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MicroRNAs (miRNAs) are short regulatory RNAs that negatively modulate protein expression at a post-transcriptional level. Emerging evidence suggests that miRNAs play important roles in the pathogenesis of several types of cancers. However, the further mechanisms of miRNA remain unknown. In this study, we aimed to explore the coordinated function of miR-221/222 in glioma by bioinformatics and experiment methods. Bioinformatics analysis revealed that miR-221/222 had the potential to regulate about 70 common target genes and may exert a cooperative effect on regulation and function via Akt signaling pathway. Overexpression of miR-221/222 increased glioma cell proliferation and invasion in vitro and induced glioma growth in a subcutaneous mouse model. Furthermore, miR-221/222 overexpression resulted in an obvious activation of p-Akt and significant changes of Akt-related gene expression in glioma cells. Our results suggest that miR-221/222 co-enhance the glioma malignant phenotype via activation of the Akt pathway mediated by regulation of common gene expression.

Notch receptors play an essential role in cellular processes during embryonic and postnatal development, including maintenance of stem cell self-renewal, proliferation, and determination of cell fate and apoptosis. Deregulation of Notch signaling has been implicated in some genetic diseases and tumorigenesis. The function of Notch signaling in a variety of tumors can be either oncogenic or tumor-suppressive, depending on the cellular context. In this study, Notch1 overexpression was observed in the majority of 45 astrocytic gliomas with different grades and in U251MG glioma cells. Transfection of siRNA targeting Notch1 into U251 cells in vitro downregulated Notch1 expression, associated with inhibition of cell growth, arrest of cell cycle, reduction of cell invasiveness, and induction of cell apoptosis. Meanwhile, tumor growth was delayed in established subcutaneous gliomas in nude mice treated with Notch1 siRNA in vivo. These results suggest that Notch1 plays an important oncogenic role in the development and progression of astrocytic gliomas. Furthermore, knockdown of Notch1 expression by siRNA simultaneously downregulated the expression of EGFR and the important components of its downstream pathways, including PI3K, p-AKT, K-Ras, cyclin D1 and MMP9, indicating the crosstalk and interaction of Notch and EGFR signaling pathways.

MicroRNAs (miRNAs) are a class of endogenous small noncoding RNAs that regulate gene expression after transcription. Aberrant expression of miRNAs has been shown to be involved in tumorigenesis. We showed that miR-21 was one of the most frequently overexpressed miRNA in human glioblastoma (GBM) cell lines. To explore whether miR-21 can serve as a therapeutic target for glioblastoma, we downregulated miR-21 with a specific antisense oligonucleotide and found that apoptosis was induced and cell-cycle progression was inhibited in vitro in U251 (PTEN mutant) and LN229 (PTEN wild-type) GBM cells; xenograft tumors from antisense-treated U251 cells were suppressed in vivo. Antisense-miR-21-treated cells showed a decreased expression of EGFR, activated Akt, cyclin D, and Bcl-2. Although miR-21 is known to regulate PTEN and downregulation of miR-21 led to increased PTEN expression both endogenously and in a reporter gene assay, the GBM suppressor effect of antisense-miR-21 is most likely independent of PTEN regulation because U251 has mutant PTEN. Microarray analysis showed that the knockdown of miR-21 significantly altered expression of 169 genes involved in nine cell-cycle and signaling pathways. Taken together, our studies provide evidence that miR-21 may serve as a novel therapeutic target for malignant gliomas independent of PTEN status.

