Ferritin, a naturally occurring iron storage protein, has gained significant attention as a drug delivery platform due to its inherent biocompatibility and capacity to encapsulate therapeutic agents. In this study, we successfully genetically engineered human H ferritin by incorporating 4 or 6 tryptophan residues per subunit, strategically oriented towards the inner cavity of the nanoparticle. This modification aimed to enhance the encapsulation of hydrophobic drugs into the ferritin cage. Comprehensive characterization of the mutants revealed that only the variant carrying four tryptophan substitutions per subunit retained the ability to disassemble and reassemble properly. As a proof of concept, we evaluated the loading capacity of this mutant with ellipticine, a natural hydrophobic indole alkaloid with multimodal anticancer activity. Our data demonstrated that this specific mutant exhibited significantly higher efficiency in loading ellipticine compared to human H ferritin. Furthermore, to evaluate the versatility of this hydrophobicity-enhanced ferritin nanoparticle as a drug carrier, we conducted a comparative study by also encapsulating doxorubicin, a commonly used anticancer drug. Subsequently, we tested both ellipticine and doxorubicin-loaded nanoparticles on a promyelocytic leukemia cell line, demonstrating efficient uptake by these cells and resulting in the expected cytotoxic effect.
- Keywords
- doxorubicin, drug delivery, ellipticine, ferritin, hydrophobic drugs, nanoparticle, protein engineering, tumor cells,
- MeSH
- Apoferritins genetics MeSH
- Doxorubicin pharmacology chemistry MeSH
- Ellipticines * MeSH
- Ferritins genetics chemistry MeSH
- Hydrophobic and Hydrophilic Interactions MeSH
- Drug Delivery Systems MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Nanoparticles * chemistry MeSH
- Drug Carriers chemistry MeSH
- Antineoplastic Agents * pharmacology chemistry MeSH
- Tryptophan MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Apoferritins MeSH
- Doxorubicin MeSH
- Ellipticines * MeSH
- Ferritins MeSH
- Drug Carriers MeSH
- Antineoplastic Agents * MeSH
- Tryptophan 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.
- Keywords
- Apoferritin nanoparticles, Cytochrome P450-mediated metabolism, Cytotoxicity, DNA adducts, Ellipticine, Neuroblastoma,
- MeSH
- DNA Adducts genetics metabolism MeSH
- Apoferritins chemistry pharmacology MeSH
- Cytochrome P-450 CYP3A metabolism MeSH
- Ellipticines chemistry pharmacology MeSH
- Phosphorylation MeSH
- Histones metabolism MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Nanoparticles * MeSH
- Neuroblastoma drug therapy enzymology genetics pathology MeSH
- Drug Carriers * MeSH
- Drug Compounding MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- Drug Liberation MeSH
- Cell Survival drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA Adducts MeSH
- Apoferritins MeSH
- CYP3A4 protein, human MeSH Browser
- Cytochrome P-450 CYP3A MeSH
- Ellipticines MeSH
- ellipticine MeSH Browser
- H2AX protein, human MeSH Browser
- Histones MeSH
- Drug Carriers * MeSH
- Antineoplastic Agents MeSH
The anticancer drug ellipticine exerts its genotoxic effects after metabolic activation by cytochrome P450 (CYP) enzymes. The present study has examined the role of cytochrome P450 oxidoreductase (POR) and cytochrome b5 (Cyb5), electron donors to P450 enzymes, in the CYP-mediated metabolism and disposition of ellipticine in vivo. We used Hepatic Reductase Null (HRN) and Hepatic Cytochrome b5/P450 Reductase Null (HBRN) mice. HRN mice have POR deleted specifically in hepatocytes; HBRN mice also have Cyb5 deleted in the liver. Mice were treated once with 10 mg/kg body weight ellipticine (n = 4/group) for 24 h. Ellipticine-DNA adduct levels measured by 32P-postlabelling were significantly lower in HRN and HBRN livers than in wild-type (WT) livers; however no significant difference was observed between HRN and HBRN livers. Ellipticine-DNA adduct formation in WT, HRN and HBRN livers correlated with Cyp1a and Cyp3a enzyme activities measured in hepatic microsomes in the presence of NADPH confirming the importance of P450 enzymes in the bioactivation of ellipticine in vivo. Hepatic microsomal fractions were also utilised in incubations with ellipticine and DNA in the presence of NADPH, cofactor for POR, and NADH, cofactor for Cyb5 reductase (Cyb5R), to examine ellipticine-DNA adduct formation. With NADPH adduct formation decreased as electron donors were lost which correlated with the formation of the reactive metabolites 12- and 13-hydroxy-ellipticine in hepatic microsomes. No difference in adduct formation was observed in the presence of NADH. Our study demonstrates that Cyb5 contributes to the P450-mediated bioactivation of ellipticine in vitro, but not in vivo.
