Mapping chromosome band 11q23 in human acute leukemia with biotinylated probes: identification of 11q23 translocation breakpoints with a yeast artificial chromosome.

Abstract

Translocations involving chromosome 11, band q23, are frequent recurring abnormalities in human acute lymphoblastic and acute myeloid leukemia. We used 19 biotinlabeled probes derived from genes and anonymous cosmids for hybridization to metaphase chromosomes from leukemia cells that contained four translocations involving band 1 Iq23: t(4;11)(q21;q23), t(6;11)(q27;q23), t(9;11)(p22;q23), and t(11;19)(q23;pl3). The location of the cosmid probes relative to the breakpoint in 11q23 was the same in all translocations. Of the cosmid clones containing known genes, CD3D was proximal and PBGD, THYI, SRPR, and ETSI were distal to the breakpoint on 11q23. Hybridization of genomic DNA from a yeast clone containing yeast artificial chromosomes (YACs), that carry 320 kilobases (kb) of human DNA including CD3D and CD3G genes, showed that the YACs were split in all four translocations. These results indicate that the breakpoint at 11q23 in each of these translocations occurs within the 320 kb encompassed by these YACs; whether the breakpoint within the YACs is precisely the same in the different translocations is presently unknown)

Analysis of genes and chromosomes by nonisotopic in situ hybridization

“…In certain diagnostic applications, such as the detection of trisomy 21, small probes are more informative than painting of whole chromosomes, because the more focal signals are easier to quantitate [48,160]. Furthermore, Single probes flanking or spanning a chromosomal breakpoint can be used to detect a diagnostically important breaking event [161][162][163] or to characterize further a breakpoint region [11,164,165]. An example of a breakpoint in the short arm of chromosome 11 from a Potter's facies Syndrome patient was previously reported and is shown in Figure IB.…”

“…An example of a breakpoint in the short arm of chromosome 11 from a Potter's facies Syndrome patient was previously reported and is shown in Figure IB. This approach seems particularly useful in analyzing specific translocations in blood cell tumors [162,163,165]. The details, implications, and prospects of this application of nonisotopic in situ hybridization are reviewed elsewhere in this Journal [3].…”

Characterization of two marker chromosomes in a patient with acute nonlymphocytic leukemia by two-color fluorescence in situ hybridization

“…Multiple-color FISH approaches are presently being developed using combinations of three or even more fluorochromes to label chromosome-specific library probes and regional probes, such as centromere-specific repetitive DNA probes or band-specific YAC probes [19]. FISH with YAC clones spanning breakpoint regions of interest appear ideally suited for detection of specific translocations in tumor cells at any stage of the cell cycle [9,20,21]. These developments make possible new strategies to identify the origin of translocated materials in marker chromosomes rapidly in cases in which chromosome banding analyses do not provide unequivocal results.…”

MLL is fused to CBP, a histone acetyltransferase, in therapy-related acute myeloid leukemia with a t(11;16)(q23;p13.3)

“…FISH was performed as previously described (39). A mixture of cosmids c365F4, c444A4, c443G8, c388H4, c304A10, c312B2, c379G3, c330H2, c58E12, c307E6 (NAD) as well as cosmids TES2, 541E10-c23, TES 5, 541E10-C53, and 376E2-C1 (JB) were used for FISH on patient material.…”