they did not band with other tested human cancer linse. NcAb SZ-39 have no cross-reaction with lymphocyte, ABC red blood cells, white blood cells, blood platelet, normal bone marrow cells, fibroblast cells and 12 normal human tissues.The result indicated the antigen recognized by McAb SZ-39 may be a glioma-associated antigen <GAA). This GAA was analyzed by means of Western blotting. It was a MW 180 Kd glycopro-tein. The 131I-McAb SZ-39 specifically localized in human glioma xenografted in nude mice that indicate it may be useful in radioimmunoimaging and as a target for immunotherapy on human glioma.

Activation of CD40 by Soluble Recombinant Human CD40 Ligand Inhibits Human Glioma Cells Proliferation via Nuclear Factor-κB Signaling Pathway

As CD40 transduces activation signals involved in inflammatory and immune disorders,we explored the expression and response to CD40 engagement in human glioma cell lines in this study.The CD40 expression in BT-325 and U251 cells was flow cytometrically detected.The cells were incubated with srhCD40L for 72 h to assess its effects on cell growth in vitro.TNF-α expression was quantified by real-time PCR,and protein expression was analyzed by ELISA.The I-κb mRNA was detected by RT-PCR.I-κB expression decreased after stimulation with 1 μg/mL srhCD40L,but it was upregulated after the cells were pretreated with CD40 antibody.srhCD40L significantly inhibited the proliferation of the CD40+ human glioma cells.The stimulation of CD40+ glioma cells with soluble CD40L (CD154) up-regulated the expression of TNF-α at both mRNA and protein levels.We are led to conclude that CD40L/CD40 could inhibit human glioma cells through I-κb signaling pathway.Interferon-γ can augment CD40 expression and the inhibitory effect of CD40 ligand on cell growth in vitro.These results suggest that srhCD40L may benefit the therapy strategy of glioma.

The influence of small interfering RNA on the expression of Survivin in human glioma cells

Objective This study aims to investigate the feasibility of knockdown of Survivin gene with small interfering RNA and to observe the apoptosis in gliomas which is influenced by siRNA. Methods Survivin specific siRNA oligonucleotides were designed and synthesized artificially. This siRNA

Induction of apoptosis and inhibition of proliferation of C6 glioma cells in vitro by tamoxifen

Objective To investigate the anti-tumor effect and mechanism of tamoxifen on rat C6 glioma cells. Methods C6 cells were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with 3% fetal calf serum (FCS), and treated with tamoxifen of different concentrations, i.e. group A (1.25μmol/L), group B (2.50 μmol/L), group C (5.00 μmol/L), group D (10.00 μmol/L), group E (20.00 μmol/L) and control group (0.00 μmol/L). Morphological changes, MTT assay and 5-bromo-2’-deoxyuriding labeling ratio were assessed. Apoptosis was observed by flow cytometry. Results C6 cells treated with different doses of tamoxifen for 24, 48, and 72 hours became irregular in shape, while cells treated with vehicle grew normally. MTT assay showed that tamoxifen did not suppress C6 cell growth until 72 hours after treatment. Seventy-two hours after treatment, there were significant differences in cell viable rate between group A versus groups C, D and E; so did group B versus group D as well as group E (P<0.05). BrdU incorporation assay indicated significant difference of BrdU labbled index (BrdU LI) among groups A, C, E and control group 48 hours after treatment (P<0.05). And the BrdU LI decreased with the increased concentration of tamoxifen. Flow cytometry (FCM) showed significant difference between treated group and control group at 24, 48, and 72 hours after treatment (P<0.05). Conclusion Tamoxifen significantly suppresses the growth of C6 glioma cells in a time-and dose-dependent manner. The mechanism of tamoxifen suppressing C6 glioma cells may be inhibiting proliferation and inducing apoptosis. Therefore, tamoxifen can be a candidate as a chemotherapy agent for glioma.

