Interaction between p53 and p16 expressed by adenoviral vectors in human malignant glioma cell lines

2002 ◽  
Vol 97 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Seung-Ki Kim ◽  
Kyu-Chang Wang ◽  
Byung-Kyu Cho ◽  
Hyun-Tai Chung ◽  
Young-Yim Kim ◽  
...  

Object. Multiple gene replacements have been examined as a potential treatment modality for malignant gliomas. Nevertheless, no reports are available that detail the synergy, additivity, or antagonism of multiple genes. The aim of this study was to assess the interaction between p53 and p16 genes in the growth of glioma cell lines. Methods. The human glioma cell lines U87MG and U373MG were transduced using an adenoviral vector with Ad-p53, Ad-p16, or both. Western blotting was performed to determine the expression of the protein products of the transduced p53 and p16 genes. To establish whether the combination of Ad-p53 and Ad-p16 would be beneficial, the effects of gene combinations at the median inhibitory concentration level were analyzed using the isobologram method. Annexin assays and cell cycle analyses were performed on the transduced cells. Western blotting demonstrated the expression of p53 and p16 in transduced cells. Simultaneous exposure to Ad-p53 and Ad-p16 produced additive effects in both glioma cell lines. Experimental data points in U373MG lay near the Mode I line, indicating that the vectors had a different mode of action. The restoration of normal p53-encoded protein in the mutant cell lines induced apoptosis, whereas in the wild-type p53 cell lines, the overexpression of wild-type p53 resulted in a moderate degree of apoptosis and G1 arrest. Furthermore, Ad-p16 induced more marked G1 arrest than Ad-p53 in cells with wild-type p53. Conclusions. The results show that interaction between Ad-p53 and Ad-p16 is additive, regardless of p53 gene status.

2003 ◽  
Vol 98 (3) ◽  
pp. 570-577 ◽  
Author(s):  
Prakash Sampath ◽  
Eric Amundson ◽  
Monroe E. Wall ◽  
Betty M. Tyler ◽  
Mansukh C. Wani ◽  
...  

Object. The authors compared and characterized several new classes of camptothecin (CPT) analogs (a total of 22 drugs) directed against human and murine glioma cell lines in vitro, trying to identify CPT analogs that can be used for local therapy in future clinical trials. Camptothecin is a naturally occurring alkaloid that inhibits the DNA-replicating enzyme topoisomerase I. Moreover, CPT and its analogs have shown promising antitumor activity against both systemic and intracranial neoplasms. Because the CPTs have poor bioavailability and are unable to cross the blood—brain barrier, they may best be delivered to the central nervous system by polymers. The authors have previously shown that local delivery of Na-CPT by implantable polymers prolongs survival in a rat intracranial glioma model. In recent years, a number of newly synthesized CPT analogs have been developed that exhibit more potency and stability than Na-CPT. Methods. Cytotoxicities of the drugs were tested using modified clonogenic and monotetrazolium assays in three glioma cell lines. A potassium chloride—sodium dodecyl sulfate coprecipitation assay was used to determine the frequency of drug-stabilized cleavable complexes. Of the CPT analogs analyzed, the 10,11-methylenedioxy (MD) class consistently demonstrated the greatest cytotoxicity. Three of these analogs, 10,11-MD-20(RS)-CPT, 10,11-MD-20(S)-CPT-glycinate ester (Gly).HCl, and 9-amino-10,11-MD-20(S)-CPT-Gly, exhibit significantly greater antiproliferative activities than CPT, Na-CPT, or 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) against all three glioma cell lines. In addition, the 10,11-MD20(RS)-CPT analog induces more cleavable complexes than Na-CPT at every concentration. Conclusions. The increased potency and greater stability of CPT analogs hold promise for more effective local antitumor treatments against malignant intracranial brain tumors. The greater cytotoxicity of 10,11-MD CPTs in comparison with other CPT analogs as well as CPT, BCNU, or Na-CPT, may present an ideal candidate drug class for development against both primary and metastatic brain tumors.


1991 ◽  
Vol 74 (3) ◽  
pp. 460-466 ◽  
Author(s):  
Tsuyoshi Matsumoto ◽  
Eiichi Tani ◽  
Keizo Kaba ◽  
Hideki Shindo ◽  
Katsuya Miyaji

✓ The expression of P-glycoprotein, a product of multidrug resistance gene 1, was studied by Western blotting and immunohistochemistry in five human glioma cell lines. One glioma cell line was resistant to vincristine, Adriamycin (doxorubicin), and etoposide, and the other four glioma cell lines were sensitive to each drug. The multidrug-resistant cell line showed a high expression of P-glycoprotein in Western blot analysis and a positive immunostaining for P-glycoprotein mainly along the cell membrane, whereas all multidrug-sensitive glioma cell lines demonstrated no expression of P-glycoprotein in Western blotting and no immunostaining for P-glycoprotein, thus showing a good correlation between the expression level of P-glycoprotein and the extent of multidrug resistance. In 18 human surgical glioma specimens, there was no evidence of complete absence of immunostaining for P-glycoprotein. With a definition of more than 20% of P-glycoprotein-positive cells as positive, from 10% to 20% as intermediate, and less than 10% as negative, immunostaining for P-glycoprotein was positive in one specimen and intermediate in six of 15 specimens taken from virgin gliomas, and positive in two specimens and intermediate in one of three recurrent gliomas treated previously with irradiation, ACNU (1-(4-amino-2-methyl-pyrimidine-5-yl)-methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride), cisplatin, vincristine, and/or procarbazine.


1999 ◽  
Vol 91 (3) ◽  
pp. 483-489 ◽  
Author(s):  
Michael A. Vogelbaum ◽  
Jianxin X. Tong ◽  
Rajashri Perugu ◽  
David H. Gutmann ◽  
Keith M. Rich

Object. Cells that lose their ability to undergo apoptosis may promote the development of neoplasms and result in resistance to clinical treatment with DNA-damaging modalities such as radio- and chemotherapy. Four established human glioma cell lines that are resistant to apoptosis were transfected with the proapoptotic gene bax and assessed for their sensitivity to a proapoptotic stimulus.Methods. Two cell lines had a wild-type p53 genotype (U87 and D247MG) and two had mutant p53 genotypes (U138 and U373). Constitutive overexpression of murine bax was achieved in U138 and U373 only, which resulted in an increased sensitivity of these lines to the apoptosis-inducing effect of cytosine arabinoside (ara-C). Multiple attempts to produce constitutive overexpression of bax in U87 and D247MG cells resulted in spontaneous, near-complete cell loss. Vector-only control transfections were successful in all four cell lines. Inducible overexpression of bax was achieved in the U87 cells and elevated levels of BAX were observed as early as 6 hours after gene induction. This overexpression of BAX resulted in the spontaneous induction of apoptosis in these cells.Conclusions. Overexpression of BAX in four human glioma cell lines resulted in increased sensitivity to apoptosis. In the two lines that had a wild-type p53 genotype, overexpression of BAX produced spontaneous apoptosis. In contrast, the lines that had mutant, nonfunctional P53 did not undergo spontaneous apoptosis, but they were rendered more sensitive to the apoptosis-inducing effect of ara-C. Modulation of BAX expression may be a useful therapeutic modality for gliomas, regardless of p53 genotype.


2005 ◽  
Vol 102 (6) ◽  
pp. 1055-1068 ◽  
Author(s):  
Roksana Rodak ◽  
Hisashi Kubota ◽  
Hideyuki Ishihara ◽  
Hans-Pietro Eugster ◽  
Dilek Könü ◽  
...  

