Comparative resistance of idarubicin, doxorubicin and their C-13 alcohol metabolites in human MDR1 transfected NIH-3T3 cells

Comparative study on ABCB1-dependent efflux of anthracyclines and their metabolites: consequences for cancer resistance

1. ABCB1 (P-glycoprotein, MDR1) is one of the most important transporter involved in cancer multi-drug resistance. It also plays a significant role in cancer resistance against anthracyclines, an anticancer group of drugs, including doxorubicin and daunorubicin. Several intracellular enzymes metabolise anthracyclines to carbonyl-reduced, hydroxy metabolites, which have impaired cytotoxic properties. However, metabolite efflux by ABCB1 transporter is not well characterised, while it may be the mechanism responsible for the metabolites' lack of activity.2. In this study recombinant ABCB1 ATPase transporter assay; anthracyclines accumulation assay in resistant cells overexpressing ABCB1; and molecular modelling were used to investigate anthracyclines: doxorubicin and daunorubicin and their carbonyl-reduced metabolites (doxorubicinol, daunorubicinol) susceptibility for ABCB1-dependent efflux.3. Based on the kinetics parameters of ATPase activity of ABCB1, it was found that daunorubicinol exerted an exceptionally high potential for being effluxed by the ABCB1 transporter. ABCB1 significantly affected the accumulation pattern of studied chemicals in resistant cancer cells. Doxorubicin and daunorubicinol accumulation were influenced by the activity of ABCB1 modulator - valspodar.4. Results indicate that ABCB1 activity affects not only anthracyclines but also their metabolites. Therefore crosstalk between the process of anthracyclines metabolism and metabolite efflux may be the mechanism of impairing anticancer properties of anthracyclines metabolites.

Isocitrate dehydrogenase 2 inhibitor enasidenib synergizes daunorubicin cytotoxicity by targeting aldo-keto reductase 1C3 and ATP-binding cassette transporters

Targeting mutations that trigger acute myeloid leukaemia (AML) has emerged as a refined therapeutic approach in recent years. Enasidenib (Idhifa) is the first selective inhibitor of mutated forms of isocitrate dehydrogenase 2 (IDH2) approved against relapsed/refractory AML. In addition to its use as monotherapy, a combination trial of enasidenib with standard intensive induction therapy (daunorubicin + cytarabine) is being evaluated. This study aimed to decipher enasidenib off-target molecular mechanisms involved in anthracycline resistance, such as reduction by carbonyl reducing enzymes (CREs) and drug efflux by ATP-binding cassette (ABC) transporters. We analysed the effect of enasidenib on daunorubicin (Daun) reduction by several recombinant CREs and different human cell lines expressing aldo-keto reductase 1C3 (AKR1C3) exogenously (HCT116) or endogenously (A549 and KG1a). Additionally, A431 cell models overexpressing ABCB1, ABCG2, or ABCC1 were employed to evaluate enasidenib modulation of Daun efflux. Furthermore, the potential synergism of enasidenib over Daun cytotoxicity was quantified amongst all the cell models. Enasidenib selectively inhibited AKR1C3-mediated inactivation of Daun in vitro and in cell lines expressing AKR1C3, as well as its extrusion by ABCB1, ABCG2, and ABCC1 transporters, thus synergizing Daun cytotoxicity to overcome resistance. This work provides in vitro evidence on enasidenib-mediated targeting of the anthracycline resistance actors AKR1C3 and ABC transporters under clinically achievable concentrations. Our findings may encourage its combination with intensive chemotherapy and even suggest that the effectiveness of enasidenib as monotherapy against AML could lie beyond the targeting of mIDH2.

Cardiotoxic Effects of the Antineoplastic Doxorubicin in a Model of Metabolic Syndrome: Oxidative Stress and Transporter Expression in the Heart

