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Seizures represent a frequent symptom in gliomas and significantly impact patient morbidity and quality of life. Although the pathogenesis of tumor-related seizures is not fully understood, accumulating evidence indicates a key role of the peritumoral microenvironment. Brain cancer cells interact with neurons by forming synapses with them and by releasing exosomes, cytokines, and other small molecules. Strong interactions among neurons often lead to the synchronization of their activity. In this paper, we used an in vitro model to investigate the role of exosomes released by glioma cell lines and by patient-derived glioma stem cells (GSCs). The addition of exosomes released by U87 glioma cells to neuronal cultures at day in vitro (DIV) 4, when neurons are not yet synchronous, induces synchronization. At DIV 7-12 neurons become highly synchronous, and the addition of the same exosomes disrupts synchrony. By combining Ca2+ imaging, electrical recordings from single neurons with patch-clamp electrodes, substrate-integrated microelectrode arrays, and immunohistochemistry, we show that synchronization and de-synchronization are caused by the combined effect of (i) the formation of new neuronal branches, associated with a higher expression of Arp3, (ii) the modification of synaptic efficiency, and (iii) a direct action of exosomes on the electrical properties of neurons, more evident at DIV 7-12 when the threshold for spike initiation is significantly reduced. At DIV 7-12 exosomes also selectively boost glutamatergic signaling by increasing the number of excitatory synapses. Remarkably, de-synchronization was also observed with exosomes released by glioma-associated stem cells (GASCs) from patients with low-grade glioma but not from patients with high-grade glioma, where a more variable outcome was observed. These results show that exosomes released from glioma modify the electrical properties of neuronal networks and that de-synchronization caused by exosomes from low-grade glioma can contribute to the neurological pathologies of patients with brain cancers.

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Objective To establish a model of malignant transformation of human cells in vitro to study the lung cancer induced by radon and cigarette smoke. Methods The immortalized human bronchial epithelial cells BEAS-2B were divided into control group( C ), radon group ( Rn), cigarette smoke group (Sm) and combined group (Rn-Sm). Cells were planted onto transwell membrane one day before exposure and were directly exposed to radon and cigarette smoke pumped in a gas inhalation box. After the exposure cells were trypsinized into dishes for further growth and malignancy transformation phenotype was detected in order to compare the effects due to radon and cigarette smoke exposure. Results BEAS-2B cells showed malignantly transformed phenotype by exposure to radon and cigarette smoke. A series of sequential steps emerged among transformed cells, including altered growth kinetics, resistance to serum has changed from 0. 31 ± 0. 18 to 1.92 ± 0. 27,2. 03 ± 0. 14,2.95 ± 0. 60, and anchorage-independence growth increased from (0.01 ±0.02)% to (4.89 ±0.30)%,(8.36 ±0.50)%,(11.74 ±0.69)%.After being subculture for 20 generations, cell apoptosis of the fifth generation cells exposed to radon,cigarette smoke and both was significant decreased from ( 11.76 ± 0. 17 ) % to (4. 62 ± 0. 42 ) %、 ( 8.63 ±0. 15 )%、 (3.68 ± 0. 33 )%. Conclusions BEAS-2B cells could be malignancy transformed by radon and cigarette smokein vitro, which could be used as a cell model in lung bronchial carcinogenesis.

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Objective To screen and identify the differential expression genes on peripheral blood cells of mice based on the experimental animal model of radon exposure. Methods BALB/c mice were exposed in a type HD-3 multifunctional radon-room, with the accumulative doses of radon-exposure group at 105 WLM and control group at 1 WLM. Total RNA was extracted from peripheral blood cells and the methods of SMART for dscDNA synthesis and SSH for gene screening was applied. With the construction of the cDNA library enriched with differentially expressed genes, the pMD 18-T plasmid containing LacZ operator at the multiple cloning site was used to allow a blue-white screening. The TA clones were amplified by nested PCR and the reverse Northern blot was used to identify up and down regulation of the clones. The differently expressed cDNA was then sequenced and analyzed. Results The subtracted cDNA libraries were successfully constructed. A total of 390 recombinant white colonies were randomly selected. Among the 312 cDNA monoelones selected from bath forward- and reverse-subtracted libraries,41 clones were chosen to sequence for their differential expressions based on reverse Northern blot. Among the 41 sequenced clones, 10 clones with known function/annotation and 3 new ESTs with the GenBank accession numbers were obtained. Most of the known function/annotation genes were revealed to be related with cell proliferation, metabolism, cellular apoptosis and carcinogenesis. Conclusions The animal model of radon exposure was established and the cDNA library of peripheral blood cells was suceessfully constructed. Radon exposure could up- and down-regulate a series of genes. Differentially expressed genes could be identified by using SSH technique and the results may help exploring mechanisms of random exposure.

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Objective To study the DNA damage of bone marrow cells of mice after exposure to Radon.Methods Twenty-four mice were randomly divided into four groups, one control group and three experimental groups with the cumulative doses of radon at 27 WLM (low dose group), 52 WLM (middle dose group) and 105 WLM ( high dose group). DNA damage induced by radon in bone marrow of mice was detected by methods of single cell gel electrophoresis (SCGE), micronucleus(MN) and laser scanning confocal microscope (LSCM) observation. Results The DNA strand breakage, rate of MN and apoptosis increased significantly in the high dose group, but not in the middle and low dose groups. Conclusions Exposure to radon could induce DNA damage in bone marrow cells of mice at high levels.

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Objective To detect the changes in protein profile of rats'lung inhaled radon using two- dimensional electrophoresis(2-DE)and MS.Methods Male Wistar rats were exposed to radon with the cumulative dose up to 100,200 and 400 working level months(WLM).The total proteins of rats'lung were extracted and isolated by 2-DE.The different protein expressions were analyzed with ImageMaster 2D Platinum software and obviously altered proteins were digested by trypsin and identified by MALDI-TOF-MS.Resuits Comparison of the 2-DE images between the control and radon-exposed groups indicated 14 up-regulated and 9 down-regulated protein spots,15 of which were identified by MALDI-TOF or MALDI-TOF/TOF MS.Conclusions The 2-DE image of radon groups'lung has changed,and the lung damage effect of radon is related to some proteins.