Discovery of naphthacemycins as a novel class of PARP1 inhibitors.

Poly (ADP-ribose) polymerase-1 (PARP-1) is an abundant nuclear protein that plays important roles in a variety of nuclear processes, and it has been proved a prominent target in oncology for its key function in DNA damage repair. In this study, we discovered a series of naphthacemycins as a new class of PARP1 inhibitors from a microbial metabolites library via high-throughput screening. Compound I, one of this series of compounds, could reduce cellular poly (ADP-ribose) level, trap PARP1 on the damaged DNA and elevate the level of γ-H2AX, and showed the selective cytotoxicity against BRCA1-deficient cell line. Our study provided a potential scaffold for the development of new PARP1 inhibitors in cancer therapy.

Tetracenomycin X Exerts Antitumour Activity in Lung Cancer Cells through the Downregulation of Cyclin D1.

Tetracenomycin X (Tcm X) has been reported to have antitumour activity in various cancers, but there have not been any studies on its activity with respect to lung cancer to date. Therefore, this study aims to investigate the anti-lung cancer activity of Tcm X. In this study, we found that tetracenomycin X showed antitumour activity in vivo and selectively inhibited the proliferation of lung cancer cells without influencing lung fibroblasts. In addition, apoptosis and autophagy did not contribute to the antitumour activity. Tetracenomycin X exerts antitumour activity through cell cycle arrest induced by the downregulation of cyclin D1. To explore the specific mechanism, we found that tetracenomycin X directly induced cyclin D1 proteasomal degradation and indirectly downregulated cyclin D1 via the activation of p38 and c-JUN proteins. All these findings were explored for the first time, which indicated that tetracenomycin X may be a powerful antimitotic class of anticancer drug candidates for the treatment of lung cancer in the future.

Erythroleukemia relapsing as precursor B-cell lymphoblastic leukemia.

AML relapsing as ALL has rarely been reported. We describe the case of a 62-yr-old man who was diagnosed with erythroleukemia with a complex karyotype and achieved complete hematologic and cytogenetic remission after induction chemotherapy. However, 4 months after the initial diagnosis, he showed relapse with blasts showing a different morphology and immunophenotype and was diagnosed with precursor B-cell ALL. The relapsing precursor B-cell ALL presented with the same leukemic clones as the primary erythroleukemia. Cytogenetic analysis of his bone marrow (BM) at the time of the primary erythroleukemia showed complex karyotypic abnormalities, including monosomy 5 and monosomy 7. At relapse, his BM showed reemergence of these leukemic clones of complex karyotypic abnormalities with clonal switch. To our knowledge, this is the first case of a lineage switch from erythroleukemia to ALL.

[Genotoxic and mutagenic activity of antineoplastic anthracyclines and their aglycones: study in two test-systems]. / Genotoksicheskaia i mutagennaia aktivnost' protivoopukholevykh antratsiklinov i ikh aglikonov: izuchenie v test-sistemakh.

Mutagenic (Ames tests) and genotoxic (SOS chromotest) activities of highly-efficient natural anthracycline monosaccharides possessing antitumor activity-daunorubicin (also known as daunomycin or rubomycin), doxorubicin (adriamycin), and carminomycin-were studied. At the same time, the hypothesis was tested that intercalation of the antibiotic moiety into the helix of cell DNA, which was mediated by the saccharide amino group, played a crucial role in genotoxicity of these anthracyclines. The hydrolysis products of these antibiotics (the corresponding aglycones) and aclacynomycin A (an anthracycline trisaccharide), as well as aclavinone (its derivative aglycone), were studied. All these compounds lacked the saccharide amino group necessary for intercalation. It was found that all anthracycline monosaccharides studied had a strong mutagenic effect on strain TA98 and a moderate effect on strain TA100 of Salmonella typhimurium. Aclacynomycin A was found to have no mutagenic effect on any strain. Lack of the glycoside amino group did not necessarily result in loss of mutagenic activity in the derivative aglycones of anthracycline monosaccharides: they exhibited moderate mutagenic activity in strain TA98 and low but significant activity in strain TA100. The S9 microsomal fraction did not alter the mutagenic activity of either anthracycline monosaccharides or their aglycones; however, it dramatically increased the mutagenic activity of aclavinone: correspondence between positive responses in Ames tests and the SOS chromotest was found. Apparently, the mutagenic activity of the substances studied in bacterial cells was mediated by inducing the SOS-repair process. If the compound contained the amino glycoside moiety, functional and structural precursors of the SOS response were formed via intercalation of the reagents into the DNA duplex; if the substance did not contain this moiety, the precursors were formed via ionic interaction.

