ABSTRACT
Chemotherapy on gliomas is not satisfactorily efficient because the presence of blood-brain barriers (BBB) leads to inadequate exposure of tumor cells to administered drugs. In order to facilitate chemotherapeutics to penetrate BBB and increase the treatment efficacy of gliomas, electromagnetic pulse (EMP) was applied and the 1-(2-Chlorethyl)-cyclohexyl-nitrosourea (CCNU) lomustine concentration in tumor tissue, tumor size, tumor apoptosis, and side effects were measured in glioma-bearing rat model. The results showed that EMP exposure could enhance the delivery of CCNU to tumor tissue, facilitate tumor apoptosis, and inhibit tumor growth without obvious side effects. The data indicated that EMP-induced BBB disruption could enhance delivery of CCNU to glioblastoma multiforme and increase treatment efficacy in glioma-bearing rats. Bioelectromagnetics. 39:60-67, 2018. © 2017 Wiley Periodicals, Inc.
Subject(s)
Antineoplastic Agents/metabolism , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/radiation effects , Drug Delivery Systems/methods , Electromagnetic Phenomena , Glioblastoma/drug therapy , Glioblastoma/metabolism , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Cell Line, Tumor , Glioblastoma/pathology , Male , Rats , Rats, Sprague-Dawley , Treatment Outcome , Tumor Burden/drug effectsABSTRACT
Metformin has received increasing attention for its potential anticancer activity against certain human leukemia cells, but its effects on human megakaryoblastic cells are unclear. This study aimed to investigate the effects of metformin on proliferation and apoptosis of human megakaryoblastic cells (Dami and MEG-01) and the underlying molecular mechanisms. CCK8 assay was employed to measure cell proliferation. Flow cytometry was adopted to detect cell apoptosis. Western blot was further employed to measure apoptosis-related proteins. In Dami and MEG-01 cells, metformin significantly inhibited proliferation and promoted apoptosis in a dose- and time-dependent manner, and metformin (4 mM) was selected for subsequent experiments. Metformin inhibited ERK1/2, JNK, and PI3K/Akt, but activated p38 pathway in these two cells. Moreover, inhibition of ERK1/2, JNK or PI3K/Akt pathway alone induced cell apoptosis compared to the control group. The combination of specific inhibitors of ERK1/2, JNK or PI3K/Akt pathway and metformin further promoted cell apoptosis and the up-regulation of p21, Bax, Bad, cleaved caspase-3 and -9 as well as the down-regulation of Bcl-2 mediated by metformin alone, but inhibition of p38 pathway exhibited the opposite results. These findings support the possibility of metformin treatment as a new therapeutic strategy against acute megakaryoblastic leukemia (AMKL).
Subject(s)
Apoptosis/drug effects , Apoptosis/genetics , Cell Proliferation/drug effects , Cell Proliferation/genetics , Hypoglycemic Agents/pharmacology , Megakaryocyte Progenitor Cells/cytology , Megakaryocyte Progenitor Cells/pathology , Metformin/pharmacology , Cell Line , Cells, Cultured , Dose-Response Relationship, Drug , Humans , Hypoglycemic Agents/therapeutic use , JNK Mitogen-Activated Protein Kinases , Leukemia, Megakaryoblastic, Acute/drug therapy , Leukemia, Megakaryoblastic, Acute/genetics , MAP Kinase Signaling System/genetics , MAP Kinase Signaling System/physiology , Metformin/therapeutic use , Molecular Targeted Therapy , Phosphatidylinositol 3-Kinases , Signal Transduction/drug effects , Signal Transduction/genetics , p38 Mitogen-Activated Protein KinasesABSTRACT
The biological effects of electromagnetic pulse (EMP) on the brain have been focused on for years. It was reported that gelatinase played an important role in maintaining brain function through regulating permeability in the blood-brain barrier (BBB). To investigate the effects of EMP on gelatinase of BBB, an in vitro BBB model was established using primary cultured rat brain microvascular endothelial cells (BMVEC), astrocytes and half-contact culture of these cells in a transwell chamber. Cultured supernatant and cells were collected at different time points after exposure to EMP (peak intensity 400 kV/m, rise time 10 ns, pulse width 350 ns, 0.5 pps and 200 pulses). Protein levels of cellular gelatinase MMP-2 and MMP-9, and endogenous inhibitor TIMP-1 and TIMP-2 were detected by Western blot. The activity of gelatinase in culture supernatant was detected by gelatin zymography. It was found that compared with the sham-exposed group, the protein level of MMP-2 was significantly increased at 6 h (p < 0.05), and the protein level of its endogenous inhibitor TIMP-2 did not change after EMP exposure. In addition, the protein levels of MMP-9 and its endogenous inhibitor TIMP-1 did not change after EMP exposure. Gelatin zymography results showed that the activity of MMP-2 in the inner pool and the outer pool of the transwell chamber was significantly increased at 6 h after EMP exposure compared with that of the sham group. These results suggested that EMP exposure could affect the expression and activity of MMP-2 in the BBB model.
