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494 Action of methylprednisolone on human glioma cells in vitro
169s
492
FRfXESTIHRECEPTU6IHNXU+'LLEPT(MNIMs
H. tWXUB4Tl I-Instit& &e,
P.M. M4lTIH2 D. F&
OFHMdNKUTS R.P. VIQXKUX2
and M. ~ISYX?.
Paris.2-F&ultide t&cjne, Marseille. 3-C.H.U. Piti&alp&ri&e, Paris.
Cytosolic and/ornuclear bindirq sitesfor 'H -R 5020 were cl&e&& in 6/6sarp1e.s of nomal lepminges obtained at thetimeof operationin human tits operatedfor intracranialtunx-s. In 3 cut Of the ~CX,~_Y,B+I~IY the bmx was sirmltanecuslyassayed,the levelof binding siteswashigher in the le@mnirqessa-rples (rarqe:14O - 1780 firole/gtissue)than in the nei$bming tullDr. tno sets of pooled sal@e-s Bindingparmtersfor 'H-R 5oMweredetetinedbyscatchard plotson representi~ respectively (A) 4 and (6)17 sarples of mnml lepminges. Tn poolA (0.4M KC1 tissueextract, i-e*cytosolic and ruclear receptors) as wellas in pool6 (cytosolic receptors), the bindingsystms shmed limited capacity and hi@ affinity (kd= 2 and0.5 fi respectively) as previously notedforproqestin receptors in hunm mningims. Theseoriqinaldata andthosealreadymllectedon tumnmmirgiams (tumrsarising in theleptininqealt&e) suggestthatleptunznirges are a wttissue foratleastonetype of steroidhorm~ .
493
Effect
of dexamethasone on glutamine synthetase(GS) and glial fibrillary acidic(GFA) proteins in normal and transformed astrocytes. M.D.Weir, C.S.M.Tahourdin, A. Hunt, A.J. Pate1 and D.G.T.Thomas, Dept. Neurol. Surgery & MRC Develop. Neurobiol. Unit, Inst. of Neurology, London. WClN 386. Astroglial cells of the CNS are enriched in GS and GFA proteins.Developmental increases in GS and GFA proteins are very similar in the olfactory bulb and forebrain, but differ markedly in the cerebellum. Major increases in these astrocyte enriched proteins are found to relate to maturation rather than proliferation of astrocytes. There are also marked differences in the regional distribution of these two proteins which may relate to functional differences. In the human glioma cell line U251MG, treatment with dexamethasone(luM;24h), increases GS and decreases GFA proteins by comparison with the vehicle treated controls. Surprisingly, alcohol (vehicle) treatment on its own is found to decrease GS and increase GFA proteins in a dose dependent manner. Total protein content and the gross morphology of the cells appeared to be unaffected by alcohol, suggesting a negligible effect on cell proliferation. Fractionation of the homogenate supernatants by SDS-gel electrophoresis showed marked changes in the protein profiles after alcohol treatment. The effect of alcohol appears to be specific to the line U251MG, as alcohol (up to 1%) has no effect on normal astrocytes derived from immature rat brain. Furthermore, in normal astrocyte cultures dexamethasone treatment resulted in a marked increase in GS without any appreciable alteration in GFA protein concentration. Our results show differential effects of various factors on cell specific proteins in normal and transformed astrocytes.
494
ACTION
OF METHYLPREDNISOLONE
C. Solheid
and M. Titeca,
ON HUMAN GLIOMA CELLS IN VITRO
Born-Bunge
Foundation,
Antwerp,
Belgium.
The action of methylprednisolone succinate (MPS) was studied by addition of this steroid hormone to the culture medium of in vitro growing human gliomas and fibroblasts, in different concentrations (IO-100 ng/ml) and for various periods of time (5 min.-6 days). Cytotoxicity was assessed by a CR51 uptake assay, the action on the cell cycle was assessed by H3 thymidine uptake and autoradiography. With regard to the incubation time, 24 hours H3T labelling did not show any significant difference in labelling index (LI) in fibroblasts and 2 glioma lines. In one glioma line, there was a dose-dependent decrease of the LI even after a two days incorporation. On the other hand, pulse labelling allowed a better differentiation between gliomas and fibroblasts. 24 hours labelling did not show, as With regard to the influence of MPS concentration, a rule, marked LI differences before 5-6 days of MPS incubation, even in fibroblasts. On the contrary, pulse labelling demonstrated different sensitivity among the glioma lines while the control fibroblasts were not affected at all. From this we may conclude that glioma lines in culture show individual reaction patterns in the presence of MPS. The CR51 uptake assay showed a dose-dependent decrease in cell number after 6 days incubation, with in some cases an initial growth stimulation at low doses (IO30 ug/ml). Correlations between the two techniques will be discussed.
