Novel ruthenium complex K-2[Ru(dmgly)Cl-4] center dot 2H(2)O is toxic to C6 astrocytoma cell line, but not to primary rat astrocytes

A novel class of ruthenium (111) complexes of formulas K[Ru(sar)(2)Cl-2] - 1/2HO and K-2[Ru(dmgly)Cl-4] . 1/2H(2)O, containing biden2 tate chelates N-methylglycine (sarcosine, sar) or N,N-dimethylglycine (dnigly) and additional chloro ligands were synthesized. The complexes have been obtained by direct reaction of ruthenium(III) chloride with corresponding bidentate ligand followed by addition of base (KOH). These new complexes were characterized by elemental analysis, IR and electronic absorption spectroscopy. As astrocytomas, the most common of all brain tumors, are still very difficult to treat, we examined the influence of newly synthesized ruthenium-based complexes, as well as the earlier synthesized analogue platinum(IV) complexes [Pt(dmglY)(2)Cl-2], [Pt(sar)(2)Br-2] and [Pt(dmgly)(2)Br-2] on rat astrocytoma C6 cells in vitro. Among these complexes only K-2[Ru(dmglY)Cl-4].2H(2)O and [Pt(dMgIY)(2)Br-2] markedly inhibited the viability of non-confluent C6 cells. Furthermore, only complex K-2[Ru(dmgly)Cl4] .2H20 was able to reduce viability in confluent C6 cultures. Importantly, this complex was not toxic to primary rat astrocytes or macrophages. Having in mind that appropriate chemotherapy should be effective against tumor cells without harming normal tissues, complex K,[Ru(dmglY)Cl-4] - 2H(2)O could be a promising agent for developing therapeutics against astrocytomas. (C) 2004 Elsevier Inc. All rights reserved.nul

Novel octahedral Pt(IV) complex with di-n-propyl-(S,S)-ethylenediamine-N,N '-di-2-(3-cyclohexyl)propanoato ligand exerts potent immunomodulatory effects

We have recently reported that a novel octahedral Pt(IV) complex with di-n-propyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoato ligand has a potent cytotoxic effect on glioma, melanoma and fibrosarcoma cell lines. In this work, we investigated the influence of the Pt(IV) compound on immune cells. We determined its effect on the viability of spleen cells and lymph node cells and on their capability to produce interferon (IFN)-gamma and interleukin (IL)-17. Also, we researched the compound's impact on peritoneal macrophages and generation of NO in these cells. Our results show that the complex has limited influence on cell viability of immune cells, but profound inhibitory effect on the production of examined immune mediators. These results are valuable as they show that the novel Pt(IV) complex applied in concentrations which are effective against tumor cells do not affect immune cell viability. Moreover, they also imply that the complex has immunomodulatory properties. (C) 2011 Elsevier Masson SAS. All rights reserved.Ministry of Education and Science Republic of Serbia [172035, 173013

Novel octahedral Pt(IV) complex with di-n-propyl-(S,S)-ethylenediamine-N,N '-di-2-(3-cyclohexyl)propanoato ligand exerts potent immunomodulatory effects

We have recently reported that a novel octahedral Pt(IV) complex with di-n-propyl-(S,S)-ethylenediamine-N,N'-di-2-(3-cyclohexyl)propanoato ligand has a potent cytotoxic effect on glioma, melanoma and fibrosarcoma cell lines. In this work, we investigated the influence of the Pt(IV) compound on immune cells. We determined its effect on the viability of spleen cells and lymph node cells and on their capability to produce interferon (IFN)-gamma and interleukin (IL)-17. Also, we researched the compound's impact on peritoneal macrophages and generation of NO in these cells. Our results show that the complex has limited influence on cell viability of immune cells, but profound inhibitory effect on the production of examined immune mediators. These results are valuable as they show that the novel Pt(IV) complex applied in concentrations which are effective against tumor cells do not affect immune cell viability. Moreover, they also imply that the complex has immunomodulatory properties. (C) 2011 Elsevier Masson SAS. All rights reserved.Ministry of Education and Science Republic of Serbia [172035, 173013

Novel methylene modified cyclohexyl ethylenediamine-N,N '-diacetate ligands and their platinum(IV) complexes. Influence on biological activity

