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ABSTRACT: Microglial cells are the predominant immune cells in malignant brain tumors, but tumors may release some factors to reduce their defensive functions. Restoration of the anti-cancer function of microglia has been proposed as a treatment modality for glioblastoma. We examined the effect of intra-cranially administered recombinant adeno-associated virus encoding interleukin-12 (rAAV2/IL12) on transfection efficiency, local immune activity and survival in a rat model of glioblastoma multiforme.
F344 rats were injected with rAAV2/IL12 and implanted with syngeneic RG2 cells (glioblastoma cell line). Intracerebral interleukin-12 and interferon-γ concentrations were determined by ELISA. Activation of microglia was determined by expressions of ED1 and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) which were evaluated by Western blotting and immunohistochemistry. The proliferation of cancer cells was evaluated with Ki67 immunohistochemistry and apoptosis of cancer cells with TUNEL.
The brains treated with rAAV2/IL-12 maintained high expression of interleukin-12 and interferon-γ for at least two months. In syngeneic tumor model, brains treated with rAAV2/IL12 exhibited more infiltration of activated microglia cells as examined by ED1 and TRAIL stains in the tumor. In addition, the volume of tumor was markedly smaller in AAV2/IL12-treated group and the survival time was significantly longer in this group too.
The intra-cerebrally administered rAAV2/IL-12 efficiently induces long lasting expression of IL-12, the greater infiltration of activated microglia cells in the tumor associated improved immune reactions, resulting in the inhibited growth of implanted glioblastoma and the increased survival time of these rats.
Journal of Biomedical Science 04/2012; 19:45. · 2.01 Impact Factor
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ABSTRACT: Augmentation of the cerebral blood supply to correct cerebral hemodynamic insufficiency by extracranial-intracranial bypass may be an appropriate method to reduce the risk of ischemic stroke. Eighty-five patients with ischemic symptoms, decreased regional cerebral blood flow, and decreased regional cerebrovascular reactivity were recruited for surgery. The post-bypass mean regional blood flow increased by 35.8% compared to the pre-bypass value (p<0.001). Only minor re-establishment of vasculature after anastomosis was detected in three of four patients with middle cerebral artery stenosis, which suggests that there are fewer benefits of bypass surgery in this situation. Cerebral infarction occurred immediately post-operation in one patient who was predisposed to stroke due to a bilateral carotid occlusion. Hyperperfusion injury was infrequent in this series; only one patient developed intracerebral hemorrhage three weeks after the bypass. One ischemic and one hemorrhagic stroke occurred during the 90 months following surgery.
Journal of Clinical Neuroscience 04/2012; 19(6):814-9. · 1.25 Impact Factor
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ABSTRACT: Microglia have been found to infiltrate into malignant brain tumors. However, their function is usually reversed by cancerous cells thus contributing to cancer growth and metastasis. We propose that microglial immuno-activity can be modulated with interleukin-12, by which the anti-cancer ability might be restored. To this end, a strategy was designed using AAV2 carrying interleukin-12 to activate microglia to eliminate cancerous cells. Under this strategy, recombinant AAV2 encoding interleukin-12 was constructed and evaluated for its transduction efficacy on cancerous and CNS cells. The bioactivity of microglia modulated by interleukin-12 was examined and death receptors 4 and 5 were detected on cancerous cells. The effects of interleukin-12 on microglial cytotoxicity were evaluated by MTT assay. The human cell line DBTRG, surgical specimens of GBM and rat astrocytes expressed AAV2-mediated GFP quite strongly. Interleukin-12 secretion was detected in DBTRG, RG2 and astrocytes after the transduction of AAV2 encoding interleukin-12. TRAIL releasing and phagocytotic activity of microglia were significantly increased after interleukin-12 stimulation. MTT assay of microglial cytotoxicity elicited significant increase after the stimulation with interleukin-12 protein. In conclusion, AAV2 is an effective vector in transferring therapeutic genes such as interleukin-12 to enhance microglial anti-cancer activity and to eliminate cancerous cells.
Oncology Reports 03/2011; 25(5):1373-80. · 1.84 Impact Factor
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ABSTRACT: Curcumin has been verified as an anti-cancer compound via multiple molecular targets. Its effective mechanisms include cell cycle arrest, inducing apoptosis, suppressing oncogenes, and enhancing tumor suppressor genes. The resistance of cells to chemotherapy, however, derives from the variable genetic aberration of cancer cells. Consequently, the core signaling pathways of glioblastoma have been explored to evaluate the efficacy of curcumin in proceeding through mutated genes in those pathways. In this study, the efficacy of curcumin was investigated in DBTRG cells. The cytotoxic ability was detected with MTT assay, and the influence of the cell cycle was checked with flow cytometry. The influence of the core signaling pathways was evaluated by Western blotting through the predominantly mutated proteins which included p53, p21, and cdc2 in the p53 pathway, CDKN2A/p16 and RB in the RB pathway, and EGFR, mTOR, Ras, PTEN, and Akt in the RTK-Ras-PI3K pathway. In addition, the apoptotic effect was determined by apoptosis-associated proteins Bcl-2, Bax, and caspase 3. Curcumin exhibits superior cytotoxicity on glioblastoma in a dose- and time-dependent manner in the MTT assay. In the core signaling pathways of glioblastoma, curcumin either significantly influences the p53 pathway by enhancing p53 and p21 and suppressing cdc2 or significantly inhibits the RB pathway by enhancing CDKN2A/p16 and suppressing phosphorylated RB. In the apoptotic pathway, the Bax and caspase 3 are significantly suppressed by curcumin and the Giemsa stain elucidates apoptotic features of DBTRG cells as well. In conclusion, curcumin appears to be an effective anti-glioblastoma drug through inhibition of the two core signaling pathways and promotion of the apoptotic pathway.