Object. Taurolidine, a derivative of the amino acid taurin, was recently found to display a potent antineoplastic effect both in vitro and in vivo. The authors therefore initiated studies to assess the potential antineoplastic activity of taurolidine in human glioma cell lines and in ex vivo malignant cell cultures. They also studied the mechanisms that induce cell death and the impact of taurolidine on tumor-derived vascular endothelial growth factor (VEGF) production. Methods. Cytotoxicity and clonogenic assays were performed using crystal violet staining. In the cytotoxicity assay 100% of glioma cell lines (eight of eight) and 74% of ex vivo glioma cultures (14 of 19) demonstrated sensitivity to taurolidine, with a mean median effective concentration (EC50) of 51 ± 28 µg/ml and 56 ± 23 µg/ml, respectively. Colony formation was inhibited by taurolidine, with a mean EC50 of 7 ± 3 µg/ml for the cell lines and a mean EC50 of 3.5 ± 1.7 µg/ml for the ex vivo glioma cultures. On observing this high activity of taurolidine in both assays, the authors decided to evaluate its cell death mechanisms. Fragmentation of DNA, externalization of phosphatidylserine, activation of poly(adenosine diphosphate—ribose) polymerase, loss of the mitochondrial membrane potential followed by a release of apoptosis-inducing factor, and typical apoptotic features were found after taurolidine treatment. Cell death was preceded by the generation of reactive O2 intermediates, which was abrogated by N-acetylcysteine but not by benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone. Moreover, taurolidine also induced suppression of VEGF production on the protein and messenger RNA level, as shown by an enzyme-linked immunosorbent assay and by reverse transcription—polymerase chain reaction. Conclusions. Given all these findings, taurolidine may be a promising new agent in the treatment of malignant gliomas; it displays a combination of antineoplastic and antiangiogenic activities, inducing tumor cell apoptosis and inhibiting tumor-derived VEGF production.


1998 ◽  
Vol 88 (3) ◽  
pp. 529-534 ◽  
Author(s):  
Shiro Isoe ◽  
Hirofumi Naganuma ◽  
Shin Nakano ◽  
Atsushi Sasaki ◽  
Eiji Satoh ◽  
...  

Object. The aim of this study was to investigate the mechanism by which malignant glioma cells escape from growth inhibition mediated by transforming growth factor-β (TGF-β), a ubiquitous cytokine that inhibits cell proliferation by causing growth arrest in the G1 phase of the cell cycle. Methods. The authors measured the response of eight malignant glioma cell lines to the growth-inhibiting activity of TGF-β in vitro and the expression of TGF-β Types I and II receptors in malignant glioma cells. The effect of TGF-β on the expression of a p27Kip1 cyclin-dependent kinase inhibitor was also investigated to assess the downstream signal transmission from TGF-β receptors. All malignant glioma cell lines were insensitive to growth inhibition by TGF-β1 and TGF-β2. Analyses of TGF-β receptors by means of affinity labeling in which 125I-TGF-β1 was used showed that six glioma lines had both TGF-β Types I and II receptors on their cell surfaces, whereas two lines had very small amounts of TGF-β Type I and/or Type II receptors. Northern blot analysis showed that all tumor lines expressed variable levels of messenger RNAs for both TGF-β Types I and II receptors. Flow cytometric analyses revealed that treatment of malignant glioma cells with TGF-β1 significantly downregulated the expression of p27Kip1 protein in all malignant glioma cell lines except one. Conclusions. The authors suggest that most malignant glioma cells express TGF-β Types I and II receptors, which can transmit some signals downstream and that the loss of response to TGF-β growth inhibition may not be caused by an abnormality of the TGF-β receptors.


