Androgen receptor (AR) signalling is triggered by androgens that have lipophilic nature. Since it was indicated that graphene oxide (GO) might facilitate passive diffusion of lipophilic compounds probably via Trojan horse-like mechanism, we tested the hypothesis if this suggestion would apply for androgens as well. Thus, we investigated if GO affects dihydrotestosterone (DHT)-triggered signalling of AR in two prostate cancer-derived cell lines, 22Rv1 and LNCaP. These cell lines differ in number of AR variants, i.e. there are two variants in 22Rv1 cells (full length and truncated) but only one in LNCaP cells (full length). Graphene oxide had no effect on basal luciferase activity but significantly decreased DHT-inducible AR-dependent luciferase activity in stably transfected cells. In 22Rv1 cells, it induced concentration-dependent decrease of DHT-inducible KLK3 mRNA and PSA protein after 24 h. While there was no effect on UBE2C mRNA (regulated by truncated variant), there was synergistic effect of DHT and GO on UBE2C protein level. Translocation of full-length AR (AR-FL) was potentiated by GO in the presence of DHT in 22Rv1 cells but it was suppressed in LNCaP cells. DHT-stimulated enrichment of AR-FL on KLK3 promoter was not significantly affected by GO in any tested cell line neither was KLK3 mRNA at 4 h of incubation. In conclusion, GO affects DHT-triggered signalling in both types of cells in similar manner, but ligand-triggered redistribution of AR-FL is affected differently. One of the reasons may be the presence of truncated variant of androgen receptor.
- MeSH
- androgenní receptory * genetika MeSH
- androgeny MeSH
- dihydrotestosteron farmakologie MeSH
- grafit MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory prostaty * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Graphene oxide (GO) is an engineered nanomaterial which was demonstrated to have outstanding capacity for adsorption of organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), the ligands and activators of the aryl hydrocarbon receptor (AhR). Due to the partially overlapping ligand capacity of AhR and pregnane X receptor (PXR), we tested the impact of GO particles on their signalling. While reporter gene assay revealed potentiating effect of GO on ligand-activated AhR-dependent luciferase activity, there was no effect for PXR. However, inducible target genes for AhR (CYP1A1) or PXR (ABCB1) were decreased at mRNA as well as protein levels by the presence of GO in HepG2 (for AhR), LS180 (for PXR) or primary human hepatocytes (both receptors). Moreover, the presence of GO diminished PXR and AhR protein levels in primary cultures of human hepatocytes. This was partially reversed by proteasome inhibitor MG132 for AhR but not for PXR. In conclusion, GO decreases ligand-stimulated activities of AhR and PXR in human cells.
- MeSH
- biotransformace MeSH
- cytochrom P-450 CYP1A1 metabolismus MeSH
- grafit chemie MeSH
- hepatocyty účinky léků MeSH
- lidé MeSH
- messenger RNA metabolismus MeSH
- pregnanový X receptor MeSH
- receptory aromatických uhlovodíků metabolismus MeSH
- reportérové geny MeSH
- signální transdukce MeSH
- steroidní receptory genetika MeSH
- xenobiotika chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Mycophenolate Mofetil (MYC) is a transplant drug used to prevent rejection in heart and kidneys transplant patients. Inosine monophosphate dehydrogenase (IMPDH), an enzyme involved in de novo synthesis of guanosine nucleotides, was considered as a primary target for MYC. Recently, we described that MYC was activates aryl hydrocarbon receptor and it antagonizes glucocorticoid receptor. Here we describe an androgen receptor (AR) as another off-target for MYC. We found that MYC increased basal and dihydrotestosterone (DHT)-inducible AR-dependent luciferase activity in AIZ-AR cells. In the same manner it induced or augmented mRNA level of KLK3 (prostate specific antigen; PSA) in 22Rv1 cells. Herein it displayed a hormetic effect on proliferation activity, since it significantly stimulated proliferation in lower concentrations but inhibited in higher (>1 µg/ml) concentrations in the presence of DHT. In contrast, MYC suppressed DHT-inducible KLK3 mRNA expression and cell proliferation in androgen-dependent LNCaP cells. MYC augmented DHT-inducible nuclear translocation of AR and increased the expression of MAPK8/9 (JNK46/54) resulting in the drop of their phosphorylation status. Moreover, MYC sensitized DHT-treated 22Rv1 cells to JNK-IN-8 mediated growth inhibition with the drop of IC50 from 1425 nM to 84 nM within 24 hrs. In conclusion, we suggest that, castrate-resistant prostate cancers progression might be retarded with the combination of MYC and chemical JNK inhibitors, involving AR-dependent mechanism.
