Inhibitory effect of antisense epidermal growth factor receptor RNA on the proliferation of rat C6 glioma cells in vitro and in vivo

2000 ◽  
Vol 92 (1) ◽  
pp. 132-139 ◽  
Author(s):  
Peiyu Pu ◽  
Xuwen Liu ◽  
Aixue Liu ◽  
Jianling Cui ◽  
Yunting Zhang

Object. The goal of this study was to evaluate the effect of antisense epidermal growth factor receptor (EGFR) RNA on the growth of rat glioma cells in vitro and in vivo and to determine the feasibility of targeting the EGFR gene for gene therapy in gliomas.Methods. Antisense EGFR complementary (c)DNA was transfected into C6 glioma cells by using lipofectamine. In vitro studies, Southern and Northern blot analyses, in situ hybridization, and immunohistochemical staining were designed to examine the integration and expression of antisense EGFR constructs. The 3′(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide (MTT) assay and the average number of argyrophilic nuclear organizer regions (Ag-NORs) were used to evaluate cell proliferation, whereas the terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate nick-end labeling (TUNEL) method and microscopy were used to observe cell apoptosis. As part of the in vivo studies, parental C6 cells and C6 cells transfected with EGFR antisense cDNA were implanted stereotactically into the right caudate nucleus of Wistar rats (C6-injected animals and transfected C6-injected animals). Rats with well-established cerebral C6 glioma foci were treated intratumorally with either antisense EGFR cDNA or empty-vector DNA by using lipofectamine (treated-C6 and control treated group). The general behavior and survival of the rats, findings on magnetic resonance images of their brains, histopathological changes, proliferation activity, and apoptosis of the cerebral gliomas in each group of rats were examined.Exogenous antisense EGFR cDNA was integrated into the genome of C6 cells and expressed. In clones with a high expression of the antisense construct, there was a dramatic decrease in endogenous EGFR messenger RNA and protein levels, reduced proliferation activity, and induction of apoptosis in vitro. The mean survival time of rats injected with C6 cells was 17.3 days. The mean survival time of rats injected with C6 cells followed by treatment with empty vector in lipofectamine was 15.4 days. Survival time was significantly prolonged in 100% of the rats injected with antisense-transfected C6 cells and in two thirds of the rats injected with C6 cells followed by antisense EGFR cDNA. Magnetic resonance imaging revealed distinct cerebral tumor foci in C6-injected rats and in control rats of the treated group, but none were found in the rats injected with transfected C6 cells. Furthermore, tumor foci disappeared completely in C6-injected rats treated with antisense EGFR cDNA. The cerebral gliomas of the rats treated by injection of antisense EGFR RNA were characterized by reduced proliferation activity and the induction of apoptosis.Conclusions. The results of this study indicate that EGFR plays an important role in the genesis of malignant gliomas. It may, therefore, be an effective target of antisense gene therapy in patients with gliomas.

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 228-235 ◽  
Author(s):  
Qiang Jia ◽  
Yanhe Li ◽  
Desheng Xu ◽  
Zhenjiang Li ◽  
Zhiyuan Zhang ◽  
...  

