BACKGROUND: Growing evidence suggests that long non-coding RNAs (lncRNAs) exert pivotal roles in fostering chemoresistance across diverse tumors. Nevertheless, the precise involvement of lncRNAs in modulating chemoresistance within the context of gallbladder cancer (GBC) remains obscure. This study aimed to uncover how lncRNAs regulate chemoresistance in gallbladder cancer, offering potential targets to overcome drug resistance. METHODS: To elucidate the relationship between gemcitabine sensitivity and small nucleolar RNA host gene 1 ( SNHG1 ) expression, we utilized publicly available GBC databases, GBC tissues from Renji Hospital collected between January 2017 and December 2019, as well as GBC cell lines. The assessment of SNHG1, miR-23b-3p, and phosphatase and tensin homolog (PTEN) expression was performed using in situ  hybridization, quantitative real-time polymerase chain reaction, and western blotting. The cell counting kit-8 (CCK-8) assay was used to quantify the cell viability. Furthermore, a GBC xenograft model was employed to evaluate the impact of SNHG1 on the therapeutic efficacy of gemcitabine. Receiver operating characteristic (ROC) curve analyses were executed to assess the specificity and sensitivity of SNHG1. RESULTS: Our analyses revealed an inverse correlation between the lncRNA SNHG1 and gemcitabine resistance across genomics of drug sensitivity in cancer (GDSC) and Gene Expression Omnibus (GEO) datasets, GBC cell lines, and patients. Gain-of-function investigations underscored that SNHG1 heightened the gemcitabine sensitivity of GBC cells in both in vitro and in vivo  settings. Mechanistic explorations illuminated that SNHG1 could activate PTEN -a commonly suppressed tumor suppressor gene in cancers-thereby curbing the development of gemcitabine resistance in GBC cells. Notably, microRNA (miRNA) target prediction algorithms unveiled the presence of miR-23b-3p binding sites within SNHG1 and the 3'-untranslated region (UTR) of PTEN . Moreover, SNHG1 acted as a sponge for miR-23b-3p, competitively binding to the 3'-UTR of PTEN , thereby amplifying PTEN expression and heightening the susceptibility of GBC cells to gemcitabine. CONCLUSION The SNHG1/miR-23b-3p/PTEN axis emerges as a pivotal regulator of gemcitabine sensitivity in GBC cells, holding potential as a promising therapeutic target for managing GBC patients.
Humans ; Deoxycytidine/pharmacology* ; PTEN Phosphohydrolase/genetics* ; Gemcitabine ; RNA, Long Noncoding/metabolism* ; MicroRNAs/genetics* ; Gallbladder Neoplasms/genetics* ; Cell Line, Tumor ; Animals ; Mice ; Drug Resistance, Neoplasm/genetics* ; Mice, Nude ; Antimetabolites, Antineoplastic ; Gene Expression Regulation, Neoplastic

