sodium-dodecyl-sulfate and Astrocytoma

gamma-L-glutamyl-L-cysteinylglycine (GSH) has been shown to inactivate 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and quench DNA crosslink precursors of BCNU. Because of the central role of 2-chloroethyl-nitrosoureas in brain tumor chemotherapy, we investigated the intracellular GSH content and the expression of specific glutathione-S-transferases (GSTs) in three human malignant astrocytoma cell lines (UWR1, UWR2, and UWR3) of varying BCNU resistance to determine the interrelationship of these parameters with brain tumor BCNU resistance. GSH was assayed by ion-exchange high performance liquid chromatography after derivatization with 1-fluoro-2,4 dinitrobenzene. Both bulk and specific GST (acid, near-neutral, and basic) activities were examined using substrates that show high specificities to the different GSTs. Western blot analyses with antisera against GST-alpha, -mu, and -tau subunits were also performed on partially purified GST from the cells of each cell line. The results showed GSH content of 91, 46.5, and 28.3 nmol GSH/mg protein for UWR1, UWR2, and UWR3, respectively. Bulk GST activity (with 1-chloro-2,4-dinitrobenzene as substrate) also correlated with increasing BCNU resistance. Of the three GST classes examined by both substrate specificities and Western blotting, only the expression of the acidic form, GST-tau, correlated significantly with the rank order of BCNU resistance of the cell lines. GST-mu and -alpha were present in only trace amounts in all three cell lines.

Topics: Astrocytoma; Blotting, Western; Brain Neoplasms; Carmustine; Cisplatin; DNA, Neoplasm; Drug Resistance; Electrophoresis, Polyacrylamide Gel; Glutathione; Glutathione Disulfide; Glutathione Transferase; Humans; Sodium Dodecyl Sulfate; Substrate Specificity; Tumor Cells, Cultured

The immunoblotting technique was used to study the glycoproteins in human brain tumor samples including astrocytoma, glioblastoma, meningioma and oligodendroglioma, as well as in normal human brain. Glycoproteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, electrophoretically transferred to nitrocellulose membrane and characterized, using binding with 11 different lectins. Tumor-associated glycoproteins were found using the lectins peanut agglutinin (PNA), soybean agglutinin, Limulus polyhemus, Lotus tetragonolobus, Ricinus communis 1, (RCA-1) and wheat germ agglutinin (WGA). Their molecular masses ranged from 50 to 180 kDa. Several of them were common to the 3 types of tumors: astrocytomas, oligodendrogliomas and meningiomas. PNA, RCA-1 and WGA were the 3 most feasible lectins with regard to tumor specificity, simplicity and reproducibility.

Topics: Astrocytoma; Brain Neoplasms; Electrophoresis, Polyacrylamide Gel; Glioblastoma; Glycoproteins; Humans; Lectins; Meningioma; Molecular Weight; Neoplasm Proteins; Oligodendroglioma; Sodium Dodecyl Sulfate

Topics: Animals; Astrocytoma; Brain Chemistry; Dimethylamines; Electrophoresis, Polyacrylamide Gel; Ethylenediamines; Evaluation Studies as Topic; Methods; Molecular Weight; Myelin Sheath; Neoplasm Proteins; Nerve Tissue Proteins; Proteins; Rats; Sodium Dodecyl Sulfate; Solubility; Tritium; Tryptophan

Topics: Ammonium Sulfate; Animals; Astrocytoma; Brain; Brain Chemistry; Chemical Precipitation; Cross Reactions; Electrophoresis, Polyacrylamide Gel; Goats; Haplorhini; Humans; Hydrogen-Ion Concentration; Immunodiffusion; Lysine; Macaca; Male; Molecular Weight; Nerve Tissue Proteins; Nucleoproteins; Organ Specificity; RNA; Sodium Dodecyl Sulfate; Tritium; Uridine