TEL/AML1 shows dominant-negative effects over TEL as well as AML1.
The TEL/AML1 chimeric gene is generated by the t(12;21) translocation in pre-B cell acute lymphoblastic leukemia. TEL/AML1 consists of the helix-loop-helix (HLH) dimerization domain from TEL and almost the entire of AML1, but loses the ETS DNA-binding domain from TEL. Dominant-negative effects of TEL/AML1 over wild-type-AML1 are believed to trigger the development of this type of leukemia. However, it could also be possible that TEL/AML1 affects wild-type-TEL's molecular and tumor suppressive functions through the HLH domain. To test this possibility, we first confirmed that TEL/AML1 associates with wild-type-TEL. TEL/AML1 neither bound to the ETS-binding consensus site nor repressed transcription through it. Regardless, this prevented wild-type-TEL-induced transcriptional repression. Moreover, TEL/AML1 concomitantly inhibited wild-type-TEL-induced growth suppression and wild-type-AML1-mediated transforming activity in NIH3T3 cells. All these data indicate that TEL/AML1 exerts dominant-interfering effects on both AML1 and TEL, and that expression of TEL/AML1 could result in inactivation of TEL's tumor suppressive functions in t(12;21)-carrying leukemia.
Department of Hematology, Dokkyo University School of Medicine, Tochigi 321-0293, Japan.
Hisako
H
Gunji
Kazuo
K
Waga
Fumihiko
F
Nakamura
Kazuhiro
K
Maki
Ko
K
Sasaki
Yuichi
Y
Nakamura
Kinuko
K
Mitani
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004843:Epistasis, Genetic; D005786:Gene Expression Regulation / Q000502:physiology; D015448:Leukemia, B-Cell / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D051379:Mice; D041681:NIH 3T3 Cells; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014178:Translocation, Genetic; D000097764:ETS Translocation Variant 6 Protein
D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D015514:Oncogene Proteins, Fusion; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012097:Repressor Proteins; D014157:Transcription Factors; D000097764:ETS Translocation Variant 6 Protein; C493726:Runx1 protein, mouse; C102421:TEL-AML1 fusion protein