This study aimed to investigate the effects of Zhiwei Fuwei Pills on mitochondrial apoptosis in the rat model of precancerous lesions of gastric cancer(PLGC) based on the microRNA-21(miRNA-21)/B-cell lymphoma-2(Bcl-2) signaling pathway. Eighty-five 5-week-old male SPF-grade SD rats were selected, of which 75 were fed with N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) for multifactorial modeling, and the PLGC model was established after 26 weeks. The rats were randomly grouped as follows: model, folic acid(0.002 g·kg~(-1)), low-dose(0.42 g·kg~(-1)) Zhiwei Fuwei Pills, medium-dose(0.84 g·kg~(-1)) Zhiwei Fuwei Pills, and high-dose(1.67 g·kg~(-1)) Zhiwei Fuwei Pills, with 15 rats in each group. Additionally, 10 rats were assigned to a blank group and administrated with an equivalent volume of normal saline by gavage. After four weeks of continuous drug administration, the gastric mucosal tissue was collected. Hematoxylin-eosin(HE) staining was performed to reveal the pathological changes in the gastric mucosa. Terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL) was employed to detect apoptosis in gastric mucosal epithelial cells. RT-PCR was adopted to determine the mRNA levels of miRNA-21, phosphatase and tensin homolog(PTEN), Bcl-2, Bcl-2-associated X protein(Bax), and cysteinyl aspartate-specific protease 3(caspase-3). Western blot was employed to determine the protein levels of PTEN, Bcl-2, Bax, and caspase-3. Immunohistochemistry(IHC) was used to detect the positive expression of PTEN, Bcl-2, and Bax in the gastric mucosal tissue. Transmission electron microscopy(TEM) was employed to observe the morphological and structural changes in mitochondria. The results showed that compared with model group, the drug administration groups showed alleviated pathological changes, with increased apoptotic cells, down-regulated mRNA levels of miRNA-21 and Bcl-2, up-regulated mRNA and protein levels of PTEN, Bax, and caspase-3, and down-regulated protein level of Bcl-2. In addition, the drug administration groups exhibited mitochondrial swelling and rupture and reduction of cristae, which indicated mitochondrial apoptosis. These findings suggest that Zhiwei Fuwei Pills can effectively improve mitochondrial apoptosis in PLGC cells by regulating the miRNA-21/Bcl-2 signaling pathway.
Animals ; MicroRNAs/metabolism* ; Male ; Apoptosis/drug effects* ; Stomach Neoplasms/physiopathology* ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Rats ; Rats, Sprague-Dawley ; Drugs, Chinese Herbal/administration & dosage* ; Mitochondria/genetics* ; Signal Transduction/drug effects* ; Precancerous Conditions/drug therapy* ; Humans ; PTEN Phosphohydrolase/genetics*

OBJECTIVE: To investigate the influence and mechanism of atorvastatin on glycolysis of adriamycin resistant acute promyelocytic leukemia (APL) cell line HL-60/ADM. METHODS: HL-60/ADM cells in logarithmic growth phase were treated with different concentrations of atorvastatin, then the cell proliferation activity was measured by CCK-8 assay, the apoptosis was detected by flow cytometry, the glycolytic activity was checked by glucose consumption test, and the protein expressions of PTEN, p-mTOR, PKM2, HK2, P-gp and MRP1 were detected by Western blot. After transfection of PTEN-siRNA into HL-60/ADM cells, the effects of low expression of PTEN on atorvastatin regulating the behaviors of apoptosis and glycolytic metabolism in HL-60/ADM cells were further detected. RESULTS: CCK-8 results showed that atorvastatin could inhibit the proliferation of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.872, r=0.936), and the proliferation activity was inhibited most significantly when treated with 10 μmol/L atorvastatin for 24 h, which was decreased to (32.3±2.18)%. Flow cytometry results showed that atorvastatin induced the apoptosis of HL-60/ADM cells in a concentration-dependent manner (r=0.796), and the apoptosis was induced most notably when treated with 10 μmol/L atorvastatin for 24 h, which reached to (48.78±2.95)%. The results of glucose consumption test showed that atorvastatin significantly inhibited the glycolytic activity of HL-60/ADM cells in a concentration-dependent and time-dependent manner (r=0.915, r=0.748), and this inhibition was most strikingly when treated with 10 μmol/L atorvastatin for 24 h, reducing the relative glucose consumption to (46.53±1.71)%. Western blot indicated that the expressions of p-mTOR, PKM2, HK2, P-gp and MRP1 protein were decreased in a concentration-dependent manner (r=0.737, r=0.695, r=0.829, r=0.781, r=0.632), while the expression of PTEN protein was increased in a concentration-dependent manner (r=0.531), when treated with different concentrations of atorvastatin for 24 h. After PTEN-siRNA transfected into HL-60/ADM cells, it showed that low expression of PTEN had weakened the promoting effect of atorvastatin on apoptosis and inhibitory effect on glycolysis and multidrug resistance. CONCLUSION Atorvastatin can inhibit the proliferation, glycolysis, and induce apoptosis of HL-60/ADM cells. It may be related to the mechanism of increasing the expression of PTEN, inhibiting mTOR activation, and decreasing the expressions of PKM2 and HK2, thus reverse drug resistance.
Humans ; Atorvastatin/pharmacology* ; PTEN Phosphohydrolase/pharmacology* ; Sincalide/metabolism* ; Drug Resistance, Neoplasm/genetics* ; TOR Serine-Threonine Kinases/metabolism* ; Leukemia, Promyelocytic, Acute/drug therapy* ; Doxorubicin/pharmacology* ; Apoptosis ; RNA, Small Interfering/pharmacology* ; Glycolysis ; Glucose/therapeutic use* ; Cell Proliferation

