17β-hydroxysteroid dehydrogenase type 1 improves survival in serous epithelial ovarian tumors

Benzophenone UV-filters: Inhibition on human and rat 17β-hydroxysteroid dehydrogenase 1 - insights from 3D-QSAR and docking studies

Benzophenone (BP) UV-filters have been extensively used for the prevention of UV-induced adverse effects in personal care products. Their potential to interfere with steroidogenesis in the female reproductive system remains uncertain. 17β-Hydroxysteroid dehydrogenase 1 (17β-HSD1) facilitates the conversion of estrone to estradiol, playing a key role in estrogen activation. This study delves into the effects of eleven BPs on human and rat 17β-HSD1, while also analysing the 3D-quntitative structure-activity relationship (3D-QSAR) and the underlying mechanisms. The inhibitory potency of inhibiting human placental 17β-HSD1 was found to be in the order of BP-2 (IC50, 11.42 μM) > BP-1 (14.17 μM) > BP-4 (49.05 μM) > BP-6 (63.49 μM) = BP-8 (63.46 μM) > others. BP-1 and BP-2 markedly inhibited estradiol secretion by human placental BeWo cells at ≥ 1 μM. In contrast, the inhibitory strength of suppressing rat ovarian 17β-HSD1 activity was found to be in the order of BP-2 (IC50, 13.33 μM) > BP-1 (15.09 μM) > BP-4 (22.68 μM) > BP-12 (31.12 μM) > BP-3 (97.11 μM) > BP (119.99 μM) > others. Mode action analysis revealed that these BP compounds acted as mixed inhibitors of both human and rat 17β-HSD1. The introduction of a 4-hydroxyl substitution in the benzene ring was found to markedly increase the inhibitory potency against human and rat 17β-HSD1. BP-1 and BP-2 demonstrated the ability to penetrate human BeWo cells and inhibit estradiol secretion at ≥ 1 μM. Docking analysis revealed that the 2-hydroxyl group of BP-1 and BP-2 forms a hydrogen bond with catalytic residue Ser142 of human 17β-HSD1. 3D-QSAR pharmacophore analysis showed that there are hydrophobic regions and hydrogen bond donor can interact with BPs. In conclusion, this study establishes that BP-2 is the most potent inhibitors of human 17β-HSD1 among the BPs under investigation, highlighting a significant difference in the structure-activity relationship.

Steroid metabolism and hormonal dynamics in normal and malignant ovaries

The ovaries are key steroid hormone production sites in post-pubertal females. However, current research on steroidogenic enzymes, endogenous hormone concentrations and their effects on healthy ovarian function and malignant development is limited. Here, we discuss the importance of steroid enzymes in normal and malignant ovaries, alongside hormone concentrations, receptor expression and action. Key enzymes include STS, 3β-HSD2, HSD17B1, ARK1C3, and aromatase, which influence ovarian steroidal action. Both androgen and oestrogen action, via their facilitating enzyme, drives ovarian follicle activation, development and maturation in healthy ovarian tissue. In ovarian cancer, some data suggest STS and oestrogen receptor α may be linked to aggressive forms, while various oestrogen-responsive factors may be involved in ovarian cancer metastasis. In contrast, androgen receptor expression and action vary across ovarian cancer subtypes. For future studies investigating steroidogenesis and steroidal activity in ovarian cancer, it is necessary to differentiate between disease subtypes for a comprehensive understanding.

Potent inhibition of human and rat 17β-hydroxysteroid dehydrogenase 1 by curcuminoids and the metabolites: 3D QSAR and in silico docking analysis

Curcumin, an extensively utilized natural pigment in the food industry, has attracted considerable attention due to its potential therapeutic effects, such as anti-tumorigenic and anti-inflammatory activities. The enzyme 17β-Hydroxysteroid dehydrogenase 1 (17β-HSD1) holds a crucial position in oestradiol production and exhibits significant involvement in oestrogen-responsive breast cancers and endometriosis. This study investigated the inhibitory effects of curcuminoids, metabolites, and analogues on 17β-HSD1, a key enzyme in oestradiol synthesis. Screening 10 compounds, including demethoxycurcumin (IC50, 3.97 μM) and dihydrocurcumin (IC50, 5.84 μM), against human and rat 17β-HSD1 revealed varying inhibitory potencies. These compounds suppressed oestradiol secretion in human BeWo cells at ≥ 5-10 μM. 3D-Quantitative structure-activity relationship (3D-QSAR) and molecular docking analyses elucidated the interaction mechanisms. Docking studies and Gromacs simulations suggested competitive or mixed binding to the steroid or NADPH/steroid binding sites of 17β-HSD1. Predictive 3D-QSAR models highlighted the importance of hydrophobic regions and hydrogen bonding in inhibiting 17β-HSD1 activity. In conclusion, this study provides valuable insights into the inhibitory effects and mode of action of curcuminoids, metabolites, and analogues on 17β-HSD1, which may have implications in the field of hormone-related disorders.

Not exclusively the activity, but the sweet spot: a dehydrogenase point mutation synergistically boosts activity, substrate tolerance, thermal stability and yield

Catalytic activity is undoubtedly a key focus in enzyme engineering. The complicated reaction conditions hinder some enzymes from industrialization even though they have relatively promising activity. This has occurred to some dehydrogenases. Hydroxysteroid dehydrogenases (HSDHs) specifically catalyze the conversion between hydroxyl and keto groups, and hold immense potential in the synthesis of steroid medicines. We underscored the importance of 7α-HSDH activity, and analyzed the overall robustness and underlying mechanisms. Employing a high-throughput screening approach, we comprehensively assessed a mutation library, and obtained a mutant with enhanced enzymatic activity and overall stability/tolerance. The superior mutant (I201M) was identified to harbor improved thermal stability, substrate susceptibility, cofactor affinity, as well as the yield. This mutant displayed a 1.88-fold increase in enzymatic activity, a 1.37-fold improvement in substrate tolerance, and a 1.45-fold increase in thermal stability when compared with the wild type (WT) enzyme. The I201M mutant showed a 2.25-fold increase in the kcat/KM ratio (indicative of a stronger binding affinity for the cofactor). This mutant did not exhibit the highest enzyme activity compared with all the tested mutants, but these improved characteristics contributed synergistically to the highest yield. When a substrate at 100 mM was present, the 24 h yield by I201M reached 89.7%, significantly higher than the 61.2% yield elicited by the WT enzyme. This is the first report revealing enhancement of the catalytic efficiency, cofactor affinity, substrate tolerance, and thermal stability of NAD(H)-dependent 7α-HSDH through a single-point mutation. The mutated enzyme reached the highest enzymatic activity of 7α-HSDH ever reported. High enzymatic activity is undoubtedly crucial for enabling the industrialization of an enzyme. Our findings demonstrated that, when compared with other mutants boasting even higher enzymatic activity, mutants with excellent overall robustness were superior for industrial applications. This principle was exemplified by highly active enzymes such as 7α-HSDH.