STAT-related transcription factors are constitutively activated in peripheral blood cells from acute leukemia patients.
A signal transduction pathway activated by many cytokines has recently been elaborated. The JAK kinases and the signal transducers and activators of transcription (STAT) factors have been found to be essential components. In this report, we describe the presence of constitutively activated STAT factors in peripheral blood cells from patients with acute leukemia. We used oligonucleotide probes from the beta-casein and IRF-1 gene promoters and the ISRE probe to detect STAT proteins in nuclear extracts from acute leukemia cells in bandshift assays. Specific DNA protein complex formation was observed with the probes from the beta-casein and IRF-1 gene promoters, but not with the ISRE oligonucleotide probe, when cell extracts from acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) were investigated. We used nonradioactive oligonucleotides as competitors to show the specificity of the complex formation. Specific antibodies directed against the individual STAT proteins were used in supershift experiments. STAT5- and STAT1-related factors were detected in ALL and STAT1-, STAT3-, and STAT5-related proteins were present in nuclear cell extracts from AML. Since the cells were not treated with cytokines before the nuclear proteins were extracted, we conclude that these factors are constitutively activated in vivo. It is likely that the constitutive activation of STAT proteins is a part of the events of leukemogenesis.
Gouilleux-Gruart
V
V
Laboratoire d'Immunologie, Centre Hospitalier Universitaire d'Amiens, France.
Gouilleux
F
F
Desaint
C
C
Claisse
J F
JF
Capiod
J C
JC
Delobel
J
J
Weber-Nordt
R
R
Dusanter-Fourt
I
I
Dreyfus
F
F
Groner
B
B
Prin
L
L
D000208:Acute Disease; D000328:Adult; D000368:Aged; D001483:Base Sequence; D001773:Blood Cells / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000097:blood; D004268:DNA-Binding Proteins / Q000097:blood*; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D007938:Leukemia / Q000097:blood* / Q000235:genetics; D046911:Macromolecular Substances; D008894:Milk Proteins; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000097:blood*; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor; D050799:STAT5 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000097:blood*; D014158:Transcription, Genetic
D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D008894:Milk Proteins; D009363:Neoplasm Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D050799:STAT5 Transcription Factor; D015534:Trans-Activators