Concentrations Of Mitoxantrone Research Articles

Hydrogel-Coated SERS Microneedles for Drug Monitoring in Dermal Interstitial Fluid.

In vivo drug monitoring is crucial for evaluating the effectiveness and safety of drug treatment. Blood sampling and analysis is the current gold standard but needs professional skills and cannot meet the requirements of point-of-care testing. Dermal interstitial fluid (ISF) showed great potential to replace blood for in vivo drug monitoring; however, the detection was challenging, and the drug distribution behavior in ISF was still unclear until now. In this study, we proposed surface-enhanced Raman spectroscopy (SERS) microneedles (MNs) for the painless and real-time analysis of drugs in ISF after intravenous injection. Using methylene blue (MB) and mitoxantrone (MTO) as model drugs, the innovative core-satellite structured Au@Ag SERS substrate, hydrogel coating over the MNs, rendered sensitive and quantitative drug detection in ISF of mice within 10 min. Based on this technique, the pharmacokinetics of the two drugs in ISF was investigated and compared with those in blood, where the drugs were analyzed via liquid chromatography-mass spectrometry. It was found that the MB concentration in ISF and blood was comparable, whereas the concentration of MTO in ISF was 2-3 orders of magnitude lower than in blood. This work proposed an efficient tool for ISF drug monitoring. More importantly, it experimentally proved that the penetration ratio of blood to ISF was drug-dependent, providing insightful information into the potential of ISF as a blood alternative for in vivo drug detection.

Development and Validation of a New High-Performance Liquid Chromatography-Ultraviolet Assay for Quantification of Mitoxantrone in Plasma of BALB/c-nu Mice.

The concentration of mitoxantrone in the blood of mice was determined by a high-performance liquid chromatography-ultraviolet method with aloe-emodin as the internal standard. The separation was performed on a Hypersil BDS2 column (4.6 × 250mm, 5μm) as the analytical column, the mobile Phase A was acetonitrile, and B was 20-mM potassium dihydrogen phosphate (adding 1% triethylamine and adjusting the pH to 2.8 with phosphoric acid) and 4.6-mM sodium octyl sulfonate. The flow rate was 1.0mL·min-1, the detection wavelength was 243nm, the column temperature is 25 ± 5°C and the injection amount was 20μL. Finally, the linear range of mitoxantrone was 5-200μg·mL-1, and the correlation coefficient was r = 0.9999. The recovery rate of the method was 91.93-105.5%, and the extraction recovery rate was 91.45-105.5%. The intraday precision and interday precision were <3.29% (limit of detection = 0.3μg·mL-1). The HPLC method established in this paper was simple, rapid, sensitive and accurate, and can be used to determine the content of mitoxantrone in mouse plasma after tail vein injection.

Interaction of mitoxantrone with abasic sites - DNA strand cleavage and inhibition of apurinic/apyrimidinic endonuclease 1, APE1

Mitoxantrone (1,4-dihydroxy-5,8-bis[2-(2-hydroxyethylamino)ethylamino]-anthracene-9,10-dione) is a clinically-relevant synthetic anthracenedione that functions as a topoisomerase II poison by trapping DNA double-strand break intermediates. Mitoxantrone binds to DNA via both stacking interactions with DNA bases and hydrogen bonding with the sugar-phosphate backbone. It has been shown that mitoxantrone inhibits apurinic/apyrimidinic (AP) endonuclease 1 (APE1)-catalyzed incision of DNA containing a tetrahydrofuran (THF) moiety and more recently, that mitoxantrone forms Schiff base conjugates at AP sites in DNA. In this study, mitoxantrone-mediated inhibition of APE1 at THF sites was shown to be consistent with preferential binding to, and thermal stabilization of DNA containing a THF site as compared to non-damaged DNA. Investigations into the properties of mitoxantrone at AP and 3′ α,β-unsaturated aldehyde sites demonstrated that in addition to being a potent inhibitor of APE1 at these biologically-relevant substrates (∼ 0.5 μM IC50 on AP site-containing DNA), mitoxantrone also incised AP site-containing DNA by catalyzing β- and β/δ-elimination reactions. The efficiency of these reactions to generate the 3′ α,β-unsaturated aldehyde and 3′ phosphate products was modulated by DNA structure. Although these cell-free reactions revealed that mitoxantrone can generate 3′ phosphates, cells lacking polynucleotide kinase phosphatase did not show increased sensitivity to mitoxantrone treatment. Consistent with its ability to inhibit APE1 activity on DNAs containing either an AP site or a 3′ α,β-unsaturated aldehyde, combined exposures to clinically-relevant concentrations of mitoxantrone and a small molecule APE1 inhibitor revealed additive cytotoxicity. These data suggest that in a cellular context, mitoxantrone may interfere with APE1 DNA repair functions.

Luminescence behavior of colloid quantum dots in the presence anthracycline antibiotic mitoxantrone: Surface interaction and luminescence quenching, size and composition dependence, potential for clinical study

The luminescence of colloidal quantum dots (QDs) is often affected by the passivating layer, the stabilizing ligand, and the interactions in solution. The anthracycline antibiotic mitoxantrone (MTX) effectively quenches QDs luminescence while attaching to their surface in the aqua colloid. Careful selection of the architecture of QDs with significant luminescence quenching in the presence of MTX will make future for developing a simple and fast luminescence turn-off method to determine the concentration of MTX. To find the most sensitive QDs architecture to the presence of MTX, two types of nanoparticles were examined as detector systems: (i) a series of size-selected fractions of non-cadmium AgInS/ZnS QDs and (ii) alloyed CdZnSeS and CdZnSeS/ZnS QDs. All tested QDs in aqueous colloids were coated with thioglycolic acid as a surface stabilizing ligand. An examination of luminescence intensity and lifetime decreasing in the presence of MTX allowed us to evaluate the effect of the structure and composition of QDs on the efficiency of luminescence quenching by MTX. A detailed study demonstrates a predominantly static quenching mechanism, via the formation of complexes with high binding constants (∼106-107 M−1). The wide variability in the composition and size of QDs made it possible to achieve a low MTX detection limits (3 and 5 nM for the third fraction of AgInS/ZnS and CdZnSeS/ZnS QDs, respectively). Thus, the use of luminescent QDs as a direct detection system is promising for monitoring MTX concentrations

Mitoxantrone Quantification by HPLC-MS/MS in Caco-2 Culture Media

Mitoxantrone is a marker substrate of breast cancer resistance protein (BCRP). BCRP is involved in a number of pharmacokinetic drug-drug interactions. The transporter’s possible saturability makes it advisable to use low concentrations of mitoxantrone for in vitro studies. Consequently, mitoxantrone quantification requires a method with high sensitivity.The aim of the study was to develop and validate a procedure for mitoxantrone quantification in Caco-2 culture media by HPLC-MS/MS.Materials and methods. The authors used an Ultimate 3000 HPLC system and a TSQ Fortis triple quadrupole mass spectrometer by Thermo Fisher Scientific and a Selectra C18 column (4.6×100 mm, 5 μm, 100 Å) by United Chemical Technologies. The elution ran in a gradient mode with a mobile phase of 1% formic acid solution and methanol. Experimental parameters were as follows: eluent flow rate, 0.3 mL/min; separation column temperature, 35 °C; injection volume, 5 μL; ana lysis time, 10 min; approximate mitoxantrone retention time, 5.51 min. The sample preparation involved protein precipitation from the culture medium with methanol, followed by centrifugation at 13,000 g for 10 min. The detection was performed using electrospray ionisation in the positive ion mode. Detection parameters were as follows: electrospray voltage, 3700 V; sheath gas flow rate, 50 L/min; auxiliary gas flow rate, 10 L/min; sweep gas flow rate, 1 L/min; ion-transfer tube temperature, 300 °C; and evaporator temperature, 350 °C. The detection was set at mass transitions of m/z 455 to 88.2 and m/z 455 to 358.1, with the collision energy for these transitions amounting to 25 V and 18 V, respectively. The source fragmentation was at 0, and the CID gas pressure was at 2 mTorr.Results. The analytical procedure showed selectivity, high sensitivity (limit of detection, 10 nmol/L; lower limit of quantification, 50 nmol/L), accuracy, precision, and linearity in the concentration range of 50–1000 nmol/L. The authors observed no carryover or matrix effects. A simulation of real-life storage conditions demonstrated high stability of mitoxantrone samples. Thus, the analytical procedure enables preclinical evaluation of medicinal product effects on the functional activity of BCRP, based on assessing the transcellular mitoxantrone transport in the presence of a test product.Conclusion. The authors developed and validated the analytical procedure for mitoxantrone quantification in Caco-2 culture media by HPLC-MS/MS.