Effects of verapamil on uptake and in vitro toxicity of anthracyclines in human leukemic blast cells.

The effect of a calcium channel blocker, verapamil, on intracellular uptake and cytotoxicity of anthracyclines in vitro was studied on leukemic cells from 32 patients with acute non-lymphoblastic leukemia. Cells were isolated from peripheral blood or bone-marrow and incubated with a concentration of 0.2 mumol/l, 0.5 mumol/l and/or 1.0 mumol/l of doxorubicin or daunorubicin in the absence and presence of verapamil at a concentration of 2 mumol/l and/or 10 mumol/l. Intracellular uptake was determined at the end of the incubations by photofluorometer and the in vitro cytotoxicity was determined after 5 days culturing in liquid medium by dye exclusion according to Weisenthal. Verapamil significantly increased the intracellular uptake of anthracyclines 0.5 mumol/l and 1.0 mumol/l and the cytotoxic effect of anthracyclines 0.2 mumol/l and 0.5 mumol/l and affected doxorubicin and daunorubicin equally. There were no significant differences between the two concentrations of verapamil. Cells from different FAB-groups were equally affected by verapamil. The effect on intracellular uptake was higher in cells from patients who were resistant to therapy compared to those who achieved a complete remission. We conclude that verapamil has an effect on intracellular uptake and cytotoxicity of anthracyclines on tumor cells from patients with acute non-lymphoblastic leukemia. The prognostic and therapeutic relevance of this has to be further evaluated.

[Effect of MX-2, a morpholino anthracycline derivative, against human and rat glioma cells and experimental leptomeningeal tumors in rats].

MX-2, a new morpholino anthracycline derivative, showed broad anti-neoplastic activity against experimental tumors. Molecular weight of MX-2 is 622.07, and it can cross blood-brain barrier because of its high lipid solubility. In this report, we described its in vitro and in vivo effects on brain tumors. The growth of rat 9L and human KNS-42 glioma cells were markedly inhibited by the medium containing more than 1 ng/ml of MX-2. The inhibitory concentration of MX-2 for 50% cell kill was 1.8 ng/ml for 9L cell and 18 ng/ml for KNS-42, respectively. These values were the almost same as those reported with P388 leukemia. In rats with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells, the median survival time was significantly prolonged. The increased life span was 40, 40, 40 (p less than 0.01), and 20% (p less than 0.05) in the animals given intravenous MX-2 of 1.5, 1.0, 0.75, and 0.375 mg/kg on day 1, 5, and 9 after tumor inoculation respectively. These results indicate that MX-2 may be a promising new antineoplastic agent for the treatment of malignant brain tumor.

[Phase I study of SM-5887, a new anthracycline derivative].

SM-5887, a new totally synthetic anthracycline derivative, was studied in a phase I setting. Twenty-nine evaluable courses of treatment were conducted in groups at doses increasing from 10 to 130 mg/m2. At 130 mg/m2 the median lowest WBC count was 0.7 x 10(3)/mm3 (range 0.3-1.8) and the median lowest platelet count was 57 x 10(3)/mm3 (range 4-176). Nonhematological side effects were mild gastrointestinal symptoms and hair loss. The recommended dose and schedule for a phase II setting is 100 mg/m2 every 3 weeks.

