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Messenger RNA from human brain gliomas and meningiomas directs the synthesis of cholinesterase in microinjected Xenopus oocytes
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Messenger RNA from human brain gliomas and meningiomas directs the synthesis of cholinesterase in microinjected Xc~topcc5 oocytes. Razon, N* , •evln-Sonkln, D. , S11man, I. and Soreo~, . Weizmann Institute of Science, Dept. of Neurobiology**, Rehovot,and Ichilov ilospital, Dept. of Neurosurgery*, Tel-Aviv Medical Center, Israel. In order to investigate the biosynthesis of cholinesterases (Chl!s) it', particular eel] types within the human nervous system, we have examined the expression of acetylcholin esterase (ACHE) and of pseudocholinesterase (¢ChE) in frozen primary human glkogenous tumors and meningiomas. Brain ChE activity was 0.3-1.0 vmol of degraded 311-acetylcholine/min/gr tissue. Significant amounts (up to 40%) of "~ChE activity were found in most of the gliomas, whereas in all of the control tissues and in meningiomas AChE activity predominated (>90%). Sucrose gradient analysis revealed two AChE components, of sedimentation coefficient ca. 4.5S and 10S, in the neuroectoderm-originated gliomas and non-malignant brain tissue. In the mesenchyme-originated meningioma, the lighter (4.5S) form of AChE appears exclusively. So as to determine the level of Chll-mRNA, po]y(A)containing RNA from the above sources was microinjected into X~'~cl.x~5 oecytes. Oocvteproduced ChE, degrading 5 to 40 nmol ACh/~g mRNA/hr, was detected when mRNA from meningiomas and gliomas was injected. Our findings suggest that both dcdif'fercntiated gliogenous cells and meningeal cells within the human nervous system synthesize Chli, and t h a t t h e ChEs i n t h e s e c e l l t y p e s d i f f e r i n t h e i r s u b s t r a t e s p e c i f i c i t i e s and m i g r a t i o n properties. S u p p o r t e d by t h e USARMED and t h e M u s c u l a r D y s t r o p h y A s s o c i a t i o n . -
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RNA sequences from mouse and human fetal brain contains sequences homologous to insulin" Villa-Komaroff, L.; Gonzalez, A.; Dobner, P.; Song Hou-Yan; Morin, B.; and Wentworth, B. M. Univ. Mass. Medical Sch., Dept. Molec. Gen. & Micro., Worcester, MA. 01605. We have used cloned sequences encoding rat and human insulin to look for RNAs homologous to insulin in nonpancreatic tissues and cell lines. We detect sequences with varying degrees of homology to insulin in RNAs isolated from human fetal brain, human insulinoma cells, a human fibrosarcoma cell l i ne , and mouse fetal and neonatal brain. We do not detect sequences with substantial homology to insulin in RNA from adult mouse brain or adult mouse l i v e r . To further characterize these sequences, we have prepared double-stranded cDNA libraries using the RNAs from various tissues as template. We have isolated and characterized several clones: including one from fetal brain and one from fetal pancreas. We are continuing to screen the libraries for additional sequences. These sequences do not appear to encode insulin, but rather members of a family of sequences related to insulin.
ROUNDTABLE
Do neurotransmitters
exert epigenetic
i
influences on neural development?
Lauder, J.M. 1 and Wallace, J.A. 2, Organizers. Depts. of Anatomy, Univ. of N.C. Sch. of Medicine, Chapel Hill, N.C. 1 and Univ. of New Mexico, Albuquerque, N.M. 2 USA The question of whether neurotransmitters play non-transmission roles in development has been debated both pro and con since the concept was introduced in the early 1960's by Buznikov and collaborators. Since that time, substances such as the monoamines, acetylcholine, and neuro-peptides have been found in a variety of strategic locations during early phases of development in both vertebrate and invertebrate species. However~ attempts to elucidate their functions during morphogenesis, differentiation and synaptogenesis have been complicated by possible non-specific effects of the drugs or other techniques used to alter their synthesis, uptake, receptor interactions or degredation, as well as contradictory results obtained by different laboratories using similar experimental paradigms. The speakers in this session have been asked to debate this issue, using examples from their own or related work to defend their positions. It is hoped that this discussion will provide new thoughts on the question of when, where and whether neurotransmitter substances exert epigenetic influences on neural development.
