Transient apoptosis elicited by insulin in serum-starved glioma cells involves Fas/Fas-L and Bcl-2.
The expression of fas gene in glioma cells varies with growth stage. When insulin-elicited transient apoptosis of glioma cells was in progress, the expression of fas gene increased at both transcriptional and translational levels. In contrast, the expression of fas-L gene in glioma cells remained constant. Apoptosis occurred in the cells having high level of surface Fas protein. When the expression of Fas-L in U-373MG cells was suppressed by ribozyme, the insulin-elicited transient apoptosis vanished. Overexpression of Bcl-2 in U-373MG cells did not alter significantly the cell cycle progression and the expression of fas gene. However, these cells were resistant to insulin-trigged death. Therefore, insulin-elicited apoptosis involved Fas-related death signal, and which could be prevented by the protective effect of Bcl-2.
Yang
B C
BC
Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, Republic of China. y1357@mail.ncku.edu.tw
Wang
Y S
YS
Wang
C H
CH
Lin
H H
HH
Tang
M J
MJ
Yang
T L
TL
D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D001932:Brain Neoplasms; D002455:Cell Division / Q000502:physiology; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D005910:Glioma; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D016337:RNA, Catalytic / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D014158:Transcription, Genetic / Q000502:physiology; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000737:chemistry / Q000166:cytology / Q000201:enzymology; D019014:fas Receptor / Q000235:genetics* / Q000378:metabolism
D000954:Antigens, Surface; D016895:Culture Media, Serum-Free; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D007004:Hypoglycemic Agents; D007328:Insulin; D008562:Membrane Glycoproteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016337:RNA, Catalytic; D019014:fas Receptor