Aclacinomycin A and etoposide (VP-16-213): an effective regimen in previously treated patients with refractory acute myelogenous leukemia.

Thirty-five patients with acute myelogenous leukemia were treated with aclacinomycin A (60 mg/m2/day for 5 days) and VP-16-213 (100 mg/m2/day for 5 days). All were previously treated and had relapsed or were refractory to primary treatment. Most patients (28) had received prior DAT (daunorubicin, cytosine arabinoside, and 6-thioguanine) induction therapy followed by one or more courses of high-dose cytosine arabinoside (HD-Ara C) as consolidation therapy or as treatment for relapse. One patient was in her fourth relapse, one had relapsed acute megakaryoblastic leukemia (following remission with DAT and HD-Ara-C), one had a treatment-induced leukemia, and four patients were treated for primary treatment failures following two induction courses with DAT or a similar regimen. Fourteen patients had infections at start of therapy. Ten patients died within 14 days of treatment, all from sepsis or bleeding, before their marrow could be evaluated for leukemic response. Fourteen patients (40%) responded; 12 (34%) entered complete remission and two (6%) a partial remission (PR). Two of the four patients who were treated for primary treatment failures went into CR. The median CR duration was 99 days (range 30 to 455 days). Side effects from this treatment were similar to the conventional DAT regimen, although the gastrointestinal toxicity and mucositis appeared to be more severe. In addition, two of the patients had severe but reversible ventricular arrhythmias. The overall response (40%) and CR rate (34%) in this group of previously treated AML patients is encouraging, and further studies are needed to evaluate these preliminary findings.

Physical-chemical properties shared by compounds that modulate multidrug resistance in human leukemic cells.

Multidrug resistance (MDR), typified by resistance to Vinca alkaloids and anthracyclines, is a well characterized experimental phenomenon that may have some clinical correlates. Verapamil, chloroquine, and related drugs have been shown previously to be capable of enhancing anticancer drug cytotoxicity in multi-drug-resistant cells, but the mechanism(s) by which these agents do this is(are) unclear. Since these agents did not seem to have common features, we studied these and other compounds for their ability to "modulate" Vinca alkaloid resistance in order to determine whether they possessed any common chemical or physical features. In addition to verapamil, 24 compounds, consisting of indole alkaloids, lysosomotropic agents, and amines, were tested for their ability to enhance the cytotoxicity of vinblastine and/or vincristine in our human leukemic multidrug-resistant cell line, CEM/VLB100. Seventeen compounds that enhance the cytotoxicity of the Vinca alkaloids by more than 5-fold have been identified. These include quinolines (chloroquine, quinine, chinchonidine, and primaquine), acridines (acridine, acridine orange, and quinacrine), and indole alkaloids (yohimbine, corynanthine, reserpine, physostigmine, and the vindoline and catharanthine moieties of the Vinca alkaloids), as well as other alkaloids and amines (chlorpromazine, propranolol, atropine, and tryptamine). Vindoline, catharanthine, and quinacrine also enhanced the cytotoxicity of doxorubicin and teniposide in these cells, indicating that this "modulation" was not limited to Vinca alkaloids. We examined some well known lysosomotropic compounds (methylamine, epinephrine, suramin, and trypan blue) and found that they were not able to enhance the cytotoxicity of vincristine in the CEM/VLB100 cells, indicating that lysosomotropic activity per se is not required for modulator activity. Three-dimensional computer modeling permitted molecular comparisons of conformationally related congeners of vinblastine, vindoline, and verapamil and revealed three regions of structural homology. We measured the hydrophobicity (by oil/water partitioning) and calculated the molar refractivity (by the additive substituent constant method) of active and inactive compounds. We found that those cationic agents--verapamil, quinacrine, indole alkaloids, and quinolines--that were lipid soluble at physiologic pH and had similar molar refractivities were best able to enhance the cytotoxicity of the Vinca alkaloids in our multidrug-resistant cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Therapeutic and pharmacological studies of tetrachloro(d,l-trans)1,2-diaminocyclohexane platinum (IV) (tetraplatin), a new platinum analogue.