ABSTRACT

The aim of the present work was to examine whether metabolic syndrome-like conditions in rats with fructose (F) overload modify the cardiotoxic effects induced by doxorubicin (DOX) and whether the treatment altered the expression of P-gp, breast cancer resistance protein, and organic cation/carnitine transporters in the heart. Male Sprague-Dawley rats received either tap water (control group [C]; n = 16) or water with F 10% wt/vol (n = 16) during 8 weeks. Three days before being killed, the animals received a single dose of DOX (6 mg/kg, ip, md) (C-DOX and F-DOX groups) or vehicle (VEH; ISS 1 mL/kg BW; ip) (C-VEH and F-VEH groups) (n = 8 per group). F overload enhanced thiobarbituric acid-reactive substance levels in the left ventricle, and DOX injection further increased those values. DOX did not alter thiobarbituric acid-reactive substance production in C animals. DOX caused a decrease of 30% in the ejection fraction and a nearly 40% reduction in the fractional shortening in F animals, but not in C rats. Cardiac tissue levels of P-gp decreased by about 30% in F rats compared with the C groups. DOX did not modify cardiac P-gp expression. Breast cancer resistance protein and organic cation/carnitine transporter (OCTN 1/2/3) protein levels did not change with either F or DOX. It is suggested that DOX could cause greater cardiotoxicity in rats receiving F, probably due to enhanced cardiac lipid peroxidation and lower expression of cardiac P-gp. These results support the hypothesis that the cardiotoxicity of DOX could be increased under metabolic syndrome-like conditions or in other health disorders that involve cardiovascular risk factors.

Is there scope for better individualisation of anthracycline cancer chemotherapy?

Anthracyclines are used to treat solid and haematological cancers, particularly breast cancers, lymphomas and childhood cancers. Myelosuppression and cardiotoxicity are the primary toxicities that limit treatment duration and/or intensity. Cardiotoxicity, particularly heart failure, is a leading cause of morbidity and mortality in cancer survivors. Cumulative anthracycline dose is a significant predictor of cardiotoxicity risk, suggesting a role for anthracycline pharmacokinetic variability. Population pharmacokinetic modelling in children has shown that doxorubicin clearance in the very young is significantly lower than in older children, potentially contributing to their higher risk of cardiotoxicity. A model of doxorubicin clearance based on body surface area and age offers a patient-centred dose-adjustment strategy that may replace the current disparate initial-dose selection tools, providing a rational way to compensate for pharmacokinetic variability in children aged <7 years. Population pharmacokinetic models in adults have not adequately addressed older ages, obesity, hepatic and renal dysfunction, and potential drug-drug interactions to enable clinical application. Although candidate gene and genome-wide association studies have investigated relationships between genetic variability and anthracycline pharmacokinetics or clinical outcomes, there have been few clinically significant reproducible associations. Precision-dosing of anthracyclines is currently hindered by lack of clinically useful pharmacokinetic targets and models that predict cumulative anthracycline exposures. Combined with known risk factors for cardiotoxicity, the use of advanced echocardiography and biomarkers, future validated pharmacokinetic targets and predictive models could facilitate anthracycline precision dosing that truly maximises efficacy and provides individualised early intervention with cardioprotective therapies in patients at risk of cardiotoxicity.

PU.1 supports TRAIL-induced cell death by inhibiting NF-κB-mediated cell survival and inducing DR5 expression

The hematopoietic Ets-domain transcription factor PU.1/SPI1 orchestrates myeloid, B- and T-cell development, and also supports hematopoietic stem cell maintenance. Although PU.1 is a renowned tumor suppressor in acute myeloid leukemia (AML), a disease characterized by an accumulation of immature blast cells, comprehensive studies analyzing the role of PU.1 during cell death responses in AML treatment are missing. Modulating PU.1 expression in AML cells, we found that PU.1 supports tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis via two mechanisms: (a) by repressing NF-κB activity via a novel direct PU.1-RelA/p65 protein-protein interaction, and (b) by directly inducing TRAIL receptor DR5 expression. Thus, expression of NF-κB-regulated antiapoptotic genes was sustained in PU.1-depleted AML cells upon TRAIL treatment and DR5 levels were decreased. Last, PU.1 deficiency significantly increased AML cell resistance to anthracycline treatment. Altogether, these results reveal a new facet of PU.1's tumor suppressor function during antileukemic therapies.

Metabolic carbonyl reduction of anthracyclines - role in cardiotoxicity and cancer resistance. Reducing enzymes as putative targets for novel cardioprotective and chemosensitizing agents

Anthracycline antibiotics (ANT), such as doxorubicin or daunorubicin, are a class of anticancer drugs that are widely used in oncology. Although highly effective in cancer therapy, their usefulness is greatly limited by their cardiotoxicity. Possible mechanisms of ANT cardiotoxicity include their conversion to secondary alcohol metabolites (i.e. doxorubicinol, daunorubicinol) catalyzed by carbonyl reductases (CBR) and aldo-keto reductases (AKR). These metabolites are suspected to be more cardiotoxic than their parent compounds. Moreover, overexpression of ANT-reducing enzymes (CBR and AKR) are found in many ANT-resistant cancers. The secondary metabolites show decreased cytotoxic properties and are more susceptible to ABC-mediated efflux than their parent compounds; thus, metabolite formation is considered one of the mechanisms of cancer resistance. Inhibitors of CBR and AKR were found to reduce the cardiotoxicity of ANT and the resistance of cancer cells, and therefore are being investigated as prospective cardioprotective and chemosensitizing drug candidates. In this review, the significance of a two-electron reduction of ANT, including daunorubicin, epirubicin, idarubicin, valrubicin, amrubicin, aclarubicin, and especially doxorubicin, is described with respect to toxicity and efficacy of therapy. Additionally, CBR and AKR inhibitors, including monoHER, curcumin, (−)-epigallocatechin gallate, resveratrol, berberine or pixantrone, and their modulating effect on the activity of ANT is characterized and discussed as potential mechanism of action for novel therapeutics in cancer treatment.

