Leukemia L1210 Cell Line Research Articles

Nitrogen-Containing Verticillene Diterpenoids from the Taiwanese Soft Coral Cespitularia taeniata

Extensive column chromatography of the ethanolic extract of the soft coral Cespitularia taeniata collected in Taiwan has resulted in the isolation of eight new nitrogen-containing verticillene diterpenes, designated cespitulactams D-K ( 1- 8), together with three known diterpenes, cespitulactams A ( 9) and B ( 10) and cespitularin F. In addition, one new derivative, 6- O-acetylcespitulactam F ( 11), was prepared from compound 3. The structures of these compounds were elucidated on the basis of spectroscopic analyses, especially HRMS and 2D NMR experiments. The cytotoxicity against human oral epidermoid carcinoma (KB) and murine L1210 leukemia cell lines and antimicrobial activities of 1- 8 and 11 were tested and evaluated. A biogenetic pathway for these novel diterpene alkaloids was also proposed.

Safety and Efficacy of Marqibo (Vincristine Sulfate Liposomes Injection, OPTISOME™) in for the Treatment of Adults with Relapsed or Refractory Acute Lymphoblastic Leukemia (ALL).

Introduction: Vincristine sulfate (VCR) is a lipophilic, cell-cycle specific, antineoplastic agent that inhibits cell division by specifically binding to tubulin in mitotic spindles. The activity of VCR is dose and time-dependent, but central and peripheral neuropthy prohibits its use beyond doses of 1.4 mg/m2 (capped at 2 mg). Marqibo is a formulation of VCR encapsulated in a sphingomyelin/cholesterol liposome (OPTISOME) with a longer half-life than VCR. In murine models using L1210 or P388 lymphoid leukemia cell lines, Marqibo demonstrated greater anti-tumor activity compared with VCR. Marqibo was therefore an appropriate agent to study in relapsed or refractory ALL.Methods: Two clinical trials have been completed. First, a phase II trial of single agent Marqibo given at 2 mg/m2 (no dose capping) every 2 weeks enrolled 16 patients (pts) [Thomas et al, Cancer 106:120, 2006]. A multicenter dose escalation phase I trial using weekly Marqibo (1.5, 1.825, 2.0, 2.25, 2.4 mg/m2) in combination with pulse dexamethasone followed. There were no restrictions on the number of prior therapies. Subjects with grade 2 or greater central or peripheral neuropathy were ineligible.Results: In total, 52 pts with relapsed or refractory ALL were treated in the two studies combined. Median age was 34 years (range, 19–77), 31 males/21 females, with a median number of prior salvage regimens of 2 (range, 1–3). Nine pts had confirmed Philadelphia positive disease (8 in the pre-imatinib era, 1 resistant to tyrosine kinase inhibitor therapy). All pts had previously received conventional VCR therapy. There were 8 complete remissions and 3 partial remissions for an overall response rate of 21% [95% CI, 11, 35]. An additional 12 pts (23%) achieved hematological improvements (e.g., clearance of marrow blasts, platelet transfusion independence). Five responders were able to undergo allogeneic stem cell transplantation following therapy with Marqibo. The maximum tolerated dose in the phase I trial was 2.25 mg/m2 owing to grade 3 motor neuropathy, grade 4 seizure, and grade 4 hepatotoxicity observed in 1 patient each at the 2.4 mg/m2 dose level. Grade 1–2 peripheral neuropathy was manageable with dose modifications and anti-neuralgia agents such as gabapentin. Commonly observed toxicities included febrile neutropenia, myelosuppression, abdominal pain, nausea, constipation, diarrhea, fatigue, and infusion-related pyrexia.Conclusions: In reviewing the clinical experience to date, Marqibo with or without pulse dexamethasone has provided clinically meaningful activity in heavily pre-treated adults with ALL. A multicenter trial of single agent Marqibo in the setting of second salvage therapy for adults with relapsed ALL is underway. A phase III multicenter trial of Marqibo in combination with standard chemotherapy for de novo elderly ALL is in the planning phase.