Tetrachloro(d,l-trans)1,2-diaminocyclohexane platinum (IV) (tetraplatin), a new platinum analogue, showed greater therapeutic efficacy after i.p. administration than either cis-dichlorodiammineplatinum (II) (cisplatin) or cis-diammine-1,1-cyclobutanedicarboxylate platinum (II) (carboplatin) in mice bearing i.p. implanted L1210 leukemia. At an optimal dose of 5.7 mg/kg/injection given as a single dose on days 1, 5, and 9, tetraplatin increased the median life span over controls by more than 566% with 5 of 8 long-term (50-day) survivors. In contrast, cisplatin at the same optimal dose increased survival by 186% with 2 of 8 long-term survivors, and carboplatin at an optimal dose of 75.6 mg/kg/injection increased survival by only 120% with no long-term survivors. Tetraplatin also was more effective than cisplatin when treatment was delayed until days 3, 7, and 11 after i.p. implant. A combination of tetraplatin and Adriamycin in mice bearing i.p. implanted L1210 leukemia produced more long-term survivors over a wider range of doses than could be achieved with either drug alone. Tetraplatin at 5.7 mg/kg/injection and Adriamycin at 3 mg/kg/injection on days 1, 5, and 9 increased survival by more than 566% with 8 of 8 50-day survivors. Using the same treatment schedule, combinations of tetraplatin with either cisplatin, carboplatin, daunomycin, or 5-fluorouracil did not produce therapeutic efficacy greater than that seen with tetraplatin alone. The in vitro cellular uptake of platinum by L1210 cells at 37 degrees C was about 4-fold higher after exposure to tetraplatin compared to cisplatin following a 2-h incubation at the two concentrations examined (2.5 and 5 micrograms/ml). Comparative pharmacological studies were performed in rats at a single dose of 3 mg/kg i.v. The t1/2 beta for total platinum in plasma was 29.10 h (7.47 h for unbound platinum) after the administration of tetraplatin and 23.70 h (13.09 h for unbound platinum) after cisplatin. By 48 h the urinary excretion of platinum after tetraplatin and cisplatin was 30.1% and 41.4%, respectively. Tissue distribution of platinum was similar after either complex. Thus, tetraplatin has similar pharmacological properties to cisplatin and like cisplatin is a candidate for combination chemotherapy. However, tetraplatin may be superior to cisplatin in some therapeutic situations based on its greater efficacy against selected tumors.

Investigations with monoclonal antibody drug (anthracycline) conjugates.

The development of monoclonal antibody-drug (anthracycline) conjugates (immunocytostatics) that has emerged during the last decade is briefly reviewed. Stress is layed on the various procedures that have been employed for the chemical attachment of daunorubicin (daunomycin) and doxorubicin (adriamycin) to spacers, high-molecular weight carrier molecules, and immunoglobulins. Anthracycline conjugates that have proved effective in mice with respect to the treatment of cancer are especially evaluated. Also a new method developed for the conjugation of rhodosaminyl anthracyclinones via a hydrolysable spacer, developed in our laboratories, is briefly communicated. Finally, import aspects for further developments of monoclonal antibody-drug conjugates are discussed.

Rodorubicin, a new tetraglycosidic anthracycline.

Rodorubicin is a new tetraglycosidic anthracycline, which was detected because of its activity against human tumors in a human tumor based screening system. Rodorubicin is not active in the typical animal transplantation tumors and might therefore be a new leading structure with preferential activity against slow proliferating human tumors. In spite the fact that Rodorubicin is a chemical anthracycline, the drug has an untypical spectrum of activity and toxicity when compared to standard anthracyclines. The drug is not toxic to bone marrow in animals or humans, however, the dose limiting toxicity is delayed nephrotoxicity in all species, starting with proteinuria and finally clearance reduction. Rodorubicin might be an interesting new candidate for further clinical evaluation and is the first drug being developed clinically in spite its inactivity in animal transplantation tumor systems.