Pharmacokinetics and pharmacogenomics of daunorubicin in children: a report from the Children's Oncology Group

PURPOSE

We explored the impact of obesity, body composition, and genetic polymorphisms on the pharmacokinetics (PK) of daunorubicin in children with cancer.

PATIENTS AND METHODS

Patients ≤21 years receiving daunorubicin as an infusion of any duration <24 h for any type of cancer were eligible. Plasma drug concentrations were measured by high-performance liquid chromatography. Body composition was measured by dual-energy X-ray absorptiometry. Obesity was defined as a BMI >95% for age or as body fat >30%. NONMEM was used to perform PK model fitting. The Affymetrix DMET chip was used for genotyping. The impact of genetic polymorphisms was investigated using SNP/haplotype association analysis with estimated individual PK parameters.

RESULTS

A total of 107 subjects were enrolled, 98 patients had PK sampling, and 50 patients underwent DNA analysis. Population estimates for daunorubicin clearance and volume of distribution were 116 L/m(2)/h ± 14% and 68.1 L/m(2) ± 24%, respectively. Apparent daunorubicinol clearance and volume of distribution were 26.8 L/m(2)/h ± 5.6% and 232 L/m(2) ± 10%, respectively. No effect of body composition or obesity was observed on PK. Forty-four genes with variant haplotypes were tested for association with PK. FMO3-H1/H3 genotype was associated with lower daunorubicin clearance than FMO3-H1/H1, p = 0.00829. GSTP1*B/*B genotype was also associated with lower daunorubicin clearance compared to GSTP1*A/*A, p = 0.0347. However, neither of these associations was significant after adjusting for multiple testing by either Bonferroni or false discovery rate correction.

CONCLUSIONS

We did not detect an effect of body composition or obesity on daunorubicin PK. We found suggestive associations between FMO3 and GSTP1 haplotypes with daunorubicin PK that could potentially affect efficacy and toxicity.

Pharmacokinetic Comparison of 120-Hour InfusionVersusHyperfractionated Oral Administration of Idarubicin

The aim of this study was to compare the pharmacokinetics of idarubicin (IDA) and its active metabolite idarubicinol (IDOL) after chronic oral and continuous intravenous (i.v.) IDA administration in order to establish the oral doses needed to reach the i.v. equiactive plasma drug exposure. The pharmacokinetic profile of IDA and IDOL was investigated in 23 patients receiving 12 mg/m2 IDA by 120-h i.v. infusion (2.4 mg/m2/day) combined with cyclophosphamide, etoposide and prednisone in comparison to 28 patients receiving oral IDA doses ranging from 2 to 10 mg/day for 21 days in a phase I study. We found that IDA AUC24h/dose/m2 was 4.7-fold greater during i.v. than oral administration, whereas IDOL AUC24h/dose/m2 was only about 2-fold higher after i.v. administration. The metabolic ratio between IDOL AUC24h and IDA AUC24h in plasma was about 3-fold higher after oral administration. Based on these results we were able to estimate that equiactive plasma drug exposure was reached with an approximately 2.5-fold greater oral dose/m2 of IDA than the corresponding i.v. dose.

Randomized study of induction therapy comparing standard-dose idarubicin with high-dose daunorubicin in adult patients with previously untreated acute myeloid leukemia: the JALSG AML201 Study

We conducted a multi-institutional randomized study to determine whether high-dose daunorubicin would be as effective as standard-dose idarubicin in remission-induction therapy for newly diagnosed adult patients younger than 65 years of age with acute myeloid leukemia. Of 1064 patients registered, 1057 were evaluable. They were randomly assigned to receive either daunorubicin (50 mg/m(2) daily for 5 days) or idarubicin (12 mg/m(2) daily for 3 days) in combination with 100 mg/m(2) of cytarabine by continuous infusion daily for 7 days as induction therapy. Complete remission was achieved in 407 (77.5%) of 525 patients in the daunorubicin group and 416 (78.2%) of 532 in the idarubicin group (P = .79). Patients achieving complete remission received intensive postremission therapy that consisted of either 3 courses of high-dose cytarabine or 4 courses of standard-dose therapy. Overall survival rates at 5 years were 48% for the daunorubicin group and 48% for the idarubicin group (P = .54), and relapse-free survival rates at 5 years were 41% and 41% (P = .97), respectively. Thus, high-dose daunorubicin and standard-dose idarubicin were equally effective for the treatment of adult acute myeloid leukemia, achieving a high rate of complete remission and good long-term efficacy. This study is registered at http://www.umin.ac.jp/ctrj/ as C000000157.

