Balkan endemic nephropathy is a chronic tubulointerstitial disease with insidious onset, slowly progressing to end-stage renal disease and frequently associated with urothelial carcinoma of the upper urinary tract (UTUC). It was described in South-East Europe at the Balkan peninsula in rural areas around tributaries of the Danube River. After decades of intensive investigation, the causative factor was identified as the environmental phytotoxin aristolochic acid (AA) contained in Aristolochia clematitis, a common plant growing in wheat fields that was ingested through home-baked bread. AA initially was involved in the outbreak of cases of rapidly progressive renal fibrosis reported in Belgium after intake of root extracts of Aristolochia fangchi imported from China. A high prevalence of UTUC was found in these patients. The common molecular link between Balkan and Belgian nephropathy cases was the detection of aristolactam-DNA adducts in renal tissue and UTUC. These adducts are not only biomarkers of prior exposure to AA, but they also trigger urothelial malignancy by inducing specific mutations (A:T to T:A transversion) in critical genes of carcinogenesis, including the tumor-suppressor TP53. Such mutational signatures are found in other cases worldwide, particularly in Taiwan, highlighting the general public health issue of AA exposure by traditional phytotherapies.

• MeSH
• adukty DNA MeSH
• Aristolochia MeSH
• balkánská nefropatie chemicky indukované   diagnóza   patologie   terapie   MeSH
• karcinogeny toxicita   MeSH
• karcinom z přechodných buněk chemicky indukované   MeSH
• kyseliny aristolochové toxicita   MeSH
• lidé MeSH
• nádory ledvin chemicky indukované   MeSH
• nádory močovodu chemicky indukované   MeSH
• plošný screening MeSH
• vystavení vlivu životního prostředí škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Although ellipticine (Elli) is an efficient anticancer agent, it exerts several adverse effects. One approach to decrease the adverse effects of drugs is their encapsulation inside a suitable nanocarrier, allowing targeted delivery to tumour tissue whereas avoiding healthy cells. We constructed a nanocarrier from apoferritin (Apo) bearing ellipticine, ApoElli, and subsequently characterized. The nanocarrier exhibits a narrow size distribution suggesting its suitability for entrapping the hydrophobic ellipticine molecule. Ellipticine was released from ApoElli into the water environment under pH 6.5, but only less than 20% was released at pH 7.4. The interaction of ApoElli with microsomal membrane particles containing cytochrome P450 (CYP) biotransformation enzymes accelerated the release of ellipticine from this nanocarrier making it possible to be transferred into this membrane system even at pH 7.4 and facilitating CYP-mediated metabolism. Reactive metabolites were formed not only from free ellipticine, but also from ApoElli, and both generated covalent DNA adducts. ApoElli was toxic in UKF-NB-4 neuroblastoma cells, but showed significantly lower cytotoxicity in non-malignant fibroblast HDFn cells. Ellipticine either free or released from ApoElli was concentrated in the nuclei of neuroblastoma cells, concentrations of which being significantly higher in nuclei of UKF-NB-4 than in HDFn cells. In HDFn the higher amounts of ellipticine were sequestrated in lysosomes. The extent of ApoElli entering the nuclei in UKF-NB-4 cells was lower than that of free ellipticine and correlated with the formation of ellipticine-derived DNA adducts. Our study indicates that the ApoElli form of ellipticine seems to be a promising tool for neuroblastoma treatment.

• MeSH
• adukty DNA genetika   metabolismus   MeSH
• apoferritiny chemie   farmakologie   MeSH
• cytochrom P-450 CYP3A metabolismus   MeSH
• elipticiny chemie   farmakologie   MeSH
• fosforylace MeSH
• histony metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nanočástice * MeSH
• neuroblastom farmakoterapie   enzymologie   genetika   patologie   MeSH
• nosiče léků * MeSH
• příprava léků MeSH
• protinádorové látky chemie   farmakologie   MeSH
• uvolňování léčiv MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Benzo[a]pyrene (BaP) is an environmental pollutant that, based on evidence largely from in vitro studies, exerts its genotoxic effects after metabolic activation by cytochrome P450s. In the present study, Hepatic Reductase Null (HRN) and Hepatic Cytochrome b 5 /P450 Reductase Null (HBRN) mice have been used to study the role of P450s in the metabolic activation of BaP in vivo. In HRN mice, cytochrome P450 oxidoreductase (POR), the electron donor to P450, is deleted specifically in hepatocytes. In HBRN mice the microsomal haemoprotein cytochrome b 5 , which can also act as an electron donor from cytochrome b 5 reductase to P450s, is also deleted in the liver. Wild-type (WT), HRN and HBRN mice were treated by i.p. injection with 125 mg/kg body weight BaP for 24 h. Hepatic microsomal fractions were isolated from BaP-treated and untreated mice. In vitro incubations carried out with BaP-pretreated microsomal fractions, BaP and DNA resulted in significantly higher BaP-DNA adduct formation with WT microsomal fractions compared to those from HRN or HBRN mice. Adduct formation (i.e. 10-(deoxyguanosin-N2-yl)-7,8,9-trihydroxy-7,8,9,10-tetrahydro-BaP [dG-N2-BPDE]) correlated with observed CYP1A activity and metabolite formation (i.e. BaP-7,8-dihydrodiol) when NADPH or NADH was used as enzymatic cofactors. BaP-DNA adduct levels (i.e. dG-N2-BPDE) in vivo were significantly higher (~ sevenfold) in liver of HRN mice than WT mice while no significant difference in adduct formation was observed in liver between HBRN and WT mice. Our results demonstrate that POR and cytochrome b 5 both modulate P450-mediated activation of BaP in vitro. However, hepatic P450 enzymes in vivo appear to be more important for BaP detoxification than its activation.

• MeSH
• adukty DNA metabolismus   MeSH
• benzopyren metabolismus   MeSH
• cytochrom-B(5)-reduktasa metabolismus   MeSH
• hepatocyty enzymologie   MeSH
• jaterní mikrozomy enzymologie   MeSH
• myši knockoutované MeSH
• myši MeSH
• NADPH-cytochrom c-reduktasa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH