The translocation (1;14)(p34;q11) in human T-cell leukemia: chromosome breakage 25 kilobase pairs downstream of the TAL1 protooncogene.
Nearly 30 percent of patients with T-cell acute lymphoblastic leukemia (T-ALL) exhibit a tumor-specific rearrangement of the TAL1 gene (also called TCL5 or SCL). These rearrangements are generated by either local DNA deletion or a (1;14)(p34;q11) chromosome translocation, and they typically result in structural alterations of the TAL1 transcription unit. In this report we present a molecular characterization of the t(1;14)(p34;q11) from a T-ALL patient. As a consequence of the translocation, TAL1 is transposed from its normal position on chromosome 1 into the T-cell receptor alpha/delta chain locus on chromosome 14. Unlike previous cases, the chromosome 1 breakpoint in this patient did not disrupt the continuity of the TAL1 transcription unit, but instead occurred approximately 25 kilobase pairs (kb) downstream of TAL1. This observation suggests that malignant alteration of TAL1 can be mediated by long-range cis-activating mechanisms that are triggered by DNA rearrangement at a distant site. Genes Chrom Cancer 4:211-216 (1992).
Xia
Y
Y
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.
Brown
L
L
Tsan
J T
JT
Yang
C Y
CY
Siciliano
M J
MJ
Crist
W M
WM
Carroll
A J
AJ
Baer
R
R
D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D015139:Blotting, Southern; D002648:Child; D002878:Chromosomes, Human, Pair 1; D002883:Chromosomes, Human, Pair 14; D004247:DNA / Q000032:analysis; D015342:DNA Probes; D004268:DNA-Binding Proteins / Q000235:genetics*; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D015183:Restriction Mapping; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors; D014178:Translocation, Genetic
D051792:Basic Helix-Loop-Helix Proteins; D004247:DNA; D015342:DNA Probes; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D016692:Receptors, Antigen, T-Cell, gamma-delta; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors; C067143:TAL1 protein, human