EWS rearrangements, t(22q12)
The Ewing sarcoma protein (EWS) is a well-known player in cancer biology for the specific translocations occurring in sarcomas. Translocations of the EWS gene are found in soft tissue tumors such as Ewing tumors (ET), including bone sarcoma and soft tissue sarcoma (ES), peripheral neuroectodermal primitive tumors (PNET), Askin tumors, clear cell sarcoma (CCS), soft tissue malignant melanoma, liposarcoma and myxoid Chondrosarcoma.
Ewing´s tumor is the second most common primary bone tumor. t(11; 22) (q24; q12) is found in 85% of these tumors and leads, in all cases, to the fusion gene EWS-FLI1. Rearrangements between the EWS gene and other members of the ETS family have also been found: ERG gene located at 21q22.2 region, ETV1 gene on the 7p22 region, ETV4 gene located on 17q21 or E1AF gene located on 17q12 region. A dual-color, break-apart FISH probe, which allows detection of EWS (22q12) gene rearrangemen has been used in several studies. In a study of 67 round cell tumors, including 27 EWS/PNET, this probe detected 90% of EWS/PNET cases with no false positives. The sensitivity and specificity are significantly higher than the RT-PCR in paraffin tissue. Patel et al. also used this probe to distinguish a unique and recurrent aberration identified in 70% to over 90% of clear cell sarcomas: t(12;22)(q13;q12) involving the EWS gene and resulting in the fusion protein EWS-ATF1.
References
- Paronetto MP, et al. (2013) Int J Cell Biol. 2013:642853.
- Rougemont AL, et al. (2012) Cancer Genet. 205(1-2):55-60.
- Romeo S, et al. (2010) Virchows Arch. 456(2):219-34.
- Wang WL, et al. (2009) Mod Pathol. 22(9):1201-9.
- Tanas MR, et al. (2009) Adv Anat Pathol. ;16(6):383-91.
- Patel RM, et al. (2005) Modern Pathology 18:1585-1590.
