Abstract
The t(12;21) (p 13; q22) results in the fusion of the TEL gene located on chromosome 12 with the AML1 gene located on the derivative chromosome 21. Because this translocation is difficult to detect using standard cytogenetic techniques, 27 previously karyotyped B-lineage acute lymphoblastic leukemia (ALL) cell lines were evaluated for the presence of the TEL-AML1 fusion using the reverse transcriptase-polymerase chain reaction (RT-PCR), fluorescence in situ hybridization (FISH), and cDNA sequencing. Six cell lines expressed the TEL-AML1 chimeric transcript by RT-PCR and the t(12;21) was confirmed by FISH analysis with probes for TEL, AML1, and chromosome 12. While only one of the 6 cell lines with the t(12;21) lost the der(12)t(12;21)-encoded AML1-TEL fusion transcript, 4 cell lines lacked expression of the nontranslocated allele of TEL and 5 cell lines lacked expression of CDKN2. Moreover, in 2 patients (1 with the TEL-AML1 transcript and 1 without), TEL expression was lost with disease progression; le, TEL was expressed in the initial cell lines (established at diagnosis or first relapse) whereas TEL was not expressed in the cell lines established from these patients in late-stage disease. These data show the coexistence of multiple genetic defects in childhood B-lineage ALL Cell lines with t(12;21) will facilitate the study of TEL-AML1 and AML1-TEL fusion proteins as well as TEL and CDKN2 gene inactivation in leukemia transformation and progression.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Base Sequence
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Burkitt Lymphoma / genetics*
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Burkitt Lymphoma / pathology
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Carrier Proteins / biosynthesis
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Carrier Proteins / genetics*
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Child
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Chromosomes, Human, Pair 12 / genetics*
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Chromosomes, Human, Pair 12 / ultrastructure
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Chromosomes, Human, Pair 21 / genetics*
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Chromosomes, Human, Pair 21 / ultrastructure
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Core Binding Factor Alpha 2 Subunit
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Cyclin-Dependent Kinase Inhibitor p16
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DNA, Neoplasm / genetics
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DNA-Binding Proteins / biosynthesis
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism*
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Disease Progression
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ETS Translocation Variant 6 Protein
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Gene Expression Regulation, Leukemic*
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Genes, Tumor Suppressor*
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Humans
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In Situ Hybridization, Fluorescence
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Molecular Sequence Data
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Neoplasm Proteins / genetics*
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Polymerase Chain Reaction
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Precursor Cell Lymphoblastic Leukemia-Lymphoma / genetics*
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Precursor Cell Lymphoblastic Leukemia-Lymphoma / pathology
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Proto-Oncogene Proteins c-ets
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Proto-Oncogene Proteins*
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Repressor Proteins*
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Transcription Factors / biosynthesis
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Transcription Factors / genetics*
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Transcription Factors / metabolism*
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Translocation, Genetic*
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Tumor Cells, Cultured
Substances
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Carrier Proteins
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Core Binding Factor Alpha 2 Subunit
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Cyclin-Dependent Kinase Inhibitor p16
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DNA, Neoplasm
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DNA-Binding Proteins
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Neoplasm Proteins
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Proto-Oncogene Proteins
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Proto-Oncogene Proteins c-ets
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RUNX1 protein, human
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Repressor Proteins
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Transcription Factors