Targeting steroid-metabolizing enzymes with 15β-substituted estrone analogues : dual discovery of AKR1C2/17β-HSD1 inhibitors and a fluorescent 17β-HSD1 ligand

Resch, Vivien (author), Gjorgoska, Marija (author), Hafner, Eva (author), Bacsa, Ildikó (author), Kovács, Benjamin (author), Büdefeld, Tomaž (author), Hunyadi, Attila (author), Huliák, Ildikó (author), Kiricsi, Mónika (author), Paragi, Gábor (author), Lanišnik-Rižner, Tea (author), Mernyák, Erzsébet (author)

Background/objectives: Aldo-keto reductase isoforms AKR1C1-3 and 17β-hydroxysteroid dehydrogenase 1 and 2 (17β-HSD1 and 17β-HSD2) are key enzymes in steroid metabolism and validated targets in hormone-dependent cancers. Methods: In this study, Δ15- and 15β-substituted estrone derivatives were evaluated as inhibitors of AKR1C1-3 and 17β-HSD1 using enzymatic assays, cell viability assaysand computational modeling. Cellular uptake of the fluorescent estrone-based inhibitor was investigated using confocal microscopy. Results: The Δ15-estrone derivative showed potent and selective inhibition of 17β-HSD1 in the low nanomolar range, while 15β-O-propargyl and 15β-azide derivatives exhibited dual inhibitory activity against 17β-HSD1 and AKR1C2. The Δ15- and 15β-azide derivatives reduced cell viability in hormone-dependent breast, endometrial, and ovarian cancer cell lines in the sub- to low-micromolar range. A BODIPY-labeled 15β-O-propargyl analogue retained submicromolar inhibitory potency toward 17β-HSD1, representing the first fluorescent estrane-based inhibitor with preserved biological activity. Confocal microscopy confirmed efficient cellular uptake and predominant cytosolic localization in MCF-7 cells. Conclusions: These findings identify Δ15- and 15β-modified estrone derivatives as promising single- and dual-target inhibitors and introduce a fluorescent probe suitable for investigating intracellular steroid metabolism in hormone-dependent malignancies.

• Language: English
• Keywords: 17β-HSD1 enzyme, AKR1C1–3 enzymes, antiproliferative, chemoresistance, fluorescent labeling, inhibitor
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: MF - Faculty of Medicine
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 19 str.
• Numbering: Vol. 18, iss. 12, art. 1889
• PID: 20.500.12556/RUL-184373
• UDC: 577.2
• ISSN on article: 2072-6694
• DOI: 10.3390/cancers18121889
• COBISS.SI-ID: 283168259
• Publication date in RUL: 06.07.2026

Record is a part of a journal

• Title: Cancers
• Shortened title: Cancers
• Publisher: MDPI
• ISSN: 2072-6694
• COBISS.SI-ID: 517914137

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: encim 17β-HSD1, encimi AKR1C1–3, antiproliferativen, kemorezistenca, fluorescenčno označevanje, inhibitor