Exploring the binding of mitoxantrone to DNA using optical tweezers.

Mitoxantrone (MTX) is a synthetic anti-cancer drug that displays intercalation binding mode with DNA. It has been widely studied using conventional methods, but not using single molecule techniques which can provide molecular level details of the interactions. Here we explored the binding of MTX with DNA using optical tweezers. Our optical tweezers set-up uses two counter propagating lasers to trap and manipulate a single DNA molecule that is stretched to measure the force response as a function of extension. The DNA stretching was repeated in the presence of various nano-molar concentrations of MTX at different pulling rates. Stretching at much slower pulling rates exhibited closer to binding equilibrium, indicating MTX is a slow binder with the time scale of seconds compared to classical intercalators which have microsecond binding kinetics. This will provide more detail about the binding mechanism of MTX that can be used to better understand the binding of MTX and also develop similar drug designs.

R(h)oad to antitumour therapy.

R(h)oad to antitumour therapy.

β1-Integrin binding to collagen type 1 transmits breast cancer cells into chemoresistance by activating ABC efflux transporters

Molecular interactions of tumor cells with the microenvironment are regarded as onset of chemotherapy resistance, referred to as cell adhesion mediated drug resistance (CAM-DR). Here we elucidate a mechanism of CAM-DR in breast cancer cells in vitro. We show that human MCF-7 and MDA-MB-231 breast cancer cells decrease their sensitivity towards cisplatin, doxorubicin, and mitoxantrone cytotoxicity upon binding to collagen type 1 (COL1) or fibronectin (FN). The intracellular concentrations of doxorubicin and mitoxantrone were decreased upon cell cultivation on COL1, while cellular cisplatin levels remained unaffected. Since doxorubicin and mitoxantrone are transporter substrates, this refers to ATP binding cassette (ABC) efflux transporter activities. The activation of the transporters BCRP, P-gp and MRP1 was shown by fluorescence assays to distinguish the individual input of these transporters to resistance in presence of COL1 and related to their expression levels by western blot. An ABC transporter inhibitor was able to re-sensitize COL1-treated cells for doxorubicin and mitoxantrone toxicity. Antibody-blocking of β1-integrin (ITGB1) induced sensitization towards the indicated cytostatic drugs by attenuating the increased ABC efflux activity. This refers to a key role of ITGB1 for matrix binding and subsequent transporter activation. A downregulation of α2β1 integrin following COL1 binding appears as clear indication for the relationship between ITGB1 and ABC transporters in regulating resistance formation, while knockdown of ITGB1 leads to a significant upregulation of all three transporters. Our data provide evidence for a role of CAM-DR in breast cancer via an ITGB1 – transporter axis and offer promising therapeutic targets for cancer sensitization.

Comparison of LC-MS/MS-based targeted proteomics and conventional analytical methods for monitoring breast cancer resistance protein expression

AimsMultidrug resistance is a major obstacle in chemotherapy, which is mainly caused by the overexpression of ATP-binding cassette (ABC) transporters. Breast cancer resistance protein (BCRP) is one of the ABC transporters and is strongly associated with multidrug resistance. Results of studies on BCRP and multidrug resistance are always uncomparable and contradictory, which may be stem from the disadvantages of qualitative and semi-quantitative techniques. In addition, there are few literatures studying at low resistance level which is more similar to the clinical situation. Thus, it is imperative to develop a quantitative method to quantitate the expression of BCRP accurately and reveal its relationship with multidrug resistance. MethodsSMMC-7721, MCF-7 and HepG-2 were induced by different concentrations of mitoxantrone, doxorubicin and methotrexate respectively to establish resistance cells. An advanced liquid chromatography linked to tandem mass spectrometry (LC-MS/MS) based method with surrogate peptide was developed and validated for determining BCRP at low resistant cells. The amount of BCRP was also evaluated by real-time-polymerase chain reaction (RT-PCR) and Western Blot (WB). Key findingsThe LC-MS/MS-based method we developed is more sensitive and stable than the similar methods and can monitor the slight variation of BCRP expression accurately and sensitively, while RT-PCR and WB cannot. SignificanceThis study provides a solid foundation for understanding the development of drug resistance in cells and can be used to explain the conflicting results of published studies. Moreover, clinical multidrug resistances are mostly at low levels, which have not been discussed in current quantitative studies of BCRP.

