Endometrial stromal sarcomas (ESS) are genetically heterogeneous uterine tumors in which a JAZF1-SUZ12 chimeric gene resulting from the chromosomal translocation t(7;17)(p15;q21) as well as PHF1 rearrangements (in chromosomal band 6p21) with formation of JAZF1-PHF1, EPC1-PHF1, and MEAF6-PHF1 chimeras have been described.
Fluorescence in-situ hybridization demonstrated JAZF1 breakaparts in five of six ESNs and 16 of 25 ESSs; however, only three of nine ESS variants were positive.
The present study evaluates the prevalence of the t(7;17)(p15;q21) and JAZF1-JJAZ1 gene fusion in a series of 6 cases of primary extrauterine endometrial stromal sarcoma.
The chimeric transcripts described in endometrial stromal sarcomas (ESS) are JAZF1/SUZ12, YWHAE/FAM22, ZC3H7/BCOR, MBTD1/CXorf67, and recombinations of PHF1 with JAZF1, EPC1, and MEAF6.
JAZF1-JJAZ1 fusion transcript was detected in 6 (50%) out of 12 ESS-LG and in 1 (33%) of 3 UES-U, whereas it was not detected in any of the cases of UES-P. ESS-LG and UES-U frequently showed positive immunoreaction for estrogen receptor (ESS-LG: 94%, UES-U: 57%) and progesterone receptor (ESS-LG: 94%, UES-U: 57%), whereas all the UES-P were negative for these receptors.
The chimeric transcripts described in endometrial stromal sarcomas (ESS) are JAZF1/SUZ12, YWHAE/FAM22, ZC3H7/BCOR, MBTD1/CXorf67, and recombinations of PHF1 with JAZF1, EPC1, and MEAF6.
Endometrial stromal sarcomas (ESSs) frequently harbor genetic fusions, including JAZF1-SUZ12 and equivalent fusions in low-grade ESS (LGESS) and YWHAE-NUTM2 in high-grade ESS (HGESS).
Gene expression profiles of seven ESS (including three with YWHAE and two with JAZF1 rearrangements) and four UES without specific chromosomal aberrations indicated clustering of tumors with MBTD1-CXorf67 fusion together with low-grade JAZF1-associated ESS.
In combination with other established methods, accurate reverse transcriptase-polymerase chain reaction analysis of JAZF1/JJAZ1 gene fusion may be useful in diagnosing difficult or unusual ESS/UES cases.
Tumors with YWHAE-FAM22 rearrangements constitute a distinct group of ESS, which is associated with high-grade morphology and aggressive clinical behavior compared to JAZF1 ESS.
Three endometrial stromal sarcomas with JAZF1-SUZ12 or JAZF1-PHF1 fusion harboured unprecedented mutations (p.D54G in two, and p.Q48* in one).All remaining tumours were wild-type.
Immunohistochemically, the high-grade round cell component of all 12 YWHAE-FAM22 ESS demonstrated diffuse (≥70%) moderate to strong nuclear cyclin D1 staining, and this diffuse positivity was not seen in 34 ESSs with JAZF1 and equivalent genetic rearrangements or in 21 low-grade ESS with no demonstrable genetic rearrangements.
Endometrial stromal sarcoma (ESS) characterized by YWHAE-FAM22 genetic fusion is histologically higher grade and clinically more aggressive than ESS with JAZF1-SUZ12 or equivalent genetic rearrangements, hence it is clinically important to recognize this subset of ESS.
The (7;17)(p15;q21) chromosomal translocation present in most cases of endometrial stromal sarcomas (ESSs) results in the in-frame fusion of the JAZF1 and SUZ12 genes.
YWHAE-FAM22 fusion gene knockdowns were performed with shRNAs and siRNAs targeting various FAM22A exons in an t(10;17)-bearing ESS cell line (ESS1): Fusion protein expression was inhibited, with corresponding reduction in cell growth and migration.
Although recurrent gene fusions such as JAZF1-JJAZ1 are considered driver events for endometrial stromal sarcoma (ESS) development, other genomic alterations remain largely unknown.
Four low-grade ESSs harboured JAZF1-PHF1 fusions with different junctional sequences, and all were correctly identified because of the open-ended nature of the assay design, using anchored multiplex polymerase chain reaction.
Cytogenetic and molecular genetic analyses of endometrial stromal sarcoma: nonrandom involvement of chromosome arms 6p and 7p and confirmation of JAZF1/JJAZ1 gene fusion in t(7;17).
The present study evaluates the prevalence of the t(7;17)(p15;q21) and JAZF1-JJAZ1 gene fusion in a series of 6 cases of primary extrauterine endometrial stromal sarcoma.
In an update based on the 2014 WHO classification, low-grade ESS is often associated with gene rearrangement bringing about the JAZF 1-SUZ12 (formerly JAZF1-JJAZ1) fusion gene, whereas high-grade ESS is associated with the YWHAE-NUTM fusion gene.