1. Inhibition of the Sterol Regulatory Element Binding Protein SREBF-1 Overcomes Docetaxel Resistance in Advanced Prostate Cancer.
- Author
-
Brandt MP, Vakhrusheva O, Hackl H, Daher T, Tagscherer K, Roth W, Tsaur I, Handle F, Eigentler A, Culig Z, Thomas C, Erb HHH, Haferkamp A, Jüngel E, and Puhr M
- Subjects
- Male, Humans, Prostatic Neoplasms pathology, Prostatic Neoplasms drug therapy, Prostatic Neoplasms metabolism, Prostatic Neoplasms genetics, Mifepristone pharmacology, Cell Line, Tumor, Prostatic Neoplasms, Castration-Resistant drug therapy, Prostatic Neoplasms, Castration-Resistant pathology, Prostatic Neoplasms, Castration-Resistant metabolism, Prostatic Neoplasms, Castration-Resistant genetics, Gene Expression Regulation, Neoplastic drug effects, Antineoplastic Agents pharmacology, Docetaxel pharmacology, Drug Resistance, Neoplasm drug effects, Sterol Regulatory Element Binding Protein 1 metabolism, Sterol Regulatory Element Binding Protein 1 genetics
- Abstract
Resistance to antiandrogens and chemotherapy (Cx) limits therapeutic options for patients with metastatic hormone-sensitive (mHSPC) and metastatic castration-resistant (mCRPC) prostate cancer. In this context, up-regulation of the glucocorticoid receptor is identified as a potential bypass mechanism in mCRPC. A combination of docetaxel and mifepristone (Doc + RU-486), an inhibitor of the glucocorticoid receptor, re-sensitizes docetaxel-resistant cell models to Cx. This study was designed to elucidate the molecular mechanisms responsible for this phenomenon. RNA sequencing was performed in docetaxel-resistant prostate cancer cell models after Doc + RU-486 treatment with consecutive functional assays. Expression of selected proteins was verified in prostatic tissue from prostate cancer patients with progressive disease. Treatment with Doc + RU-486 significantly reduced cancer cell viability, and RNA sequencing revealed sterol regulatory element of binding transcription factor 1 (SREBF-1), a transcription factor of cholesterol and lipid biosynthesis, as a significantly down-regulated target. Functional assays confirmed that SREBF-1 down-regulation is partially responsible for this observation. In concordance, SREBF-1 knockdown and pharmacologic sterol regulatory element binding protein inhibition, together with other key enzymes in the cholesterol pathway, showed similar results. Furthermore, SREBF-1 expression is significantly elevated in advanced prostate cancer tissues, showing its potential involvement in tumor progression and emerging therapy resistance. Therefore, specific inhibition of cholesterol and lipid biosynthesis might also target Cx-resistant cancer cells and represents a potential additive future therapeutic option to improve mCRPC therapy., (Copyright © 2024 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF