SATB2

Special AT-rich sequence-binding protein 2 known as DNA-binding protein SATB2. SATB2 is part of the family of matrix attachment region-binding transcription factors, and has developmental roles in craniofacial, neural, and osteoblastic differentiation. SATB2 has gained interest as a relatively specific marker of colorectal differentiation, with potential applications including determining origin of adenocarcinomas of unknown primary and distinguishing primary ovarian mucinous adenocarcinomas from colorectal metastases. It is a nuclear marker normally expressed by epithelium of the lower gastrointestinal tract, brain, nongerminal centre lymphoid cells, ductal epithelium of the testis and epididymis (1-3).

Recommended Controls

The criteria for acceptable staining is nuclear. The recommended positive control to use for a SATB2 stain is either appendix, tonsil and testis which act as both a positive and negative tissue controls. For a high expressor control to use colon tumour and normal colon.

Appendix

Colon tumour

Normal colon

Tonsil

Disclaimer

These methods are intended as a guide only. Laboratories that wish to implement these methods should perform internal validation/verification prior to use. The RCPAQAP does not make any claim or warranty for the accuracy or performance of these methods.