L1210 Lymphoid Leukemia Cells Research Articles

Design, synthesis and antiproliferative activity of some 3-benzylidene-2,3-dihydro-1-benzopyran-4-ones which display selective toxicity for malignant cells

A series of 3-benzylidene-4-chromanones 1a– l were prepared and their cytotoxicity towards human Molt 4/C8 and CEM T-lymphocytes as well as murine L1210 lymphoid leukemia cells were compared to the previously generated biodata in these three assays for the isosteric 2-benzylidene-1-tetralones 2a– l. Over 40% of the compounds in series 1 were more potent than their counterparts in series 2, while equipotency was noted in one-third of the comparisons made. In general the IC 50 values of 1a– l towards the human T-lymphocytes were in the low micromolar range. Molecular modelling revealed differences in shapes of representative molecules in series 1 and 2 which may contribute to the variation in cytotoxic potencies. Most of the compounds in series 1 displayed greater potencies towards HSC-2, HSC-3, HSC-4 and HL-60 neoplasms than HGF, HPC, and HPLF normal cells and were well tolerated in mice.

Synthesis and cytotoxic action of 1-oxoalkyl and 1,2-dioxoalkyl-1,2,4-triazolidine-3,5-diones in murine and human tissue cultured cells.

1-Oxoalkyl and 1,2-dioxoalkyl-1,2,4-triazolidine-3,5-diones proved to be potent antineoplastic agents in mouse tumors and potent cytotoxic agents particularly against the growth of suspended tumor cells. The compounds with shorter substituents in position 1 or positions 1 and 2 afforded the better activity. In L1210 lymphoid leukemia cells DNA, RNA, and protein syntheses were inhibited at 100 microM after 60 min. Multiple enzyme sites in nucleic acid metabolism were affected by the compounds, i.e. DNA polymerase alpha, PRPP-amido transferase, dihydrofolate reductase, thymidylate synthetase, and nucleoside kinases. These effects of the agents are probably additive in bringing about inhibition of DNA synthesis and cell death.

Investigations on the mechanism of action of the novel antitumor agents 2-benzothiazolyl, 2-benzoxazolyl, and 2-benzimidazolyl hydrazones derived from 2-acetylpyridine.

2-Acetylpyridine hydrazone derivatives of benzothiazole, benzoxazole, and benzimidazole were found to exhibit potent cytotoxic activity against the growth of suspended leukemia and lymphomas. They were also active in a number of solid tumor screens, e.g. HeLa uterine carcinoma, SOS bone osteosarcoma, lung MB9812, lung A549, Mcf-7 breast growth. In L1210 lymphoid leukemia cells the compounds preferentially inhibited RNA synthesis followed by DNA synthesis at 100 microM after 60 min. The reduction of de novo purine synthesis by the compounds at the regulatory sites PRPP-amido transferase, IMP dehydrogenase and dihydrofolate reductase was responsible for the suppression of nucleic synthesis. Other minor sites where the agents have metabolic effects were thymidylate synthetase and thymidine kinase which would be additive with the overall inhibition of cell growth. The ct-DNA studies suggest that the compounds also interacted with the DNA molecule itself, probably affecting template activity.

Investigations on the Mechanism of Action of the Novel Antitumor Agents 2-Benzothiazolyl, 2-Benzoxazolyl, and 2-Benzimidazolyl Hydrazones Derived from 2-Acetylpyridine

2-Acetylpyridine hydrazone derivatives of benzothiazole, benzoxazole, and benzimidazole were found to exhibit potent cytotoxic activity against the growth of suspended leukemia and lymphomas. They were also active in a number of solid tumor screens, e.g. HeLa uterine carcinoma, SOS bone osteosarcoma, lung MB9812, lung A549, Mcf-7 breast growth. In L1210 lymphoid leukemia cells the compounds preferentially inhibited RNA synthesis followed by DNA synthesis at 100 μM after 60 min. The reduction of de novo purine synthesis by the compounds at the regulatory sites PRPP-amido transferase, IMP dehydrogenase and dihydrofolate reductase was responsible for the suppression of nucleic synthesis. Other minor sites where the agents have metabolic effects were thymidylate synthetase and thymidine kinase which would be additive with the overall inhibition of cell growth. The ct-DNA studies suggest that the compounds also interacted with the DNA molecule itself, probably affecting template activity.