Daunorubicin in patients with relapsed and refractory acute nonlymphoblastic leukemia previously treated with anthracycline.

While the efficacy of daunorubicin (DNR) in first induction of patients with acute nonlymphoblastic leukemia (ANLL) has been well documented, little data are available concerning the activity of DNR in patients with relapsed and refractory ANLL previously treated with anthracycline. We administered DNR (60 mg/m2/day for 3-5 days) in 21 patients with relapsed (n = 12) or refractory (n = 9) ANLL previously treated with anthracycline. The general response rate was 48%, with a complete response (CR) rate of 38%. Five of 12 patients with relapsed ANLL and 3 of 9 patients with refractory ANLL achieved CR. Among these cases with CR in refractory ANLL, the evolution of one patient is particularly illustrative since he had received previously a large cumulative dose of anthracycline (540 mg/m2) and has been shown to be refractory to high-dose cytosine arabinoside. This study suggests that previous administration of DNR or adriamycin does not induce significant resistance to anthracycline: DNR appears to be almost as efficient in patients with relapsed and refractory ANLL previously treated with anthracycline as in first induction.

Anthracyclines in the treatment of malignancy in pregnancy.

This article reports two cases and reviews the literature regarding chemotherapy using anthracyclines during pregnancy. Twenty-six additional cases using this class of agents to treat malignancy during pregnancy are summarized from 18 reports for a total of 28 pregnancies. Final outcome of pregnancy is analyzed with regard to the following factors: diagnosis, gestational age at start of therapy, total dose of anthracycline, number and type of agents used, neonatal pathologic findings and months of follow-up of infants. Final outcome of 28 pregnancies resulted in 24 normal infants including a set of twins in the current report. Limited pharmacokinetic information is inconclusive with regard to the appearance of anthracyclines and their known metabolites in placental or fetal tissue.

Assessment of left ventricular diastolic function in patients receiving anthracycline therapy.

Abnormalities in left ventricular filling have been described as an early finding in coronary artery disease and in cardiomyopathy. The present study was undertaken to determine whether impaired diastolic function may be an early sign of anthracycline cardiotoxicity. Radionuclide left ventricular curves of 30 treated patients were compared with the curves of 17 normal, agematched, volunteers. The curves were analyzed for ejection fraction, peak filling rate (normalized for end diastolic counts and for stroke counts), time to peak filling rate and filling fraction in the first third of diastole normalized for cycle length. In 20 patients (Groups A and B), we analyzed the radionuclide ventriculography preceding the decrease of systolic function or a clinical congestive heart failure. In ten patients (Group C) who ended a treatment regimen without systolic dysfunction or clinically evident cardiotoxicity, we analyzed the ventriculography at the end of the therapy. Among the diastolic indexes, only the first third filling fraction was abnormal in a minority of the patients (6/20 in Groups A and B). Our findings suggest that diastolic dysfunction is uncommon in anthracycline treated patients prior to systolic dysfunction.

Phase I study of pirarubicin.

A Phase I trial of pirarubicin (4'-O-tetrahydropyranyl-doxorubicin) was undertaken to study its toxicity and to gain preliminary knowledge of its efficacy. The dose was escalated by increments of 10 from 30 to 70 mg/m2. Out of 20 patients, 19 were evaluable for toxicity and response to treatment. Hematologic toxicity was dose limiting and dose related. Other adverse effects included nausea and vomiting, hair loss, and stomatitis. No acute cardiotoxicity was encountered. In 2 patients with metastatic breast cancer who had not been pretreated with cytostatic agents, a partial remission was achieved lasting for 5 months. In 6 patients, tumor parameters did not change for a median of 3 months, and 11 patients suffered progressive disease.