Pleiotropic effects of gold(I) mixed-ligand complexes of 9-deazahypoxanthine on transcriptional activity of receptors for steroid hormones, nuclear receptors and xenoreceptors in human hepatocytes and cell lines.
Development of metal-based compounds is an important research avenue in anti-cancer and anti-inflammatory drug discovery. Here we examined the effects of three gold (I) mixed-ligand complexes with the general formula [Au(Ln)(PPh3)] (1, 2, 3) involving triphenylphosphine (PPh3) and a deprotonated form of O-substituted derivatives of 9-deazahypoxanthine (Ln) on the transcriptional activity of aryl hydrocarbon receptor (AhR), androgen receptor (AR), glucocorticoid receptor (GR), thyroid receptor (TR), pregnane X receptor (PXR) and vitamin D receptor (VDR), employing gene reporter assays. In addition, we measured mRNA (RT-PCR) and protein (western blot) expression of target genes for those receptors, including drug-metabolizing P450s, in primary human hepatocytes and cancer cell lines LS180 and HepG2. The tested compounds displayed anti-glucocorticoid effects, as revealed by inhibition of dexamethasone-inducible transcriptional activity of GR and down-regulation of tyrosine aminotransferase. All the compounds slightly and dose-dependently activated PXR and AhR, and moderately induced CYP3A4 and CYP1A1/2 genes in human hepatocytes and LS180 cells. The complexes antagonized basal and ligand-activated AR and VDR, indicating inverse agonist behaviour. Both basal and thyroid hormone-inducible transcriptional activity of TR was dose-dependently increased by all tested compounds. In contrast, the expression of SPOT14 mRNA was decreased by tested compounds in human hepatocytes and HepG2 cells. In conclusion, if intended for human pharmacotherapy, the potential of the complexes 1-3 to influence studied receptors should be taken in account.
Department of Cell Biology and Genetics, Faculty of Science, Palacký University, Slechtitelu 27, CZ-783 71, Olomouc, Czech Republic.
Kateřina
K
Kubešová
Department of Inorganic Chemistry, Faculty of Science, Palacký University, Tr.17.listopadu 12, CZ-771 46, Olomouc, Czech Republic.
Zdeněk
Z
Trávníček
Department of Cell Biology and Genetics, Faculty of Science, Palacký University, Slechtitelu 27, CZ-783 71, Olomouc, Czech Republic. Electronic address: moulin@email.cz.
Zdeněk
Z
Dvořák
D045744:Cell Line, Tumor; D006046:Gold / Q000737:chemistry*; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D007042:Hypoxanthines / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry* / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics*; D014158:Transcription, Genetic / Q000187:drug effects*
C580787:9-deazahypoxanthine; D007042:Hypoxanthines; D009942:Organometallic Compounds; D012333:RNA, Messenger; D011987:Receptors, Steroid; D006046:Gold
Cytochrome P450; Gold complexes; Human hepatocytes; Nuclear receptors; Xenobiotics