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Aim To detect the expression of miRNA-99b and mTOR in glioma tissues and to investigate the effect of miRNA-99b on the cell invasion ability of hu-man glioma cell line U251. Methods The expres-sions of miRNA-99b and mTOR mRNA in glioma tis-sues and normal brain tissues were detected by real-time PCR. After co-transfection with miRNA-99b mim-ics and wild or mutation type mTOR 3′UTR recombina-tion vector,the specific binding ability of miRNA-99b to 3′-UTR in mTOR gene was examined by luciferase gene reporter system. The expression levels of miRNA-99b,mTOR mRNA and mTOR protein in glioma cell line U251 after transfected with miRNA-99b mimics were measured by real-time PCR and Western blot,re-spectively. The cell invasion was measured by Tran-swell assay. The changes of mTOR and miRNA-99b expression levels in U251 cells after transfection with mTOR PsiCHECK were detected by real-time PCR. The correlation between the expression of miRNA-99b and prognosis was analyzed statistically. Results The expressed level of miRNA-99b was lower, and the ex-pression level of mTOR was higher in the glioma tissues than that in the normal brain tissues. The expression of miRNA-99b was up-regulated, and the expressions of mTOR mRNA and protein were down-regulated in U251 cells after transfection with miRNA-99b mimics. However, the abilities of invasion of U251 cells after transfection with miRNA-99b mimics were inhibited. The relative protein expression levels of mTOR in mTOR PsiCHECK group were significantly different from those in negative control group, but the relative expression levels of miRNA-99b had no signifi-cant difference compared with those in negative control group. Over-expression of mTOR restored the abilities of cell invasion in U251 cells, which was reduced by miRNA-99b. The Kaplan—Meier analysis and Log-Rank Test showed that there were significant differ-ences in overall survival (OS) between the miRNA-99b high-expression and low-expression group. Con-clusions The expression level of miRNA-99b is low in human glioma tissue. miRNA-99b may inhibit the cell invasion activity of glioma cell line U251 in vitro via inhibiting mTOR expression.
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Objective To investigate the effects of transient axonal glycoprotein-1 (TAG-1) on activity of U251 cells and expressions of AICD, p53 and EGFR genes in the cells. Methods The viability of U251 cells was tested by MTT assay at 48 h following the addition of various concentrations of TAG-1 (0, 5, 10 and 20 μg/mL). The expression ofamyloid precursor protein (ALP) was detected by immunofluorescent staining. The apoptotic cells were examined by TUNEL. Real-time PCR was employed to detect the influence of TAG-1 on the expressions of AICD, p53 and EGFR genes in U251 cells. Results TAG-1 did not play an inhibitory effect on the proliferation of the U251 cells. APP was abundantly expressed on membrane of the U251 cells. U251 cells did not show apoptotic cells but increased expressions of AICD, p53 and EGFR genes were noted when U251 cells were exposed at 10 μg/mL of TAG-1. Conclusion TAG-1 plays an important role in regulating the proliferation of glioma and may not induce the apoptosis of U251 cells through the signal pathway of TAG-1/APP/AICD/p53 or TAG- 1/APP/AICD/EGFR.
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Objective To map the vision cortex of rats by dynamic manganese-enhanced functional magnetic resonance imaging and provide a method for researching the nervous function. Methods Six adult male Wistar rats were chosen and the process was divided into 4 continuous phases. No agent was injected into the rats in the first phase (5 min). Disrupting the BBB with marmitol and injecting manganese chloride were performed in the fight internal carotid artery (ICA) in the second phase (10 min). In the third phase (15 min), manganese chloride was administrated into theright ICA and vision stimulation was performed before the imaging process. The mixed liquor of manganese chloride and glutamate was injected into the rats in the forth phase (5 min). MRI was performed instantly after the handles in each phase. SPM and Matlab software were employed to help analyze the imaging data. Region-of-interest (ROI) was recorded to observe the stimulated regions and compare the signal intensity in the visual cortex. Results No specific enhanced region was found in the rat brain in the first and second phases. The right visual cortex was enhanced specifically on T1WI in the third phase. Many brain regions of the right hemisphere, the sites that agents was injected, were obviously enhanced in the forth 2008A1-E4011)phase. ROI analysis showed that the signal intensity in the third phrase (1.897±0.172) was significantly stronger as compared with that in the second phrase(1.549±0.163)(P<0.05). Conclusion The dynamic manganese-enhanced functional magnetic resonance imaging can analyze the functional activities of the vision cortex in rats and provide a new method for researching the function of the nervous system.