Levels of breakpoint t(12;16) and TERT C228T ctDNA correlated with the clinical course and tumor burden in patients with myxoid liposarcomas (n = 4). ctDNA could detect minimal residual disease and tumor recurrence.
It might be that the specific combination of concurrent Xq duplication and 6q-deletion results in gain of possible oncogenes on Xq and loss of possible tumor suppressor genes on 6q that are important for the leukemic propagation of t(12;21)-positive hematopoietic cells in a subset of ALLs.
The tumor in case 2 was negative in both its elements for the t(12;15) translocation, but ETV6 gene rearrangement was detected in both components in all 3 cases.
The tumor occurred in the right tibia of a 35-year-old man and showed the balanced chromosomal translocation t(12;15;20)(q11;q24;p13.3), among other numeric chromosomal abnormalities.
Transgenic mouse models of T(12;15)/t(8;14), including newly developed "iMyc" gene-insertion mice, will be useful in elucidating the role of these CSR factors in the progression of Myc-induced B cell tumors.
BCL2 transgenic C57BL/6 mice exclusively developed B lymphomas (11 of 20, 55%) that also contained T(12;15) translocations (11 of 11 cases) with breakpoints in the near 5' flank of Myc (five of five tumors).
Beside the two predominant alterations t(3;12) (q27 through 28;q14 through q15) and t(12;14)(q14 through q15;q23 through q24), the t(12;13)(q14 through q15;q12 through q14) is another aberration observed recurrently in these tumors.
Fluorescence in situ hybridization (FISH) analysis showed that this contig spanned the t(12;14) breakpoints in three uterine leiomyomas and that the breakpoints in these tumors occurred within a 1 Mb region.
Our efforts have focused on cloning the t(12;14)(q14-q15;q23-q24) breakpoint in uterine leiomyoma to further our understanding of the biology of these tumors.
Although only a few lipoblastomas have been investigated cytogenetically, it is increasingly clear that these adipose tissue tumor generally show rearrangements of 8q11-q13 region but lack the t(12;16) that allows these tumors to be distinguished from myxoid liposarcomas.
An apparently identical translocation t(12;22) has been described recently in four clear cell sarcomas, indicating that this constitutes a primary cytogenetic change specific for this type of tumor.
The analysis of these five uterine leiomyomas and the collation of the results with previously obtained data lead us to conclude that del(7)(q21q31) is secondary to t(12;14) and + 12 in this tumor type, and that ring formation involving chromosome 1 material, often with duplication of segments, is a common phenomenon during clonal evolution.