Object The authors sought to evaluate modification of the radiation response of C6 glioma cells in vitro and in vivo by inhibiting the expression of Ku70. To do so they investigated the effect of gene transfer involving a recombinant replication-defective adenovirus containing Ku70 short hairpin RNA (Ad-Ku70shRNA) combined with Gamma Knife treatment (GKT). Methods First, Ad-Ku70shRNA was transfected into C6 glioma cells and the expression of Ku70 was measured using Western blot analysis. In vitro, phenotypical changes in C6 cells, including proliferation, cell cycle modification, invasion ability, and apoptosis were evaluated using the MTT (3′(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay, Western blot analysis, and cell flow cytometry. In vivo, parental C6 cells transfected with Ad-Ku70shRNA were implanted stereotactically into the right caudate nucleus in Sprague-Dawley rats. After GKS, apoptosis was analyzed using the TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling) method. The inhibitory effects on growth and invasion that were induced by expression of proliferating cell nuclear antigen and matrix metalloproteinase–9 were determined using immunohistochemical analyses. Results The expression of Ku70 was clearly inhibited in C6 cells after transfection with Ad-Ku70shRNA. In vitro following transfection, the C6 cells showed improved responses to GKT, including suppression of proliferation and invasion as well as an increased apoptosis index. In vivo following transfection of Ad-Ku70shRNA, the therapeutic efficacy of GKT in rats with C6 gliomas was greatly enhanced and survival times in these animals were prolonged. Conclusions Our data support the potential for downregulation of Ku70 expression in enhancing the radiosensitivity of gliomas. The findings of our study indicate that targeted gene therapy–mediated inactivation of Ku70 may represent a promising strategy in improving the radioresponsiveness of gliomas to GKT.


2001 ◽  
Vol 94 (4) ◽  
pp. 596-604 ◽  
Author(s):  
Adília Hormigo ◽  
David R. Friedlander ◽  
Perry A. Brittis ◽  
David Zagzag ◽  
Martin Grumet

Object. A variant of C6 glioma cells, C6R-G/H cells express hygromycin phosphotransferase (HPT) and appear to have reduced tumorigenicity in the embryonic brain. The goal of this study was to investigate their reduced capacity to generate tumors in the adult rat brain. Methods. Cell lines were implanted into rat brains and tumorigenesis was evaluated. After 3 weeks, all rats with C6 cells showed signs of neurological disease, whereas rats with C6R-G/H cells did not and were either killed then or allowed to survive until later. Histological studies were performed to analyze tumor size, malignancy, angiogenesis, and cell proliferation. Cells isolated from rat brain tumors were analyzed for mutation to HPT by testing their sensitivity to hygromycin. Conclusions. The results indicate that HPT suppresses tumor formation. Three weeks after implantation, only 44% of animals implanted with C6R-G/H cells developed tumors, whereas all animals that received C6 glioma cells developed high-grade gliomas. The C6R-G/H cells filled a 20-fold smaller maximal cross-sectional area than the C6 cells, and exhibited less malignant characteristics, including reduced angiogenesis, mitosis, and cell proliferation. Similar results were obtained in the brain of nude rats, indicating that the immune system did not play a significant role in suppressing tumor growth. The combination of green fluorescent protein (GFP) and HPT was more effective in suppressing tumorigenesis than either plasmid by itself, indicating that the GFP may protect against inactivation of the HPT. Interestingly, hygromycin resistance was lost in tumor cells that were recovered from a group of animals in which C6R-G/H cells formed tumors, confirming the correlation of HPT with reduced tumorigenicity.


1987 ◽  
Vol 66 (2) ◽  
pp. 251-255 ◽  
Author(s):  
Tatsuo Yoshida ◽  
Keiji Shimizu ◽  
Yukitaka Ushio ◽  
Heitaro Mogami ◽  
Yukiya Sakamoto

✓ Reserpine enhanced in vitro the cytotoxicity of 1-(4-amino-2-methyl-5-pyrimidinyl) methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) in both the C6 glioma and its ACNU-resistant subline, C6/ACNU. Reserpine also enhanced the chemotherapeutic effect of ACNU in C6/ACNU-bearing (C6/ACNU-meningeal gliomatosis) rats, in which ACNU resistance could be modulated by combined ACNU and reserpine therapy. When 10 μM reserpine was added to ACNU in culture, the concentration of drug required for 50% inhibition of cell growth (IC50) of ACNU for C6/ACNU cells decreased to the level of that for C6 cells. When 20 μM reserpine was added to the culture, intracellular uptake of ACNU in C6/ACNU cells increased further and the efflux of the drug from the cells decreased. In in vivo experiments in rats, combined chemotherapy with ACNU (1 mg/kg) and reserpine (250 μg/kg) by intrathecal injection significantly increased the life span of the rats as compared to results with ACNU chemotherapy alone. The enhanced cytotoxicity of ACNU in ACNU-resistant glioma cells in vitro and in vivo may be explained by the increase of intracellular concentration of ACNU resulting from the inhibition of ACNU efflux from the resistant cells by reserpine. It was concluded that ACNU resistance could be modulated in vitro and in vivo by combined therapy with ACNU and reserpine.