Cytotoxicity of Poly(Phenolic)Sulfonates and Their Sodium Salts in L1210 Lymphoid Leukemia Cells

Poly(phenolic)-sulfonates demonstrated very good cytotoxicity against the growth of tumor cell lines (L1210, Tmolt-3, HeLa-S3) and are comparable in potency with typical clinically used anticancer drugs. Four of the most active compounds, i.e. GL-2021, GL-2029, GL-2041 and GL-2063, were selected for a mode of action study in L1210 lymphoid leukemia cells at concentration of 25μM to 100μM for 60 min. The agents did not alkylate bases of ct-DNA, cause intercalation between base pairs, produce cross linking of ct-DNA strands or generate free radicals although L1210 DNA fragmentation was observed after 24 hr incubation. L1210 DNA synthesis was preferentially inhibited which was achieved by (1) suppressing DNA polymerase α activity which reduced the synthesis of new strands of DNA, (2) reducing of de novo purine synthesis at the regulatory enzyme PRPP amido transferase which reduced d(GMP) levels, and (3) inhibiting of nucleoside kinase activities which further reduced DNA synthesis. DNA template activity was altered by the poly(phenolic)sulfonates since they reduced DNA polymerase α and m-RNA and t-RNA polymerase activities. The kinetic studies at 50 μM over 2 hr demonstrated that the agents’ effect on PRPP-amido transferase activity is probably a major target of the compounds.

Cytotoxicity of Metallic Complexes of Furan Oximes in Murine and Human Tissue Cultured Cell Lines

The copper complexes of furan oxime derivatives were found to be potent cytotoxic agents in both murine and human tissue cultured cell lines which were suspended as well as solid tumors. Mode of action studies in murine L1210 lymphoid leukemia cells showed that the compounds suppressed DNA, RNA and protein synthesis after 60 min at 100 μM. Inhibition of purine and pyrimidine de novo syntheses, as well as inhibition of ribonucleoside reductase and nucleoside kinase activities with DNA strand scission occurred. All of these effects of the drug probably added to its ability to cause cell death but most important was the inhibition of DNA topoisomerase II activity with IC50 values lower than those afforded by VP-16, the standard, which should cause apoptosis. © 1997 John Wiley & Sons, Ltd.

Hypolipidemic, anti-obesity, anti-inflammatory, anti-osteoporotic, and anti-neoplastic properties of amine carboxyboranes.

The amine-carboxyborane derivatives were shown to be effective antineoplastic/cytotoxic agents with selective activity against single-cell and solid tumors derived from murine and human leukemias, lymphomas, sarcomas, and carcinomas. The agents inhibited DNA and RNA synthesis in preference to protein synthesis in L1210 lymphoid leukemia cells. Inosine-monophosphate dehydrogenase apparently is a target site of the compounds; similar effects on phosphoribosyl-pyrophosphate amido transferase, orotidine-monophosphate decarboxylase, and both nucleoside and nucleotide kinases were observed. Deoxyribonucleotide pool levels were reduced in the cells; DNA strand scission was observed with the agents. In rodents, the amine carboxyboranes were potent hypolipidemic agents, lowering both serum cholesterol and triglyceride concentrations, in addition to lowering cholesterol content of very low-density lipoprotein and low-density lipoprotein (LDL) and elevating high-density lipoprotein (HDL) cholesterol concentrations. De novo regulatory enzymes involved in lipid synthesis were also inhibited (e.g., hypocholesterolemic 3-hydroxy-3-methyl-Coenzyme A reductase, acyl-Coenzyme A cholesterol acyltransferase, and sn-glycerol-3-phosphate acyltransferase). Concurrently, the agents modulated LDL and HDL receptor binding, internalization, and degradation, so that less cholesterol was delivered to the plaques and more broken down from esters and conducted to the liver for biliary excretion. Tissue lipids in the aorta wall of the rat were reduced and fewer atherosclerotic morphologic lesions were present in quail aortas after treatment with the agents. Cholesterol resorption from the rat intestine was reduced in the presence of drug. Genetic hyperlipidemic mice demonstrated the same types of reduction after treatment with the agents. The agents would effectively lower lipids in tissue based on the inhibition of regulatory enzymes in pigs. These findings should help improve domestic meat supplies from fowl and pigs. The amine-carboxyboranes were effective anti-inflammatory agents against septic shock, induced edema, pleurisy, and chronic arthritis at 2.5 to 8 mg/kg. Lysosomal and proteolytic enzyme activities were also inhibited. More significantly, the agents were dual inhibitors of prostaglandin cyclooxygenase and 5'-lipoxygenase activities. These compounds also affected cytokine release and white cell migration. Subsequent studies showed that the amine-carboxyboranes were potent anti-osteoporotic agents reducing calcium resorption as well as increasing calcium and proline incorporation into mouse pup calvaria and rat UMR-106 collagen.