Using LC-MS/MS-based targeted proteomics to monitor the pattern of ABC transporters expression in the development of drug resistance.

PurposeThe overexpression of ATP-binding cassette transporters (ABC transporters), mainly including permeability glycoproteins (P-gp), multidrug resistance (MDR)-related protein 1 (MRP1), and breast cancer resistance proteins (BCRP), is one of the main reasons for the development of MDR which directly leads to chemotherapy failure. However, most of the currently used detection methods in MDR-related studies are qualitative or semiquantitative, but not quantitative. As a result, the measurement criteria of different experiments are not unified. Moreover, there are many contradictory results of the studies of the induction effect of drugs on ABC transporters. So, it is necessary to establish a quantitative assay for the quantification of P-gp, MRP1, and BCRP to study the mechanism of drug resistance.MethodsIn this paper, a novel and advanced liquid chromatography/mass spectrometry (MS)/MS-based targeted proteomics method for the quantification of P-gp, MRP1, and BCRP was developed and validated. Then, the cell lines MCF-7, HepG-2, and SMMC-7721 were, respectively, induced by different concentrations of doxorubicin (adriamycin [ADM]), mitoxantrone (MX), and methotrexate (MTX), to establish resistance cell lines. The method established was used to quantify the expression of P-gp, MRP1, and BCRP.ResultsThe result showed that the induction effects of drugs on protein were relatively stable and selective. ADM, MX, and MTX could induce overexpression of P-gp, MRP1, and BCRP. And, the induction effect of different drugs on proteins was selective. The pattern of overexpression of ABC transporters in the three types of resistance cell lines was different.ConclusionDuring the development of drug resistance, the cell type and patch, but not drug type, were the most important determinant factors of the overexpression level of ABC transporters in resistance cell lines. This study provides a good foundation for understanding the development of drug resistance in cell lines and can be used to explain the contradictory results in other published studies as described above.

An electrochemical sensor based on a molecularly imprinted polymer for determination of anticancer drug Mitoxantrone

A novel electrochemical sensor based on the molecularly imprinted polymer (MIP) film is presented for the determination of an anticancer drug Mitoxantrone (MTX). The MIP film was prepared by electrochemical polymerization of β-cyclodextrins (β-CD) and MTX on a glassy carbon electrode (GCE) for the first time, wherein β-CD served as the functional monomer, MTX as the template that was extracted afterwards, thereby creating the imprinted cavities complementary to the template in the polymer matrix. MTX could be specifically recognized and binding by the imprinted cavities. The developed MIP sensor exhibits a rapid electrochemical response, high sensitivity and selectivity for the determination of MTX in pharmaceutical formulations and spiked urine samples. Moreover, the proposed approach presents distinct advantages over reported electrochemical methods for determination of MTX because it is a one-step preparation and the template molecule could be easily removed by cyclic voltammetry scans, and no elution reagent is required. Under the optimal experimental conditions, the linear response range for MTX concentrations by the MIP sensor was 6×10−8M–1×10−5M with a detection limit of 3×10−8M (S/N=3), showing a good sensitivity and low LOD for MTX detection. This study demonstrates that the proposed MIP sensor is feasible for the detection of anticancer drugs.

