Discovery of the selective androgen receptor modulator MK-0773 using a rational development strategy based on differential transcriptional requirements for androgenic anabolism versus reproductive physiology.
Selective androgen receptor modulators (SARMs) are androgen receptor (AR) ligands that induce anabolism while having reduced effects in reproductive tissues. In various experimental contexts SARMs fully activate, partially activate, or even antagonize the AR, but how these complex activities translate into tissue selectivity is not known. Here, we probed receptor function using >1000 synthetic AR ligands. These compounds produced a spectrum of activities in each assay ranging from 0 to 100% of maximal response. By testing different classes of compounds in ovariectomized rats, we established that ligands that transactivated a model promoter 40-80% of an agonist, recruited the coactivator GRIP-1 <15%, and stabilized the N-/C-terminal interdomain interaction <7% induced bone formation with reduced effects in the uterus and in sebaceous glands. Using these criteria, multiple SARMs were synthesized including MK-0773, a 4-aza-steroid that exhibited tissue selectivity in humans. Thus, AR activated to moderate levels due to reduced cofactor recruitment, and N-/C-terminal interactions produce a fully anabolic response, whereas more complete receptor activation is required for reproductive effects. This bimodal activation provides a molecular basis for the development of SARMs.
Schmidt
Azriel
A
Department of Molecular Endocrinology, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.
Kimmel
Donald B
DB
Bai
Chang
C
Scafonas
Angela
A
Rutledge
Sujane
S
Vogel
Robert L
RL
McElwee-Witmer
Sheila
S
Chen
Fang
F
Nantermet
Pascale V
PV
Kasparcova
Viera
V
Leu
Chih-Tai
CT
Zhang
Hai-Zhuan
HZ
Duggan
Mark E
ME
Gentile
Michael A
MA
Hodor
Paul
P
Pennypacker
Brenda
B
Masarachia
Patricia
P
Opas
Evan E
EE
Adamski
Sharon A
SA
Cusick
Tara E
TE
Wang
Jiabing
J
Mitchell
Helen J
HJ
Kim
Yuntae
Y
Prueksaritanont
Thomayant
T
Perkins
James J
JJ
Meissner
Robert S
RS
Hartman
George D
GD
Freedman
Leonard P
LP
Harada
Shun-ichi
S
Ray
William J
WJ
D000728:Androgens / Q000378:metabolism*; D000818:Animals; D001378:Azasteroids / Q000737:chemistry / Q000494:pharmacology*; D019556:COS Cells; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002522:Chlorocebus aethiops; D015195:Drug Design; D005260:Female; D006727:Hormone Antagonists / Q000494:pharmacology*; D006801:Humans; D008024:Ligands; D008297:Male; D008954:Models, Biological; D017434:Protein Structure, Tertiary; D051381:Rats; D011944:Receptors, Androgen / Q000737:chemistry*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D013256:Steroids / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
C550076:3-fluoro-N-(3H-imidazo(4,5-b)pyridin-2-ylmethyl)-1,4a,6a-trimethyl-2-oxo-2,4a,4b,5,6,6a,7,8,9,9a,9b,10,11,11a-tetradecahydro-1H-indeno(5,4-f)quinoline-7-carboxamide; D000728:Androgens; D001378:Azasteroids; D006727:Hormone Antagonists; D008024:Ligands; D011944:Receptors, Androgen; D018160:Receptors, Cytoplasmic and Nuclear; D013256:Steroids