- Publikační typ
- časopisecké články MeSH
Aryl hydrocarbon receptor (AhR) is a transcription factor, the activity of which is modulated by hormones including glucocorticoids and estrogens. In this study, we examined the effects of triiodothyronine (T3), a ligand and activator of thyroid hormone receptor (TR), on transcriptional activity of AhR and the expression of its target gene CYP1A1. Study was carried out in human hepatocellular carcinoma cells HepG2 and primary cultures of human hepatocytes (HH). Gene reporter assay in stably transfected AZ-AhR cells revealed that T3 dose-dependently augmented 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible AhR-dependent luciferase activity. In contrast, T3 had no effect on TCDD-inducible expression of CYP1A1 mRNA, protein and catalytic activity. Incubation of human hepatocytes with T3 had modulatory and inter-individual (7 cell cultures from 7 different liver donors) effects on both basal and dioxin-inducible CYP1A1/2. Since there was no correlation between T3 effects on CYP1A expression and T3-dependent expression of Spot14 mRNA, the involvement of additional factors besides TR is supposed. Overall, the co-incubation of normal and cancer human hepatic cells with TCDD and T3 suggested transcriptional cross-talk between AhR and TR, which may have physiological and toxicological implications.
- MeSH
- buňky Hep G2 MeSH
- cytochrom P-450 CYP1A1 biosyntéza genetika MeSH
- dospělí MeSH
- hepatocyty účinky léků metabolismus MeSH
- induktory cytochromu P450 CYP1A2 toxicita MeSH
- interakce mezi receptory a ligandy MeSH
- kokultivační techniky MeSH
- lidé středního věku MeSH
- lidé MeSH
- polychlorované dibenzodioxiny toxicita MeSH
- receptory aromatických uhlovodíků genetika metabolismus MeSH
- receptory thyreoidních hormonů metabolismus MeSH
- senioři MeSH
- trijodthyronin farmakologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
In this paper we investigated the effects of several drugs used in transplant medicine, i.e. cyclosporine A, tacrolimus, rapamycin, everolimus, mycophenolate mofetil, fluvastatin and rosuvastatin, on the expression of major drug-metabolizing enzymes in human hepatocytes. Moreover, we tested the ability of these drugs to affect transcriptional activity of glucocorticoid (GR) and aryl hydrocarbon receptor (AhR). We found that most of tested compounds did not induce expression of CYP1A1/1A2/3A4/2A6/2B6/2C9 mRNAs in human hepatocytes. Slight induction was observed for CYP2A6/2C9 mRNAs and CYP2A6 protein in the rapamycin-treated hepatocytes. Decrease of CYP2A6 and CYP2B6 proteins was observed in rosuvastatin-treated cells. Mycophenolate mofetil antagonized the effects of dexamethasone on GR but it potentiated the action of dioxin on AhR. Induction of CYP1A1 mRNA in HepG2 cells by dioxin was modestly antagonized by mycophenolate mofetil, while the induction by benzo[a]pyren or S-omeprazole was significantly potentiated by this drug. In general, tested compounds can be considered safe in the terms of possible drug-drug interaction caused by induction of drug-metabolizing cytochromes P450. Nevertheless, mycophenolate mofetil is of possible concern and its combination with drugs, environmental pollutants or food constituents, which activate AhR, may represent a significant toxicological risk.
- MeSH
- buněčné linie MeSH
- buňky Hep G2 MeSH
- dexamethason farmakologie MeSH
- dospělí MeSH
- hepatocyty účinky léků metabolismus MeSH
- imunologické faktory farmakologie MeSH
- kultivované buňky MeSH
- lékové interakce MeSH
- lidé středního věku MeSH
- lidé MeSH
- luciferasy genetika metabolismus MeSH
- messenger RNA metabolismus MeSH
- polychlorované dibenzodioxiny farmakologie MeSH
- receptory aromatických uhlovodíků genetika MeSH
- receptory glukokortikoidů genetika MeSH
- systém (enzymů) cytochromů P-450 genetika MeSH
- xenobiotika metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
