Application of Interphase Fluorescence In Situ Hybridization for the Detection of the Burkitt Translocation t(8;14)(q24;q32) in B-Cell Lymphomas

Abstract

The translocation t(8;14)(q24;q32) is the characteristic chromosomal aberration of Burkitt's-type lymphomas and leukemias (BLs). On the molecular level, the t(8;14) juxtaposes the c-myc gene in 8q24 next to the IgH locus in 14q32, resulting in overexpression of the transcription factor c-Myc. The detection of a t(8;14) is a major aim in the diagnostic process of all patients with high-grade B-cell lymphomas because treatment strategies differ between BL and other high-grade lymphomas. As chromosome analyses are sometimes hampered by the low yield or poor quality of metaphase spreads and as the application of molecular genetic techniques is limited by the distribution of the 8q24 breakpoints over a region of about some hundred kilobases, we set out to establish an interphase fluorescence in situ hybridization (FISH) assay for the detection of the t(8;14). A cosmid probe hybridizing to the IgH constant region in 14q32 was combined with a differently labeled probe of pooled cosmid clones spanning the c-myc locus in 8q24. Interphase nuclei lacking a t(8;14) show two separated signals corresponding to each probe, whereas interphase nuclei carrying a t(8;14) display a split of the c-myc probe and a colocalization of at least one of the splitted signals with the IgH probe. Based on the results of extensive control studies, the cutoff level for this stringent (type I) criteria was set at 2%. Additionally, colocalization of at least one c-myc signal with one IgH signal alone (without signal split for the c-myc probe) was used as a less stringent (type II) criteria with a cutoff limit of 11%. Nine BLs and one Burkitt-like lymphoma were investigated by this approach. Cytogenetically, all tumors contained a translocation t(8;14)(q24;q32) except for one BL, in which cytogenetic analysis had failed. In interphase FISH, all lymphomas and leukemias met the less stringent criteria for the diagnosis of the t(8;14). Additionally, in all tumors but the Burkitt-like lymphoma, a t(8;14) could be diagnosed according to the stringent criteria. The percentage of cells found to harbor the t(8;14) by FISH ranged from 4.3% to 100%. Comparison of cytogenetic and FISH results revealed a significantly lower percentage of t(8;14)+ interphase nuclei than metaphase cells (P = .004). In conclusion, the described FISH assay provides a feasible and sensitive tool for the routine detection of the translocation t(8;14) in interphase cells which might also offer new insights into the biology of high-grade B-cell lymphomas.

Homogeneous immunophenotype and paucity of secondary genomic aberrations are distinctive features of endemic but not of sporadic Burkitt's lymphoma and diffuse large B‐cell lymphoma with MYC rearrangement

“…Recently described probe sets were applied for the detection of the Burkitt translocation t(8;14)(q24;q32) and its variants 19–22. Moreover, the commercially available LSI MYC BAP and LSI IGH/BCL2 probes (Vysis, Downers Grove, IL, USA) were used for the detection of breakpoints in the MYC locus and for determination of the t(14;18)(q32;q21).…”

Novel FISH probes designed to detect IGK-MYC and IGL-MYC rearrangements in B-cell lineage malignancy identify a new breakpoint cluster region designated BVR2

“…1;q32.3)/IGH-MYC, t(2;8)(p11.2; q24.1)/IGK-MYC and t(8;22)(q24.1;q11.2)/IGL-MYC balanced translocations in BCL is important for diagnostic and prognostic purposes. FISH studies employing novel BAP and D-FISH probe designs for detecting MYC or IGH-MYC translocations in BCL are relatively common,8,15,[32][33][34][35][36] but those detecting IGK-MYC and IGL-MYC are not. Here, we have described the design, validation and efficacy studies performed on four FISH probes used to assist in the detection of IGK-MYC and IGL-MYC rearrangements.…”

Improved Long-Distance Polymerase Chain Reaction for the Detection of t(8;14)(q24;q32) in Burkitt's Lymphomas

“…It has the limitation, though, that the breakpoints on the two chromosomes cannot be characterized so precisely as by LD-PCR, and it might suffer from excess false positive or false negative results, depending on the criteria used to interpret the results. 26 A disadvantage common to both cytogenetic and FISH analyses, compared to LD-PCR techniques, is that they are not suitable for minimal residual disease studies.…”