ERB-26 is a
syntheticestrogen and a
selectiveagonist of the
ERβ.[1][2] It is the
activeenantiomer of the
racemic mixtureERB-79.[1] Whereas ERB-79 shows 484-fold selectivity for the ERβ over the ERα,[3] ERB-26 differs slightly in that it is even more selective, showing greater than 1,000-fold selectivity for
transactivation of the ERβ relative to the ERα.[1] Its
EC50 value for the ERβ is 0.21 nM (4-fold weaker than
estradiol) and for the ERα is 260 nM (10,000-fold weaker than estradiol).[1] It has no
antagonistic activity at either receptor.[1] ERB-26 is active in prevention of
prostate cancer development in
preclinicalmodels.[1] In contrast to ERB-26, the selective ERα agonist
ERA-45 induced prostate cancer development in preclinical models when it was given in combination with
testosterone, whereas testosterone alone did not do so.[1] These findings suggest opposing roles of the ERα and ERβ in the
prostate gland.[1] The
chemical structure of ERB-26 does not appear to have been disclosed.
^
abcdefghAttia DM, Ederveen AG (2012). "Opposing roles of ERα and ERβ in the genesis and progression of adenocarcinoma in the rat ventral prostate". Prostate. 72 (9): 1013–22.
doi:
10.1002/pros.21507.
PMID22025007.
S2CID12951793.
ERB-26 is a
syntheticestrogen and a
selectiveagonist of the
ERβ.[1][2] It is the
activeenantiomer of the
racemic mixtureERB-79.[1] Whereas ERB-79 shows 484-fold selectivity for the ERβ over the ERα,[3] ERB-26 differs slightly in that it is even more selective, showing greater than 1,000-fold selectivity for
transactivation of the ERβ relative to the ERα.[1] Its
EC50 value for the ERβ is 0.21 nM (4-fold weaker than
estradiol) and for the ERα is 260 nM (10,000-fold weaker than estradiol).[1] It has no
antagonistic activity at either receptor.[1] ERB-26 is active in prevention of
prostate cancer development in
preclinicalmodels.[1] In contrast to ERB-26, the selective ERα agonist
ERA-45 induced prostate cancer development in preclinical models when it was given in combination with
testosterone, whereas testosterone alone did not do so.[1] These findings suggest opposing roles of the ERα and ERβ in the
prostate gland.[1] The
chemical structure of ERB-26 does not appear to have been disclosed.
^
abcdefghAttia DM, Ederveen AG (2012). "Opposing roles of ERα and ERβ in the genesis and progression of adenocarcinoma in the rat ventral prostate". Prostate. 72 (9): 1013–22.
doi:
10.1002/pros.21507.
PMID22025007.
S2CID12951793.