- Keywords
- Cytochrome P450, Cytochrome b(5), DNA Adducts, Metabolism, Mouse models,
- MeSH
- DNA Adducts metabolism MeSH
- Aryl Hydrocarbon Hydroxylases metabolism MeSH
- Cytochrome P-450 CYP3A MeSH
- Cytochrome-B(5) Reductase deficiency genetics MeSH
- Cytochromes b5 deficiency genetics MeSH
- Ellipticines metabolism pharmacology MeSH
- Phenotype MeSH
- Genotype MeSH
- Hepatocytes enzymology MeSH
- Microsomes, Liver enzymology MeSH
- Liver enzymology MeSH
- Activation, Metabolic MeSH
- Mice, Inbred C57BL MeSH
- Mice, Knockout MeSH
- NADPH-Ferrihemoprotein Reductase metabolism MeSH
- Antineoplastic Agents metabolism pharmacology MeSH
- Cytochrome P-450 Enzyme System metabolism MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA Adducts MeSH
- Aryl Hydrocarbon Hydroxylases MeSH
- CYP3A protein, mouse MeSH Browser
- Cytochrome P-450 CYP3A MeSH
- Cytochrome-B(5) Reductase MeSH
- Cytochromes b5 MeSH
- Ellipticines MeSH
- ellipticine MeSH Browser
- NADPH-Ferrihemoprotein Reductase MeSH
- Antineoplastic Agents MeSH
- Cytochrome P-450 Enzyme System MeSH
OBJECTIVES: Vandetanib¸ lenvatinib, and cabozantinib are tyrosine kinase inhibitors (TKIs) targeting VEGFR subtypes 1 and 2, EGFR and the RET-tyrosine kinase, thus considered as multiple TKIs. These TKIs have already been approved for treating patients suffering from thyroid cancer and renal cell carcinoma. Ellipticine, a DNA-damaging drug, is another anticancer agent that is effective against certain tumors of the thyroid gland, ovarian carcinoma, breast cancer and osteolytic breast cancer metastasis. Its anticancer efficiency is dictated by its oxidation with cytochrome P450 (CYP) and peroxidase enzymes. A number of studies testing the effectiveness of individual anticancer drugs, the pharmacological efficiencies of which are affected by their metabolism, alone or in a combination with other cytostatics demonstrated that such combination can have both positive and negative effects on treatment regimen. The aim of this study was to study the effect of vandetanib, lenvatinib and cabozantinib on oxidation of ellipticine which dictates its pharmacological efficiency. METHODS: Ellipticine oxidation catalyzed by hepatic microsomes, recombinant CYP enzymes and peroxidases (horseradish peroxidase, lactoperoxidase and myeloperoxidase) and the effect of TKIs (vandetanib, lenvatinib and cabozantinib) on this oxidation were analyzed by HPLC used for separation of ellipticine metabolites and quantification of their amounts formed during oxidation. RESULTS: The CYP enzymatic system oxidizes ellipticine up to five metabolites (9-hydroxy-, 12-hydroxy-, 13-hydroxy-, 7-hydroxyellipticine, and ellipticine N2- oxide), while peroxidases form predominantly ellipticine dimer. Ellipticine oxidation catalyzed by rat and human hepatic microsomes was inhibited by vandetanib and cabozantinib, but essentially no inhibition was caused by lenvatinib. Of individual CYP enzymes catalyzing oxidation of ellipticine, TKIs inhibited oxidation of ellipticine catalyzed by CYP2D6 > 2D1 > 2C9 > 3A1 > 3A4, the CYP enzymes participating in ellipticine oxidation to metabolites increasing the ellipticine anticancer efficiency. On the contrary, they have essentially no inhibition effect on ellipticine oxidation catalyzed by CYP1A1 and 1A2, which are the enzymes that predominantly detoxify this drug. All tested TKIs had essentially no effect on oxidation of ellipticine by used peroxidases. CONCLUSION: The results found demonstrate that TKIs vandetanib, lenvatinib and cabozantinib cause a decrease in oxidative activation of DNA-damaging drug ellipticine by several CYP enzymes in vitro which might lead to a decrease in its pharmacological efficiency. In contrast, they practically do not influence its detoxification catalyzed by CYP1A1, 1A2 and peroxidases. The present study indicates that tested TKIs seem not to have a potency to increase ellipticine anticancer efficiency.