Synthesis, DNA Interaction, and Cytotoxic Activity of a Novel Proflavine−Dithiazolidinone Pharmacophore

Five novel proflavine-dithiazolidinone derivatives 4a-4e have been designed and synthesized by the reaction of dialkyl acridin-3,6-diyl dithioureas 3a-3e with methyl bromoacetate. The binding affinity of dithiazolidinone hydrochlorides 5a-5e with calf thymus DNA and plasmid (pUC19) DNA was investigated by a variety of spectroscopic techniques including UV-vis, fluorescence, and CD spectroscopy. The effects of 5a-5e on the thermal denaturation profiles of calf thymus DNA were also studied. From spectrophotometric and spectrofluorimetric titrations, the binding constants for the pUC19 DNA-drug complexes were determined (K = 6.2-2.2 x 104 M-1). In vitro cytotoxic activities of compounds 5a-5e toward murine leukemia cell line L1210 and human uterus carcinoma HeLa cells were also examined. 2',2' '-[(Acridin-3,6-diyl)diimino]-3',3' '-dipropyl-1,3-dithiazolidin-4-one hydrochloride (5b) showed the highest activity against these cells with IC50 values of 6.3 microM and 12.9 microM over the course of 72 h.

Four New Macrocyclic Trichothecenes from Two Strains of Marine-derived Fungi of the Genus Myrothecium

Three new macrocyclic trichothecenes, named 12'-hydroxyroridin E (1), roridin Q (2), and 2',3'deoxyroritoxin D (3), were isolated from the marine-derived fungus Myrothecium roridum TUF 98F42, and a new macrocyclic trichothecene, named roridin R (4), was isolated from Myrothecium sp. TUF 02F6 together with roridins A and H and isororidin E. The structures of new compounds were determined on the basis of their spectral data. Compound 2 possessed a unique ether moiety at the 13' position of 1. Compound 4 was a 2',3'-dihydro-2'-hydroxy derivative of roridin H. The IC50 values of compounds 1, 2, and 4 against the murine leukemia cell line L1210 were 0.19, 31.2, and 0.45 microM, respectively. Compound 3 showed antiyeast activity to Saccharomyces cerevisiae at 1 microg/disc (inhibition zone: 12.2 mm), which was about 10 time more active than roritoxin D (10.2 mm at 10 microg/disc).

Design and synthesis of novel amino-substituted xanthenones and benzo[ b]xanthenones: Evaluation of their antiproliferative activity and their ability to overcome multidrug resistance toward MES-SA/D × 5 cells

A number of new xanthenone and benzo[ b]xanthenone amino derivatives and their pyrazole-fused counterparts have been designed and synthesized possessing structural analogy to the potent anticancer agent 9-methoxypyrazoloacridine. The synthesis of the compounds proceeds through nucleophilic substitution of 1-chloro-4-nitroxanthenone or the corresponding benzo[ b]xanthenone by the appropriately substituted amine or hydrazine, reduction of the nitro group, and conversion into the suitable dialkylaminoacetamides. This method cannot be applied for synthesis of the pyrazole-fused benzo[ b]xanthenones, consequently a different, simple, and high-yielding synthetic procedure was developed for the preparation of the target molecules. In vitro cytotoxic potencies of the new derivatives toward the murine leukemia L1210 cell line, human colorectal adenocarcinoma (HT-29), and human uterine sarcoma (MES-SA and its 100-fold resistant to doxorubicin variant MES-SA/D × 5) cell lines are described and compared to those of reference drugs. The compounds exhibited significant cytotoxic activity against the tested cell lines and in addition they retain activity against the multidrug resistant MES-SA/D × 5 subline, showing resistant factors close to 1. A number of derivatives were found to posses DNA binding capacity, according to a standard ethidium bromide displacement assay. The majority of the studied compounds induce a G2/M arrest, although among them some G1 or S blockers have also been identified.

Melophlins P, Q, R, and S: Four New Tetramic Acid Derivatives, from Two Palauan Marine Sponges of the Genus Melophlus

Four new tetramic acid derivatives, named melophlins P, Q, R, and S (1-4), were isolated from two marine sponges of the genus Melophlus collected at Palau, together with seven known melophlins A, D, E, G, H, I, and O. The structures of the new compounds were elucidated on the basis of their spectral data. The absolute stereochemistries at the tetramic acid moieties of the new compounds were determined as 1 : 1 mixtures (racemic) by ESI-LC/MS analysis of derivatives obtained by oxidation and hydrolysis of the respective parent compounds. Melophlins P-S (1-4) showed cytotoxicity against the murine leukemia cell line L1210 with IC(50) values of 20.0, 10.5, 0.85, and 5.13 microM, respectively.

Cytotoxicity and induction of apoptosis by 4-amino-3-acetylquinoline in murine leukemia cell line L1210.

