Alternately spliced WT1 antisense transcripts interact with WT1 sense RNA and show epigenetic and splicing defects in cancer.
Many mammalian genes contain overlapping antisense RNAs, but the functions and mechanisms of action of these transcripts are mostly unknown. WT1 is a well-characterized developmental gene that is mutated in Wilms' tumor (WT) and acute myeloid leukaemia (AML) and has an antisense transcript (WT1-AS), which we have previously found to regulate WT1 protein levels. In this study, we show that WT1-AS is present in multiple spliceoforms that are usually expressed in parallel with WT1 RNA in human and mouse tissues. We demonstrate that the expression of WT1-AS correlates with methylation of the antisense regulatory region (ARR) in WT1 intron 1, displaying imprinted monoallelic expression in normal kidney and loss of imprinting in WT. However, we find no evidence for imprinting of mouse Wt1-as. WT1-AS transcripts are exported into the cytoplasm and form heteroduplexes with WT1 mRNA in the overlapping region in WT1 exon 1. In AML, there is often abnormal splicing of WT1-AS, which may play a role in the development of this malignancy. These results show that WT1 encodes conserved antisense RNAs that may have an important regulatory role in WT1 expression via RNA:RNA interactions, and which can become deregulated by a variety of mechanisms in cancer.
Dallosso
Anthony R
AR
CLIC Sargent Research Unit, Department of Cellular and Molecular Medicine, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom.
Hancock
Anne L
AL
Malik
Sally
S
Salpekar
Ashreena
A
King-Underwood
Linda
L
Pritchard-Jones
Kathy
K
Peters
Jo
J
Moorwood
Kim
K
Ward
Andrew
A
Malik
Karim T A
KT
Brown
Keith W
KW
D017398:Alternative Splicing; D000818:Animals; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics; D015470:Leukemia, Myeloid, Acute / Q000235:genetics; D051379:Mice; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics*; D016372:RNA, Antisense / Q000235:genetics*; D012334:RNA, Neoplasm / Q000235:genetics*; D014158:Transcription, Genetic; D025721:WT1 Proteins / Q000235:genetics*; D009396:Wilms Tumor / Q000235:genetics
D009363:Neoplasm Proteins; D016372:RNA, Antisense; D012334:RNA, Neoplasm; D025721:WT1 Proteins