Expression of the Ikaros gene family in childhood acute lymphoblastic leukaemia.
The Ikaros (Ik) gene family, which includes Ik, Aiolos (Ai), and Helios (He), is a primary regulator of lymphocyte differentiation, and is involved in the development of acute lymphoblastic leukaemia (ALL). We analysed the expression of the Ik gene family isoforms in 97 ALL cases, consisting of 64 childhood and 33 infant ALL cases, using reverse transcription-polymerase chain reaction (RT-PCR). Expression of Ik was detected in all cases, 87 of which expressed either Ik1 or Ik2, or both, five of which expressed Ik1/Ik2 and Ik6, and another five of which expressed only Ik6. Therefore, the dominant negative isoform of Ik6 was expressed in 10 of the 38 cases of childhood precursor B ALL, but was absent in other types of childhood ALL (26.3%, chi2-test, P = 0.0001). In terms of Aiolos and Helios expression, 49 (65.3%) out of the 75 and 40 (50%) out of the 80 ALL cases tested showed non-spliced Ai1 and He1 respectively. Only one case of T lineage ALL expressed a small-sized isoform of Helios (designated as He6). It was also found that the expression of Ai1 and He1 was low in Ik6-positive patients (Fisher's exact test; Ai1 P = 0.005, Hel P = 0.035).
Takanashi
Mami
M
Department of Pediatrics, Kyoto Prefectural University of Medicine, Kajiicho 465 Hirokoji, Kamigyoku, Kyoto 602-8566, Japan. mamikiti@koto.kpu-m.ac.jp
Yagi
Tomohito
T
Imamura
Toshihiko
T
Tabata
Yasuhiro
Y
Morimoto
Akira
A
Hibi
Shigeyoshi
S
Ishii
Eiichi
E
Imashuku
Shinsaku
S
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004268:DNA-Binding Proteins; D015870:Gene Expression; D006801:Humans; D051740:Ikaros Transcription Factor; D007223:Infant; D015850:Interleukin-6 / Q000378:metabolism; D009363:Neoplasm Proteins / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics*; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; C497239:IKZF1 protein, human; D015850:Interleukin-6; D009363:Neoplasm Proteins; D020033:Protein Isoforms; D014157:Transcription Factors; D051740:Ikaros Transcription Factor