Subject(s)
Blood-Brain Barrier/enzymology , Blood-Brain Barrier/radiation effects , Electromagnetic Phenomena , Gelatinases/metabolism , Animals , Blood-Brain Barrier/metabolism , Female , Gene Expression Regulation, Enzymologic/radiation effects , Male , Rats , Tissue Inhibitor of Metalloproteinase-1/metabolism , Tissue Inhibitor of Metalloproteinase-2/metabolismABSTRACT
OBJECTIVES: To search for more effective radiation protectors with minimal toxicity, a water-soluble nitroxides Acetamido-Tempol (AA-Tempol) was evaluated for potential radioprotective properties in HUVEC cells (Human Umbilical Vein Endothelial cell line). METHODS: To study the anti-radiation effect of AA-Tempol in cell culture, the viability of irradiated HUVEC cells using a clonogenic survival assay was examined. The anti-apoptosis effects of AA-Tempol using Annexin V/propidium iodide staining in a flow cytometry assay was also evaluated. To elucidate the molecular mechanism of the anti-apoptosis effect of AA-Tempol against X-radiation induced HUVEC cell apoptosis, the expression of Bax, Bcl-2 and p53 and caspase-3 were examined. The changes in the level of malondialdehyde (MDA) and glutathione (GSH) in HUVEC cells after X-radiation were also investigated. RESULTS: Pretreatment of the HUVEC cells colony with AA-Tempol 1 h before X-radiation significantly increased the colony survival (p < 0.05) compared with the cells without pretreatment. This demonstrates that AA-Tempol provides an effective radiation protection in the irradiated HUVEC cells, thus reducing apoptosis from 20.1 ± 1.3% in 8 Gy X-radiated cells to 12.2 ± 0.9% (1.0 mmol/L-1 AA-Tempol) in AA-Tempo pretreated HUVEC cells. This implies that 1.0 mM AA-Tempol treatment significantly block the increase of caspase-3 activity in radiated HUVEC cells (P < 0.01), causing down-regulation in expressions of Bax and P53 and up-regulation in the expression of Bcl-2. Pretreatment with AA-Tempol also decreased the MDA activities (P < 0.01) and increase the GSH level (P < 0.05) in HUVEC cells compared to the 8Gy X-radiated cells without pretreatment. CONCLUSIONS: These observations indicate that AA-Tempol is a potential therapeutic agent against the radiation damage.
Subject(s)
Cyclic N-Oxides/pharmacology , Radiation-Protective Agents/pharmacology , Apoptosis/drug effects , Human Umbilical Vein Endothelial Cells , HumansABSTRACT
Electromagnetic fields are considered to potentially affect embryonic development, but the mechanism is still unknown. In this study, human embryonic stem cell (hESC) line HUES-17 was applied to explore the mechanism of exposure on embryonic development to pulsed electromagnetic field (PEMF) for 400 pulses at different electric field intensities and the differentiation of HUES-17 cells was observed after PEMF exposure. The expression of alkaline phosphatase (AP), stage-specific embryonic antigen-3 (SSEA-3), SSEA-4 and the mRNA level and protein level of Oct4, Sox2 and Nanog in HUES-17 cells remained unchanged after PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m. Four hundred pulses PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m did not affect the differentiation of HUES-17 cells. The reason why electromagnetic fields affect embryonic development may be due to other mechanisms rather than affecting the differentiation of embryonic stem cells.
