Inhibitory Effects of Ginsenoside Rb1 on Apoptosis Caused by HSV-1 in Human Glioma Cells

To investigate the inhibitory effects of Ginsenoside Rbl （GRbl） on apoptosis caused by Herpes Simplex Virus-1 （HSV-1） in Human Glioma Cells （U251）, U251 cells were infected by HSV-1 at a multiplicity of infection of 5 and GRbl, GRbl＋HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRbl on the apoptosis of U251 cells that caused by HSV-1 infection for various concentrations of drug and virus treatments by MTT assay. We found that in the 400 μg/mL GRb 1 and 400 μg/mL GRbl＋HSV-1 groups, MTT values were higher than control group at all times （P〈0.05）. Moreover, the apoptosis rate in the 400 μg/mL GRbl＋HSV-1 group was lower than the HSV-1 group （P〈0. 05）. These results confirmed that, at appropriate concentrations, GRbl could inhibit nerve cell apoptosis in HSV-1 infections.

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

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.

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-