Objective: To study the radiation-sensitizing effect of up-regulating p27(kip1) expression by knocking down miR-221/222 in the U251 human glioblastoma cell line., Methods: By bioinformatic analysis, we searched the miRNA-221/222 sequence and found the relationship between p27(kip1) and miRNA-221/222. miRNA-221/222 antisense oligonucleotides were transfected into U251 human glioblastoma cells. Northern blot analysis was conducted to detect the expression of miR-221/222 in control, scrambled oligonucleotide (ODN) transfected and anti-mi-221/222ODNs transfected cell groups. The cell cycle kinetics was detected by flow cytometry. Clonogenic assay was used to measure the mitotic cell death and p27(kip1) expression was examined by Western blot analysis., Results: Based on bioinformatic analysis, we found that the seed sequences of miR-221 and miR-222 coincide with each other, and p27(kip1) is a target for miRNA-221/222. The expression level of miR-221/222 was significantly knocked down in cells transfected with antimiR-221/222 as compared to the parental cells or cells transfected with scrambled ODN. Cell cycle was arrested in G0 or G1 phase in the anti-miR-221/222 group. When combined with irradiation, S phase fraction in the anti-miR-221/222 cell group is lower than that in the other two control groups. Anti-miR-221/222 combined with irradiation could synergistically enhance mitotic cell death. The expression of p27(kip1) was up regulated in the anti-miR-221/222 group revealed by Western blot analysis., Conclusion: Anti-miR-221/222 may enhance the radiosensitivity of U251 human glioblastoma through upregulation of p27(kip1).

Notch signaling pathway plays an integral role in determining cell fates in development. Growing evidence demonstrates that Notch signaling pathway has versatile effects in tumorigenesis depending on the tumor type, grade and stage. Notch signaling pathway is deregulated in some brain tumors. To examine the differential expression of Notch family members (Notch1, 2, 3, 4) in human astrocytomas and medulloblastomas, and to evaluate their roles in the development of both tumor types. Immunohistochemical staining and Western blot analysis were used to detect Notch1, 2, 3, 4 expression in tissue microarray and freshly resected tissue samples of normal brain, astrocytomas and medulloblastomas. Notch family members were not expressed or barely detectable in normal brain tissues. Notch1, 3, 4 were highly expressed but Notch2 was not expressed in astrocytomas. The percentage of immunopositive tumor cells and level of Notch1 expression was increased with tumor grade. In addition, overexpression of Notch2 was detected in medulloblastomas in contrast to low or no expression of Notch1, 3, 4. Differential expression of Notch1, 2, 3, 4 is detected in astrocytomas and medulloblastomas, that may be related to their different roles playing in the development of brain tumors.

Cyclooxygenase-2 (COX-2) and phosphatidylinositol 3-kinase (PI3K)/Akt play a critical role in the formation of many malignant tumors, and have been shown to be important therapeutic targets. In the present study, small hairpin RNA (shRNA) expression constructs that target sequences of human COX-2, Akt1 and PIK3R1 were used to examine the proliferation and invasion inhibition effects on SGC7901 gastric adenocarcinoma cells and U251 glioma cells. Cell growth was inhibited by over 70%, as indicated by a MTT assay, and was accompanied by G1/G0 phase arrest in the shRNA treated group, indicating poor cell growth activities. The number of cells invading through the matrigel in the shRNA treated group were significantly decreased (26.4+/-4.6) compared with that of the control group (105+/-4.0) and the nonsense sequence group (102.5+/-6.4). In addition, the tumor volumes in the SGC7901 subcutaneous nude mouse model treated with shRNA was significantly smaller than those of the control group and nonsense sequence group. When COX-2, Akt1 and PIK3R1 were dramatically downregulated, proliferating cell nuclear antigen (PCNA), CyclinD1 and matrix metalloproteinases (MMP-2, MMP-9) were downregulated, while tissue-inhibitor of metalloproteinase-2 (TIMP-2) and P53 were upregulated. Our results demonstrated that shRNA targeting COX-2, Akt1 and PIK3R1 downregulates their expression significantly in a sequence-specific manner, exerting proliferation and invasion inhibition effects on SGC7901 and U251 cells. In conclusion, our data suggest a novel mechanism for the regulation of malignant tumor cell growth and provide evidence for new combinatory gene therapy for malignant tumors.

MicroRNAs (miRNAs) are short (≈22-nt) non-coding RNA molecules implicated in both development and disease that act by repressing translation or by inducing the cleavage of target RNA transcripts. Emerging evidence suggests that the altered regulation of miRNA may be involved in the pathogenesis of cancer. Here, we investigated the expression of the miRNA gene miR-221 by real-time PCR in human glioma tissues of varying grades of malignancy. The expression level of miR-221 was found to increase with glioma malignancy, whereas protein levels of a putative target, the cell cycle inhibitor and tumor suppressor gene p27Kip1, decreased. Using a luciferase reporter assay, we further confirmed the translational repression activity of miR-221 on p27 by identifying the target recognition element within the 3'UTR of p27. Our results suggest that miR-221 is a regulator of the tumor suppressor gene p27, and that its increased expression in advanced gliomas might contribute to glioma cell proliferation by a mechanism involving the repression of p27.

