Heterogeneity of protein kinase C activity in human U-373 and G-26 mice glioma cells.
Protein kinase C (PKC) enzyme activity in a mouse glioma cell line G-26 and a human glioma cell line U-373 were compared at similar cell confluency in-vitro to establish if a G-26 in-vivo mouse model would be useful to examine the role of PKC inhibitors in controlling human glioma growth in-vivo. Original crude cytosolic and membrane PKC fractions of both mouse glioma G-26 and human glioma U-373 cells did not display significant PKC activity compared to partially purified PKC. Partial purification of mouse glioma G-26 and U-373 cytosolic and membrane fractions showed different cytosolic and membrane PKC activity profiles. Total PKC activity was higher (rho = 0.0001) in human glioma U-373 (7840 picomoles/mg/min) than in mouse glioma G-26 cells (2890 picomoles/mg/min). Thus, results from trials using nude mice human glioma xenografts may be more valid than those obtained from a G-26 in-vivo mouse model for studying the effects of therapeutic drugs on PKC isozymes.
Acevedo-Duncan
M
M
Department of Radiology, University of South Florida College of Medicine, Tampa 33612.
Zhang
R
R
D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D005910:Glioma / Q000201:enzymology*; D006801:Humans; D051379:Mice; D011493:Protein Kinase C / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D011493:Protein Kinase C