492
FRfXESTIHRECEPTU6IHNXU+'LLEPT(MNIMs
H. tWXUB4Tl I-Instit& &e,
P.M. M4lTIH2 D. F&
OFHMdNKUTS R.P. VIQXKUX2
and M. ~ISYX?.
Paris.2-F&ultide t&cjne, Marseille. 3-C.H.U. Piti&alp&ri&e, Paris.
Cytosolic and/ornuclear bindirq sitesfor 'H -R 5020 were cl&e&& in 6/6sarp1e.s of nomal lepminges obtained at thetimeof operationin human tits operatedfor intracranialtunx-s. In 3 cut Of the ~CX,~_Y,B+I~IY the bmx was sirmltanecuslyassayed,the levelof binding siteswashigher in the le@mnirqessa-rples (rarqe:14O - 1780 firole/gtissue)than in the nei$bming tullDr. tno sets of pooled sal@e-s Bindingparmtersfor 'H-R 5oMweredetetinedbyscatchard plotson representi~ respectively (A) 4 and (6)17 sarples of mnml lepminges. Tn poolA (0.4M KC1 tissueextract, i-e*cytosolic and ruclear receptors) as wellas in pool6 (cytosolic receptors), the bindingsystms shmed limited capacity and hi@ affinity (kd= 2 and0.5 fi respectively) as previously notedforproqestin receptors in hunm mningims. Theseoriqinaldata andthosealreadymllectedon tumnmmirgiams (tumrsarising in theleptininqealt&e) suggestthatleptunznirges are a wttissue foratleastonetype of steroidhorm~ .
493
Effect
of dexamethasone on glutamine synthetase(GS) and glial fibrillary acidic(GFA) proteins in normal and transformed astrocytes. M.D.Weir, C.S.M.Tahourdin, A. Hunt, A.J. Pate1 and D.G.T.Thomas, Dept. Neurol. Surgery & MRC Develop. Neurobiol. Unit, Inst. of Neurology, London. WClN 386. Astroglial cells of the CNS are enriched in GS and GFA proteins.Developmental increases in GS and GFA proteins are very similar in the olfactory bulb and forebrain, but differ markedly in the cerebellum. Major increases in these astrocyte enriched proteins are found to relate to maturation rather than proliferation of astrocytes. There are also marked differences in the regional distribution of these two proteins which may relate to functional differences. In the human glioma cell line U251MG, treatment with dexamethasone(luM;24h), increases GS and decreases GFA proteins by comparison with the vehicle treated controls. Surprisingly, alcohol (vehicle) treatment on its own is found to decrease GS and increase GFA proteins in a dose dependent manner. Total protein content and the gross morphology of the cells appeared to be unaffected by alcohol, suggesting a negligible effect on cell proliferation. Fractionation of the homogenate supernatants by SDS-gel electrophoresis showed marked changes in the protein profiles after alcohol treatment. The effect of alcohol appears to be specific to the line U251MG, as alcohol (up to 1%) has no effect on normal astrocytes derived from immature rat brain. Furthermore, in normal astrocyte cultures dexamethasone treatment resulted in a marked increase in GS without any appreciable alteration in GFA protein concentration. Our results show differential effects of various factors on cell specific proteins in normal and transformed astrocytes.
494
ACTION
OF METHYLPREDNISOLONE
C. Solheid
and M. Titeca,
ON HUMAN GLIOMA CELLS IN VITRO
Born-Bunge
Foundation,
Antwerp,
Belgium.
The action of methylprednisolone succinate (MPS) was studied by addition of this steroid hormone to the culture medium of in vitro growing human gliomas and fibroblasts, in different concentrations (IO-100 ng/ml) and for various periods of time (5 min.-6 days). Cytotoxicity was assessed by a CR51 uptake assay, the action on the cell cycle was assessed by H3 thymidine uptake and autoradiography. With regard to the incubation time, 24 hours H3T labelling did not show any significant difference in labelling index (LI) in fibroblasts and 2 glioma lines. In one glioma line, there was a dose-dependent decrease of the LI even after a two days incorporation. On the other hand, pulse labelling allowed a better differentiation between gliomas and fibroblasts. 24 hours labelling did not show, as With regard to the influence of MPS concentration, a rule, marked LI differences before 5-6 days of MPS incubation, even in fibroblasts. On the contrary, pulse labelling demonstrated different sensitivity among the glioma lines while the control fibroblasts were not affected at all. From this we may conclude that glioma lines in culture show individual reaction patterns in the presence of MPS. The CR51 uptake assay showed a dose-dependent decrease in cell number after 6 days incubation, with in some cases an initial growth stimulation at low doses (IO30 ug/ml). Correlations between the two techniques will be discussed.