Synthesis and Cytotoxic Evaluation of Some Cyclic Arylidene Ketones and Related Oximes, Oxime Esters, and Analogs

A number of arylidene derivatives of alicyclic ketones and some corresponding oximes, oxime esters, and related compounds were prepared as candidate cytotoxic agents. All of the compounds were evaluated against murine L1210 lymphoid leukemia cells. In general, cytotoxicity was greatest with the α,β‐unsaturated ketones and diminished with the oximes, and the oxime esters had little or no activity in this screen. When the same compounds were examined in both thein vitroL1210 and P388 leukemia screens, in the majority of cases the L1210 cells were more sensitive to these derivatives. Over half of the compounds prepared were evaluated against approximately 55 human tumorsin vitroand showed selective toxicity toward one or more groups of neoplastic diseases, particularly leukemia. Some correlations between structure and bioactivity were discerned. The cytotoxicity screening and stability studies of representative compounds suggested that the ketones, oximes, and oxime esters were stable under the conditions of bioevaluation. X‐ray crystallography of four representative compounds revealed structural features associated with cytotoxicity which may be considered in the design of future candidate cytotoxins.

The effects of boron containing peptides on L1210 lymphoid leukemia metabolism

The purpose of this study was to establish the efficacy and mode of action of peptide boron derivatives as antineoplastic agents and to evaluate their safety in vivo. Boron-containing phenylalanine and tyrosine methyl esters were found to be potent cytotoxic agents in a number of murine and human cancer cell lines. DNA, RNA and protein syntheses were inhibited by selected agents, e.g. [(trimethylamine boryl)carbonyl]-phenylalanine-acetyl ester (9) andN-acetyl-p-boron-phenyl-alanyl-phenlalanine-methyl ester (10), in L1210 lymphoid leukemia cells. IMP dehydrogenase, OMP decarboxylase, m-RNA, t-RNA, r-RNA polymerase and ribonucleoside reductase activities were inhibited. d(CTP) levels were reduced. DNA strand scission occurred after 24 hr incubation. Acute toxicity studies in mice demonstrated that the key derivative was safe at therapeutic levels with no effects on histology of major organs, hematopoietic parameters and clinical values.

The cytotoxicity of copper(II) complexes of heterocyclic thiosemicarbazones and 2-substituted pyridine N-oxides

Thiosemicarbazone complexes of copper(II) were shown to be potent cytotoxic/antineoplastic agents against the growth of murine and human tumor cells. Selectivity of some agents was demonstrated against specific solid tumor growth. In L1210 lymphoid leukemia cells the copper complexes preferentially inhibited DNA synthesis with their major effects on the purine de novo pathway at PRPP amido transferase, IMP dehydrogenase and dihydrofolate reductase. The reductions of purines correlated positively with inhibition of DNA synthesis and cytotoxicity of the agents tested. DNA itself was fragmented after incubation with the drug; however, no binding of the agent to nucleotide bases or intercalation between base pairs was evident.

The anti-neoplastic activity of 2,3-dihydrophthalazine-1,4-dione and N-butyl-2,3-dihydrophthalazine-1,4-dione in human and murine tumor cells.

2,3-Dihydrophthalazine-1,4-dione derivatives demonstrated potent cytotoxicity against the growth of murine leukemia cells and human single cell suspension, i.e. Tmolt3 leukemia and HeLa-S3, as well as colon adenocarcinoma and KB nasopharynx. However, only select compounds demonstrated activity against bronchogenic lung, osteosarcoma and glioma growth. 2,3-Dihydrophthalazine-1,4-dione was active in vivo against L1210 leukemia, Lewis lung and Ehrlich ascites carcinoma growth. In L1210 cells the agents inhibited both DNA and RNA synthesis, and a few of the compounds were capable of inhibiting protein synthesis at 3 times their ED50 values. When 2,3-dihydrophthalazine-1,4-dione and N-butyl-2,3-dihydrophthalazine-1,4-dione were examined for their mode of action in the L1210 lymphoid leukemia cells, the sites of inhibition by the agents appear to be the de novo purine pathway at the enzymes IMP dehydrogenase and PRPP amido transferase. IMP dehydrogenase activity was inhibited at least 45% by 45 min at 100 microM concentration of drugs whereas the remaining enzymes that were affected by the drugs were not inhibited as early. Secondary sites were dihydrofolate reductase and thymidylate synthetase. The d(NTP) levels were also reduced specifically dATP and dCTP levels.

