Rodent Glioma Research Articles

Nonoxidative ethanol metabolism: Expression of fatty acid ethyl ester synthase-III in cultured neural cells

Alcohol metabolism in the human brain has been characterized as essentially nonoxidative in nature, with the esterification of ethanol with fatty acids via fatty acid ethyl ester synthase. This pathway of ethanol metabolism is related to end organ damage in the brain but the neural cell type expressing FAEES has not been identified. In this study human and rodent neuroblastoma and glioma cell lines are assayed for fatty acid ethyl ester synthase activity. Cells with neuronal properties demonstrated higher activity than glioma cell lines. We confirmed the presence of the mRNA for one type of synthase, fatty acid ethyl ester synthase-III in three neuronal cell lines - N1E115 cells, PC12 cells, and SK-N-MC cells. These results support the hypothesis that FAEES activity is expressed chiefly in cells with neuronal properties and suggest that non-oxidative ethanol metabolism is potentially related to the toxic effect of ethanol on the human brain.

Mouse cerebellar granule neurons arrest the proliferation of human and rodent astrocytoma cells in vitro

To understand the control of glial tumor cell proliferation, we have examined the effects of neurons on a number of human and rodent glioma lines. These included C6, G26-24, U-251, HTB-16, and A-172 cells of astroglial lineage and G26-20 of bipotential astrocytic and oligodendrocytic lineage. Rapid, specific binding of granule neurons to the human A-172, HTB-16, and U-251 and mouse G26-24 cell lines occurred, after which 3H-thymidine incorporation by these astrocytoma cells dropped 2-5-fold within 12 hr. The number of glial cells remained constant for 5-7 d when the glia were cocultured with granule neurons. Thereafter many neurons detached from the glial cells and glial proliferation commenced again. No effects on glial cell number were seen when PC12 cells were substituted for cerebellar granule neurons. To test the mechanism of neuronal control of glioma cell growth, we added granule neurons or PC12 cells that had been fixed lightly with paraformaldehyde, a plasma membrane fraction of purified granule cells, PC12 cells or astrocytoma cells, or medium conditioned by either granule cells or a mixed population of cerebellar neurons and astroglia. The proliferation of responsive glioma cell lines ceased in the presence of either fixed granule neurons or plasma membranes purified from granule neurons. The addition of fixed PC12 cells or plasma membranes purified from PC12 cells, 3T3 cells, or astrocytoma cells had no effect on glial cell growth.(ABSTRACT TRUNCATED AT 250 WORDS)

A monoclonal antibody recognising the site of limited proteolysis of protein kinase C

A monoclonal antibody to protein kinase C is described that recognises the site of limited proteolysis on the native enzyme. Binding of the antibody to the purified kinase in vitro blocks partial proteolysis by trypsin, and introduction of the Fab fragment into a rodent glioma cell line inhibits phorbol-ester-induced down-regulation of the kinase. These observations are discussed in the context of the domain structure of protein kinase C and the agonist-induced proteolysis of the kinase in vivo.