Fluorescence In Situ Hybridization to Visualize Genetic Abnormalities in Interphase Cells of Acinar Cell Carcinoma, Ductal Adenocarcinoma, and Islet Cell Carcinoma of the Pancreas

Abstract Trisomy 12 is the most common cytogenetic abnormality in chronic lymphocytic leukemia (CLL), and a number of studies have suggested that it may be an adverse prognostic indicator. We have evaluated the usefulness of fluorescence in situ hybridization with a chromosome 12- specific probe as a simple means for detecting trisomy 12 in interphase cells. Forty cases of B-cell CLL previously studied with conventional cytogenetic techniques were analyzed with a biotinylated probe to the centromeric region of chromosome 12. Thirty of these retrospective cases could be reevaluated with in situ hybridization. Our analysis showed three hybridization signals (ie, trisomy 12) in interphase cells from seven of seven cases found previously to have trisomy 12. Trisomy 12 was also detected in five additional cases: in one case thought to have a normal karyotype, in two cases that had been inadequate for routine cytogenetic analysis, and in two cases that had been found to have an abnormal karyotype without trisomy 12. In a prospective series of 20 newly accrued CLL cases, all cases were analyzed successfully by in situ hybridization and six (30%) showed trisomy 12. We were able to perform the analysis on routinely prepared and previously Wright- stained peripheral blood smears. We conclude that fluorescence in situ hybridization is a simple means for the detection of trisomy 12 in CLL. The technique is more sensitive than conventional cytogenetic analysis and would be a useful tool in clinical studies.

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Detection of 11q13 rearrangements in hematologic neoplasias by double- color fluorescence in situ hybridization

Blood ◽

10.1182/blood.v87.4.1512.bloodjournal8741512 ◽

1996 ◽

Vol 87 (4) ◽

pp. 1512-1519 ◽

Cited By ~ 50

Author(s):

LJ Coignet ◽

E Schuuring ◽

RE Kibbelaar ◽

TK Raap ◽

KK Kleiverda ◽

...

Keyword(s):

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Hematologic Malignancies ◽

Current Data ◽

Lymphocytic Leukemia ◽

Cell Nuclei ◽

Interphase Cell ◽

Interphase Cells ◽

Chromosomal Breaks

Rearrangements within the chromosome 11q13 region are frequent in hematologic malignancies. 50% of 75% of mantle cell lymphomas (MCLs) carry a translocation t(11;14) (q13;q32). Using Southern blot analysis, a BCL1 breakpoint can be detected in approximately 50% of MCLs. It is not known whether other MCLs harbor also breakpoints at 11q13. Breakpoints in this region not involved in t(11;14), are detected in chronic lymphocytic leukemia and acute myeloid leukemia. To detect and localize breakpoints at 11q13 more accurately, we have developed fluorescence in situ hybridization using two probe sets of differently labeled cosmids, symmetrically localized at either side of the major translocation cluster of BCL1. These probes span a region of 450 to 750 kb. We applied this assay to a series of hematologic malignancies with 11q13 abnormalities identified by classical cytogenetics. All four samples with a t(11;14) (q13;q32) showed dissociation of the differently colored signals in metaphase and interphase cells, thereby indicating a chromosomal break in the region defined by the probe sets. The frequency of abnormal metaphase and interphase cells was comparable with that observed in any of the 13 malignancies with other chromosomal 11q13 abnormalities, indicating that these chromosomal breaks occurred outside the 450- to 750-kb region covered by the probes. One patient showed triplication and one patient showed monoallelic loss of this region. The current data show that double-color fluorescence in situ hybridization is a simple and reliable method for detection of the t(11;14)(q13;q32) in interphase cell nuclei and that is can be used to distinguish this translocation from other 11q13 rearrangements in hematologic malignancies.

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