Exon scrambling of MLL transcripts occur commonly and mimic partial genomic duplication of the gene.
Gene
; 208(2): 167-76, 1998 Feb 27.
Article
em En
| MEDLINE
| ID: mdl-9540777
ABSTRACT
The MLL gene is frequently rearranged in acute human leukemia of both the myeloid and lymphoid lineages. Using a sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay, we identified several abnormally spliced transcripts in which MLL exons were joined in an order different from the genomic orientation (scrambled exons). Mis-splicing of MLL was present in both normal and malignant tissues. Although the majority of these scrambled transcripts were joined accurately at consensus splice sites, there were several examples in which the junctions of exons spliced in aberrant order were at non-consensus sites. A number of features differentiate mis-splicing of MLL from the previously described cases of scrambled exons and circular RNAs. Some scrambled transcripts appear to be present in the polyadenylated fraction of RNA. No correlation of exon scrambling with exon skipping was found, and there was no particular tendency for the exons involved to be near large introns. Our data show that splicing of MLL is extremely complex. The presence of scrambled transcripts in both normal and leukemic cells, indistinguishable from transcripts resulting from genomic MLL rearrangements, precludes the use of nested RT-PCR as a screening method for detection of tandem duplication of tandem duplication of MLL.
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Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
/
Transcrição Gênica
/
Proto-Oncogenes
/
Leucemia
/
Família Multigênica
/
Éxons
/
Processamento Alternativo
/
Proteínas de Ligação a DNA
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
1998
Tipo de documento:
Article