Aktuelle Masterarbeitsthemen der Forschungsgruppe Molekulare & Systemische Toxikologie
Current Master's Theses-Projects of the Research Group in Molecular & Systems Toxicology
|MSc Pharmazie||MSc Drug Sciences||Bemerkungen|
Investigation of androgen metabolism by 3α-hydroxysteroid dehydrogenases
Prostate cancer is one of the most common cancer types in men, in which the androgen receptor (AR) plays a major role and 5α-dihydrotestosterone (DHT) is the main ligand of the AR. DHT cannot only be formed by the 5α-reduction of testosterone performed by 5α-reductases, but also via the so-called “backdoor pathway”, in which androsterone is used as a precursor for DHT instead of testosterone. Several 3α-hydroxysteroid dehydrogenases (3α-HSDs) are suspected to play a role in the formation of DHT from androsterone, or alternatively in the inactivation of DHT to less potent androgens . The aim of this project is to investigate the oxidative/reductive activity of different 3α-HSDs and the results will help to understand the role of these enzymes in the “backdoor pathway” in prostate cancer.
Methods: Cell culture, quantitative PCR, transactivation assay, western blot, cell activity assay. Mohler JL, Titus MA, Bai S, Kennerley BJ, Lih FB, Tomer KB, Wilson EM. Activation of the androgen receptor by intratumoral bioconversion of androstanediol to dihydrotestosterone in prostate cancer. Cancer Res. 2011 Feb 15;71(4):1486-96
Involvement of retinoic acid-related orphan receptor gamma in long-chain fatty acid synthesis regulation (NOT AVAILABLE ANY MORE)
The retinoic acid-related orphan receptor gamma (RORγ) is a nuclear receptor that is involved in the regulation of proliferation of different types of cancer. We are interested in elucidating the role of RORγ on long-chain fatty acid synthesis in cancer cell lines, which is partially mediated via the 17β-hydroxysteroid dehydrogenase type 12 (17β-HSD12). Recently, silencing of 17β-HSD12 in breast cancer cells showed significant effects on cell proliferation and migration . This project aims to study the role of RORγ in cancer cell lines and its influence on the long-chain fatty acid synthesizing enzyme 17β-HSD12. The results of this study will provide further valuable insight into the mechanisms of cancer cell physiology.
Methods: cell culture, western blotting, quantitative PCR, luciferase reporter assays, gene knockdown, cell proliferation and migration assays.
 Tsachaki M. et al. manuscript submitted
Study of the transcriptional regulation of Hexose-6-phosphate dehydrogenase
Hexose-6-phosphate dehydrogenase (H6PD) is an enzyme producing NADPH in the lumen of the endoplasmic reticulum (ER). Although the physiological significance of NADPH in this cell compartment is not entirely clear, our previously published results have shown that silencing of H6PD in breast cancer cells reduced their ability to proliferate and migrate1. In order to better understand the function of H6PD, we aim at studying how this enzyme is regulated at the transcriptional level. Candidate transcription factors for binding at the promoter of H6PD have already been identified in silico, and will be functionally validated. By manipulating the expression or activity of these transcription factors, tumor cell growth could be controlled. The outcomes from this project will prove valuable for further elucidating the importance of H6PD and the ER NADPH pool for cancer cell physiology. Methods: cell culture, western blotting, quantitative PCR, luciferase reporter assays, immunofluorescence, introduction of point mutations/deletions in cDNA, cell viability and migration assays.
Tsachaki, M., Mladenovic, N., Stambergova, H., Birk, J. & Odermatt, A. Hexose-6-phosphate dehydrogenase controls cancer cell proliferation and migration through pleiotropic effects on the unfolded-protein response, calcium homeostasis, and redox balance. FASEB J32, 2690-2705, doi:10.1096/fj.201700870RR (2018).
Investigating Drug liver injury through AKR1D1 and SRD5A1
The liver is the central organ responsible for the selective uptake, metabolism and excretion of endogenous and exogenous compounds, including drugs. Drug induced liver injury (DILI) can be caused by various chemical and can present as an array of different pathologies, dependent on the specific function of the liver that is impaired. Numerous drugs have been shown to cause liver injury but the manifestations of drug-induced hepatotoxicity are highly variable, ranging from asymptomatic alterations of liver enzymes to fulminant hepatic failure. AKR1D1 and SRD5A1 are two important enzymes involved in bile acid synthesis from cholesterol in the liver. The disruption of their function has been associated with different liver pathologies including inflammation, NASH/NAFLD, fibrosis, cancer and infections.
In the present project, we aim to investigate a selected range of drugs screened by bioinformatics tools for potential inhibitory effects towards AKR1D1 and SRD5A1. Upon establishing activity assays for these two enzymes the most promising hits will be investigated for their potential to inhibit their enzyme activities and the consequences for bile acid homeostasis.
Methods: RNA/DNA/proteins extractions and quantification, bacterial transformation and eukaryotic cell culture, cloning, DNA amplification (mini/maxiprep), transfection, cell line culture and maintenance, enzyme activity assays, western blot, PCR/qPCR, protein purification.