Nitrogen heterocyclic compounds are used in the pharmaceutical industry, in medicine and in agriculture for their biological activity. 4-Amino-3-acetylquinoline, a new synthetically prepared quinoline derivative, was the most effective compound in our primary cytotoxic screening. In this study, we evaluated cytotoxic/antiproliferative activity of quinoline using murine leukemia cell line L1210. Its ability to induce apoptosis was studied, too. Quinoline derivative acted cytotoxically on tumor cell line L1210, the IC(100) value were 50 microg/ml (for 24 h), 25 microg/ml (for 48 h) and 10 microg/ml (for 72 h). The IC(50) values was found to be less than 4 microg/ml, a limit put forward by the National Cancer Institute (NCI) for classification of he compound as a potential anticancer drug. The cytotoxic concentrations of 4-amino-3-acetyl quinoline induced morphological changes of L1210 cells and the apoptotic DNA fragmentation.

4-Methylideneisoxazolidin-5-ones—A new class of α-methylidene-γ-lactones with high cytostatic activity

A novel, general method of synthesis of 4-methylideneisoxazolidin-5-ones 10 is described. The target compounds were synthesized starting from ethyl 2-diethoxyphosphoryl-2-alkenoates 6 or dicyclohexylammonium 4-diethoxyphosphoryl-2-alkenoates 7. Addition of N-methylhydroxylamine hydrochloride to these Michael acceptors, lactonization to 4-diethoxyphosphorylisoxazolidin-5-ones 9, and Horner–Wadsworth–Emmons olefination of formaldehyde using 9 gave the title isoxazolidinones 10. All obtained compounds were tested against L-1210, HL-60, and NALM-6 leukemia cell lines. Several isoxazolidinones 10 were found to be very potent with IC 50 < 1 μM. The highest cytostatic activity against HL-60 was observed for 10a and against NALM-6 for 10b with IC 50 values of 0.74 and 0.34 μM, respectively.

Structures, biogenetic relationships, and cytotoxicity of pimarane-derived diterpenes from Petalostigma pubescens

Extraction of Petalostigma pubescens heartwood followed by chromatographic purifications and crystallizations afforded five tricyclic diterpenes: 5,9-syn-rosanes petalostigmones A and B ( 1 and 2), the erythroxylane petalostigmone C ( 3), the norditerpene lactone pubescenone ( 4), and the known ent-cleistanthane diterpene (−)-sonderianol ( 5). The structures and relative stereochemistry were elucidated by means of spectroscopic methods, chemical correlations, and, in the cases of 1 and 4, by X-ray crystallographic analyses. The new isolates 1– 4 are assumed to belong to the same absolute configurational family (9αCH 3) of ent-pimarane-derived diterpenes as the known co-occurring (−)- 5 (10αCH 3). Biogenetic schemes originating from a common ent-copalyl diphosphate intermediate are presented to rationalize the structures of these natural products. A novel ring contraction–ring expansion mechanism is suggested to account for the 7-membered B ring of pubescenone. Compounds 1– 5 were evaluated for their cytotoxicity; sonderianol ( 5) showed the highest activity against mouse leukemia cell lines L1210, P388 and mouse liver cancer cells HEPA1c1c7.

Novel Thermosensitive 5-Fluorouracil−Cyclotriphosphazene Conjugates: Synthesis, Thermosensitivity, Degradability, and in Vitro Antitumor Activity

A novel thermosensitive macromolecular prodrug of 5-fluorouracil (5-FU) was synthesized using cyclotriphosphazene, and its thermosensitivity, degradability, and in vitro antitumor activity were studied. A series of alpha-substituted glycine derivatives of 5-FU containing carboxylic groups were prepared, and cyclotriphosphazenes with amino groups were synthesized via the stepwise substitution of hexachlorocyclotriphosphazene (NPCl(2))(3) with methoxy-poly(ethylene glycol) (MPEG) or alkoxy ethylene oxide and lysine ethyl ester (LysOEt). The coupling reaction of the two derivatives, and their subsequent deprotection, yielded a thermosenstive 5-FU-cyclotriphosphazene conjugate, which exhibited a unique octopus-shaped molecular structure, in which the three hydrophilic PEG groups (or alkoxy ethylene oxides) were oriented in one direction, opposing the other three hydrophobic groups containing 5-FU, with respect to the trimer ring plane. This conjugate exhibited a reversible and thermosensitive phase transition in an aqueous medium, from soluble to insoluble states. The lower critical solution temperature (LCST) of the conjugate was controlled by substitution with different hydrophilic/hydrophobic side groups, and a few of the conjugates displayed LCSTs which were just below body temperature. This, of course, implies possible applications for local drug delivery by direct intratumoral injection. The conjugate exhibited gradual degradation at 37 degrees C in both neutral and acidic buffer solutions, and high temperature significantly facilitated its hydrolytic degradation. All of the conjugates displayed dose-dependent cytotoxicity against the leukemia L1210 cell line and exhibited more pronounced cytotoxic effects than did 5-FU.