2010 ◽  
Vol 16 (4) ◽  
pp. 509-514 ◽  
Author(s):  
Qiang Huang ◽  
Zhibo Xia ◽  
Yongping You ◽  
Peiyu Pu

1983 ◽  
Vol 59 (3) ◽  
pp. 424-430 ◽  
Author(s):  
Junkoh Yamashita ◽  
Hajime Handa ◽  
Yasuhiko Tokuriki ◽  
Young Soo Ha ◽  
Shin-Ichi Otsuka ◽  
...  

✓ The authors examined the growth rate of mouse 203 glioma cells in vitro and found it to be markedly inhibited after exposure to ACNU for 5 minutes at a drug concentration of 100 µg/ml. Rats that had undergone intracranial implantation of T1 neurogenic tumor were treated by 5 mg/kg of ACNU administered either intravenously or intra-arterially. The median survival times for the control animals and the animals undergoing intravenous or intracarotid administration of ACNU were 23, 29, and 46 days, respectively. The difference in survival time between the intravenous and intracarotid administration groups was statistically significant (p < 0.01) when examined by the Cox-Mantel test. In a clinical trial, 17 patients with glioblastoma were treated by ACNU, eight intravenously and nine by the intra-arterial route. The drug was given in doses of 2 to 3 mg/kg at least twice before and twice after a course of postoperative radiotherapy. Intra-arterial administration was performed over a period of 5 minutes under local anesthesia. The median postoperative survival time for the patients in the intra-arterial group was 12.5 months, compared with 9.0 months for those in the intravenous group. The survival rate for the intra-arterial group was slightly higher, although statistically not significant, probably because the number of cases was small. The degree of thrombocytopenia due to ACNU tended to be less marked in the intra-arterially treated patients. The theoretical advantages of the intra-arterial administration of ACNU are discussed.


2017 ◽  
Vol 39 (4) ◽  
pp. 258-263 ◽  
Author(s):  
L D Liubich ◽  
L M Kovalevska ◽  
M I Lisyany ◽  
V M Semenova ◽  
T A Malysheva ◽  
...  

The aim of the work was to study the impact of fetal rat brain cell supernatant (FRBCS) on the expression of transforming growth factor β1 (TGF-β1) and p53 in C6 cells of rat glioma in vitro. Materials and Methods: FRBCS was obtained from suspensions of fetal rat brain cells on the 14th (E14) day of gestation. C6 glioma cells were cultured for 48 h in the presence of FRBCS or FRBCS + anti-TGF-β1 monoclonal antibody. Immunocytochemical staining for TGF-β1 and p53 was performed. Results: The proportion of TGF-β1-immunopositive tumor cells in C6 glioma cultures was statistically significantly higher than in the control cell cultures of normal fetal rat brain. FRBCS reduced the proportion of TGF-β1-immunopositive tumor cells and increased the proportion of p53-immunopositive cells in C6 glioma cultures. In cells cultured with FRBCS + anti-TGF-β1 monoclonal antibody, the above effects of FRBCS were abrogated. Conclusion: The obtained results suggest that TGF-β1 seems to be responsible for decrease in TGF-β1 expression and increase in p53 expression in C6 glioma cells treated with FRBCS.