The antineoplastic activity of trimethylamine carboxyboranes and related esters and amides in murine and human tumor cell lines

Trimethylamine carboxyboranes including their esters and amides were shown to have antineoplastic activity in vivo against Ehrlich ascites carcinoma growth. The derivatization to the ester or amide did not necessarily improve activity. Cytotoxicity of the derivatives was observed against the growth of murine and human tumor cells. Selectivity was demonstrated by the boron derivatives in the human solid tumor screens. Almost all the compounds demonstrated cytotoxicity against single-cell suspension growths, eg Tmolt3, L1210, HeLa-S3. Selection of two compounds to examine their mode of action in L1210 lymphoid leukemia cells showed that the agents perferentially inhibited DNA synthesis followed by protein and RNA synthesis. The d(TTP) pools were markedly reduced because of inhibition of nucleotide kinase activity. The agents also inhibited regulatory enzymes in the de novo purine pathway and afforded DNA strand scission. These effects by the agents were probably additive to bring about tumor cell death.

ChemInform Abstract: NUCLEOSIDE CONJUGATES. V: SYNTHESIS AND BIOLOGICAL ACTIVITY OF 9‐(β‐D‐ARABINOFURANOSYL)ADENINE CONJUGATES OF CORTICOSTEROIDS

Eight 5′-(steroid-21-phosphoryl)-9-(β-D-arabinofuranosyl)-adenines (IV-XI) have been prepared and evaluated against L1210 lymphoid leukemia in culture. These include the 9-(β-D-arabinofuranosyl)adenine conjugates of hydrocortisone (IV), cortisone (V), corticosterone (VI), cortexolone (VII), 11-deoxycorticosterone (VIII), prednisolone (IX), prednisone (X), and dexamethasone (XI). Conjugates IV, IX, X, and XI inhibited the in vitro growth of L1210 lymphoid leukemia cells by 50% (ED50) at a concentration of 2.3-7.8 μM, while 9-(β-D-arabinofuranosyl)adenine (vidarabine, I) and its 5′-monophosphate (II) each showed ED50 value of 30 μM. All of the conjugates were enzymatically hydrolyzed to the corresponding steroid and II, the latter undergoing further hydrolysis to I, by phosphodiesterase I, 5′-nucleotidase, and acid phosphatase. However, these congugates were resistant to hydrolysis by alkaline phosphatase and adenosine deaminase.

Nucleoside Conjugates V: Synthesis and Biological Activity of 9-(β-D-Arabinofuranosyl)adenine Conjugates of Corticosteroids

Eight 5′-(steroid-21-phosphoryl)-9-(β-D-arabinofuranosyl)-adenines (IV-XI) have been prepared and evaluated against L1210 lymphoid leukemia in culture. These include the 9-(β-D-arabinofuranosyl)adenine conjugates of hydrocortisone (IV), cortisone (V), corticosterone (VI), cortexolone (VII), 11-deoxycorticosterone (VIII), prednisolone (IX), prednisone (X), and dexamethasone (XI). Conjugates IV, IX, X, and XI inhibited the in vitro growth of L1210 lymphoid leukemia cells by 50% (ED50) at a concentration of 2.3-7.8 μM, while 9-(β-D-arabinofuranosyl)adenine (vidarabine, I) and its 5′-monophosphate (II) each showed ED50 value of 30 μM. All of the conjugates were enzymatically hydrolyzed to the corresponding steroid and II, the latter undergoing further hydrolysis to I, by phosphodiesterase I, 5′-nucleotidase, and acid phosphatase. However, these congugates were resistant to hydrolysis by alkaline phosphatase and adenosine deaminase.

1-β- d-Arabinofuranosylcytosine conjugates of corticosteroids as potential antitumor agents

The antitumor activity and toxicity of two new 1-β- d-arabinofuranosylcytosine (ara-C) conjugates of cortisol and corticosterone linked through a phosphodiester bond between the 5′ and 21 positions of the respective moieties (cortisol- and corticosterone- p-ara-C) were investigated in L1210 lymphoid leukemia cells in mice. They are highly active against both i.p.- and i.c.-implanted ara-C-sensitive lymphoid leukemia in mice, exceeding the activity produced by the parent drug, ara-C. For example, corticosterone- p-ara-C exhibited the respective ILS values of 306% at 50 mg/kg/day × 9 and 294% at 75 mg/kg/day × 9 on survivals of i.p.- and i.c.-inoculated L1210 leukemic mice. The effectiveness of the conjugates seems to depend on schedules of the treatments. The 9-day continuous treatments showed a better therapeutic effectiveness than those with either a 5-day, a single or a widely spaced (q 4 d., 1, 5, 9) treatment. However, they were found to be marginally effective against i.p.-implanted ara-C-resistant L1210 leukemia in mice. They were also inhibitory against proliferation of human leukemia-lymphoid cells in culture. Their superior antitumor activity and resistance to cytidine deaminase suggests that they serve as a prodrug form of ara-C or ara-CMP.