Messenger RNA from human brain gliomas and meningiomas directs the synthesis of cholinesterase in microinjected Xc~topcc5 oocytes. Razon, N* , •evln-Sonkln, D. , S11man, I. and Soreo~, . Weizmann Institute of Science, Dept. of Neurobiology**, Rehovot,and Ichilov ilospital, Dept. of Neurosurgery*, Tel-Aviv Medical Center, Israel. In order to investigate the biosynthesis of cholinesterases (Chl!s) it', particular eel] types within the human nervous system, we have examined the expression of acetylcholin esterase (ACHE) and of pseudocholinesterase (¢ChE) in frozen primary human glkogenous tumors and meningiomas. Brain ChE activity was 0.3-1.0 vmol of degraded 311-acetylcholine/min/gr tissue. Significant amounts (up to 40%) of "~ChE activity were found in most of the gliomas, whereas in all of the control tissues and in meningiomas AChE activity predominated (>90%). Sucrose gradient analysis revealed two AChE components, of sedimentation coefficient ca. 4.5S and 10S, in the neuroectoderm-originated gliomas and non-malignant brain tissue. In the mesenchyme-originated meningioma, the lighter (4.5S) form of AChE appears exclusively. So as to determine the level of Chll-mRNA, po]y(A)containing RNA from the above sources was microinjected into X~'~cl.x~5 oecytes. Oocvteproduced ChE, degrading 5 to 40 nmol ACh/~g mRNA/hr, was detected when mRNA from meningiomas and gliomas was injected. Our findings suggest that both dcdif'fercntiated gliogenous cells and meningeal cells within the human nervous system synthesize Chli, and t h a t t h e ChEs i n t h e s e c e l l t y p e s d i f f e r i n t h e i r s u b s t r a t e s p e c i f i c i t i e s and m i g r a t i o n properties. S u p p o r t e d by t h e USARMED and t h e M u s c u l a r D y s t r o p h y A s s o c i a t i o n . -
"
"
**
"
"
**
If**
RNA sequences from mouse and human fetal brain contains sequences homologous to insulin" Villa-Komaroff, L.; Gonzalez, A.; Dobner, P.; Song Hou-Yan; Morin, B.; and Wentworth, B. M. Univ. Mass. Medical Sch., Dept. Molec. Gen. & Micro., Worcester, MA. 01605. We have used cloned sequences encoding rat and human insulin to look for RNAs homologous to insulin in nonpancreatic tissues and cell lines. We detect sequences with varying degrees of homology to insulin in RNAs isolated from human fetal brain, human insulinoma cells, a human fibrosarcoma cell l i ne , and mouse fetal and neonatal brain. We do not detect sequences with substantial homology to insulin in RNA from adult mouse brain or adult mouse l i v e r . To further characterize these sequences, we have prepared double-stranded cDNA libraries using the RNAs from various tissues as template. We have isolated and characterized several clones: including one from fetal brain and one from fetal pancreas. We are continuing to screen the libraries for additional sequences. These sequences do not appear to encode insulin, but rather members of a family of sequences related to insulin.
ROUNDTABLE
Do neurotransmitters
exert epigenetic
i
influences on neural development?
Lauder, J.M. 1 and Wallace, J.A. 2, Organizers. Depts. of Anatomy, Univ. of N.C. Sch. of Medicine, Chapel Hill, N.C. 1 and Univ. of New Mexico, Albuquerque, N.M. 2 USA The question of whether neurotransmitters play non-transmission roles in development has been debated both pro and con since the concept was introduced in the early 1960's by Buznikov and collaborators. Since that time, substances such as the monoamines, acetylcholine, and neuro-peptides have been found in a variety of strategic locations during early phases of development in both vertebrate and invertebrate species. However~ attempts to elucidate their functions during morphogenesis, differentiation and synaptogenesis have been complicated by possible non-specific effects of the drugs or other techniques used to alter their synthesis, uptake, receptor interactions or degredation, as well as contradictory results obtained by different laboratories using similar experimental paradigms. The speakers in this session have been asked to debate this issue, using examples from their own or related work to defend their positions. It is hoped that this discussion will provide new thoughts on the question of when, where and whether neurotransmitter substances exert epigenetic influences on neural development.