Differential regulation of myelin gene expression in SV40 T antigen-transfected rat glioma C6 cells.
Rat glioma C6 cells were stably transfected with a pSV3-neo plasmid containing SV40 T antigen gene, and geniticin-resistant transfectants (designated C6T cells) were cloned. The C6T cells grew as well-defined foci of cells showing squamous or irregular morphology. The doubling time for transfected cells was reduced by approximately 40% as compared to control C6 cells. The transfection with T-antigen also affected the expression of genes coding for structural myelin proteins and for myelin-associated enzymes. The steady-state level of proteolipid protein (PLP)-specific mRNA in C6T cells was 44% lower than in parental C6 cells. On the other hand, the transfection upregulated the expression of myelin-associated glycoprotein (MAG) by 153%. The activity of 2':3' cyclic AMP phosphodiesterase (CNP) was increased by approximately 80% in the C6T cells as compared to untransfected, control cells. The activity of calcium-activated neutral proteinase (CANP) was also significantly elevated in the transfectants by approximately 50% and 220% for millimolar and micromolar form respectively. The results indicate that T antigen affects the expression of myelin genes, although, individual genes appear to be differently regulated implying the existence of several independent regulatory mechanisms.
Bong
M
M
Department of Neurology, Medical University of South Carolina, Charleston 29425.
Chakrabarti
A
A
Banik
N
N
Hogan
E L
EL
Kanoh
M
M
Wiggins
R C
RC
Konat
G
G
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000235:genetics; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D002154:Calpain / Q000235:genetics; D005786:Gene Expression Regulation; D005910:Glioma / Q000235:genetics; D009185:Myelin Proteins / Q000235:genetics*; D018991:Myelin Proteolipid Protein; D018992:Myelin-Associated Glycoprotein; D051381:Rats; D014162:Transfection; D014407:Tumor Cells, Cultured
D000952:Antigens, Polyomavirus Transforming; D009185:Myelin Proteins; D018991:Myelin Proteolipid Protein; D018992:Myelin-Associated Glycoprotein; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002154:Calpain