Novel Benzopyridothiadiazepines as Potential Active Antitumor Agents

The synthesis of novel thiadiazepine derivatives, that could be considered as constraint analogues of E-7010, are reported. These molecules were evaluated for their antiproliferative activity toward the murine L1210 leukemia cell line. Flow cytometric studies performed on L1210 cells with the most cytotoxic compounds showed an accumulation of the cells in the G2/M phases of the cell cycle with a significant percentage of tetraploid cells (8N DNA content). Submicromolar cytotoxicities were observed with compounds 2b, 4b, 4e, 4g, and 4i. Two of them, compounds 2b and 4b, were found to be potent inhibitors of tubulin polymerization with IC50 of respectively 3.8 and 2.4 microM compared to 2.4 microM for desoxypodophyllotoxin. A 4-methoxyphenylethyl substitution on the pyridinyl nitrogen of the benzopyridothiadiazepine was found to be essential for the antiproliferative activity. The in vitro activities of compounds 2b and 4b make benzopyridothiadiazepine dioxides a promising new class of tubulin binders which warrant further in vivo evaluation.

Enantioselective Synthesis and Cytotoxic Evaluation of 4,5-Dihydro-5-[aryl(hydroxy)methyl]-3-methylidenefuran-2(3H)-ones

A series of enantiomerically enriched 4,5-dihydro-5-[aryl(hydroxy)methyl]-3-methylidenefuran-2(3H)-ones (8) were synthesized by means of asymmetric Sharpless dihydroxylation of the 2-phosphorylated 5-aryl-pent-4-enoic acids 13, followed by Horner-Wadsworth-Emmons reaction of the resulting furanones 15 (Scheme 2). An enantiomeric excess (ee) of 20-95% was achieved for compounds 8, and their absolute configurations were determined by the Mosher ester method. Cytotoxic evaluation against L-1210 and HL-60 leukemia cell lines revealed that the target compounds 8 are active in the micromolar concentration range (Table 2). Thereby, significant differences in activity between the corresponding enantiomers were observed for the HL-60 cell line.

A macromolecular prodrug of doxorubicin conjugated to a biodegradable cyclotriphosphazene bearing a tetrapeptide

A new biodegradable water-soluble phosphazene trimer–doxorubicin conjugate was synthesized, in which equimolar hydrophilic methoxy-poly(ethylene glycol) with a molecular weight of 350 (MPEG350) and a tumor-specific tetrapeptide (Gly-Phe-Leu-Gly) were grafted to cyclotriphosphazene. The present conjugate exhibited cytotoxicity lower than that of free doxorubicin (IC 50 = 0,10 μM) but a reasonably higher in vitro cytotoxicity (IC 50 = 1.1 μM) against the leukemia L1210 cell line probably due to its enzymatically controlled release.

Preparation of antitumor oxaliplatin/cisplatin docking dinuclear platinum complex

A new dinuclear docking Pt(II) complex, ( cis-diammine) ( l-1,2-cyclohexanediamine)(μ-dichloro)-diplatinum(II) oxalate was synthesized by reacting oxaliplatin( l-OHP, [Pt(oxalato)( l-dach)]), l-dach = 1R, 2R-cyclohexanediamine), with cisplatin (CDDP). Elemental analysis of the compound indicated that it was 1:1 molar ratio complex of oxaliplatin and cisplatin. A plausible chemical structure has been proposed as Cl – bridged dinuclear complex, judged from its yellow coloration and NMR spectral analysis. This complex can be denoted as, i.e. [Pt 2Cl 2(NH 3) 2 ( l-dach)](COO) 2 ( l-OHP/CDDP). The complex showed higher cytotoxicity against L1210 than the parent complexes and low cross-resistance against L1210/CDDP and L1210/DACH. Its antitumor activity was also tested in vivo against murine leukemia L1210 cell lines. The complex showed much higher activity than the mixture(1:1 molar ratio) of oxaliplatin and cisplatin. The antitumor effect against L1210/CDDP was very high, showing collateral sensitivity, being similar to that of oxaliplatin, and against L1210/DACH it showed no cross-resistance.