Preparation, Release-control and Cell Apoptosis of C_6 Glioma Cells in PEG-PLGA-Rg3 Nanoparticles

With biodegradable material poly（ethylene glycol）-poly（lactide-co-glycolide） （PEG-PLGA） as substrate, the size distribution of Rg3-NPs was approved by the scanning electron microscopy. MTT assay was used to detect the effects of Rg3-NPs on the growth rate of C6 cells at various concentrations and flow cytometry（FCM） was applied to assay the cell cycle and cell apoptosis of C6 glioma cells. Western blot analysis was used to measure the protein level of PCNA. The results show that Rg3-NPs are slick and uniformity, the average diameter of the nanoparticles is about 75-90 nm, entrapment efficiency is （89.7±1.7）%. MTT assay shows the growth of C6 Glioma Cells can be significantly inhibited by Rg3-NPs in a dose-dependence manner. FCM and Western blot analysis show Rg3 can be released from the conjugated nanoparticles to function in the cell nuclei so as to lead to the changes in the growth cycle of the cells, which results in the arrest of G0-G1 cell cycle and induces the apoptosis of C6 cells. Therefore, Rg3-NPs may be used for the auxiliary therapy of brain glioma.

RNA interference affects tumorigenicity and expression of insulin-like growth factor-1,insulin-like growth factor-1 receptor,and basic fibroblast growth factor-2 in rat C6 glioma cells

BACKGROUND： Human gliomas are more likely to express basic fibroblast growth factor-2 （FGF-2） insulin-like growth factor-1（IGF-1）, and IGF-1 receptor （IGF-1R） than normal brain tissue. These factors activate signal transduction systems of Ras/MAPK and PI3K/Akl, which promote glioma growth. OBJECTIVE： To utilize RNA interference （RNAi） technique to down-regulate FGF-2, IGF-1, and IGF-1R gene expression, and to investigate the effects of these genes on rat C6 glioma cells, as well as the feasibility of RNAi for treating glioma. DESIGN, TIME AND SETTING： This neurooncological, randomized, controlled, in vivo and in vitro experiment, which used RNAi methodology, was performed at the Laboratory of Molecular Biology, Institute of Biochemistry, Chinese Academy of Sciences between August 2005 and February 2008. MATERIALS： Rat C6 cell lines were purchased from Shanghai Institute of Cellular Biology Affiliated to Chinese Academy of Sciences. Small interfering RNA （siRNA） was synthesized by Shanghai GenePharma. Anti-IGF-1, anti-IGF-1R, anti-FGF-2, anti-mouse and anti-rabbit IgG G1-HRP antibodies were provided by Santa Cruz Biotechnology, USA. Four to six week-old BALB/c nude mice were purchased from the Laboratory Animal Center, Chinese Academy of Sciences. METHODS： C6 glioma cells were transfected with siRNA, which was chemically synthesized in vitro to correspond to endogenous FGF-2, IGF-1, and IGF-1R genes. The inhibition ratio of targeting mRNA expression was detected by semiquantitative RT-PCR, and protein expression was determined by Western blot analysis. C6 glioma cell proliferation was observed using a growth curve C6 glioma cell apoptosis rate and cell cycle were detected by flow cytometry. C6 glioma cell growth regression was observed by transwell migration assay. In addition, nude mouse subcutaneous tumor models were used in this study. For studying the anti-tumor effects of IGF-1 and IGF-1R siRNA, two blank control groups, with six mice each, were set up： A （2.5 μg siRNA was injected one week after C6 cells were inoculated, Le., when tumor volume reached 8 mm × 8 mm） and B （siRNA was injected at the same time with C6 cells were inoculated. To study the effects of FGF-2 siRNA, the groups consisted of a blank control group, negative control group, 2.6 μg siRNA group, 4 μg siRNA group, and 5.3 μg siRNA group, with six mice each. MAIN OUTCOME MEASURES： mRNA and protein inhibition ratio of FGF-2, IGF-1, and IGF-1 R; C6 glioma cell proliferation, apoptosis, and cycle growth arrest; C6 glioma cell growth regression and subcutaneous tumorigenicity rates. RESULTS： All siRNA constructs proved to be effective. After 48 hours, transfection of 200 nmol/L siRNA resulted in a FGF-2 or IGF-1R gene inhibition ratio 〉 80% and an IGF-1 gene inhibition ratio of approximately 70%. Protein expression levels for FGF-2, IGF-1, and IGF-1R decreased in a dose-dependent manner following siRNA transfection, with an inhibition rate 〉 85%, 60%, and 50%, respectively. C6 glioma cell proliferation and apoptosis rates increased in proportion to siRNA. The apoptosis rate of C6 glioma cells induced by FGF-2, IGF-1, and IGF-1R siRNA was 39.96%, 15.07% and 22.47%, respectively （P 〈 0.01）. Transfection of 200 nmol/L IGF or IGF-1R siRNA for 48 hours suppressed C6 glioma cell migration. At 30 days after intratumoral injection of 2.6, 4, and 5.3 tJg FGF-2 siRNA, tumor growth regression rate of FGF-2 siRNA was 56%, 67%, and 86%, respectively. The tumor growth regression rate was 71.88% and 45.71%, respectively, when IGF-1 or IGF-1R siRNA was intratumorally injected 1 week after C6 glioma cell transplantation. When IGF-1 or IGF-1 R siRNA was intratumorally injected during C6 glioma cell transplantation, the tumor growth regression rate was 78.13% and 74.29%, respectively. CONCLUSION： siRNA transfection downregulated gene expression of FGF-2, IGF-1, and IGF-1R In addition, siRNA treatment markedly suppressed glioma cell proliferation, growth, and migration, and concomitantly reduced subcutaneous tumorigenicity.