Amrubicin for the treatment of advanced lung cancer

Although the advancement of the chemotherapy of non-small cell lung cancer and small cell lung cancer is remarkable in recent years, it is still unsatisfactory. Therefore, some new agents or a new treatment strategy for lung cancer is required. Amrubicin is a totally synthetic anthracycline anticancer drug that acts as a potent topoisomerase II inhibitor. Recently, amrubicin has been approved in Japan for the treatment of small- and non-small cell lung cancers and some clinical trials about amrubicin were conducted in Japan, and promising results have been reported for the treatment of small cell lung cancer in particular. The preclinical, pharmacology and clinical data of amrubicin for the treatment of advanced lung cancer are reviewed.

Characterization of the enzymes involved in thein vitrometabolism of amrubicin hydrochloride

The in vitro metabolism of amrubicin by rat and human liver microsomes and cytosol was examined. The main metabolic routes in both species were reductive deglycosylation and carbonyl group reduction in the side-chain. In vitro metabolism of amrubicinol by rat and human liver microsomes and cytosol was also examined and the main metabolic route of this active metabolite was reductive deglycosylation. Metabolism of amrubicin in human liver microsomes was inhibited by TlCl(3) and that in human liver cytosol was inhibited by dicumarol and quercetin. Generation of amrubicinol was inhibited only by quercetin. The results indicate that metabolism of amrubicin is mediated by NADPH-cytochrome P450 reductase, NADPH:quinone oxidoreductase and carbonyl reductase. In addition, generation of amrubicinol is mediated by carbonyl reductase. Metabolism of amrubicinol in human liver microsomes was inhibited by TlCl(3) and that in human liver cytosol was inhibited by dicumarol. The results indicate that metabolism of amrubicinol is mediated by NADPH-cytochrome P450 reductase and NADPH:quinone oxidoreductase. To investigate the influence of cisplatin on the metabolism of amrubicin and amrubicinol, human liver microsomes and cytosol were pre-incubated with cisplatin. This did not change the rates of amrubicin and amrubicinol metabolism in either human liver microsomes or cytosol.

Evaluation of the clinical relevance of the expression and function of P-glycoprotein, multidrug resistance protein and lung resistance protein in patients with primary acute myelogenous leukemia

The multidrug resistance (MDR) transporter-proteins P-glycoprotein (Pgp), multidrug resistance protein (MRP) and lung resistance protein (LRP) have been associated with treatment failure. The aim of this study was to investigate prospectively the clinical significance of expression and function of the MDR proteins, considering other prognostic factors, such as age, immunophenotype, and cytogenetics. Mononuclear cells of peripheral blood or bone marrow from 61 patients with de novo acute myelogenous leukemia (AML) were analyzed. The monoclonal antibodies JSB1, MRPm6 and LRP56 were used for expression studies. Accumulation and retention studies were performed using the substrates Daunorubicin, Calcein-AM, Rhodamine-123 and DiOC(2) in the presence or absence of the modifiers Verapamil, Genistein, Probenecid, BIBW22S and PSC833. Induction treatment consisted of a 3+7 combination of Ida/Ara-C for patients < or = 60 years of age and a 3+5 Ida/VP-16 combination per OS for patients >60. MDR function was expressed as the ratio of mean fluorescence intensity substrate in the presence of modifier over the substrate alone (resistance index, RI). Patients with advanced age, low CD15 expression and high RI for accumulation of DiOC(2) in the presence of BIBW22S had significantly lower complete remission (CR) rates. No factor was prognostic for event-free survival analysis, which was limited to remitters only. Overall survival was shorter in patients with advanced age, poor prognosis cytogenetics, high CD7 expression, and high RI for Daunorubicin efflux modulated by Verapamil. These results suggest that MDR transporter-proteins have a limited role in the treatment failure of patients treated with Idarubicin-based regimens.