Phaseococcin, an antifungal protein with antiproliferative and anti-HIV-1 reverse transcriptase activities from small scarlet runner beans

From the seeds of small scarlet runner beans (Phaseolus coccineus 'Minor'), an antifungal protein with an N-terminal sequence homologous to those of defensins was isolated. The antifungal protein bound to Affi-gel blue gel and Mono S but it did not bind to DEAE-cellulose. It was further purified by gel filtration on a Superdex peptide column. It exhibited a molecular mass of 5422 Da as determined by mass spectrometry. The protein, designated as phaseococcin, suppressed mycelial growth in a number of fungi including Botrytis cinerea, Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, Physalospora piricola, and Rhizoctonia solani. It also inhibited proliferation in several Bacillus species and the leukemia cell lines HL60 and L1210 and curtailed the activity of HIV-1 reverse transcriptase. It did not affect proliferation of mouse splenocytes and neither did it inhibit protein synthesis in a cell-free rabbit reticulocyte lysate system.

Vulgarinin, a broad-spectrum antifungal peptide from haricot beans ( Phaseolus vulgaris)

From the seeds of haricot beans ( Phaseolus vulgaris), an antifungal peptide with a molecular mass around 7 kDa was purified by using a simple protocol consisting of affinity chromatography on Affi-gel blue gel and gel filtration on Superdex 75. This peptide named vulgarinin manifested an antifungal activity toward fungal species such as Fusarium oxysporum, Mycosphaerella arachidicola, Physalospora piricola and Botrytis cinerea, and an antibacterial action on Mycobacterium phlei, Bacillus megaterium, Bacillus subtilis and Proteus vulgaris. It also inhibited proliferation in leukemia cell lines L1210 and M1 and breast cancer cell line MCF-7. This peptide could reduce the activity of HIV-1 reverse transcriptase and inhibited translation in a cell-free rabbit reticulocyte lysate system. Its antifungal activity was retained after incubation with trypsin.

Coccinin, an antifungal peptide with antiproliferative and HIV-1 reverse transcriptase inhibitory activities from large scarlet runner beans

An antifungal peptide, designated coccinin, with a molecular mass of 7 kDa and an N-terminal sequence resembling those of defensins, was purified from the seeds of large scarlet runner beans ( Phaseolus coccineus cv. ‘Major’). The peptide isolated was unadsorbed on DEAE-cellulose, and adsorbed on Affi-gel blue gel and Mono S. The peptide excerted antifungal activity on a number of fungal species including Botrytis cinerea, Coprinus comatus, Fusarium oxysporum, Mycosphaerella arachidicola, Physalospora piricola, and Rhizoctonia solani. It also inhibited proliferation in the leukemia cell lines HL60 and L1210, and reduced the activity of HIV-1 reverse transcriptase. However, it did not affect proliferation of mouse splenocytes.

Synthesis, Cytotoxicity, and Inhibitory Effects on Tubulin Polymerization of a New 3‐Heterocyclo Substituted 2‐Styrylquinazolinones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Transcriptional and Post-transcriptional Regulation of the PKCδ Gene by Etoposide in L1210 Murine Leukemia Cells: Implication of PKCδ Autoregulation

Protein kinase C δ (PKCδ) plays an important role in the regulation of apoptosis in response to diverse anticancer agents. PKCδ is cleaved irreversibly to a catalytically active fragment in response to apoptotic stimuli; however, little information is available about the regulation of PKCδ gene expression. In this study, we found that the amount of steady-state PKCδ mRNA and protein was increased by etoposide in mouse L1210 leukemia cells. The transcriptional rate of the PKCδ gene and the stability of PKCδ mRNA were increased by treatment with etoposide, resulting in the accumulation of PKCδ protein. Rottlerin inhibited etoposide-induced PKCδ gene expression significantly, while Go6976, LY294002 and PD98059 had no effect. Further, both stable and adenovirus-mediated expression of a dominant negative PKCδ(KR) abrogated etoposide-induced PKCδ expression. Etoposide-stimulated PKCδ transcription but not PKCδ mRNA stability was blocked completely by pretreatment with rottlerin. Our data reveal a novel mechanism whereby PKCδ gene is regulated at the transcriptional and post-transcriptional level in the L1210 leukemia cell line.

Synthesis and biological activity of novel platinum(II) complexes of glutamate tethered to hydrophilic hematoporphyrin derivatives

A new series of hematoporphyrin–platinum(II) conjugates was prepared by platination of the glutamate ligand tethered to hydrophilic hematoporphyrin derivatives, in which different numbers of ethylene oxide unit were introduced to modulate the hydrophobic/hydrophilic balance of the conjugates. The antitumor activity of the hematoporphyrin–platinum(II) conjugates was assayed in vitro and in vivo against the leukemia L1210 cell line. Among the complexes, compound 11 exhibited not only higher in vivo activity (T/C% = 192) than cisplatin (T/C% = 184) and carboplatin (T/C% = 168), but also elevated tumor-localizing effect (tumor/muscle ratio >3).