IL-6 stimulates growth and inhibits constitutive, protein synthesis-independent apoptosis of murine B-cell hybridoma 7TD1.
Interleukin-6 (IL-6) is a well-known survival/growth factor for murine B-cell hybridoma 7TD1 cells. In this study, we analyzed the behavior of 7TD1 cells in the absence or presence of IL-6. After IL-6 deprivation, the cells became growth arrested and demonstrated signs considered to be hallmarks of apoptosis. To assess the underlying molecular mechanism of IL-6-regulated apoptosis, two chemical compounds, cycloheximide (CHX) and aurintricarboxylic acid (ATA), were used to treat the cells. ATA, a DNA endonuclease inhibitor, efficiently prevented DNA fragmentation and increased cell survival in the absence of IL-6. CHX, an inhibitor of protein synthesis, failed to prevent apoptosis and blocked cell survival signals induced by IL-6. These results suggest, first, that IL-6 promotes 7TD1 cell survival by inhibiting an endogenous constitutive cell death program and, second, that this inhibition requires de novo protein synthesis.
Liu
J
J
Laboratory of Tumor Biology & Genetics, Service of Neurosurgery, University Hospital (CHUV), Lausanne, Switzerland.
Li
H
H
de Tribolet
N
N
Jaufeerally
R
R
Hamou
M F
MF
Van Meir
E G
EG
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001312:Aurintricarboxylic Acid / Q000494:pharmacology; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects*; D003513:Cycloheximide / Q000494:pharmacology; D006825:Hybridomas; D015850:Interleukin-6 / Q000494:pharmacology*; D051379:Mice; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis
D015850:Interleukin-6; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D001312:Aurintricarboxylic Acid; D003513:Cycloheximide