MicroRNAs are short regulatory RNAs that negatively modulate protein expression at a post-transcriptional level. Emerging evidence suggests that altered regulation of miRNA may be involved in the pathogenesis of several types of cancers. In the current study, an inverse relationship between the expression of miR-221/miR-222 and the cell cycle inhibitor p27Kip1 was identified in U251 glioma cells. Co-suppression of miR-221/222 directly resulted in the up-regulation of p27Kip1 in the tested cells, consequently, affects their growth potential by reducing a G1 to S shift in the cell cycle. Consistently, miR-221/222 knocked-down through antisense 2'-OME-oligonucleotides increased p27Kip1 in U251 glioma subcutaneous mice and strongly reduced tumor growth in vivo through up regulation of p27Kip1. Our results suggest that miR-221/222 is a regulator of the tumor suppressor gene p27Kip1, and co-suppression of miR-221/222 expression in advanced gliomas may inhibit glioma cell proliferation by a mechanism involving the up-regulation of p27Kip1 in vitro and in vivo.

Transferrin (Tf), an iron-transporting serum glycoprotein, which binds to receptors expressed at the surface of most proliferating cells with particularly high expression on erythroblasts and cancer cells, was chosen as the ligand to develop BCNU-loaded biodegradable poly(D,L-lactic acid) nanoparticles (NPs) containing a ligand, which specifically binds to glioma cells, and their anti-tumor ability was evaluated using a C6 glioma model. In vitro drug release behavior demonstrated that BCNU-loaded PLA NPs show certain sustained release characteristics. NPs with low molecular weight PLA showed a higher burst effect and a significantly faster drug release from PLA samples. The biodistribution of Tf-coated nanoparticles investigated by 99Tc-labeled SPECT showed that the surface-containing transferrin PLA nanoparticles were concentrated in the brain and no radioactive foci could be found outside the brain. Inhibition of tumor growth in the C6 tumor-bearing animal model showed that BCNU-loaded PLA NPs had stronger cytotoxicity and prolonged the average survival time of rats. Especially when treated at an early stage with a higher dosage of NPs, the average survival time of rats was prolonged 88.37%. Furthermore, one rat maintained normal behavior continuously for an observation period of up to 60 days.

Glioblastoma multiforme (GBM) can arise de novo or progress from a lower to higher grade and can possess a series of genetic alterations and dynamic progressions, which have been correlated with the molecular pathology of GBM. Epidermal growth factor receptor (EGFR) has been shown to be overexpressed in a variety of tumors and is one of the important mediators responsible for the development of high-grade gliomas, especially in primary glioblastomas. Most recently, RNA interference (RNAi), in which double-stranded RNA (dsRNA) induces sequence-specific degradation of the targeting messenger RNA (mRNA), has been extensively developed and studied. RNAi is able to silence the targeted gene expression more efficiently and specifically. In the present study, we silence the EGFR expression using two separate short interfering RNAs (siRNAs) targeting the extracellular ligand-binding domain and intracellular tyrosine kinase domain, respectively. We demonstrate that suppression of EGFR expression, by using either antisense or siRNA approaches, inhibits U251 glioblastoma cell growth in vitro and in vivo, and siRNA seems to be more effective than the antisense approach.