1995 ◽  
Vol 82 (6) ◽  
pp. 1035-1043 ◽  
Author(s):  
Jörg-Christian Tonn ◽  
Hans Kristian Haugland ◽  
Jaakko Saraste ◽  
Klaus Roosen ◽  
Ole Didrik Laerum

✓ The aim of this study was to investigate the antimigratory and antiinvasive potential of vincristine sulfate (VCR) on human glioma cells and to analyze whether phenytoin (5,5-diphenylhydantoin; DPH) might act synergistically with VCR. Vincristine affects the cytoplasmic microtubules; DPH has been reported to enhance VCR cytotoxicity in murine cells. In two human glioma cell lines, GaMG and D-37MG, we found VCR to reduce monolayer growth and colony formation in a dose-dependent fashion at concentrations of 10 ng/ml and above. Phenytoin increased the cytotoxic and cystostatic effects of VCR in monolayer cells but not in spheroids. Multicellular spheroids were used to investigate directional migration. A coculture system of GaMG and D-37MG spheroids with fetal rat brain aggregates was used to analyze and quantify tumor cell invasion. A dose-dependent inhibition of migration and invasion by VCR was observed in both cell lines without further enhancement by DPH. Immunofluorescence microscopy with antibodies against α-tubulin revealed dose-dependent morphological alterations in the microtubules when the cells were exposed to VCR but not after incubation with DPH. Based on the combination of standardized in vitro model systems currently in use and the present data, the authors strongly suggest that VCR inhibits migration and invasion of human glioma cells. This is not altered by DPH, which inhibits cell proliferation in combination with VCR.


2001 ◽  
Vol 94 (6) ◽  
pp. 978-984 ◽  
Author(s):  
Christine Wild-Bode ◽  
Michael Weller ◽  
Wolfgang Wick

Object. Migration and invasion are important prerequisites for the infiltrative and destructive growth patterns of malignant gliomas. Infiltrative growth prevents complete tumor resection and causes significant neurological morbidity and mortality. Methods. The authors assessed the expression of matrix metalloproteinases (MMPs) at messenger RNA and protein levels, MMP-2 and MMP-9 activities, and expression levels of a panel of anti- and proapoptotic proteins of the BCL-2 family. They then correlated their findings with αVβ3 integrin expression and the migratory and invasive potentials in 12 human malignant glioma cell lines. Multiple MMPs were expressed by most cell lines. The levels of MMP-2 and MMP-3 and the activities of MMP-2 and MMP-9 correlated with tumor cell invasion. Migration and invasion were also correlated. Although the expression levels of αVβ3 integrin did not predict migration or invasion, a neutralizing αVβ3 integrin antibody inhibited migration and invasion selectively in cell lines that contained a high level of αVβ3 integrin expression, thus indicating the important role of αVβ3 integrin for migration and invasion in this subset of cell lines. An expression pattern of BCL-2 family proteins that favor resistance to apoptosis was associated with enhanced migration, invasion, and MMP activity. Wild-type p53 cell lines migrated farther than mutant p53 cell lines. Conclusions. Activities of MMP-2 and MMP-9 are the best predictors of glioma cell invasion. The αVβ3 integrin mediates migration and invasion in a subset of glioma cell lines, but these processes do not depend on αVβ3 integrin expression. Antiapoptotic BCL-2 family protein expression is a predictor of efficient migration and invasion.


2000 ◽  
Vol 92 (6) ◽  
pp. 1002-1008 ◽  
Author(s):  
Katsuyuki Asaoka ◽  
Mitsuhiro Tada ◽  
Yutaka Sawamura ◽  
Jun Ikeda ◽  
Hiroshi Abe

Object. Recombinant adenovirus is used as a competent vector in a wide spectrum of cancer gene therapies because of its high efficiency in gene delivery. To study the feasibility of gene therapy in malignant gliomas, the authors examined the antiproliferative effect of the adenovirally transduced wild-type p53 tumor suppressor gene by using 15 different high-grade glioma cell lines.Methods. Although growth suppression in association with a high adenoviral p53 transduction efficiency was seen in five of 15 cell lines, it was not observed in the remaining 10 cell lines. To clarify the underlying mechanism, we examined the expression levels of the Coxsackievirus and adenovirus receptor (CAR), which is the primary receptor for adenovirus, and of the integrins αvβ3 and αvβ5, which promote adenoviral internalization. The expression level of the CAR gene showed a close correlation to adenoviral gene transduction efficiency in the tested cell lines, whereas the expression levels of the integrins did not. The CAR expression was decreased by wild-type p53 transduction in U251MG cells harboring mutant p53 and increased by antisense inhibition of p53 in LN443 cells with endogenous wild-type p53.Conclusions. The results of this study indicate that CAR expression is a critical determinant of transduction efficiencies in adenovirus-based gene therapy for human malignant gliomas.


