Translocation t(7;17)(p15;q21) is one of the most commonly occurring molecular markers of endometrial stromal tumors.

Translocation includes JAZF1 gene localized on the chromosome 7 and JJAZ1 gene (joined to JAZF1) (also SUZ12) located on chromosome 17. These genes belong to the "zinc-finger" family of transcription factors. JJAZ1 is also a member of "polycomb group" (PcG) family of proteins, with which it forms complexes that negatively regulate the expression of homeotic genes during embryogenesis. JAZF1 gene function is still unclear, however it is known that it encodes a transcriptional co-repressor, which binds to the "orphan" nuclear receptor TAK1.

In the chimeric gene, the N-terminal "zinc-finger" domain of JAZF1 gene with "zinc-finger" domains connects with the domain giving a signal to nuclear localization of JJAZ1 gene. The exact mechanism by which this gene product works in tumor transformation is not known.

Examination

To detect the translocation of t(7;17)(p15;q21), we use one-round RT-PCR (Fig. 1) followed by verification of the fusion product using a direct sequencing (Fig. 2).

  • Slideshow Format
    Fig.1

    Agarose gel with fusion products RT-PCR detecting translocation of t(7;17)(p15;q21). 1,3 - positive samples, 2 - negative sample, 4 - positive check, 5 - negative check, 6 - water, 7 - marker.

  • Slideshow Format
    Fig.2

    Diagram of sequencing with a marked spot of fusion of genes JAZF1 and JJAZ1.

References

  1. Hrzenjak A, Moinfar F, Tavassoli FA, Strohmeier B, Kremser ML, Zatloukal K, Denk H. JAZF1/JJAZ1 gene fusion in endometrial stromal sarcomas: molecular analysis by reverse transcriptase-polymerase chain reaction optimized for paraffin-embedded tissue. J Mol Diagn. 2005;7(3):388-395. Review.
  2. Koontz JI, Soreng AL, Nucci M, Kuo FC, Pauwels P, van Den Berghe H, Cin PD, Fletcher JA, Sklar J. Frequent fusion of the JAZF1 and JJAZ1 genes in endometrial stromal tumors. Proc Natl Acad Sci U S A. 2001;98(11):6348-6353.
  3. Nucci MR, Harburger D, Koontz J, Cin PD, Sklar J. Molecular analysis of the JAZF1-JJAZ1 gene fusion by RT-PCR and fluorescence in situ hybridization in endometrial stromal neoplasms. Am J Surg Pathol. 2007;31(1):65-70.