Subject(s)
Electromagnetic Fields , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Alkaline Phosphatase/metabolism , Antigens, Tumor-Associated, Carbohydrate/metabolism , Cell Differentiation/physiology , Cell Line , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Nanog Homeobox Protein , Octamer Transcription Factor-3/genetics , Octamer Transcription Factor-3/metabolism , SOXB1 Transcription Factors/genetics , SOXB1 Transcription Factors/metabolism , Stage-Specific Embryonic Antigens/metabolismABSTRACT
Upregulation of translationally controlled tumor protein (TCTP) has been reported in a variety of malignant tumors. However, the impact of TCTP in glioma remains unclear. The objective of this study was to investigate the expression and prognostic value of TCTP in glioma patients. Western blot analysis was used to characterize the expression patterns of TCTP in 45 glioma and 22 normal brain tissues. Immunohistochemistry on a tissue microarray containing 127 cases of glioma was performed to analyze the association between TCTP expression and clinicopathological features. Compared with normal brain tissues, TCTP expression was significantly higher in glioma tissues (p <0.001). In addition, high TCTP expression in glioma was significantly associated with advanced pathological grade (p = 0.018). Kaplan-Meier analysis showed that patients with glioma and higher TCTP expression tend to have shorter overall survival time (p <0.001). In multivariate analysis, TCTP expression was proved to be an independent prognostic factor for patients with glioma (p <0.001). In conclusion, this study confirmed the overexpression of TCTP and its association with tumor progression in glioma. It also provided the first evidence that TCTP expression in glioma was an independent prognostic factor of patients, which might be a potential diagnostic and therapeutic target of glioma.
Subject(s)
Biomarkers, Tumor/metabolism , Brain Neoplasms/metabolism , Glioma/metabolism , Adult , Blotting, Western , Brain Neoplasms/pathology , Brain Neoplasms/surgery , Disease Progression , Female , Glioma/pathology , Glioma/surgery , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Male , Middle Aged , Multivariate Analysis , Neoplasm Grading , Prognosis , Tissue Array Analysis , Treatment Outcome , Tumor Protein, Translationally-Controlled 1ABSTRACT
The aim of this study was to investigate the association between keratin 17 (K17) expression and the clinicopathological features of patients with epithelial ovarian cancer (EOC). K17 expression was detected by real-time quantitative RT-PCR in EOC and adjacent noncancerous tissues. In addition, K17 expression was analyzed by immunohistochemistry in 104 clinicopathologically characterized EOC cases. The expression levels of K17 mRNA and protein in EOC tissues were both significantly higher than those in noncancerous tissues. In addition, positive expression of K17 correlated with the clinical stage (p=0.001). Furthermore, Kaplan-Meier survival analysis showed that a high expression level of K17 resulted in a significantly poor prognosis of EOC patients. Multivariate analysis revealed that EOC expression level was an independent prognostic parameter for the overall survival rate of EOC patients. Our data are the first to suggest that increased K17 expression in EOC is significantly associated with aggressive progression and poor prognosis. K17 may be an important molecular marker for predicting the carcinogenesis, progression, and prognosis of EOC.
Subject(s)
Biomarkers, Tumor/genetics , Cystadenocarcinoma, Serous/genetics , Gene Expression Profiling , Keratin-17/genetics , Ovarian Neoplasms/genetics , Ovary/metabolism , Biomarkers, Tumor/metabolism , Case-Control Studies , Cystadenocarcinoma, Serous/metabolism , Cystadenocarcinoma, Serous/mortality , Female , Follow-Up Studies , Humans , Immunoenzyme Techniques , Keratin-17/metabolism , Middle Aged , Neoplasm Grading , Neoplasm Staging , Oligonucleotide Array Sequence Analysis , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/mortality , Prognosis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Survival RateABSTRACT
OBJECTIVE: To investigate the effect of long-term power frequency electromagnetic field (50 Hz) exposure on the proliferation and apoptosis of human lens epithelial cells (SRA01/04 cells). METHODS: SRA01/04 cells in the exponential growth phase were exposed or sham-exposed to power frequency electromagnetic field (50 Hz, 2.3 mT) for 2 hours per day, 5 days every week. After 11 weeks of exposure, the cells were collected; the cell morphology was observed under a microscope, the cell viability was measured by MTT assay, the cell cycle and apoptosis were examined by flow cytometry, and the protein expression levels of cyclin D and proliferating cell nuclear antigen (PCNA) were determined by western blot. RESULTS: Compared with the sham-exposed SRA01/04 cells, most exposed cells became rounded and more stereoscopic, and heterochromatin gathered near the nuclear membrane in some exposed cells. The MTT assay showed that the viability of exposed cells was significantly increased compared with that of the sham-exposed cells (P < 0.05). Long-term power frequency electromagnetic field exposure led to significantly increased number of cells in S phase (P < 0.05), and the proliferation index was significantly higher in the exposed cells than in the sham-exposed cells (P < 0.05). There was no significant difference in apoptotic rate between the exposed cells and sham-exposed cells (P > 0.05). The exposed cells had significantly higher protein expression levels of cyclin D and PCNA than the sham-exposed cells (P < 0.05). CONCLUSION: Long-term power frequency electromagnetic field exposure can promote cellular proliferation and change cell cycle in SRA01/04 cells, but it has no marked effect on the apoptosis of SRA01/04 cells.
