Presence of WT1 in nuclear messenger RNP particles in the human acute myeloid leukemia cell lines HL60 and K562

The WT1 gene is a key player in acute myeloid leukaemia, in which it is frequently over-expressed. WTI encodes a multifunctional zinc finger protein transcription factor, which also binds mRNA. Thus increasing evidence suggests that WTI works both at the DNA and mRNA level, not only in the urogenital system but also in other contexts. Nuclear poly(A)+ mRNP particles were isolated by oligo(dT) chromatography from the human acute myeloid leukemia cell lines HL60 and K562, and analysed by Western blotting and 2D minigels. MALDI-TOF demonstrated the presence of hnRNP proteins, splice factors, and unexpectedly vimentin in the mRNP fraction. WTI was also shown to be present in nuclear mRNP particles suggesting that in leukaemia, and by extension in all cancers in which it is involved, WTI works both at the DNA and mRNA target level. (c) 2006 Elsevier Ireland Ltd. All rights reserved.