Adiponectin Supports Human Glioma Cells Survival against Temozolomide through Enhancement of Autophagic Response in Glioma Cells

Objective: To investigate the role of adiponectin in human glioma cell lines against the temozolomide and the molecular regulation mechanism. Methods: Human glioma cell lines U251 and U-87MG were cultured in Dulbecco’s modified eagle medium (DMEM) containing 4500 mg/L glucose. MTT was used to measure cell growth ratio. Western blot was used to detect the protein levels of autophagy-related protein (Beclin 1, LC3 I/II, p62) and phosphorylated AMPK (p-AMPK) in human glioma cell lines. After AICAR and Compound C were administered, the change of p-AMPK and the autophagy level were examined by western blot. Results: While adiponectin stimulates AMPK in phosphatase and up-regulates the level of autophagy, human glioma cell lines obtain more resistance against the temozolomide, which is facilitated by AICAR and weakened by Compound C. Conclusion: As an important adipokine, adiponectin can up-regulate the glioma cell autophagy by activating the AMPK signaling pathway which increases the resistance of glioma cells to temozolomide.

Effect of Over-expressed LRIG3 on Cell Cycle and Survival of Glioma Cells

This study examined the effects of over-expression of leucine-rich repeats and immunoglobulin-like domains 3 （LRIG3） on the cell cycle and survival of human glioma cell line U87 and U251 and explored the possible mechanisms. The LRIG3 gene was transduced into U87 and U251 cells respectively by using lentivirus and the transduced cells were selected by puromycin. The changes in LRIG3 mRNA and protein levels were measured by RT-PCR and Western blotting. The apoptosis rate was detected by Annexin Ⅴ-FITC/PI double labeling and the cell cycle was flow cytometrically analyzed. Compared with control cells, LRIG3 mRNA expression in U251 and U87 cells transduced with pLVX-DsRed-LRIG3-Monomer-N1 were increased by 77.6% and 129.7%, and LRIG3 protein expression was raised by 141.3% and 322.7%, respectively. Cell cycle analysis showed that LRIG3 over-expression increased the percentage of cells at G0/G1 phase （P〈0.01）. Over-expressed LRIG3 could significantly promote the apoptosis of U87 and U251 cells （P〈0.05）. These findings suggest that the over-expression of LRIG3 could arrest the cell cycle in G0/G1 phase, and promote apoptosis of U87 and U251 cells.

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.

Red light-driven generation of reactive oxygen species for the targeted oxidation of glioma cells and thiols over covalent organic framework

Reactive oxygen species(RoS)are essential for biological processes like cell signaling and chemical processes like organic oxidation.Moreover,the sufficient generation of RoS plays a significant role in targeted tumor treatments or oxidation of organics.Herein,a hydrazone-linked porphyrin covalent organic framework(Por-DETH-COF)is developed for red light-induced generation of ROS like singlet oxygen(^(1)O_(2))or superoxide(O_(2)·^(-))to undertake different but targeted oxidations.First,^(1)O_(2)is adopted in photodynamic therapy(PDT)for the oxidation of glioma cells.The PDT efficiency of Por-DETH-COF on the apoptosis of glioma cells is explored through flow cytometry and western blot assay.The apoptosis rate of glioma cells significantly increases over Por-DETH-COF under 660nm red light illumination,suggestive of the potency of^(1)O_(2).Second,O_(2)^(·-)is employed for the targeted oxidation of thiols.A series of thiols could be efficiently oxidized to corresponding disulfides over Por-DETH-COF under 660 nm red light illumination,indicative of the significance of O_(2)^(·-).This work highlights the potential of covalent organic frameworks in generating Ros for precise medical applications of complex chemical environments.