- MeSH
- Anilides pharmacology MeSH
- Quinazolines pharmacology MeSH
- Quinolines pharmacology MeSH
- Ellipticines pharmacokinetics MeSH
- Phenylurea Compounds pharmacology MeSH
- Cytochrome P-450 Enzyme Inhibitors pharmacology MeSH
- Microsomes, Liver drug effects MeSH
- Rats MeSH
- Humans MeSH
- Oxidation-Reduction drug effects MeSH
- Peroxidases antagonists & inhibitors MeSH
- Piperidines pharmacology MeSH
- Pyridines pharmacology MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Anilides MeSH
- cabozantinib MeSH Browser
- Quinazolines MeSH
- Quinolines MeSH
- Ellipticines MeSH
- ellipticine MeSH Browser
- Phenylurea Compounds MeSH
- Cytochrome P-450 Enzyme Inhibitors MeSH
- lenvatinib MeSH Browser
- Peroxidases MeSH
- Piperidines MeSH
- Pyridines MeSH
- vandetanib MeSH Browser
Polycyclic aromatic hydrocarbons such as benzo[a]pyrene (BaP) can induce cytochrome P450 1A1 (CYP1A1) via a p53-dependent mechanism. The effect of different p53-activating chemotherapeutic drugs on CYP1A1 expression, and the resultant effect on BaP metabolism, was investigated in a panel of isogenic human colorectal HCT116 cells with differing TP53 status. Cells that were TP53(+/+), TP53(+/-) or TP53(-/-) were treated for up to 48 h with 60 μM cisplatin, 50 μM etoposide or 5 μM ellipticine, each of which caused high p53 induction at moderate cytotoxicity (60-80% cell viability). We found that etoposide and ellipticine induced CYP1A1 in TP53(+/+) cells but not in TP53(-/-) cells, demonstrating that the mechanism of CYP1A1 induction is p53-dependent; cisplatin had no such effect. Co-incubation experiments with the drugs and 2.5 μM BaP showed that: (i) etoposide increased CYP1A1 expression in TP53(+/+) cells, and to a lesser extent in TP53(-/-) cells, compared to cells treated with BaP alone; (ii) ellipticine decreased CYP1A1 expression in TP53(+/+) cells in BaP co-incubations; and (iii) cisplatin did not affect BaP-mediated CYP1A1 expression. Further, whereas cisplatin and etoposide had virtually no influence on CYP1A1-catalysed BaP metabolism, ellipticine treatment strongly inhibited BaP bioactivation. Our results indicate that the underlying mechanisms whereby etoposide and ellipticine regulate CYP1A1 expression must be different and may not be linked to p53 activation alone. These results could be relevant for smokers, who are exposed to increased levels of BaP, when prescribing chemotherapeutic drugs. Beside gene-environment interactions, more considerations should be given to potential drug-environment interactions during chemotherapy.
