Description
The 1,755 amino acid protein known as BCL-6 interacting corepressor (BCOR) binds to histone deacetylases to suppress BCL-6 transcriptionally. In many different tissues, BCOR mRNA is widely expressed. However, only the testis expresses the BCOR protein in adult tissue. A subset of small blue round, spindle cell, and undifferentiated sarcomas have recently been found to have the BCOR rearrangement, which causes the BCOR protein to be overexpressed in these tumors. These tumors include small round cell sarcoma (~100%), kidney clear cell sarcoma (100%), high-grade endometrial stromal sarcoma (100%) with YWHAE-NUTM2 translocation, and a subset of synovial sarcoma (50%). The list of cancers that test positive for BCOR is continually growing.
