ABSTRACT
Aim To establish human U87-MG glioma model in nude mice brain and to observe the characteristics of the tumor growth. Methods Human U87-MG glioma cells were cultured in vitro. 5 μL of cell suspension containing 3.0 ×1010·L-1, 4.0×1010·L-1and 5.0×1010·L-1respectively was inocula-ted into the right caudate nucleus of 18 male nude mice brain un-der the guidance of stereotaxic apparatus, separately, whereas another 6 nude mice as the control group, were inoculated into the same volume of Hanks solution. The moving and survival state of rats with gliomas were observed. The examinations of the tumors formation, volumes, metastasis and histopathology were performed and the obtained brain samples were stained with HE and immunohistochemistry. Results All the tested rats of dif-ferent inoculation doses developed brain tumors without extracra-nial metastasis. The mean survival time of three groups was (46.50 ± 3.27) d,(38.50 ± 3.28) d and (30.67 ± 3.51) d,respectively. The tumors showed the similar morphological fea-tures and immunophenotype to human glioma. There was positive expression of GFAP and S-100 in the tumors. Conclusions The orthotopic implantation model of human U87-MG glioma, by in-oculating quantitative U87-MG cells stereotaxically into the brains of the nude mice, is successfully established with 100 yield of intracranial tumor and no extracranial growth extension. It resembles the histopathological and morphological features of human glioma,which can be used as a reliable animal model for the study of the tumorigenesis, pathogenesis, biological charac-teristics and therapy of glioma.
ABSTRACT
AIM: To explore the effects of chromodomain protein 8 (CBX8) on the proliferation and apoptosis of human glioma cells.METHODS: The expression of CBX8 in the tissues and cells was detected by Western blot and RT-qPCR.The overexpression (Flag-CBX8) and silencing (sh-CBX8) vectors of CBX8 were constructed and transfected into glioma T98G cells and U87MG cells.The cell proliferation was detected by MTT assay and BrdU staining.The cell apoptosis was analyzed by flow cytometry.The protein expression of Rb/E2F1 was detected by Western blot.RESULTS: Compared with normal brain tissues and astrocytes, the expression of CBX8 was increased in the glioma tissues and glioma cells.Overexpression of CBX8 promoted the cell proliferation, inhibited the cell apoptosis, and upregulated the protein levels of Rb/E2F1.On the contrary, silencing of CBX8 inhibited the cell proliferation, promoted the cell apoptosis, and decreased the protein levels of Rb/E2F1 in the T98G cells and U87MG cells.Moreover, the expression of cyclin D1 and Bcl-2/Bax ratio were reduced after transfection with sh-E2F1 in the T98G cells and U87MG cells.CONCLUSION: CBX8 may regulate the proliferation and apoptosis of glioma cells through Rb/E2F1 pathway.
ABSTRACT
Objective To investigate the effects of salidroside on proliferation and invasive ability of glioma U87-MG cells; To discuss the its mechanism to induce apoptosis of U87-MG cells. Methods U87-MG cells were cultured in vitro for 24 h under different concentrations of salidroside and camptothecin. The proliferation of U87-MG cells was detected by MTT assay. The apoptosis rate of U87-MG cells was detected by flow cytometry. Transwell assay was used to detect the invasive ability of U87-MG cells. ROS was detected by indirect fluorescent labeling. The expressions of Caspase-3, Bcl-2, Bax, E-cadherin, N-cadherin and matrix metalloproteinase-9 (MMP-9) in U87-MG cells were detected by Western blot. Results Compared with the blank control group, U87-MG cells had significant inhibitory effect on the growth of U87-MG cells in each administration group, and the invasive ability of U87-MG cells was significantly reduced after 10, 50, 100 μg/mL salidroside was intervened, and 10, 50, 100 μg/mL salidroside for 48 h for U87-MG cells could induce apoptosis of the cells; the level of ROS was positively correlated with the concentration of salidroside; 10, 50, 100 μg/mL salidroside up-regulated the expressions of Caspase-3, Bax and E-cadherin, and down-regulated the expressions of Bcl-2, N-cadherin and MMP-9. Conclusion Salidroside can induce apoptosis of U87-MG cells and inhibit the invasive ability of U87-MG cells.
ABSTRACT
INTRODUCTION: Astrocytic gliomas are the most common intracranial central nervous system neoplasias, accounting for about 60 percent of all primary central nervous system tumors. Despite advances in the treatment of gliomas, no effective therapeutic approach is yet available; hence, the search for a more realistic model to generate more effective therapies is essential. OBJECTIVE: To develop an experimental malignant astrocytoma model with the characteristics of the human tumor. METHOD: Primary cells from subcutaneous xenograft tumors produced with malignant astrocytoma U87MG cells were inoculated intracerebrally by stereotaxis into immunosuppressed (athymic) Rowett rats. RESULTS: All four injected animals developed non-infiltrative tumors, although other glioblastoma characteristics, such as necrosis, pseudopalisading cells and intense mitotic activity, were observed. CONCLUSION: A malignant astrocytoma intracerebral xenograft model with poorly invasive behavior was achieved in athymic Rowett rats. Tumor invasiveness in an experimental animal model may depend on a combination of several factors, including the cell line used to induce tumor formation, the rat strains and the status of the animal's immune system.
Subject(s)
Animals , Female , Humans , Rats , Astrocytoma/pathology , Brain Neoplasms/pathology , Glioblastoma/pathology , Immunocompromised Host , Brain Neoplasms/immunology , Cell Line, Tumor , Disease Models, Animal , Glioblastoma/immunology , Neoplasm Transplantation , Rats, Nude , Transplantation, HeterologousABSTRACT
AIM: To investigate the role of transferrin/transferrin receptor system in transferrin-bound Yb 2 (Yb 2Tf) uptake by U-87 MG cells and the effect of transferrin-bound and -free Yb 2 on proliferation of U-87 MG cells. METHODS: Cell culture and ICP-MS measurement of Yb 2. RESULTS: Yb 2Tf uptake by U-87 MG cells increased with the concentrations of Yb 2Tf, and reached saturation as the concentration in the incubation medium was raised to about 2 ?mol/L. Also, Yb 2 uptake by the cells increased with increase of the mole ratio (Yb 2: apoTf), reaching a maximum at 1.5 mole ratio. Yb 2Tf in 0.4 ?mol/L significantly inhibited proliferation of U-87 MG cells, however, 10 ?mol/L Yb 3+ had no significant effect on proliferation of the cells. CONCLUSION: The uptake of Yb 2 by U-87 MG cells might be mediated by transferrin/transferrin receptor system. Transferrin-bound but not transferrin-free Yb 2 could significantly inhibit proliferation of U-87 MG cells.