- Keywords
- Benzo[a]pyrene, Cisplatin, Cytochrome P450, Ellipticine, Etoposide, Tumour suppressor p53,
- MeSH
- DNA Adducts metabolism MeSH
- Benzo(a)pyrene pharmacokinetics pharmacology MeSH
- Cisplatin pharmacology MeSH
- Cytochrome P-450 CYP1A1 biosynthesis metabolism MeSH
- Cytochrome P-450 CYP3A biosynthesis metabolism MeSH
- Ellipticines pharmacokinetics pharmacology MeSH
- Enzyme Induction drug effects MeSH
- Etoposide pharmacology MeSH
- Genes, p53 MeSH
- HCT116 Cells MeSH
- Carcinogens pharmacokinetics pharmacology MeSH
- Colorectal Neoplasms drug therapy genetics metabolism pathology MeSH
- Humans MeSH
- Activation, Metabolic MeSH
- Tumor Suppressor Protein p53 deficiency genetics metabolism MeSH
- DNA Damage MeSH
- Cell Survival drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA Adducts MeSH
- Benzo(a)pyrene MeSH
- Cisplatin MeSH
- CYP1A1 protein, human MeSH Browser
- CYP3A4 protein, human MeSH Browser
- Cytochrome P-450 CYP1A1 MeSH
- Cytochrome P-450 CYP3A MeSH
- Ellipticines MeSH
- ellipticine MeSH Browser
- Etoposide MeSH
- Carcinogens MeSH
- Tumor Suppressor Protein p53 MeSH
- TP53 protein, human MeSH Browser
Neuroblastoma (NBL) originates from undifferentiated cells of the sympathetic nervous system. Chemotherapy is judged to be suitable for successful treatment of this disease. Here, the influence of histone deacetylase (HDAC) inhibitor valproate (VPA) combined with DNA-damaging chemotherapeutic, ellipticine, on UKF-NB-4 and SH-SY5Y neuroblastoma cells was investigated. Treatment of these cells with ellipticine in combination with VPA led to the synergism of their anticancer efficacy. The effect is more pronounced in the UKF-NB-4 cell line, the line with N-myc amplification, than in SH-SY5Y cells. This was associated with caspase-3-dependent induction of apoptosis in UKF-NB-4 cells. The increase in cytotoxicity of ellipticine in UKF-NB-4 by VPA is dictated by the sequence of drug administration; the increased cytotoxicity was seen only after either simultaneous exposure to these drugs or after pretreatment of cells with ellipticine before their treatment with VPA. The synergism of treatment of cells with VPA and ellipticine seems to be connected with increased acetylation of histones H3 and H4. Further, co-treatment of cells with ellipticine and VPA increased the formation of ellipticine-derived DNA adducts, which indicates an easier accessibility of ellipticine to DNA in cells by its co-treatment with VPA and also resulted in higher ellipticine cytotoxicity. The results are promising for in vivo studies and perhaps later for clinical studies of combined treatment of children suffering from high-risk NBL.
- Keywords
- DNA damage, acetylation of histones, apoptosis, ellipticine, neuroblastoma, valproate,
- MeSH
- Apoptosis MeSH
- Ellipticines toxicity MeSH
- Histone Deacetylase Inhibitors toxicity MeSH
- Valproic Acid toxicity MeSH
- Humans MeSH
- Mutagens toxicity MeSH
- Cell Line, Tumor MeSH
- Neuroblastoma metabolism MeSH
- Neurons drug effects metabolism MeSH
- Drug Synergism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Ellipticines MeSH
- ellipticine MeSH Browser
- Histone Deacetylase Inhibitors MeSH
- Valproic Acid MeSH
- Mutagens MeSH
OBJECTIVES: Ellipticine is an anticancer agent that functions through multiple mechanisms participating in cell cycle arrest and initiation of apoptosis. This drug forms covalent DNA adducts after its enzymatic activation with cytochrome P450 (CYP), which is one of the most important ellipticine DNA-damaging mechanisms of its cytotoxic effects. The improvements of cancer treatment are the major challenge in oncology research. Nanotransporters (nanoparticles) are promising approaches to target tumor cells, frequently leading to improve drug therapeutic index. Ellipticine has already been prepared in nanoparticle forms. However, since its anticancer efficiency depends on the CYP3A4-mediated metabolism in cancer cells, the aim of our research is to develop nanoparticles containing this enzyme that can be transported to tumor cells, thereby potentiating ellipticine cytotoxicity. METHODS: The CYP3A4 enzyme encapsulated into two nanoparticle forms, liposomes and microsomes, was tested to activate ellipticine to its reactive species forming covalent DNA adducts. Ellipticine-derived DNA adducts were determined by the 32P-postlabeling method. RESULTS: The CYP3A4 enzyme both in the liposome and microsome nanoparticle forms was efficient to activate ellipticine to species forming DNA adducts. Two DNA adducts, which are formed from ellipticine metabolites 12-hydroxy- and 13-hydroxyellipticine generated by its oxidation by CYP3A4, were formed by both CYP3A4 nanoparticle systems. A higher effectiveness of CYP3A4 in microsomal than in liposomal nanoparticles to form ellipticine-DNA adducts was found. CONCLUSION: Further testing in a suitable cancer cell model is encouraged to investigate whether the DNA-damaging effects of ellipticine after its activation by CYP3A4 nanoparticle forms are appropriate for active targeting of this enzyme to specific cancer cells.