International Journal of Molecular Medicine 08/2010; 26(2):217-24. · 1.98 Impact Factor
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ABSTRACT: Tanshinone IIA (Tan-IIA) is extracted from Danshen and known to inhibit proliferation and induce apoptosis in many cancer cells. We aimed to elucidate its anticancer activity and molecular mechanism in human lung cancer A549 cells. The cytotoxicity of Tan-IIA in A549 cells were measured by the MTT assay. The effects of Tan-IIA on the cell cycle, mitochondrial membrane potential (MMP), calcium and reactive oxygen species (ROS) released in A549 cells were detected by flow cytometry. The protein expressions of p53, Bax, Bcl-2 and beta-actin in A549 cells were tested by Western blotting. The proliferative rates of A549 cells were obviously inhibited by Tan-IIA in a dose- and time-dependent manner. The results of FACS showed that the sub-G1 phase was increased when A549 cells were cultured with various concentrations of Tan-IIA (control, 2.5, 5 and 10 microg/ml) for 48 h. Tan-IIA induced the production of ROS, Ca+2 and decreased MMP. The outcome of Western blotting showed that protein expressions of p53 and bax were increased, but proto-oncogene bcl-2 was notably decreased, after culturing with Tan-IIA (5 microg/ml) for 6, 12 and 24 h. Tan-IIA inhibited the proliferation of non-small cell lung cancer A549 cells, possibly by decreasing the MMP and inducing apoptosis due to the induction of a higher ratio of Bax/Bcl-2.
International Journal of Molecular Medicine 02/2010; 25(2):231-6. · 1.98 Impact Factor
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ABSTRACT: Interleukin-12 has been elucidated as a powerful anti-cancer factor in pre-clinical research. However, the obstacles of this modality that emerged from human clinical trails included the toxicity of repeated large dose administration and short effective duration. Therefore, a prolonged, constant therapeutic level of interleukin-12 is required to reduce the adverse effects and enhance the therapeutic efficacy. In this study, 54 nude mice were divided into three groups treated with rAAV2 encoding interleukin-12, rAAV2 vector, and PBS, respectively. All nude mice received human glioblastoma multiforme cell line DBTRG implantation. The biochemistry studies included serum levels of interleukin-12, isotypes of immunoglobulin, interferon-gamma, and TNF-alpha. The activated NK cells were sorted from the spleen by flow cytometry and the cytotoxicity of NK cells were evaluated by LDH assay. In the rAAV2 encoding interleukin-12 group, substantial expression of interleukin-12 was obtained with a serum level of 120-150 pg/ml through the experimental course and a significant increase of activated NK cells was achieved. The splenocytes extracted from the spleen in rAAV2 encoding IL-12 mice strongly exhibited cytotoxic activity compared to the control groups (p<0.001). The IgG1, IgG2a, and IgM also showed a significant increase in the rAAV2 encoding IL-12 group compared to the control groups (p<0.05). The tumor growth rate decreased obviously in the rAAV2 encoding IL-12 group with a significant difference from the control groups (p<0.001). This study demonstrated an encouraging result of immunomodulative therapy in malignant brain tumors by rAAV2 carrying IL-12 through activating NK cells.
International Journal of Oncology 12/2009; 35(6):1361-7. · 2.40 Impact Factor
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ABSTRACT: Characterization of WM alteration using MR imaging is important in the pre- and intraoperative assessment of brain tumors. This study characterizes the extent and severity of WM tract alterations near brain tumors using DTI in an effort to determine preoperative viability or resectability of the adjacent WM tracts. Fractional anisotropy is an important DTI-derived metric of MR imaging.
Twenty-one patients underwent MR DTI. Eighty-six WM tracts composed of 43 WM lesions paired with 43 contralateral WM hemispheric controls were categorized using FA. Neuroradiologists categorized the WM tracts as edematous, displaced, disrupted, or infiltrated with tumor using directionally encoded color maps. A mixed model analysis was used to compare FA.
Of the lesioned tracts, 5 were scored as edema, 9 as infiltration, 18 as displacement, and 11 as disruption. A significant DeltaFA(%) was found between the lesioned and contralateral hemispheres only in WM disruption (P = .0056). Both edema FA and disruption FA are significantly less than displacement FA (P < .05). The FA change (DeltaFA(%) = [FA(lesion) - FA(normal)]/FA(normal) x 100%) on the lesioned side was calculated. A DeltaFA% less than -30% is likely to be associated with WM disruption. A positive DeltaFA% is likely to be associated with edema or displacement, and a DeltaFA% between 0% and -30% is likely to be associated with WM displacement or infiltration.
