NKX3.1

NKX3.1 is a prostate‑specific, androgen‑regulated nuclear transcription factor essential for normal prostatic epithelial and ductal development. In IHC it shows strong nuclear staining and serves as a highly sensitive and specific marker for identifying tumours of prostatic origin, including metastatic prostate adenocarcinoma. Loss or reduction of NKX3.1 expression is common in prostate carcinoma and high‑grade PIN due to allelic loss, promoter methylation, or post‑transcriptional silencing. Because of its high specificity compared to other prostate markers, NKX3.1 is valuable in confirming prostatic lineage in metastatic lesions of uncertain origin (1).

Recommended Controls

Criteria for acceptable staining is a nuclear staining pattern. The recommended positive control is to include a prostate cancer (high expressor). Testes will show a weak to moderate staining reaction in the spermatogonia (low expressor) and tonsil or appendix which will be negative.

Expected staining pattern

Prostate cancer

Testes

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.