1990 ◽  
Vol 73 (3) ◽  
pp. 436-440 ◽  
Author(s):  
Jun-ichi Kuratsu ◽  
Yukitaka Ushio

✓ Platelet-derived growth factor (PDGF) is produced by glioma cells. However, there is heterogeneity among glioma cell lines in the production of PDGF. It has been demonstrated that U251MG cells produce a PDGF-like molecule while U105MG cells do not. Trapidil, a specific antagonist of PDGF, competes for receptor binding with PDGF. Therefore, the inhibitory effect of trapidil on the proliferation of glioma cells was investigated in vitro using two glioma cell lines. At 100 µg/ml, trapidil significantly inhibited the proliferation of U251MG cells (which produce the PDGF-like molecule). At the same trapidil concentration, the proliferation of U105MG cells (which do not produce the PDGF-like molecule) was not inhibited. The inhibitory effect of trapidil was remarkable on Days 3 and 4 of culture. After 4 days of incubation, the proliferation of U251MG cells was 46% of the control preparation. Trapidil enhanced the antitumor effect of 3-((4-amino-2-methyl-5-pyrimidinyl)ethyl)-1-(2-chloroethyl)-1-nitro-sourea (ACNU) against U251MG cells. The enhancing effect was highest on Days 4 and 6 of culture. After 6 days of incubation in the presence of 100 µg/ml trapidil and 1 µg/ml ACNU, the proliferation of U251MG cells was 18% of the control preparation. These findings suggest that trapidil interrupts the autocrine loop at the PDGF and PDGF-receptor level and that combination therapy with trapidil and ACNU may be useful in the treatment of glioma.


1999 ◽  
Vol 91 (5) ◽  
pp. 814-821 ◽  
Author(s):  
Eric W. Sherburn ◽  
John E. Wanebo ◽  
Paul Kim ◽  
Sheng-Kwei Song ◽  
Michael R. Chicoine ◽  
...  

Object. Surgical treatment of gliomas is difficult because they are invasive. Invasion of essential cortex often limits or precludes surgical resection. A tumor model was developed in which the rodent whisker barrel cortex was used to examine how gliomas affect cortical function and structure.Methods. Both DBT (mouse) and C6 (rat) glioma cell lines were grown in culture and labeled with the fluorescent marker Dil in vitro. Labeled tumor cells were then injected into the whisker barrel cortex of adult mice and rats. Neurological assessments were made daily and magnetic resonance (MR) images were obtained. Animals were killed by perfusion 6 to 14 days after injection, and histological sections were prepared and studied.Tumors were found in all 20 rats and 10 mice that had been injected with the C6 and DBT cell lines, respectively. The animal cells had been labeled with Dil in vitro, and all in vivo tumors proved to be Dil positive. The MR images revealed the tumor locations and serial MR images demonstrated tumor growth. Histological evaluation confirmed the location of the tumor and the disruption of barrel cortex architecture.Conclusions. Both DBT and C6 glioma cell lines can be used to generate malignant glial tumors reproducibly in the whisker barrel cortex. Fluorescent labeling and cytochrome oxidase staining permit visualization of tumor growth patterns, which disrupt the barrel cortex by microscopic invasion and by gross tissue deformation. Magnetic resonance imaging demonstrates the anatomical extension of these tumors in live rodents. Using this model for further studies on the effects of malignant glioma growth on functional cerebral cortex should advance our understanding of the neurological issues and management of patients with these tumors.


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