Quantitative analysis of DTI data may provide insight as to whether WM tracts are salvageable preoperatively.
Surgical Neurology 07/2009; 72(5):464-9; discussion 469. · 1.67 Impact Factor
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ABSTRACT: Most recent studies on the effectiveness of cerebral revascularization have focused on the treatment of atherosclerotic internal carotid artery occlusive disease. The goal of the present study was to assess neurological function in 11 severe atherosclerotic middle cerebral artery (MCA) disease patients with transient ischemic attacks (TIAs) and hemodynamic compromise and determine the efficacy of superficial temporal artery-middle cerebral artery (STA-MCA) bypass. There were eight patients with MCA occlusion and three with severe MCA stenosis. After the bypass procedure, all 11 patients experienced reduction in TIAs and no stroke during a mean follow-up of 34.36 months. Surgical revascularization increased regional cerebral blood flow (mL/100g/min) from a mean of (+/- standard deviation) 25.9+/-7.39 preoperatively to 32.3+/-7.72 postoperatively, and improved regional cerebrovascular reactivity from -6.42%+/-14.61% to 30.14%+/-23.93% (p = 0.014) in the eight patients with atherosclerotic MCA occlusion. Our findings demonstrated the benefit of STA-MCA bypass for patients with medically refractory and symptomatic atherosclerotic MCA occlusion with hemodynamic compromise.
Journal of Clinical Neuroscience 05/2009; 16(8):1013-7. · 1.25 Impact Factor
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ABSTRACT: Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), is extracted from the plant Curcuma longa. It has cytotoxic effects and induces apoptosis in many human cancer cells but the molecular mechanisms are not fully understood. In the present study, we evaluated the effects of curcumin on human breast cancer MDA-MB-231 cells. The cytotoxic effects of curcumin on MDA-MB-231 cells were measured by MTT assay. The percentages of cell cycle were determined by flow cytometry. The protein expressions of p21, 53, Bax and Bcl-2 were examined by Western blotting. The results show that curcumin inhibits the proliferation of MDA-MB-231 cells and induces G2/M arrest in a dose-dependent manner. Curcumin increased the protein expressions of p21 and Bax, but decreased the protein expression of p53 and Bcl-2 in MDA-MB-231 cells. Our results show that one molecular mechanism of curcumin inhibits the proliferation of MDA-MB-231 cells either through up-regulating p21 expression and then inducing apoptosis, or through up-regulating the Bax to Bcl-2 ratio and then inducing apoptosis. Our results also show that curcumin inhibits the migratory activity of MDA-MB-231 cells through down-regulating the protein expression of NF-kappaBp65. Accordingly, the therapeutic potential of curcumin for breast cancer deserves further study.
International Journal of Molecular Medicine 05/2009; 23(4):469-75. · 1.98 Impact Factor
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ABSTRACT: Bilateral mycotic aneurysms of the intracavernous segment of the internal carotid artery (ICA) are exceedingly rare. The authors present the case of a 46-year-old man with bilateral mycotic intracavernous carotid aneurysms, which were treated with a stent-assisted vessel wall remodeling technique with preservation of the parent arteries. The patient recovered quite satisfactorily after completing the whole course of treatment. Based on an extensive review of the literature, no reported case of bilateral mycotic aneurysm of the intracavernous segment of the ICA has been treated with this mode of endovascular therapy. This mode of treatment could be a therapeutic alternative for intracavernous mycotic aneurysms.
Journal of Neurosurgery 11/2007; 107(4):868-72. · 2.96 Impact Factor
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ABSTRACT: Microglia has been found to diversify its function by cancerous cells or in a cancerous environment, thereby contributing to cancer growth and metastasis. Its immuno-activity, however, can be modulated by interleukin-12. So a strategy was designed using AAV2 carrying IL-12 to activate microglia then to eliminate cancerous cells. The transduction efficacy of AAV was evaluated with AAV2 encoding GFP and IL-12 on cancerous and CNS cells. The bioactivity of microglia modulated by IL-12 was examined and death receptors 4 and 5 were detected on cancerous cells. The effects of IL-12 and AAV2/IL-12 on microglial cytoxoxicity were evaluated too. The results demonstrated human cell line DBTRG, surgical specimen of GBM, and rat astrocyte expressed GFP quite well. Tremendous IL-12 secretion was detected in DBTRG, RG2, and astrocyte after transfection of AAV2/IL-12. TRAIL releasing and phagocytotic activity of microglia were significant, increasing (p<0.05) after the stimulation of IL-12. DR4 and DR5 were expressed in all of the examined GBM cells. MTT assay of microglial cytotoxicity elicited significant increase (p<0.05) when the IL-12 protein or RG2-secreting IL-12 could have contact with microglial cells. Conclusively, AAV2 is an effective vector in transferring therapeutic genes such as IL-12 to induce or enhance microglial anti-cancer activity.
Nature Precedings.
