NK3 Homeobox Protein 1 (NKX3-1)

The homeodomain-containing transcription factor NKX3-1 is a putative prostate tumor suppressor that is expressed in a largely prostate-specific and androgen-regulated manner. Loss of NKX3-1 protein expression is a common finding in human prostate carcinomas and prostatic intraepithelial neoplasia.

NKX3.1, encodes a deduced 234-amino acid polypeptide with greatest homology to the Drosophila NK3 gene. Northern blot analysis showed that NKX3.1 had a uniquely restricted tissue expression pattern. The 3.5-kb NKX3.1 mRNA was abundant in the prostate, present at a lower level in the testis, and absent from all other tissues tested. Androgen stimulation markedly increased NKX3.1 expression in an androgen-dependent carcinoma line.