A label-free Electrochemical DNA Biosensor for the Determination of Low Concentrations of Mitoxantrone in Serum Samples

A label-free Electrochemical DNA Biosensor for the Determination of Low Concentrations of Mitoxantrone in Serum Samples

Surfactant modified carbon nanotube paste electrode for the sensitive determination of mitoxantrone anticancer drug

&lt;p class="PaperAbstract"&gt;&lt;span lang="EN-US"&gt;Surfactant modified carbon nanotube paste electrode is prepared as electrochemical sensor with high sensitivity in responding to Mitoxantrone (MTX). Electrochemical oxidation of MTX is investigated in buffered solution by cyclic voltammetry that is found very sensitive method for detection of MTX. It is shown that the sodium dodecyl sulfate modified carbon nanotube paste electrode (SDSMCNTPE) gives enhanced current response for MTX compared to the bare carbon nanotube paste electrode (BCNTPE). Different parameters were tested to optimize the conditions for MTX determination. The effects of different surfactant and surfactant concentration, pH, scan rate, detection limit (LOD), limit of quantification (LOQ) and concentration of MTX on the oxidation peak current values were determined. Excellent results were obtained by cyclic voltammetry using SDSMCNTPE, where two MTX oxidation peaks appeared at 367 and 596 mV &lt;/span&gt;&lt;span lang="EN-US"&gt;vs.&lt;/span&gt;&lt;span lang="EN-US"&gt; SCE. Detailed analysis of the second voltammetric peak showed the linear dynamic range between 2×10&lt;sup&gt;−7&lt;/sup&gt; and 7×10&lt;sup&gt;−6&lt;/sup&gt; M MTX with the slope of co-relation coefficient of 0.99271. LOD and LOQ were determined as 3.5 ×10&lt;sup&gt;−8&lt;/sup&gt; M and 11×10&lt;sup&gt;−8&lt;/sup&gt; M, respectively. The SDSMCNTPE showed very good reproducibility, high stability in its voltammetric response, high electrochemical sensitivity and low detection limit for MTX.&lt;/span&gt;&lt;/p&gt;

Dual Function of Gold Nanoparticles in Synergism with Mitoxantrone and Microwave Hyperthermia Against Melanoma Cells

Background:This study was performed to evaluate any synergetic effects of mitoxantrone (MX) and gold nanoparticles (GNPs) as dual therapeutic approach, along with microwave (MW) hyperthermia for melanoma cancer.Methods:Various tests were performed on the DFW melanoma cell line in the presence of MX and different concentrations of GNPs, with and without MW irradiation. MTT [3-(4,5-dimethylthiazol–2-yl)-2,5-iphenyltetrazolium bromide] assays were conducted to evaluate the effectiveness of the used therapeutic methods in terms of cell survival. Relative lethal synergism (RLS) was calculated as the ratio of cell death following hyperthermia in the presence of a treatment agent to that after applying hyperthermia in the absence of the same treatment agent.Results:Results showed MX and GNPs under MW irradiation to provide maximum cell death (P < 0.001 compared to the other groups). The mean RLS for MW hyperthermia along with the MX-GNP combination was 4.14, whereas in the absence of GNP the value for MX chemotherapy was 0.94.Conclusion:MX chemotherapy in the presence of different concentrations of GNP did not alter cell survival as compared to in its absence.

Stabilities of Irradiated DNA Complexes from Sarcoma 45 Tumors with Mitoxantrone at Small Fillings

In the present work, the thermostabilities of mitoxantrone (MTX) complexes with DNA from sarcoma 45 and healthy rat liver were studied. DNAs from both sources were irradiated by resonant (64.5 GHz and 50.3 GHz) and nonresonant (48.3 GHz) frequencies of water. The obtained data showed that DNA solution irradiation by resonant frequencies of water induces a dehydration of nucleotides and Na[Formula: see text] ions in the solution. It is shown that at relatively low concentrations of MTX, when one MTX molecule binds to almost 100 pairs of bases of DNA, the thermostabilities of complexes decrease. Moreover, this change is more pronounced ([Formula: see text]C) at the complex formation with DNA released from sarcoma 45 tumor.

