Constitutive activation of LIL-Stat in adult T-cell leukemia cells.
The activation status of a recently identified STAT (signal transducers and activators of transcription) factor, LIL-Stat (lipopolysaccharide [LPS]/IL-1-inducible Stat) in adult T-cell leukemia (ATL) cells was investigated by electrophoretic mobility shift assays using nuclear extracts of leukemic cells from 7 patients with ATL and a GAS (gamma interferon activation site)-like element termed LILRE (LPS/IL-1-responsive element), which is found in the human prointerleukin 1beta (IL1B) gene. Spontaneous DNA binding of LIL-Stat was observed in all ATL cells examined. However, in normal human peripheral lymphocytes, DNA binding of LIL-Stat was detected only after stimulation with IL-1. These results demonstrated that LIL-Stat is constitutively activated in ATL cells. Furthermore, our transient transfection studies using LILRE chloramphenicol acetyltransferase (CAT) reporters argue that LIL-Stat in ATL cells functions as a transcriptional activator through binding to the LILRE in the IL1B gene. (Blood. 2000;95:2715-2718)
Tsukada
J
J
First Department of Internal Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan. jtsukada@med.uoeh-u.ac.jp
Toda
Y
Y
Misago
M
M
Tanaka
Y
Y
Auron
P E
PE
Eto
S
S
D000208:Acute Disease; D000328:Adult; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015458:Leukemia, T-Cell / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
C114046:LIL-Stat transcription factor; D014157:Transcription Factors