Objective: To investigate the effect of adenovirus-mediated shRNA down-regulating phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on vinculin, filamin A, and cortactin in activated hepatic stellate cells (HSCs). Methods: Activated rats hepatic stellate cell line (HSC-T6) was cultured in vitro. Recombinant adenovirus Ad-shRNA/PTEN carrying PTEN targeted RNA interference sequence [short hairpin RNA (shRNA)] and empty control virus Ad-GFP were transfected into HSCs. The PTEN mRNA and protein expression of HSCs in each group were detected by real-time fluorescence quantitative PCR and Western blot. The expressional change of vinculin, filamin A and cortactin in HSCs of each group were detected by confocal laser scanning immunofluorescence microscope. Image-pro plus 6.0 software was used for image analysis and processing. The integrated optical density (IOD) of the fluorescence protein expression was measured. The experiment was divided into three groups: control group (DMEM instead of adenovirus solution in the adenovirus transfection step), Ad-GFP group (transfected with empty virus Ad-GFP only expressing green fluorescent protein), and Ad-shRNA/PTEN group (recombinant adenovirus Ad-shRNA/PTEN carrying shRNA targeting PTEN and expressing green fluorescent protein). One-way analysis of variance was used for comparison of mean value among the three groups, and LSD-test was used for comparison between the groups. Results: shRNA targeted PTEN was successfully transfected and the expression of PTEN mRNA and protein in HSC (P < 0.05) was significantly down-regulated. HSCs vinculin was mainly expressed in the cytoplasm. HSCs vinculin fluorescence IOD in the Ad-shRNA/PTEN group (19 758.83 ± 1 520.60) was higher than control (7 737.16 ± 279.93) and Ad-GFP group (7 725.50 ± 373.03) (P < 0.05), but there was no statistically significant difference between control group and Ad-GFP group (P > 0.05). There was no statistically significant difference in the fluorescence IOD of Filamin A among the three groups (P > 0.05), but the subcellular distribution of Filamin A among the three groups were changed. Filamin A in the Ad-shrNA /PTEN HSC group was mainly distributed in the cytoplasm. Filamin A HSC was mainly located in the nucleus.The filamin A HSC in the control group and Ad-GFP group was mainly located in the nucleus. The nucleocytoplasmic ratio of Filamin A in the AD-shrNA /PTEN group (0.60 ± 0.15) was significantly lower than control group (1.20 ± 0.15) and Ad-GFP group (1.08 ± 0.23), P < 0.05. but there was no statistically significant difference in filamin A nucleocytoplasmic ratio of HSC between the control group and the Ad-GFP group (P > 0.05). Cortactin HSCs in the three groups was mainly distributed in the cytoplasm. The cortactin fluorescence IOD of HSCs in the Ad-shRNA/PTEN group was significantly higher than control group (22 959.94 ± 1 710.42) and the Ad-GFP group (22 547.11 ± 1 588.72 ) (P < 0.05), while there was no statistically significant difference in the IOD of cortactin fluorescence in HSCs between the control group and the Ad-GFP group (P > 0.05). Conclusion: The down-regulation of PTEN expression raises the expression of microfilament-binding protein vinculin and cortactin, and changes the subcellular distribution of another microfilament binding protein filamin A, that is, translocation from nucleus to the cytoplasm in activated HSC in vitro.
Adenoviridae/metabolism* ; Animals ; Carrier Proteins ; Cell Proliferation ; Cortactin ; Filamins/genetics* ; Hepatic Stellate Cells/metabolism* ; PTEN Phosphohydrolase/metabolism* ; RNA, Small Interfering/genetics* ; Rats ; Vinculin/genetics*

