Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:Q7LGC8 (
HSD
)
3,196
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Estradiol 17 beta-hydroxysteroid dehydrogenase (17 beta
HSD
) mediates the interconversion of estrone and estradiol in endocrine-responsive tissues such as the breast. The control of 17 beta
HSD
expression by
all-trans
-retinoic acid (RA) in T47D breast cancer cells was examined using a specific 17 beta
HSD
complementary DNA probe. Two main 17 beta
HSD
messenger RNA (mRNA) transcripts of 2.2 and 1.3 kilobases (kb) were detected, of which only the 1.3-kb mRNA was regulated. RA increased expression of the 17 beta
HSD
1.3-kb mRNA in a dose- and time-dependent manner, and the increased expression of this mRNA by RA was inhibited by a 10-fold excess of a RA antagonist Ro 41-5253. Insulin-like-growth factor-I, interleukin-1, and estradiol, previously shown to increase 17 beta
HSD
activity in breast cancer cells, had little effect on 17 beta
HSD
gene expression. To relate the effect of increased 17 beta
HSD
1.3-kb mRNA expression to 17 beta
HSD
activity, the conversion of estrone to estradiol (reductive) and that of estradiol to estrone (oxidative) were measured in intact T47D cell monolayers. Whereas RA increased 17 beta
HSD
reductive activity, it had no effect on oxidative activity. The addition of excess NAD increased 17 beta
HSD
oxidative activity in control and RA-treated cells, but the addition of NADH had no effect on 17 beta
HSD
reductive activity. These results suggest that the increased expression of the 17 beta
HSD
1.3-kb mRNA induced by RA is associated with an increase in 17 beta
HSD
reductive activity, but that endogenous cofactor levels may determine the direction in which this enzyme acts in T47D cells.
...
PMID:Regulation of estradiol 17 beta-hydroxysteroid dehydrogenase expression and activity by retinoic acid in T47D breast cancer cells. 801 76
HL60 cells are human promyeloid cells that can be induced to differentiate by physiological stimuli (e.g.
all-trans
retinoic acid (ATRA), 1 alpha,25-dihydroxyvitamin D3 (D3), granulocyte colony-stimulating factor (G-CSF)) and by non-physiological agents such as dimethysulphoxide (DMSO) and protein kinase C-activating phorbol esters. The sensitivity of HL60 cells to physiological differentiating agents, but not to DMSO, is enhanced when cells are exposed to 'anti-inflammatory agents' (e.g. indomethacin) or are 'primed' (pretreated) with a small amount of ATRA: alone, neither treatment induces differentiation. We earlier suggested that indomethacin might act by inhibiting the endogenous formation of a differentiation-suppressing prostanoid (Bunce, C.M., et al. (1994) Leukemia 8, 595-604). Studies of the formation of prostanoids by HL60 cells and of the effects of prostanoids on these cells failed to identify any prostanoid that could be implicated in sensitization by indomethacin. 3 alpha-Hydroxysteroid dehydrogenase (3 alpha-
HSD
) is another target of such 'anti-inflammatory agents'. Steroid inhibitors of 3 alpha-
HSD
sensitized HL60 cells to inducers of differentiation in a manner similar to indomethacin. 3 alpha-
HSD
is a member of the aldoketoreductase enzyme family, which comprises many enzymes of similar size and primary sequence. A protein that was recognised by an antiserum to 3 alpha-
HSD
was found in HL60 cells, but the cells showed no detectable 3 alpha-
HSD
activity. The 3 alpha-
HSD
-like protein was strikingly down-regulated by 'priming' doses of ATRA. When treatment with a differentiation-sensitizing 'anti-inflammatory agent' or steroid was combined with ATRA "priming', the effects of the different treatments were not additive: the resulting increase in sensitivity equalled that achievable by either treatment alone. We conclude that interference with a single intracellular regulatory mechanism underlies the increases in sensitivity of cells to differentiating agents that are caused by anti-inflammatory agents, by certain steroids and by 'priming' with ATRA. Decreased activity of a yet-to-be-identified member of the aldoketoreductase family of dehydrogenases is likely to be a central feature of a previously unrecognised mechanism that controls the responsiveness of cells to environmental stimuli such as retinoids and D3.
...
PMID:Potentiation of myeloid differentiation by anti-inflammatory agents, by steroids and by retinoic acid involves a single intracellular target, probably an enzyme of the aldoketoreductase family. 866 46
Retinol dehydrogenase-4 (RoDH-4) converts retinol and 13-cis-retinol to corresponding aldehydes in human liver and skin in the presence of NAD(+). RoDH-4 also converts 3 alpha-androstanediol and androsterone into dihydrotestosterone and androstanedione, which may stimulate sebum secretion. This oxidative 3 alpha-hydroxysteroid dehydrogenase (3 alpha-
HSD
) activity of RoDH-4 is competitively inhibited by retinol and 13-cis-retinol. Here, we further examine the substrate specificity of RoDH-4 and the inhibition of its 3 alpha-
HSD
activity by retinoids. Recombinant RoDH-4 oxidized 3,4-didehydroretinol-a major form of vitamin A in the skin-to its corresponding aldehyde. 13-cis-retinoic acid (isotretinoin), 3,4-didehydroretinoic acid, and 3,4-didehydroretinol, but not
all-trans
-retinoic acid or the synthetic retinoids acitretin and adapalene, were potent competitive inhibitors of the oxidative 3 alpha-
HSD
activity of RoDH-4, i.e., reduced the formation of dihydrotestosterone and androstandione in vitro. Extrapolated to the in vivo situation, this effect might explain the unique sebosuppressive effect of isotretinoin when treating acne.
...
PMID:13-cis-retinoic acid competitively inhibits 3 alpha-hydroxysteroid oxidation by retinol dehydrogenase RoDH-4: a mechanism for its anti-androgenic effects in sebaceous glands? 1264 98