Subject(s)
Apoptosis , Cell Proliferation , Electromagnetic Fields/adverse effects , Epithelial Cells/cytology , Cell Line , Cyclin D1/metabolism , Environmental Exposure/adverse effects , Humans , Lens, Crystalline/cytology , Proliferating Cell Nuclear Antigen/metabolismABSTRACT
Light exposure can profoundly affect neurological functions and behaviors. Here, we show that short-term exposure to moderate (400 lux) white light during Y-maze test promoted spatial memory retrieval and induced only mild anxiety in mice. This beneficial effect involves the activation of a circuit including neurons in the central amygdala (CeA), locus coeruleus (LC), and dentate gyrus (DG). Specifically, moderate light activated corticotropin-releasing hormone (CRH) positive (+) CeA neurons and induced the release of corticotropin-releasing factor (CRF) from their axon terminals ending in the LC. CRF then activated tyrosine hydroxylase-expressing LC neurons, which send projections to DG and release norepinephrine (NE). NE activated ß-adrenergic receptors on CaMKIIα-expressing DG neurons, ultimately promoting spatial memory retrieval. Our study thus demonstrated a specific light scheme that can promote spatial memory without excessive stress, and unraveled the underlying CeA-LC-DG circuit and associated neurochemical mechanisms.
Subject(s)
Amygdala , Light , Spatial Memory , Amygdala/cytology , Amygdala/metabolism , Animals , Mice , Anxiety , Dentate Gyrus/cytology , Dentate Gyrus/metabolism , Neurons , Locus Coeruleus/cytology , Locus Coeruleus/metabolism , Corticotropin-Releasing Hormone/metabolism , Norepinephrine/metabolism , Neural Pathways , Maze Learning , Mice, Inbred C57BLABSTRACT
BACKGROUND: NDRG2, a member of N-Myc downstream regulated gene family, plays some roles in cellular stress, cell differentiation and tumor suppression. We have found that NDRG2 expression in cervical cancer Hela cells increases significantly upon stimulation with cisplatin, the most popular chemotherapeutic agent currently used for the treatment of advanced cervical cancer. This interesting phenomenon drove us to evaluate the role of NDRG2 in chemosensitivity of Hela cells. METHODS: In the present study, RNA interference was employed to down-regulate NDRG2 expression in Hela cells. RT-PCR and Western blot were used to detect expression of NDRG2, Bcl-2 and Bax in cancer cells. Real-time PCR was applied to detect miR-15b and miR-16 expression levels. Drug sensitivity was determined with MTT assay. Cell cloning efficiency was evaluated by Colony-forming assay. Apoptotic cells were detected with annexin V staining and flow cytometry. RESULTS: In vitro drug sensitivity assay revealed that suppression of NDRG2 could sensitize Hela cells to cisplatin. Down-regulation of NDRG2 didn't influence the colony-forming ability but promoted cisplatin-induced apoptosis of Hela cells. Inhibition of NDRG2 in Hela cells was accompanied by decreased Bcl-2 protein level. However, Bcl-2 mRNA level was not changed in Hela cells with down-regulation of NDRG2. Further study indicated that miR-15b and miR-16, two microRNAs targetting Bcl-2, were significantly up-regulated in NDRG2-suppressed Hela cells. CONCLUSIONS: These data suggested that down-regulation of NDRG2 could enhance sensitivity of Hela cells to cisplatin through inhibiting Bcl-2 protein expression, which might be mediated by up-regulating miR-15b and miR-16.
Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Tumor Suppressor Proteins/deficiency , Apoptosis/drug effects , Down-Regulation , Drug Resistance, Neoplasm , Gene Knockdown Techniques , HeLa Cells , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA Interference , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolismABSTRACT
OBJECTIVE: To study the effects of electromagnetic pulse (EMP) exposure on the morphological change and excretion functions of mouse microglia (BV-2) cells and possible mechanism. METHODS: BV-2 cells were divided into two groups: the group exposed to EMP at 200 kV/m for 200 pulses and sham exposure group. At 1, 6, 12 and 24 hour after exposure the cells and culture supernatant were collected. Cellular morphological change was observed under invert microscope, the levels of TNF-α, IL-1ß and IL-10 in culture supernatant were determined by enzyme-linked immunosorbent assay (ELISA), nitric oxide (NO) and reactive oxygen species (ROS) were detected by nitrate reductase method and DCFH-DA probe, respectively. The protein and phosphorylation levels of ERK, JNK and p38 were measured by Western Blot method. After the cells pre-treated with the inhibitor of p38 (SB203580) were exposed to EMP, the levels of NO and ROS in culture supernatant were detected. RESULTS: It was found that the large ameboid shape appeared in some microglia cells exposed to EMP for 1, 6 and 12 h. Moreover, the number of microglia cells with ameboid shape increased significantly at 1 h, 6 h and 12 h after EMP exposure compared with sham group (P < 0.05). The levels of cytokines, such as TNF-α, IL-1ß and IL-10, in culture supernatant did not change obviously after EMP exposure. The levels of NO and ROS increased significantly at 1h after EMP exposure, reached the peak at 6 h, began to recover at 12 h and recovered to sham group level at 24 h (P < 0.05). Western blot results showed that the protein and protein phosphorylation levels of ERK and JNK did not change significantly after EMP exposure, however, the protein and protein phosphorylation levels of p38 increased obviously at 1 h and 6 h after EMP exposure, compared with sham group (P < 0.05). In addition, the pretreatment of p38 inhibitor (SB203580) significantly decreased NO and ROS production induced by EMP. CONCLUSION: EMP exposure may activate microglia cells and promote the production of NO and ROS in mouse microglia cells, and p38 pathway is involved in this process.
Subject(s)
Electromagnetic Fields , Microglia/cytology , Microglia/metabolism , Animals , Cell Line , Cytokines/metabolism , Mice , Nitric Oxide/metabolism , Reactive Oxygen Species/metabolism , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
OBJECTIVE: To study the effects of electromagnetic pulses (EMP) on pathological changes and apoptosis of spleen lymphocytes in mice. METHODS: The male BALB/c mice (18 â¼ 22 g) were sham-exposed or exposed to EMP at 200 kV/m for 400 pulses a day for 7 days. On the 1st, 3rd, 7th, 14th 28th days after exposure the mice were killed. The weight of mice, the pathological change and the weight of mouse spleens were observed, the spleen indexes were calculated. The lymphocytes extracted from spleens were counted. The apoptosis and cell cycle of the lymphocyte were detected by flow cytometry, and the migration of the lymphocyte was measured by transwell assay. RESULTS: No pathological changes were found on the first day after exposure. However, the expanded sinusoid and the changed structure of spleen corpuscle on the 3rd day after exposure were observed. There was no difference of spleen indexes between the sham group and the exposure group on the 1st and 14th day after exposure. On the 3rd and 7th days after exposure, the spleen indexes of exposure group were significantly higher than those of sham-exposure group (P < 0.05). On the 28th day after exposure, the spleen indexes of exposure group was significantly lower than those of sham-exposure group (P < 0.05). The number of spleen lymphocytes on the 3rd and 7th days after exposure in exposure group increased significantly, compared with sham-exposure group (P < 0.05). But there were no differences of apoptotic cells and cellular cycle between the exposure group and sham-exposure group (P > 0.05). The ability of migration of the exposure group was significantly higher than that of sham-exposure group (P < 0.05). than the sham group (P < 0.05). CONCLUSION: The spleen of the male mouse is one of the target organs of EMP. After exposure to EMP, the number of spleen lymphocytes increased. But there were no differences of cell apoptotic cells and cell cycle between the sham group and the exposure group, due to the enhanced migration of lymphocytes induced by EMP.