Carbonyl reductase

Carbonyl reductase (secondary-alcohol:NADP(+) oxidoreductase, EC 1.1. 1.184) belongs to the family of short chain dehydrogenases/reductases (SDR). Carbonyl reductases (CBRs) are NADPH-dependent, mostly monomeric, cytosolic enzymes with broad substrate specificity for many endogenous and xenobiotic carbonyl compounds. They catalyze the reduction of endogenous prostaglandins, steroids, and other aliphatic aldehydes and ketones. They also reduce a wide variety of xenobiotic quinones derived from polycyclic aromatic hydrocarbons. CBR reduces the anthracycline anticancer drugs, daunorubicin(dn) and doxorubicin (dox) to their C-13 hydroxy metabolites, changing the pharmacological properties of these drugs. Emerging data on CBRs over the last several years is generating new insights on the potential involvement of CBRs in a variety of cellular and molecular reactions associated with drug metabolism, detoxication, drug resistance, mutagenesis, and carcinogenesis.

Effect of PSC 833 on the cytotoxicity of idarubicin and idarubicinol in multidrug-resistant K562 cells

We examined the effect of PSC 833, a non-immunosuppressive cyclosporin analogue, on the cytotoxicity, accumulation and retention of idarubicin (IDA) and its 13-dihydro metabolite, idarubicinol (IDAol). P-glycoprotein (PGP)-overexpressing multidrug-resistant K562/D1-9 cells were used for these studies. PSC 833 had no effect on the cytotoxicity, intracellular accumulation, or retention of IDA and IDAol in the parent K562 cells. However, intracellular accumulation of IDA and IDAol in K562/D1-9 cells after a 60-min incubation was restored by 0.4 microM PSC 833 to 104% and 116%, respectively, of the level in parent K562 cells. The retention of IDA and IDAol in K562/D1-9 cells was also restored by 0.4 microM PSC 833. Consequently, 0.4 microM PSC 833 increased the sensitivity of K562/D1-9 cells to IDA and IDAol. The resistance index (RI) of IDA decreased from 20-fold to 4.0-fold, and the RI of IDAol decreased from 104-fold to 1.5-fold. These results suggest that the combination of IDA and PSC 833 may be effective in reversing PGP-mediated multidrug resistance in leukemia cells.

Idarubicin and idarubicinol are less affected by topoisomerase II-related multidrug resistance than is daunorubicin

We investigated the cytotoxicity and cellular pharmacology of idarubicin (IDA), idarubicinol (IDAol) and daunorubicin (DNR) in K562/VP-H2 cells, which show topoisomerase II-related multidrug resistance but do not overexpress P-glycoprotein. K562/VP-H2 cells were less resistant to IDA and IDAol than to DNR. There was no significant difference in the accumulation of each drug between K562 and K562/VP-H2 cells. The cleavage of DNA induced by each drug was decreased in K562/VP-H2 cells, however, the decrease in cleavage in K562/VP-H2 cells was less with IDA and IDAol than with DNR. These results suggest that IDA and IDAol have more cytotoxic potency than DNR in topoisomerase II-related multidrug-resistant leukemia cells.

Idarubicin and cytosine arabinoside reinduction therapy for children with multiple recurrent or refractory acute lymphoblastic leukemia: a Pediatric Oncology Group study

PURPOSE

This study was designed to determine the toxicity of and response to idarubicin and cytosine arabinoside in children and adolescents with acute lymphoblastic leukemia (ALL) who had refractory or recurrent bone marrow disease.

PATIENTS AND METHODS

Patients <21 years of age with ALL in second or later bone marrow relapse or refractory to induction therapy were eligible. Some patients also had concurrent central nervous system (CNS) relapse. Therapy consisted of cytosine arabinoside, 1 g/m2/day given as a 6-h infusion, followed by bolus idarubicin, 5 mg/m2/day, both daily for 6 days. Children achieving remission received maintenance therapy with 3 days of etoposide, 100 mg/m2/day, followed by ifosfamide, 2.8 g/m2/day, alternating every 3 weeks with 3 days of cytosine arabinoside and idarubicin in the dosages described earlier. All courses of therapy were followed by granulocyte colony-stimulating factor (G-CSF). Removal from study to undergo bone marrow transplantation (BMT) was encouraged.

RESULTS

Eighty-two patients were entered. There were 14 deaths (nine early), mostly from documented or presumed bacterial or fungal sepsis. Overall, 30 patients achieved complete remission (37%). These were mostly of brief duration--only one patient was still alive at 600+ days after BMT.

CONCLUSIONS

Cytosine arabinoside and idarubicin showed moderate activity in heavily pretreated children with ALL.