Antitumor Drug Mitoxantrone Do Not Preclude Salt-driven B-Z Transition of Poly (dG- dC)

Despite of the existence in literature of large number of reports the binding modes of mitoxantrone (MTX) with DNA must be subject to refinement. Moreover there is no any report yet on interaction of MTX with Z-DNA. Here we present results of circular dichroism (CD) studies on MTX binding to salt driven left-handed conformation of poly (dG- dC). It was shown, that in contrast with classical intercalating ligands (ethidium bromide, acridine orange etc.) that bind with B-form DNA and obstacle B-Z transition at high concentrations of NaCl MTX interferes B-Z transition, but does not prevent the transitions process, thus suggest the semi intercalating (partial stacking) mode of MTX interaction with Z-form of DNA.

Effect of mitoxantrone on proliferation and apoptosis of human multiple myeloma cell RPMI8226

This study was aimed to investigate the effects of mitoxantrone on proliferation and apoptosis of human multiple myeloma cell line RPMI-8226 and its mechanism. The inhibitory rate of RPMI8226 cells proliferation was assayed by MTT, the morphological changes of RPMI-8226 cells were observed by inverted flurescent microscopy and transmission electron microscopy, the apoptosis rate and the cell cycle distribution of RPMI-8226 cells were detected by flow cytometry. The effects of mitoxantrone on the expression of BCL-2, BAX, caspase-3 mRNA were detected by RT-PCR, the BCL-2, BAX, caspase-3 protein expression of RPMI-8226 cells was analyzed by Western blot. The results showed that mitoxantrone could inhibit the proliferation of RPMI-8226 cells in time- and dose-dependent manners. Light microscopy showed that the cell number in mitoxantrone group was significantly less than that in control group and the cell growth arrangement was irregular, apoptotic cells could be seen. Under electron microscope, typical apoptotic morphological and ultrastructural changes could be observed, these results confirmed that the mitoxantrone could induce apoptosis of RPMI-8226 cells, the difference have statistical significance (P < 0.05). The 1.0 µg/ml low concentration of mitoxantrone mainly arrested RPMI-8226 cells in the G2/M phase(P < 0.05), and the 2.0 µg/ml high concentration of mitoxantrone mainly arrested RPMI-8226 cells in the S phase (P < 0.05). The expression of BCL-2 mRNA decreased (P < 0.05),while the expression of BAX, caspase-3 mRNA increased (P < 0.05). Western blot indicated that BCL-2 protein expression also decreased (P < 0.05) and BAX, caspase-3 protein expression increased. It is concluded that the mitoxantrone can inhibit the proliferation of RPMI-8226 cells by inducing cell apoptosis. Activation of the mitochondrial and death receptor pathways of apoptosis may be involved in the mitoxantrone-induced apoptosis, the cell cycle arrest may also play an important role in the apoptosis mechanism.

Abstract 2654: Human antibodies specific for oxidized macrophage migration inhibitory factor (oxMIF) synergize with chemotherapeutic agents in animal models of cancer

Abstract Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with pleiotropic biologic effects and is pathologically associated with several types of cancer. oxMIF is an immunological and conformational distinct isoform of MIF that can be mimicked in vitro by mild oxidation of recombinant MIF. Fully human monoclonal antibodies that specifically target oxMIF were shown to inhibit downstream signaling pathways associated with tumor proliferation and progression in vitro and in vivo. We assessed the potential of anti-oxMIF antibodies combined with standard chemotherapeutic agents on the proliferation of cancer cell lines in vitro and in vivo in xenograft models. In vitro, anti-oxMIF sensitization of the prostate cancer cell lines PC3 or LnCAP significantly reduced the half maximal effective concentration (EC50) of mitoxantrone by 30% and 40%, respectively. In the ovarian cancer cell lines A2780, EC50 of cisplatin was reduced by 70% after sensitization with anti-oxMIF. In vivo, mice bearing pancreatic cancer xenografts (COLO357, BxPC3 or MiaPaCa2) treated with anti-oxMIF in combination with gemcitabine had a strong survival advantage compared with mice treated with either monotherapy. This effect was accompanied by a decrease of tumor volumes up to 70% and an increase in the expression of caspase 3 in mice bearing COLO357 xenografts. In addition, combining gemcitabine with anti-oxMIF treatment normalized blood vessel density inside the tumors, decreased their permeability by 25%, and decreased tumor VEGF levels by 40%, whereas gemcitabine alone had the opposite effect. In mice bearing the ovarian human cancer cell line A2780 xenografts, combining anti-oxMIF antibodies with cisplatin led to a 45% reduction of tumor weights. Anti-oxMIF specific antibodies decreased proliferation, angiogenesis and inflammation inside tumor xenografts, but were not cytotoxic (no antibody-dependent cell cytotoxicity or complement-dependent cytotoxicity). These experiments demonstrated synergistic effects between anti-oxMIF antibodies and cytotoxic chemotherapy. Combination treatments were superior to the corresponding monotherapies and led to a stronger inhibition of tumor growth and angiogenesis. A phase 1 clinical study of a novel human antibody that selectively targets oxMIF is currently ongoing in patients with solid malignancies (ClinicalTrials.gov identifier: NCT01765790). Citation Format: Patrice Douillard, Thorsten Hagemann, Michael Freissmuth, Michael Thiele, Alexander Schinagl, Dirk Völkel, Friedrich Scheiflinger, Randolf Kerschbaumer. Human antibodies specific for oxidized macrophage migration inhibitory factor (oxMIF) synergize with chemotherapeutic agents in animal models of cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2654. doi:10.1158/1538-7445.AM2014-2654

Therapeutic Concentrations of Mitoxantrone Elicit Energetic Imbalance in H9c2 Cells as an Earlier Event

Mitoxantrone (MTX) is a chemotherapeutic agent that emerged as an alternative to anthracycline therapy. However, MTX also causes late cardiotoxicity, being oxidative stress and mitochondrial-impaired function proposed as possible mechanisms. This work aimed to investigate the relevance of these mechanisms to the MTX toxicity in H9c2 cells, using therapeutic concentrations. The observed cytotoxicity of MTX was time and concentration dependent in both lactate dehydrogenase leakage assay and MTT reduction assay. Two therapeutic concentrations (100 nM and 1μM) and three time points were selected (24, 48, and 96h) for further studies. Both MTX concentrations caused a significant increase in caspase-3 activity, which was not prevented by inhibiting MTX CYP450-metabolism. Significant decreases were observed in the total and reduced glutathione levels only in MTX 100nM at 96h; however, neither alterations in oxidized glutathione nor increases in the malondialdehyde levels were observed at any time or concentrations tested. On the other hand, changes in the intracellular ATP levels, mitochondrial membrane potential, and intracellular calcium levels were observed in both concentrations and all time tested. Noteworthy, decreased levels of ATP-synthase expression and activity and increases in the reactive species generation were observed at 96h in both working concentrations. However, the radical scavenger N-acetylcysteine or the mitochondrial function enhancer L-carnitine did not prevent MTX cytotoxicity. Thus, this work evidenced the early MTX-induced energetic crisis as a possible key factor in the cell injury.

Evaluation of Rat In Vivo Fetal-to-Maternal Transfer Clearances of Various Xenobiotics by Umbilical Perfusion

It is important to address the tissue permeability of drugs, particularly in tissues that have a blood-tissue barrier, in terms of both lipophilicity and the contribution of transporters. Here, we employed umbilical perfusion in rats to evaluate in vivo fetal-to-maternal transfer clearances of various xenobiotics. We measured fetal-to-maternal clearance (CLfm ) of 23 compounds, which have a broad range of lipophilicity. Drugs for which CLfm was more than 300 µL/(mL min) belonged exclusively to Biopharmaceutical Drug Disposition Classification System (BDDCS) class 1 (highly permeable) and those for which CLfm was less than 50 µL/(mL min) belonged exclusively to BDDCS class 3 (poorly permeable). For most drugs, CLfm values were broadly consistent with lipophilicity. However, CLfm of digoxin was saturable and was inhibited by verapamil, suggesting that P-glycoprotein (P-gp)-mediated efflux has a substantially effect on measured clearance. CLfm of mitoxantrone continued to increase slightly at high concentrations of mitoxantrone, but placental-to-maternal clearance of mitoxantrone was saturable, implying that Bcrp1 contributes to mitoxantrone efflux across the placenta. Thus, we measured CLfm by umbilical perfusion and examined the relationship between CLfm and lipophilicity of xenobiotics. Fetal-to-maternal transport clearances measured in this study will be helpful to understand the characteristics of the blood-placental barrier.