Objective: To explore the effect of growth arrest-specific5 (GAS5) inhibition on the proliferation, colony formation, invasion, migration andepithelial-mesenchymal transition(EMT), cancer cell stem of HCT-116 and its mechanism. Methods: The colorectal carcinoma (CRC) cell HCT116 was divided into blank control, negative control (NC), si-GAS5 and si-GAS5+ miR-21 inhibitor groups. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to test the expressions of miR-21 and GAS5 at 48 h after transfection. The binding site of GAS5 and miR-21 was determined by luciferase reporter array. Cell proliferation ability was detected by CCK-8 assay. Cell colony ability was detected by colony formation assay. Cell invasion and migration abilities were detected by Transwell assay. Cell cycle and apoptosis were examined by flow cytometer (FCM). The protein levels of EMT associated factors including Snail, N-cadherin, vimentin, E-cadherin, stem cell related factors including CD44, SOX2, Oct2, and PTEN/Akt signal pathway associated factors were examined by western blotting. Results: The expression levels of miR-21 in blank, NC, si-GAS5 group were 1.00±0.10, 1.00±0.10, 1.80±0.20, the absorbance values were 0.51±0.02, 0.50±0.01 and 0.65±0.01, the cell clones were 90±4, 91±5, 200±8, the invaded cells were 118±3, 119±3, 150±4, the migrated cells were 110±2, 108±2, 127±2, the cell ratios in G(1) phase were (49.3±2.1)%, (50.1±2.0)% and (42.2±1.1)%, the cell ratios in S phase were (19.2±1.2)%, (20.2±1.1)% and (28.3±2.2)%, the cell apoptotic ratios were (14.4±2.2)%, (14.5±2.1)% and (7.2±1.3)%. These results indicated that inhibition of GAS5 up regulated the expression level of miR-21, promoted cell proliferation, invasion and migration, decreased G(1)-phase cells and increased S-phase cells, and suppressed cell apoptosis (P<0.05). Moreover, inhibition of GAS5 up regulated the expressions of Snail, N-cadherin, vimentin, Sox2, CD44, Oct2 and p-Akt in HCT-116 cells (P<0.05), while down regulated the expressions of E-cadherin and PTEN (P<0.05). Inhibition of miR-21 reversed the impact of GAS5 knockdown on PTEN/Akt signaling pathway (P<0.05). Conclusion: GAS5 can act as a competing endogenous RNA for miR-21, and down regulation of GAS5 can promote the development of CRC by activating the miR-21/PTEN/Akt signaling pathway and promoting the acquisition of EMT and tumor cell stemness.
Humans ; Cadherins/metabolism* ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Colorectal Neoplasms/pathology* ; Epithelial-Mesenchymal Transition/genetics* ; Gene Expression Regulation, Neoplastic ; MicroRNAs/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; PTEN Phosphohydrolase/metabolism* ; Vimentin/metabolism*

OBJECTIVETo investigate the relationship between plasma miR-93-5p and the risk of esophageal cancer, as well as the influence of miR-93-5p on the biological function of esophageal cancer cells, exerted through exosomes.

METHODSThe expression of plasma miR-93-5p in esophageal cancer patients and healthy controls was analysed by real-time quantitative PCR. The influence of miR-93-5p on the risk and prognosis of esophageal carcinoma was analyzed by conditional logistic regression and survival analysis. The effect of miR-93-5p on the biological function of recipient cells was investigated by establishing an in vitro donor cell co-culture model. The target gene of miR-93-5p was validated by luciferase reporter assay and Western Blotting.

RESULTSUpregulation of plasma miR-93-5p expression significantly increases the risk of esophageal cancer and is associated with poor prognosis. miR-93-5p transferred by exosomes promotes the proliferation of recipient esophageal cancer cells and affects the expression of PTEN and its downstream proteins p21 and cyclin D1.

CONCLUSIONOur study provides a reference for the identification of biomarkers for the diagnosis and prognosis of esophageal cancer.