- MeSH
- DNA Adducts metabolism MeSH
- Cytochrome P-450 CYP3A metabolism MeSH
- Ellipticines metabolism MeSH
- Antineoplastic Agents, Phytogenic metabolism MeSH
- Humans MeSH
- Liposomes * MeSH
- Microsomes * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- DNA Adducts MeSH
- CYP3A4 protein, human MeSH Browser
- Cytochrome P-450 CYP3A MeSH
- Ellipticines MeSH
- Antineoplastic Agents, Phytogenic MeSH
- Liposomes * MeSH
We studied the in vitro metabolism of 3-methylindole (3MI) in hepatic microsomes from fish. Hepatic microsomes from juvenile and adult carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) were included in the study. Incubation of 3MI with hepatic microsomes revealed the time-dependent formation of two major metabolites, 3-methyloxindole (3MOI) and indole-3-carbinol (I3C). The rate of 3MOI production was similar in both species at both ages. No differences in kinetic parameters were observed (p = 0.799 for Vmax, and p = 0.809 for Km). Production of I3C was detected only in the microsomes from rainbow trout. Km values were similar in juvenile and adult fish (p = 0.957); Vmax was higher in juvenile rainbow trout compared with adults (p = 0.044). In rainbow trout and carp, ellipticine reduced formation of 3MOI up to 53.2% and 81.9% and ketoconazole up to 65.8% and 91.3%, respectively. The formation of I3C was reduced by 53.7% and 51.5% in the presence of the inhibitors ellipticine and ketoconazole, respectively. These findings suggest that the CYP450 isoforms CYP1A and CYP3A are at least partly responsible for 3MI metabolism. In summary, 3MI is metabolised in fish liver to 3MOI and I3C by CYP450, and formation of these metabolites might be species-dependent.
- Keywords
- 3-hydroxy-3-metyloxindole, 3-methylindole, Cytochrome P450, Hepatic microsomes, Indole-3-carbinol,
- MeSH
- Water Pollutants, Chemical metabolism toxicity MeSH
- Species Specificity MeSH
- Ellipticines pharmacology MeSH
- Metabolic Detoxication, Phase I MeSH
- Indoles metabolism MeSH
- Cytochrome P-450 Enzyme Inhibitors pharmacology MeSH
- Microsomes, Liver drug effects metabolism MeSH
- Liver drug effects metabolism MeSH
- Carps metabolism MeSH
- Ketoconazole pharmacology MeSH
- Oncorhynchus mykiss metabolism MeSH
- Oxindoles MeSH
- Skatole metabolism toxicity MeSH
- Cytochrome P-450 Enzyme System metabolism MeSH
- In Vitro Techniques MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- 3-methyloxindole MeSH Browser
- Water Pollutants, Chemical MeSH
- Ellipticines MeSH
- ellipticine MeSH Browser
- indole-3-carbinol MeSH Browser
- Indoles MeSH
- Cytochrome P-450 Enzyme Inhibitors MeSH
- Ketoconazole MeSH
- Oxindoles MeSH
- Skatole MeSH
- Cytochrome P-450 Enzyme System MeSH
Liposome-based drug delivery systems hold great potential for cancer therapy. The aim of this study was to design a nanodevice for targeted anchoring of liposomes (with and without cholesterol) with encapsulated anticancer drugs and antisense N-myc gene oligonucleotide attached to its surface. To meet this main aim, liposomes with encapsulated doxorubicin, ellipticine and etoposide were prepared. They were further characterized by measuring their fluorescence intensity, whereas the encapsulation efficiency was estimated to be 16%. The hybridization process of individual oligonucleotides forming the nanoconstruct was investigated spectrophotometrically and electrochemically. The concentrations of ellipticine, doxorubicin and etoposide attached to the nanoconstruct in gold nanoparticle-modified liposomes were found to be 14, 5 and 2 µg·mL(-1), respectively. The study succeeded in demonstrating that liposomes are suitable for the transport of anticancer drugs and the antisense oligonucleotide, which can block the expression of the N-myc gene.