Background: MicroRNAs (miRs) are small noncoding RNAs that bind to complementary/partially complementary sites in the 3' untranslated regions of target genes to regulate protein production of the target transcript and to induce mRNA degradation or mRNA cleavage. The ability to perform accurate, high-throughput identification of physiologically active miR targets would enable functional characterization of individual miRs. Current target prediction methods include traditional approaches that are based on specific base-pairing rules in the miR's seed region and implementation of cross-species conservation of the target site, and machine learning (ML) methods that explore patterns that contrast true and false miR-mRNA duplexes. However, in the case of the traditional methods research shows that some seed region matches that are conserved are false positives and that some of the experimentally validated target sites are not conserved., Results: We present HuMiTar, a computational method for identifying common targets of miRs, which is based on a scoring function that considers base-pairing for both seed and non-seed positions for human miR-mRNA duplexes. Our design shows that certain non-seed miR nucleotides, such as 14, 18, 13, 11, and 17, are characterized by a strong bias towards formation of Watson-Crick pairing. We contrasted HuMiTar with several representative competing methods on two sets of human miR targets and a set of ten glioblastoma oncogenes. Comparison with the two best performing traditional methods, PicTar and TargetScanS, and a representative ML method that considers the non-seed positions, NBmiRTar, shows that HuMiTar predictions include majority of the predictions of the other three methods. At the same time, the proposed method is also capable of finding more true positive targets as a trade-off for an increased number of predictions. Genome-wide predictions show that the proposed method is characterized by 1.99 signal-to-noise ratio and linear, with respect to the length of the mRNA sequence, computational complexity. The ROC analysis shows that HuMiTar obtains results comparable with PicTar, which are characterized by high true positive rates that are coupled with moderate values of false positive rates., Conclusion: The proposed HuMiTar method constitutes a step towards providing an efficient model for studying translational gene regulation by miRs.

Although potential contribution of endothelial progenitor cells (EPCs) to angiogenesis in glioma has been proposed, the molecular mechanisms of EPCs recruitment to vasculature have not been fully elucidated. Here, we show that the supernatant from glioma cells promotes EPCs angiogenesis via VEGFR-2, not VEGFR-1. Moreover, VEGFR-2 siRNA inhibits VEGFR-2 expression in EPCs, tube formation on matrigel and cell migration. MMP-9 activity and expression and the Akt and ERK phosphorylations are decreased by VEGFR-2 siRNA. Thus, these results indicate that glioma cells enhance EPC angiogenesis via VEGFR-2, not VEGFR-1, mediated by the MMP-9, Akt and ERK signal pathways.

Objective: To study the anti-invasion effect of SEPT7 gene on U251MG glioma cells and its possible molecular mechanism., Methods: Recombinant adenovirus vector carrying SEPT7 gene (rAd5-SEPT7) was transduced to human glioma cell line U251MG, and empty adenovirus vector was used as control. Tumor invasion was examined by Transwell method and 3 D-Matrigel assay, and tumor cell migration by wound-healing method and 2 D-Matrigel assay. Three major molecular events associated with cell motility and migration, including changes of expression in MMP2, MMP9, MT1-MMP, TIMP1 and TIMP2, the alteration of integrin alpha(v)beta(3) expression, and the structural change of cytoskeleton protein, tubulin-alpha, in U251 cells transduced with rAd5-SEPT7 were studied by Western blotting, immunofluorescence and laser scanning confocal microscope, respectively., Results: The invasive and migratory capabilities of cells transduced with rAd5-SEPT7 were inhibited. The expression of extracellular matrix metalloproteinases MMP-2, MMP-9, MT1-MMP and integrin alpha(v)beta(3) was significantly decreased, while the expression of matrix metalloproteinase inhibitor TIMP1, TIMP2 was upregulated. Intracellular cytoskeleton protein-tubulin-alpha in U251 cells exhibited prominent morphological changes which including the appearance of distortion and aggregation resulting from redistribution of tubulin-alpha, and this feature of alteration was similar to the tubulin-alpha structure in normal non-tumor cells., Conclusion: SEPT7 gene can inhibit the invasion and migration ability of U251 glioma cells. Its molecular mechanism may include that SEPT7 gene reverses the imbalanced state of MMPs/TIMPs, downregulates the expression of integrin alpha(v)beta(3) and alters the structure of tubulin-alpha of U251MG glioma cells. It is suggested that SEPT7 gene could be a good candidate for gene therapy of gliomas.

Glioma cells are characterized by their invasiveness and resistance against conventional therapeutics. Telomerase activity has been suggested to be an important target for glioma treatment. Here we assessed the anticancer effects and its potential mechanisms of lentiviral vector mediated siRNA knock-down of the human telomerase reverse transcriptase (hTERT) in U87MG human glioblastoma cells. Stable expression of anti-hTERT siRNA reduced the hTERT expression and TRAP assay telomerase activity to barely detectable levels. Injection of lentiviral vectors encoding anti-hTERT siRNA significantly inhibited the growth of pre-established macroscopic xenograft tumors, which was in contrast to the finding that no obvious effects on cell growth, cell cycle progression and telomere length were observed in anti-hTERT siRNA expressing U87MG cells during short-term in vitro cultures. The in vivo glioma growth inhibition effect was already evident in the period coincided with no detectable telomere length changes, suggesting that hTERT inhibition may hinder glioma cell growth in a telomere length-independent manner. Importantly, transwell migration assay showed profound inhibitory effect on the invasive capacity of U87MG cells following short-term anti-hTERT siRNA expression. Thus, efficient knock-down of hTERT can inhibit glioma cell proliferation and migration prior to its effect on telomere length.

Object: The 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., Methods: Stable 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 x 10(3) 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 10(6) 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.

EGFR overexpression is the most frequent and important molecular event in the development of astrocytic gliomas, and the P13K signaling pathway is one of the most important downstream pathways of EGFR. EGFR and other members of the receptor tyrosine kinases (RTKs) family, such as VEGFR, PDGFR, and IGFR, et cetera, are often overexpressed in most of malignant gliomas and share common downstream signaling pathways. Therefore, it is considered that directly targeting the downstream PI3K pathway may be more effective in blocking multiple inputs. The PIK3CB gene encoding the class 1A PI3K catalytic subunit p110beta was selected as the target of therapeutic approach for malignant gliomas in the present study. Human U251 glioblastoma cells with high endogenous p110beta expression were transfected with plasmid-based siRNA targeting PIK3CB gene. It was found that downregulation of p110beta expression resulted in the suppression of cell proliferation, arrest of cell cycle, reduction of cell invasion, and promotion of cell apoptosis in vitro. In addition, the growth of the subcutaneous U251 glioma in the nude mice treated with siRNA targeting PIK3CB was significantly inhibited. These results demonstrate that PIK3CB overexpression may play an oncogenic role in the PI3K pathway, and the plasmid-based siRNA targeting of PIK3CB is a potential and promising approach for the treatment of malignant gliomas.

The oncogenic role of AKT2 in the development of malignant gliomas was examined by using antisense approach. AKT2 expression was significantly inhibited in rat C6 glioma cells transfected with antisense AKT2 cDNA construct (LXSN-AS-AKT2). In addition, the transfected cells proliferated at a lowered level and apoptosis was induced. For in vivo studies, parental C6 cells and C6 cells transfected with LXSN-AS-AKT2 were implanted stereotactically into the right caudate nucleus of SD rats (control C6 group and transfected group). The rats bearing well-established C6 gliomas were treated with LXSN-AS-AKT2 DNA or LXSN (empty vector)-lipofectamine complexes intratumorally (treated group and control treated group). The mean survival of the rats of control C6 group and treated control group was 17.8+/-0.92 days and 17.5+/-1.10 days, respectively. The mean survival of the rats of transfected and treated group was significantly prolonged. MR images revealed distinct cerebral tumor foci in all of the control rats, whereas four rats in transfected group did not develop tumors and the tumor foci in five rats of treated group were regressed and disappeared. The expression of AKT2, PCNA, MMP2/9, and cyclin D were inhibited in the tumors of rats in transfected and treated groups while GFAP expression was increased. These results suggest that AKT pathway may play an important role in the development and progression of gliomas. Anti-AKT approach will open a new perspective for a targeted molecular therapy of malignant gliomas.