2006 ◽  
Vol 105 (Supplement) ◽  
pp. 208-213 ◽  
Author(s):  
Desheng Xu ◽  
Qiang Jia ◽  
Yanhe Li ◽  
Chunsheng Kang ◽  
Peiyu Pu

ObjectThe authors sought to study the combined potential of wild-type p53 gene transfer and Gamma Knife surgery (GKS) for the treatment of glioblastomas multiforme. Modification of the radiation response in C6 glioma cells in vitro and in vivo by the wild-type p53 gene was investigated.MethodsStable expression of wild-type p53 in C6 cells was achieved by transduction of the cells with adenoviral p53. Two days later, some cells were treated with GKS. Forty-eight hours after irradiation, the comparative survival rate was assessed by monotetrazolium (MTT) assays. Treated and control C6 glioma cells (4 × 103 per well) were plated into a 96-well plate in octuplicate and tested every 24 hours. Meanwhile, immunohistopathological examination of proliferating cell nuclear antigen (PCNA) and terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate (TUNEL) assays were performed. The MTT assays indicated the p53, GKS, and combined treated cells proliferated at a significantly lower rate than those of the control group (p < 0.01, Days 2–6) and the positive fraction of PCNA in p53-treated group and GKS-treated group was 70.18 ± 3.61 and 50.71 ± 2.61, respectively, whereas the percentage in the combined group was 30.68 ± 1.49 (p < 0.01).Fifty-six male Sprague–Dawley rats were anesthetized and inoculated with 106 cultured C6 glioma cells into the cerebrum. Forty-eight hours after transduction with adenoviral p53, some rats underwent GKS. A margin dose of 15 Gy was delivered to the 50% isodose line. Two days later, six rats in each group were killed. Their brains were removed and paraffin-embedded section were prepared for immunohistopathological examination and TUNEL assays. The remaining rats were observed for the duration of the survival period. The survival curve indicated that a modest but significant enhancement of survival duration was seen in the p53-treated or GKS alone groups, whereas a more marked and highly significant enhancement of survival duration was achieved when these two treatment modalities were combined. When PCNA expression was downregulated, apoptotic cells become obvious after TUNEL staining.Conclusions The findings of this study suggest that p53-based gene therapy in combination with GKS may be superior to single-modality treatment of C6 glioma.


2006 ◽  
Vol 234 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Hsing-Chun Kuo ◽  
Wu-Hsien Kuo ◽  
Yean-Jang Lee ◽  
Wea-Lung Lin ◽  
Fen-Pi Chou ◽  
...  

2018 ◽  
Vol 19 (9) ◽  
pp. 2613 ◽  
Author(s):  
Muhammad Khalid ◽  
Muhammad Asad ◽  
Petra Henrich-Noack ◽  
Maxim Sokolov ◽  
Werner Hintz ◽  
...  

Superparamagnetic iron oxide nanoparticles (SPIO-NPs) have great potential to be used in different pharmaceutical applications, due to their unique and versatile physical and chemical properties. The aim of this study was to quantify in vitro cytotoxicity of dextran 70,000-coated SPIO-NPs labelled/unlabelled with rhodamine 123, in C6 glioma cells and primary hippocampal neural cells. In addition, we analyzed the in vitro and in vivo cellular uptake of labelled SPIO-NPs. The nanoparticles, with average size of 10–50 nm and polydispersity index of 0.37, were synthesized using Massart’s co-precipitation method. The concentration-dependent cytotoxicity was quantified by using tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Intracellular localization of SPIO-NPs was detected by confocal laser microscopy. In vivo confocal neuroimaging (ICON) was performed on male Wistar rats after intravitreal injection followed by ex vivo retina whole mount analysis. When used for in vitro testing concentrations in the range of diagnostic and therapeutic dosages, SPIO-NPs proved to be non-cytotoxic on C6 glioma cells for up to 24 h incubation time. The hippocampal cell culture also did not show impaired viability at low doses after 24 h incubation. Our results indicate that our dextran-coated SPIO-NPs have the potential for in vivo drug delivery applications.


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