[Variant fusion transcripts and genomic DNA breakpoint of sil-tal1 in T-ALL cells]

The aim of this study was to investigate the nucleotide sequence of one distinct fusion transcript of sil-tal1 in childhood T-ALL. The PCR product was cloned into plasmid vector and then sequenced. Genomic DNA was analyzed with PCR using the designed primer pairs representing distinct sequences. The product was sequenced and analyzed with database. The results indicated that 4 different fusion transcripts were detected at cDNA level, in which a part of exons or introns of sil are reserved respectively, and some additions and deletions existed. After analyzing genomic DNA sequence of leukemic cells, the breakpoint in gene sil of this case was proved to be different at DNA level from references. Hence, the sil-tal1 rearrangement was defined to be a new type. It is concluded tal1 rearrangement of leukemic cells in this case is a new type, which expresses classical and at least 3 variant fusion transcripts, presumably caused by extraordinary mechanisms of splicing and transcription in leukemic stem cells.