5α-dihydro-11-keto Testosterone (11KDHT) is a full androgen receptor agonist comparable to dihydrotestosterone (DHT) [1][2][3].
Androgen receptor is a nuclear receptor that is activated by the androgenic hormones, testosterone, or dihydrotestosterone in the cytoplasm and then translocating into the nucleus. Androgen receptor acts as a DNA-binding transcription factor that regulates gene expression.
5α-dihydro-11-keto Testosterone is a full AR agonist exhibiting similar activity to DHT at 1 nM [3]. 5α-dihydro-11-keto Testosterone is a metabolite of 11-ketotestosterone and 11β-hydroxyandrostenedione (11OHA4), which is metabolized by 11βHSD, 17βHSD and SRD5A, resulted in significant increase in androgenic activity at a physiologically relevant concentration. 5α-dihydro-11-keto Testosterone represented a novel androgen which may play an important role in driving AR-mediated gene expression [1]. In COS-1 cells, 5α-dihydro-11-keto Testosterone exhibited activity comparable to DHT (96%). 5α-dihydro-11-keto Testosterone might be implicated in driving castration-resistant prostate cancer (CRPC) in the absence of testicular T [3].
References:
[1]. Bloem LM, Storbeck KH, Schloms L, et al. 11β-hydroxyandrostenedione returns to the steroid arena: biosynthesis, metabolism and function. Molecules. 2013 Oct 25;18(11):13228-44.
[2]. Swart AC, Storbeck KH. 11β-Hydroxyandrostenedione: Downstream metabolism by 11βHSD, 17βHSD and SRD5A produces novel substrates in familiar pathways. Mol Cell Endocrinol. 2015 Jun 15;408:114-23.
[3]. Storbeck KH, Bloem LM, Africander D, et al. 11β-Hydroxydihydrotestosterone and 11-ketodihydrotestosterone, novel C19 steroids with androgenic activity: a putative role in castration resistant prostate cancer Mol Cell Endocrinol. 2013 Sep 5;377(1-2):135-46.