Approximately 30%–40%of growth hormone–secreting pituitary adenomas(GHPAs)harbor somatic activating mutations in GNAS(αsubunit of stimulatory G protein).Mutations in GNAS are associated with clinical features of sm...Approximately 30%–40%of growth hormone–secreting pituitary adenomas(GHPAs)harbor somatic activating mutations in GNAS(αsubunit of stimulatory G protein).Mutations in GNAS are associated with clinical features of smaller and less invasive tumors.However,the role of GNAS mutations in the invasiveness of GHPAs is unclear.GNAS mutations were detected in GHPAs using a standard polymerase chain reaction(PCR)sequencing procedure.The expression of mutation-associated maternally expressed gene 3(MEG3)was evaluated with RT-qPCR.MEG3 was manipulated in GH3 cells using a lentiviral expression system.Cell invasion ability was measured using a Transwell assay,and epithelial–mesenchymal transition(EMT)-associated proteins were quantified by immunofluorescence and western blotting.Finally,a tumor cell xenograft mouse model was used to verify the effect of MEG3 on tumor growth and invasiveness.The invasiveness of GHPAs was significantly decreased in mice with mutated GNAS compared with that in mice with wild-type GNAS.Consistently,the invasiveness of mutant GNASexpressing GH3 cells decreased.MEG3 is uniquely expressed at high levels in GHPAs harboring mutated GNAS.Accordingly,MEG3 upregulation inhibited tumor cell invasion,and conversely,MEG3 downregulation increased tumor cell invasion.Mechanistically,GNAS mutations inhibit EMT in GHPAs.MEG3 in mutated GNAS cells prevented cell invasion through the inactivation of the Wnt/β-catenin signaling pathway,which was further validated in vivo.Our data suggest that GNAS mutations may suppress cell invasion in GHPAs by regulating EMT through the activation of the MEG3/Wnt/β-catenin signaling pathway.展开更多
Multichannel biomagnetometers can be used to measure the spatio temporal magnetic field produced by neural activity in a human brain. The measured data are usually contaminated by noise and some artifact signals. Thes...Multichannel biomagnetometers can be used to measure the spatio temporal magnetic field produced by neural activity in a human brain. The measured data are usually contaminated by noise and some artifact signals. These artifact signals may be caused by heart beats or eye blinks. Actually, these artifact signal sources are also bioelectric activities. In this paper, we demonstrate the effectiveness of MEG MUSIC algorithm for eliminating the artifacts. In the paper, the artifact fields are not considered as noise but as signals that have a linear relationship with their bioelectric source activities. Computer simulations demonstrate that for the localization of sources distributed in the cortical region, the MEG MUSIC algorithm is also efficient under the presence of the artifacts.展开更多
The neurophysiological measurement technique known as magnetoencephalography, or MEG, has been in use since the early 1970's, and applied to clinical populations since the early 1980's. However, it was not unt...The neurophysiological measurement technique known as magnetoencephalography, or MEG, has been in use since the early 1970's, and applied to clinical populations since the early 1980's. However, it was not until the late 1980's and early 1990's that the technology was advanced to point where effective clinical use was achieved. This presentation will review the basic principles of MEG, discuss the progression of technology development and give an update on the current clinical applications of the technology.展开更多
基金supported by the Applied Basic Research Programs of Science and Technology Commission Foundation of Jiangsu Province(No.BE2015684).
文摘Approximately 30%–40%of growth hormone–secreting pituitary adenomas(GHPAs)harbor somatic activating mutations in GNAS(αsubunit of stimulatory G protein).Mutations in GNAS are associated with clinical features of smaller and less invasive tumors.However,the role of GNAS mutations in the invasiveness of GHPAs is unclear.GNAS mutations were detected in GHPAs using a standard polymerase chain reaction(PCR)sequencing procedure.The expression of mutation-associated maternally expressed gene 3(MEG3)was evaluated with RT-qPCR.MEG3 was manipulated in GH3 cells using a lentiviral expression system.Cell invasion ability was measured using a Transwell assay,and epithelial–mesenchymal transition(EMT)-associated proteins were quantified by immunofluorescence and western blotting.Finally,a tumor cell xenograft mouse model was used to verify the effect of MEG3 on tumor growth and invasiveness.The invasiveness of GHPAs was significantly decreased in mice with mutated GNAS compared with that in mice with wild-type GNAS.Consistently,the invasiveness of mutant GNASexpressing GH3 cells decreased.MEG3 is uniquely expressed at high levels in GHPAs harboring mutated GNAS.Accordingly,MEG3 upregulation inhibited tumor cell invasion,and conversely,MEG3 downregulation increased tumor cell invasion.Mechanistically,GNAS mutations inhibit EMT in GHPAs.MEG3 in mutated GNAS cells prevented cell invasion through the inactivation of the Wnt/β-catenin signaling pathway,which was further validated in vivo.Our data suggest that GNAS mutations may suppress cell invasion in GHPAs by regulating EMT through the activation of the MEG3/Wnt/β-catenin signaling pathway.
基金It is supported by the National Natural Science Foundation of China(No.5994 70 0 4)
文摘Multichannel biomagnetometers can be used to measure the spatio temporal magnetic field produced by neural activity in a human brain. The measured data are usually contaminated by noise and some artifact signals. These artifact signals may be caused by heart beats or eye blinks. Actually, these artifact signal sources are also bioelectric activities. In this paper, we demonstrate the effectiveness of MEG MUSIC algorithm for eliminating the artifacts. In the paper, the artifact fields are not considered as noise but as signals that have a linear relationship with their bioelectric source activities. Computer simulations demonstrate that for the localization of sources distributed in the cortical region, the MEG MUSIC algorithm is also efficient under the presence of the artifacts.
文摘The neurophysiological measurement technique known as magnetoencephalography, or MEG, has been in use since the early 1970's, and applied to clinical populations since the early 1980's. However, it was not until the late 1980's and early 1990's that the technology was advanced to point where effective clinical use was achieved. This presentation will review the basic principles of MEG, discuss the progression of technology development and give an update on the current clinical applications of the technology.
