Germ cell tumors and particularly seminomas reflect the epigenomic features of their parental primordial germ cells (PGCs), including genomic DNA hypomethylation and expression of pluripotent cell markers. Because the DNA hypomethylation might be a result of TET dioxygenase activity, we examined expression of TET1-3 enzymes and the level of their product, 5-hydroxymethylcytosine (5hmC), in a panel of histologically characterized seminomas and non-seminomatous germ cell tumors. Expression of TET dioxygenase mRNAs was quantified by real-time PCR. TET1 expression and the level of 5hmC were examined immunohistochemically. Quantitative assessment of 5-methylcytosine (5mC) and 5hmC levels was done by the liquid chromatography-mass spectroscopy technique. We found highly increased expression of TET1 dioxygenase in most seminomas and strong TET1 staining in seminoma cells. Isocitrate dehydrogenase 1 and 2 mutations were not detected, suggesting the enzymatic activity of TET1. The levels of 5mC and 5hmC in seminomas were found decreased in comparison to non-seminomatous germ cell tumors and healthy testicular tissue. We propose that TET1 expression should be studied as a potential marker of seminomas and mixed germ cell tumors and we suggest that elevated expression of TET dioxygenase enzymes is associated with the maintenance of low DNA methylation levels in seminomas. This "anti-methylator" phenotype of seminomas is in contrast to the CpG island methylator phenotype (CIMP) observed in a fraction of tumors of various types.
- MeSH
- 5-methylcytosin analogy a deriváty analýza MeSH
- dioxygenasy analýza genetika MeSH
- DNA vazebné proteiny analýza genetika MeSH
- dospělí MeSH
- lidé MeSH
- metylace DNA * MeSH
- oxygenasy se smíšenou funkcí analýza genetika MeSH
- protoonkogenní proteiny analýza genetika MeSH
- regulace genové exprese u nádorů MeSH
- seminom genetika patologie MeSH
- testikulární nádory genetika patologie MeSH
- testis metabolismus patologie MeSH
- upregulace MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Enzyme activities of the CYP enzymes (CYP3A4, CYP2C9 and CYP2A6) were determined using classical substrates (testosterone, diclofenac and coumarin, respectively) as well as with luminogenic or fluorogenic substrates in micromethod arrangement. The luciferin-based luminogenic substrates for CYP3A4 and CYP2C9 as well as coumarin in micromethod for assay of CYP2A6 activity gave results well comparable with the classical methods with determination of reaction products by the HPLC.
- MeSH
- aromatické hydroxylasy analýza MeSH
- cytochrom P-450 CYP3A MeSH
- diklofenak chemie MeSH
- kumariny chemie MeSH
- lidé MeSH
- oxygenasy se smíšenou funkcí analýza MeSH
- systém (enzymů) cytochromů P-450 analýza MeSH
- testosteron chemie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