- Keywords
- N-myc, doxorubicin, ellipticine, etoposide, gold nanoparticles, liposome,
- MeSH
- DNA, Antisense chemistry therapeutic use MeSH
- Doxorubicin chemistry therapeutic use MeSH
- Ellipticines chemistry therapeutic use MeSH
- Etoposide chemistry therapeutic use MeSH
- Fluorescence MeSH
- Drug Delivery Systems * MeSH
- Humans MeSH
- Liposomes chemistry therapeutic use MeSH
- Magnetite Nanoparticles chemistry therapeutic use MeSH
- Neoplasms drug therapy MeSH
- N-Myc Proto-Oncogene Protein antagonists & inhibitors genetics MeSH
- Gold chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA, Antisense MeSH
- Doxorubicin MeSH
- Ellipticines MeSH
- Etoposide MeSH
- Liposomes MeSH
- Magnetite Nanoparticles MeSH
- N-Myc Proto-Oncogene Protein MeSH
- Gold MeSH
Neuroblastoma is the most common cancer in infants and the fourth most common cancer in children. Aggressive cell growth and chemoresistance are notorious obstacles in neuroblastoma therapy. Exposure to the anticancer drug ellipticine inhibits efficiently growth of neuroblastoma cells and induces apoptosis in these cells. However, ellipticine induced resistance in these cells. The upregulation of a vacuolar (V)-ATPase gene is one of the factors associated with resistance development. In accordance with this finding, we found that levels of V-ATPase protein expression are higher in the ellipticine-resistant UKF-NB-4ELLI line than in the parental ellipticine-sensitive UKF-NB-4 cell line. Treatment of ellipticine-sensitive UKF-NB-4 and ellipticine-resistant UKF-NB-4ELLI cells with ellipticine-induced cytoplasmic vacuolization and ellipticine is concentrated in these vacuoles. Confocal microscopy and staining of the cells with a lysosomal marker suggested these vacuoles as lysosomes. Transmission electron microscopy and no effect of an autophagy inhibitor wortmannin ruled out autophagy. Pretreatment with a V-ATPase inhibitor bafilomycin A and/or the lysosomotropic drug chloroquine prior to ellipticine enhanced the ellipticine‑mediated apoptosis and decreased ellipticine-resistance in UKF-NB-4ELLI cells. Moreover, pretreatment with these inhibitors increased formation of ellipticine-derived DNA adducts, one of the most important DNA-damaging mechanisms responsible for ellipticine cytotoxicity. In conclusion, resistance to ellipticine in the tested neuroblastoma cells is associated with V-ATPase-mediated vacuolar trapping of this drug, which may be decreased by bafilomycin A and/or chloroquine.
- MeSH
- DNA Adducts metabolism MeSH
- Apoptosis MeSH
- Drug Resistance, Neoplasm * drug effects MeSH
- Chloroquine pharmacology MeSH
- Ellipticines pharmacokinetics pharmacology MeSH
- Humans MeSH
- Macrolides pharmacology MeSH
- Cell Line, Tumor MeSH
- Neuroblastoma drug therapy genetics metabolism MeSH
- Antineoplastic Agents pharmacokinetics pharmacology MeSH
- Vacuolar Proton-Translocating ATPases metabolism MeSH
- Vacuoles metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA Adducts MeSH
- bafilomycin A MeSH Browser
- Chloroquine MeSH
- Ellipticines MeSH
- ellipticine MeSH Browser
- Macrolides MeSH
- Antineoplastic Agents MeSH
- Vacuolar Proton-Translocating ATPases MeSH