Aged ; Cell Communication ; China ; Esophageal Neoplasms ; physiopathology ; Exosomes ; physiology ; Female ; Humans ; Male ; MicroRNAs ; metabolism ; Middle Aged ; PTEN Phosphohydrolase ; genetics ; metabolism ; Risk

To investigate the effect of Parkinson's disease related protein DJ-1 on the cell proliferation, apoptosis, invasion and migration in human osteosarcoma cells and the underlying molecular mechanisms. 
 Methods: The protein expression levels of DJ-1 were detected in human osteosarcoma cell lines (MG-63, Saos-2, and U2OS) and human osteoblast cell line hFOB1.19 with or without deficiency in phosphatase and tensin homolog deleted from chromosome 10 (PTEN) were detected by Western blot. Osteosarcoma cells were treated with DJ-1 siRNA, and then the protein expression levels of DJ-1 were detected by Western blot. Cell survival rate of osteosarcoma cells was detected by cell counting kit-8 (CCK-8) assay. Cell apoptosis of osteosarcoma cells was measured by annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double staining method. Cell invasive and migration ability of osteosarcoma cells were examined by transwell invasion and migration assay. 
 Results: Compared with that of human osteoblast cell line (hFOB1.19), the protein expression level of DJ-1 was significantly upregulated in human osteosarcoma cell lines (MG-63, Saos-2, and U2OS) (all P<0.05), and U2OS had the highest level of DJ-1 when compared with the other three cell lines (P<0.01). DJ-1 siRNA could significantly down-regulate the DJ-1 protein expression in U2OS cells, and also diminish the cell survival rate. Moreover, DJ-1 down-regulation of DJ-1 could promote cell apoptosis, suppress the ability of cell invasion and migration, and increase the PTEN protein expression level (all P<0.05). In addition, the protein expression level of PTEN was markedly up-regulated in human osteosarcoma cell lines when compared with that in the hFOB1.19 cells (P<0.05). 
 Conclusion: DJ-1 can promote the cell proliferation, inhibit cell apoptosis, and decrease the ability of cell invasion and migration, and the potential underlying mechanisms may be associated with the up-regulation of PTEN protein expression.
Apoptosis ; genetics ; Cell Line, Tumor ; Cell Movement ; genetics ; Cell Proliferation ; genetics ; Gene Expression Regulation, Neoplastic ; Humans ; Neoplasm Invasiveness ; genetics ; PTEN Phosphohydrolase ; genetics ; Parkinson Disease ; physiopathology ; Protein Deglycase DJ-1 ; genetics ; metabolism ; RNA, Small Interfering ; genetics

The aim of this paper was to observe the effect of gambogenic acid on angiogenesis of lung cancer and its preliminary mechanism. After culturing lung adenocarcinoma A549 cells, the conditioned medium was treated with gambogenic acid and then used to culture human umbilical vein endothelial cells (HUVECs) to establish the indirect contact cell co-culture system. A two-dimensional culture model of HUVEC was established with matrigel to observe the effect of gambogenic acid on angiogenesis. DAPI staining was used to observe the morphological changes in HUVEC cells after treatment with gambogenic acid under the fluorescence microscope. Annexin V-FITC/PI staining and flow cytometry analysis were used to determine gambogenic acid's effect on HUVEC cell apoptosis rate. The protein expressions of PI3K, p-PI3K, Akt, p-Akt were measured by Western blot. PTEN-siRNA was transfected into cells, and RT-PCR was used to detect the expression levels of PI3K and Akt genes. Gambogenic acid can significantly inhibit angiogenesis, and its inhibitory effect was dose-dependent. DAPI staining showed apoptotic morphological features of HUVEC cells under fluorescence microscope. Annexin V-FITC/PI staining showed that gambogenic acid induced apoptosis in HUVECs. The results of Western blot showed that the expressions of p-PI3K and p-Akt protein were down-regulated with gambogenic acid, while the expressions of PI3K and Akt protein was insignificant. The results of RT-PCR indicated that the expressions of PI3K and Akt protein were up-regulated by PTEN siRNA. Gambogenic acid can inhibit angiogenesis in lung cancer in vitro, and the mechanism of inhibiting angiogenesis may be related to the PI3K/Akt signaling pathway.
A549 Cells ; Apoptosis ; Coculture Techniques ; Human Umbilical Vein Endothelial Cells ; drug effects ; Humans ; Lung Neoplasms ; drug therapy ; pathology ; Neovascularization, Pathologic ; pathology ; PTEN Phosphohydrolase ; genetics ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Transfection ; Xanthenes ; pharmacology

BACKGROUNDApoptosis of endothelial cells (ECs) plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a viable target in therapeutic approaches to prevent vascular ECs apoptosis. Aberrant miR-106b-5p expression has been reported in the plasma of patients with unstable atherosclerotic plaques. However, the role and underlying mechanism of miR-106-5p in the genesis of atherosclerosis have not been addressed. In this study, we explored the anti-apoptotic role of miR-106-5p by regulating PTEN expression in vascular ECs.

METHODSReal-time reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the expression levels of miR-106b-5p in human atherosclerotic plaques and normal vascular tissues. Human umbilical vein endothelial cells (HUVEC) were transfected with miR-106b-5p mimic or negative control mimic, and apoptosis was induced by serum starvation and tumor necrosis factor-α (TNF-α) treat. Western blotting and real-time RT-PCR experiments were used to detect PTEN expression levels and TNF-α-induced apoptosis was evaluated by the activation of caspase-3 and cell DNA fragmentation levels in HUVEC.

RESULTSThe expression of miR-106b-5p was significantly downregulated in plaques than in normal vascular tissues. TNF-α significantly downregulated miR-106b-5p expression levels and upregulated activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Overexpression of miR-106b-5p with miR-106b-5p mimic inhibited PTEN expression and TNF-α-induced apoptosis in HUVEC. Luciferase reporter assays confirmed that miR-106b-5p binds to PTEN mRNA 3' untranslated region site.

CONCLUSIONMiR-106b-5p could inhibit the expression of PTEN in vascular ECs, which could block TNF-α-induced activation of caspase-3, thus prevent ECs apoptosis in atherosclerosis diseases.

Adult ; Aged ; Apoptosis ; drug effects ; Cells, Cultured ; Endothelial Cells ; cytology ; drug effects ; metabolism ; Female ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; metabolism ; Humans ; Male ; MicroRNAs ; genetics ; metabolism ; Middle Aged ; PTEN Phosphohydrolase ; metabolism ; Protein Binding ; drug effects ; Real-Time Polymerase Chain Reaction ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo investigate the role and molecular mechanism of membrane-associated guanylate kinase inverted 3 (MAGI3) in glioma cell proliferation.

METHODSThe expression levels of MAGI3 and PTEN were assessed in glioma samples by Western blotting. MAGI3 was stably transfected into C6 glioma cells to obtain C6-MAGI3 cells. Then, the proliferation, the expression levels of MAGI3 and PTEN, and Akt phosphorylation were evaluated in C6 and C6-MAGI3 cells. Xenograft tumor models were established by subcutaneous injection of C6 and C6-MAGI3 cells into nude mice, and the growth rates of xenografts in the mice were compared. The potential role of MAGI3 expression in PI3K/Akt signaling activation was further investigated by examining the correlation between MAGI3 expression and the expression of PI3K/Akt signaling downstream target genes in a glioma dataset using gene set enrichment analysis (GSEA).

RESULTSExpression levels of MAGI3 and PTEN were significantly downregulated in gliomas. Overexpression of MAGI3 in the glioma C6 cell line upregulated PTEN protein expression, inhibited the phosphorylation of Akt, and suppressed cell proliferation. MAGI3 overexpression also inhibited the growth of C6 glioma tumor xenografts in nude mice. Analysis based on the GEO database confirmed the negative correlation between activation of PI3K/Akt pathway and MAGI3 mRNA levels in human glioma samples.

CONCLUSIONThe loss of MAGI3 expression in glioma may enhance the proliferation of glioma cells via downregulation of PTEN expression, leading to the activation of the PI3K/Akt pathway. MAGI3 is a potential glioma suppressor.

Animals ; Brain Neoplasms ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; genetics ; Down-Regulation ; Glioma ; genetics ; metabolism ; pathology ; Humans ; Membrane Proteins ; genetics ; metabolism ; Mice, Nude ; PTEN Phosphohydrolase ; genetics ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats ; Signal Transduction ; Transfection ; Up-Regulation ; Xenograft Model Antitumor Assays