Subject(s)
Apoptosis , Electromagnetic Fields , Lymphocytes/pathology , Spleen/cytology , Animals , Cell Division , Cells, Cultured , Male , Mice , Mice, Inbred BALB CABSTRACT
OBJECTIVE: To establish the inner blood-retinal barrier (BRB) model in vitro by co-culturing RF/6A cells and C6 cells and to investigate the effects of EMP (200 kV/m, 200 pulses) exposure on the permeability of the inner BRB model in vitro. METHODS: RF/6A cells and C6 cells were co-cultured on transwell, and the characteristic of the inner BRB model was assessed by detecting transendothelial electrical resistance (TEER) and the permeability of horseradish peroxidase (HRP). The co-cultured model was exposed or sham exposed to the EMP (200 kV/m 200 pulses) for 0.5, 3, 6, 12, 24 h in vitro, then TEER and the permeability of HRP were measured for studying the effects of EMP on the permeability of inner BRB model in vitro. RESULTS: TEER value (145 Ωcm(2)) of the co-culturing inner BRB model significantly increased, as compared to that of RF/6A cells alone model (P < 0.05) on the 6th day after inoculation. There was significant difference of permeability of HRP between the co-culturing inner BRB model and RF/6A cells alone model (P < 0.05). The ability of inhibiting large molecular materials in the co-culturing inner BRB model enhanced. The TEER value decreased and the permeability of HRP increased as compared to the sham group at 0.5, 3, 6 h after the exposure. CONCLUSION: The inner BRB model by co-culturing RF/6A cells and C6 cells in vitro is efficient and suitable to study the alterations of the restricted permeability function of the inner BRB. EMP (200 kV/m for 200 pulses) could induce the enhanced permeability of the inner BRB model in vitro.
Subject(s)
Blood-Retinal Barrier/physiology , Electromagnetic Fields , Endothelial Cells/physiology , Retina/cytology , Animals , Cell Line, Tumor , Coculture Techniques , Electric Impedance , Macaca mulatta , Permeability , RatsABSTRACT
Hypoxia inducible factor 1 (HIF-1), the key mediator of hypoxia signaling pathways, has been shown involved in hypoxia-induced radioresistance. However, the underlying mechanisms are unclear. The present study demonstrated that both hypoxia and hypoxia mimetic cobalt chloride could increase the radioresistance of human cervical cancer Hela cells. Meanwhile, ectopic expression of HIF-1 could enhance the resistance of Hela cells to radiation, whereas knocking-down of HIF-1 could increase the sensitivity of Hela cells to radiation in the presence of hypoxia. N-Myc downstream-regulated gene 2 (NDRG2), a new HIF-1 target gene identified in our lab, was found to be upregulated by hypoxia and radiation in a HIF-1-dependent manner. Overexpression of NDRG2 resulted in decreased sensitivity of Hela cells to radiation while silencing NDRG2 led to radiosensitization. Moreover, NDRG2 was proved to protect Hela cells from radiation-induced apoptosis and abolish radiation-induced upregulation of Bax. Taken together, these data suggest that both HIF-1 and NDRG2 contribute to hypoxia-induced tumor radioresistance and that NDRG2 acts downstream of HIF-1 to promote radioresistance through suppressing radiation-induced Bax expression. It would be meaningful to further explore the clinical application potential of HIF-1 and NDRG2 blockade as radiosensitizer for tumor therapy.
Subject(s)
Hypoxia-Inducible Factor 1/metabolism , Radiation Tolerance , Tumor Suppressor Proteins/metabolism , Uterine Cervical Neoplasms/metabolism , Apoptosis , Cell Hypoxia , Cell Line, Tumor , Female , HeLa Cells , Humans , Hypoxia-Inducible Factor 1/genetics , Tumor Suppressor Proteins/genetics , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/radiotherapyABSTRACT
The aim of this study was to investigate the protective effects of three glycosides (rhodioside, ciwujianoside-B and astragaloside IV) on the hematopoietic system in the mice exposed to γ-rays, and to examine the possible mechanisms involved. Mice were pretreated with the glycosides (40 mg/kg, i.g.) daily for 7 days prior to radiation. The survival of mice pretreated with three glycosides after total body irradiation (6.0 Gy) was examined. Peripheral blood leucocytes and endogenous spleen colony counts, colony-forming unit-granulocyte macrophage assay, analysis of DNA content and apoptosis rate determination were performed to evaluate the effects of the three glycosides on hematogenesis. The fragmentation of double-stranded DNA in lymphocytes was detected by the comet assay. The changes in cell cycle were analysed by flow cytometry. Furthermore, the expression levels of Bcl-2, Bax and nuclear factor-kappa B (NF-κB) were measured by western blot and the electrophoretic mobility shift assay. The results showed that pretreatment with all of the glycosides improved survival time and increased the number of leucocytes, spleen colonies and granulocyte-macrophage colonies in mice exposed to 6.0 Gy γ-radiation. Rhodioside showed more protective efficacy than both ciwujianoside-B and astragaloside IV. All three glycosides significantly increased the proliferation abilities of bone marrow cells, and decreased the ratio of cells in G(0)/G(1) phase. Further analysis showed that these three glycosides were able to decrease DNA damage and the increment in the Bax/Bcl-2 ratio induced by radiation. In summary, the three glycosides showed radioprotective effects on the hematopoietic system in mice, which was associated with changes in the cell cycle, a reduction in DNA damage, and down-regulation of the ratio of Bax/Bcl-2 in bone marrow cells exposed to radiation.