Aim: To clarify the contributions of ulinastatin to cellular immune responses in vivo, we examined the functional alterations of splenocytes and quantitatively evaluated the effects of ulinastatin on the splenocyte function during experimental severe acute pancreatitis., Methods: Severe acute pancreatitis was induced in rats by retrograde injection of 3% sodium deoxycholate. Thirty minutes after induction of pancreatitis, the rats were randomly assigned to four groups, receiving either saline or 50,000 U/kg of ulinastatin, respectively. Splenocytes were obtained aseptically and stimulated with concanavalin A for 24 h. Then the proliferative activity of cultured splenocytes was measured by using an MTT cellular proliferation assay, and the cytokine concentrations in the culture supernatants were measured by enzyme-linked immunosorbent assays., Results: Upon stimulation, the release of interleukin-2, interleukin-10, and interferon-gamma was significantly decreased in the splenocytes from rats with pancreatitis as compared with those from sham operation and control groups. The splenocyte proliferation was also significantly suppressed in this group. In contrast, the proliferative as well as the cytokine-releasing capacities of the splenocytes from rats treated with ulinastatin were significantly increased as compared with those from rats with pancreatitis., Conclusions: The deficiencies in proliferation and cytokine release in response to antigen stimulation demonstrated an anergic state of splenocytes during severe acute pancreatitis. Treatment with ulinastatin contributed to the recovery of the immune function by improving proliferative responses and cytokine release of splenocytes. These data suggest that a protease-modulating therapy may be an effective strategy for the treatment of immunosuppression induced by severe acute pancreatitis., (Copyright (c) 2006 S. Karger AG, Basel.)

Objective: To construct the small interfering RNA (siRNA) expression constructs targeting epidermal growth factor receptor(EGFR) and express them in TJ905 human malignant cells., Methods: Two target sequences from Receptor L domain and catalytic domain were selected to create two expression constructs using psiRNA-NeoG2. Furthermore, the siRNA constructs were transfected into TJ905 cells as mediated by Lipofectamin. Meanwhile, an antisense EGFR construct p-anti-hEGFR was set as control. Immunofluorescence and Western blot were performed to detect EGFR expression., Results: With the successful construction of the two siRNA expression plasmids and the stable transfection to TJ905 cells, the expression of EGFR was down-regulated to 90% and 92% respectively, but to 82% in the anti-sense EGFR group., Conclusion: The siRNA expression constructs targeting EGFR could specifically inhibit EGFR expression, and should be a new strategy in glioma gene therapy targeting EGFR.

The aim of this study was to explore the potential role of AKT2 in glioma cell invasion. Therefore, dominant-negative (DN-AKT2) and antisense AKT2 constructs (AS-AKT2) were transfected into rat C6 glioma cells with elevated endogenous AKT2 expression. In situ hybridization and Western blot analysis were used to identify AKT2 expression. Spheroid culturing was used to assess cell migration and invasion in Matrigel from spheroids. Cell motility and invasion were also evaluated by scratch and Transwell invasion assays, respectively. The secretion of matrix metalloproteinases (MMPs), MMP2 and MMP9, was determined by gelatin zymography. AKT2 expression was inhibited in C6 cells transfected with AS-AKT2 but did not significantly change in cells transfected with DN-AKT2. The cell migration distance from spheroids or the number of cells migrating into the acellular space created by scratching was reduced in cells transfected with DN-AKT2 or AS-AKT2 compared to the control cells. The invasive distance of cells from the spheroids in Matrigel sandwich and the number of invading cells through the Matrigel were also decreased in the DN-AKT2- and AS-AKT2-transfected cells. Gelatin zymography showed that the production of MMP2 and MMP9 was inhibited in transfected cells. In conclusion, AKT2 plays an important role in glioma cell motility and invasion. Therapy based on AKT inhibition may complement currently available treatment to control glioma cell invasion.

Objective: To study the gene expression profiles of oligodendrogliomas with gene cDNA array., Methods: (32)P tagged cDNA probes converted from the total RNA, which had been extracted from 2 fresh samples of oligodendroglioma and 1 of normal brain tissue, were hybridized with the Atlas array. After washing the membranes, the autoradiography was performed and the autoradiograms were analyzed through the special software., Results: As compared to the normal brain tissue, there were 63 co-upregulated genes and 4 co-downregulated genes in these 2 tumor samples. However, a significant quantitative difference existed between them. The expression trend of some genes differed from the known information., Conclusion: cDNA array is effective for studying the gene expression profiles of oligodendrogliomas and provides new information for the further research on their molecular mechanisms.