Subject(s)
Astragalus propinquus/chemistry , Eleutherococcus/chemistry , Glycosides/pharmacology , Radiation Injuries, Experimental/prevention & control , Radiation-Protective Agents/pharmacology , Rhodiola/chemistry , Animals , Bone Marrow Cells/drug effects , Bone Marrow Cells/radiation effects , Cell Cycle/drug effects , DNA Damage/drug effects , DNA Damage/radiation effects , Gamma Rays/adverse effects , Hematopoietic System/drug effects , Hematopoietic System/radiation effects , Leukocytes/drug effects , Leukocytes/radiation effects , Male , Medicine, Chinese Traditional , Mice , Mice, Inbred BALB C , Radiation Injuries, Experimental/mortality , Random Allocation , Saponins/pharmacology , Stem Cells/drug effects , Triterpenes/pharmacology , Whole-Body Irradiation , bcl-2-Associated X Protein/drug effects , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolismABSTRACT
OBJECTIVE: We examined alterations in the expression of tumorigenesis-related genes in the pituitary gland of rats exposed to electromagnetic pulses (EMP). METHODS: The global gene expression profiles of the pituitary gland in EMP-exposed and control groups were detected by cDNA microarray analysis. We then validated and further investigated the reduced expression of two tumorigenesis-related genes, Pten, and Jund, by assessing their mRNA and protein expression by quantitative real-time-PCR, western blotting, and immunohistochemistry in the pituitary gland of rats 6 months after exposure to EMP. RESULTS: EMP exposure induced genome-wide gene expression changes in the rat pituitary gland. There was decreased expression of the Pten and Jund mRNAs and proteins in EMP-exposed rats compared with in unexposed control animals. CONCLUSION: EMP exposure alters the expression of tumorigenesis-related genes in the pituitary gland. These tumorigenesis-related genes are potentially involved in the development of pituitary gland tumors in rats.
Subject(s)
Adenoma/genetics , Electromagnetic Phenomena , PTEN Phosphohydrolase/genetics , Pituitary Neoplasms/genetics , Proto-Oncogene Proteins c-jun/genetics , Adenoma/metabolism , Adenoma/pathology , Animals , Down-Regulation , Female , Gene Expression Profiling , Oligonucleotide Array Sequence Analysis , PTEN Phosphohydrolase/metabolism , Pituitary Gland/metabolism , Pituitary Neoplasms/metabolism , Pituitary Neoplasms/pathology , Proto-Oncogene Proteins c-jun/metabolism , Rats , Rats, Wistar , Real-Time Polymerase Chain ReactionABSTRACT
Male Sprague Dawley rats were exposed to EMP irradiation of 100 kV/m peak-to-peak e-field intensity and different numbers of pulses. Rat sperm samples were prepared for analysis of sperm qualities; Testes were assessed by transmission electron microscopy and serum hormone concentrations were examined by radioimmunoassay; Enzymatic activities of Total-superoxide dismutase(T-SOD) and manganese-superoxide dismutase (MnSOD), the mRNA levels of MnSOD and cuprozinc-superoxide dismutase (CuZnSOD), and the density of malondialdehyde (MDA) were also determined. EMP irradiation did not affect spermatozoon morphology, micronucleus formation rate, sperm number or viability, but the acrosin reaction rate decreased at 24 h and 48 h and recovered by 72 h after irradiation as compared to the controls. The ultrastructure of rat testis displayed more serious damage at 24 h than at other time points (6 h, 12 h, 48 h). Serum levels of luteotrophic hormone (LH) and testosterone (T) were elevated in irradiated rats as compared to controls. After irradiation, enzymatic activities of T-SOD and MnSOD were reduced by 24 h, consistent with the changes observed in MnSOD mRNA expression; MDA content increased at 6 h in turn. These studies have quantified the morphological damage and dysfunction in the rat reproductive system induced by EMP. The mechanism of EMP induced damage may be associated with the inhibition of MnSOD expression.
Subject(s)
Electromagnetic Radiation , Gene Expression Regulation/radiation effects , Superoxide Dismutase/radiation effects , Testis/radiation effects , Animals , Dose-Response Relationship, Radiation , Luteinizing Hormone/metabolism , Luteinizing Hormone/radiation effects , Male , Microscopy, Electron, Transmission , Radioimmunoassay , Rats , Rats, Sprague-Dawley , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Testis/metabolism , Testis/pathologyABSTRACT
The presence of blood-brain barrier (BBB) is a major obstacle to effectively deliver therapeutics to the central nervous system (CNS); hence, the outcomes following treatment of CNS diseases remain unsatisfactory. Fortunately, electromagnetic pulses (EMPs) provide a non-invasive method to locally open the BBB. To obtain the optimal pulse parameters of EMP-induced BBB opening to ensure the effective delivery of CNS drugs, it is particularly important to measure and assess the effects of pulse parameters on the temperature distribution in the human head exposed to EMPs. In this paper, the specific anthropomorphic mannequin phantom was adopted and the temperature increase in the human head induced by EMPs of different parameters was estimated in the software "COMSOL Multiphysics". The results show that the temperature distribution profiles with different EMP parameters have almost similar characteristics, the highest temperature increase values in the human head are positively correlated with variations of EMP parameters, and potential hazards to the human head may occur when EMP parameters exceed the safety threshold, which will provide theoretical basis for seeking the optimal EMP parameters to open the BBB to the greatest extent within a safe range.
Subject(s)
Blood-Brain Barrier/metabolism , Capillary Permeability , Electromagnetic Radiation , Head/anatomy & histology , Models, Theoretical , Temperature , Computer Simulation , HumansABSTRACT
The blood-brain barrier (BBB) opening induced by electromagnetic pulses (EMPs) may be a drug delivery strategy of central nervous system (CNS) diseases. However, the mechanism of EMP-induced BBB opening is still ambiguous. Previous studies have shown the relation between the external field and the extent of BBB permeation (referred to as the effect), while the connection between the internal field and the effect remains unknown. Here, the influence of individual differences on the field distribution in the human brain with EMPs is investigated, the dielectric parameters of the specific anthropomorphic mannequin (SAM) and structural parameters of the spherical brain are adjusted, and the field distribution in the brain illuminated by EMPs at the frequency range of 0-0.5 GHz is simulated based on the Computer Simulation Technology (CST) Studio Suite. The results show that the average electric field in the brain is about 1/100-1/5 of the incident field within the studied frequency range, individual differences have little effect on the field distribution in the human brain; and thus, it is reliable to establish the connection between the internal field and the effect, which is of great theoretical significance for further study of the mechanism of an EMP on the brain.
Subject(s)
Brain/radiation effects , Electromagnetic Fields , Adult , Blood-Brain Barrier/radiation effects , Computer Simulation , Humans , Individuality , Male , Models, AnatomicABSTRACT
Currently, the impact of electromagnetic field (EMF) exposure on the nervous system is an increasingly arousing public concern. The present study was designed to explore the effects of continuous long-term exposure to L-band high-power microwave (L-HPM) on brain function and related mechanisms. Forty-eight male Institute of Cancer Research (ICR) mice were exposed to L-HPM at various power densities (0.5, 1.0, and 1.5 W/m2) and the brain function was examined at different time periods after exposure. The morphology of the brain was examined by hematoxylin-eosin (HE) and deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. Furthermore, cholinergic markers, oxidative stress markers, and the expression of c-fos were evaluated to identify a "potential" mechanism. The results showed that exposure to L-HPM at 1.5 W/m2 can cause generalized injuries in the hippocampus (CA1 and CA3) and cerebral cortex (the first somatosensory cortex) of mice, including cell apoptosis, cholinergic dysfunction, and oxidative damage. Moreover, the deleterious effects were closely related to the power density and exposure time, indicating that long-term and high-power density exposure may be detrimental to the nervous system.