This paper focuses on the synthesis, characterization and biological activity of new N,N'-methylene modified cyclohexyl ethylenediamine-N,N'-diacetate (edda)-type ligands and their Pt(IV) complexes. Both the ligands and complexes were characterized by infrared, UV-vis, ESI-MS, 1D (H-1, C-13, Pt-195) and 2D (COSY, HSQC, HMBC) NMR spectroscopy and elemental analysis. The possible correlation between the reduction potentials and the cytotoxicity of the complexes was examined. The potential antitumoral activity of all compounds was tested in vitro on human melanoma A375, human glioblastoma U251, human prostate cancer PC3, human colon cancer HCT116, mouse melanoma B16 and mouse colon cancer CT26CL25 cells, as well as primary fibroblasts and keratinocytes. The results obtained revealed strong antitumor potential of the newly synthesized drugs with preserved efficacy against cisplatin resistant lines and less toxicity towards nonmalignant counterparts. The mechanism found to be responsible for the observed tumoricidal action of each synthesized compound was induction of apoptosis generally accompanied with caspase activation. Taken together, the effective response to the treatment of a wide range of different cell lines, including cisplatin resistant subclones, as well as induction of apoptosis, as the mechanism suggested to be the most desirable way of eliminating malignant cells, represents a great advantage of this novel group of drugs in comparison to other members in this metallo-drug family. (C) 2012 Elsevier Inc. All rights reserved.Ministry of Science of the Republic of Serbia [172035, 173013

[Pt(HPxSC)Cl-3], a novel platinum(IV) compound with anticancer properties

There has been a continuing effort for the discovery of novel platinum(IV)-based antitumor compounds with better therapeutic performances than cisplatin. In the present work, the anticancer action of recently synthesized Pt(IV)-based complex [Pt(HPxSC)Cl-3] was investigated using rat and human astrocytoma cell lines C6 and U251. [Pt(HPxSC)Cl-3] markedly reduced the number of cultured astrocytoma Cells (IC50, 80 mu M), as determined by crystal violet assay. The Pt(IV) complex induced apoptotic death of tumor cells, as flow cytometry analysis of the propidium iodide-stained cellular DNA revealed approx. 30% of hypodiploid cells in [Pt(HPxSC)Cl-3]-treated astrocytoma cell cultures. On the other hand, [Pt(HPxSC)Cl-3] at 200 mu M did not affect the viability of rat primary astrocytes, unlike the established anticancer drug cisplatin, which displayed high toxicity toward both astrocytoma cells (IC50, 15 mu M) and primary astrocytes (IC50, 20 mu M). Moreover, [Pt(HPxSC)Cl-3] at 100 mu M did not interfere with the ability of rat peritoneal macrophages to produce important antitumor molecules nitric oxide and tumor necrosis factor-a. Finally, we assessed the ability of [Pt(HPxSC)Cl-3] to restrain growth of some bacterial and yeast strains, but it showed rather limited antimicrobial activity. (c) 2005 Elsevier B.V. All rights reserved.nul

Cyclohexyl Analogues of Ethylenediamine Dipropanoic Acid Induce Caspase-Independent Mitochondrial Apoptosis in Human Leukemic Cells

We investigated the cytotoxicity of recently synthesized (S,S)-ethyleridiamine-N,N'-di-2-(3-cyclohexyl)propanoic acid esters toward human leukemic cell lines and healthy blood mononuclear cells. Cell viability was assessed by acid phosphatase assay, apoptosis, and differentiation were analyzed by flow cytometry and electron microscopy, while intracellular localization of apoptosis-inducing factor (AIF) was determined by immunoblotting. It was demonstrated that methyl, ethyl, and n-propyl esters were toxic to HL-60, REH, MOLT-4, KG-1, JVM-2, and K-562 leukemic cell lines, while the nonesterified parental compound and n-butyl ester were devoid of cytotoxic action. The ethyl ester exhibited the highest cytotoxic activity (IC50 10.7 mu M-45.4 mu M), which was comparable to that of the prototypical anticancer drug cisplatin. The observed cytotoxic effect in HL-60 cells was associated with an increase in superoxide production and mitochondrial membrane depolarization, leading to apoptotic cell death characterized by phosphatidylserine externalization and DNA fragmentation in the absence of autophagic response. DNA fragmentation preceded caspase activation and followed AIF translocation from mitochondria to nucleus, which was indicative of caspase-independent apoptotic cell death. HL-60 cells treated with subtoxic concentration of the compound displayed morphological signs of granulocytic differentiation (nuclear indentations and presence of cytoplasmic primary granules), as well as an increased expression of differentiation markers CD11b and CD15. The cyclohexyl analogues of ethylenediamine dipropanoic acid were also toxic to peripheral blood mononuclear cells of both healthy controls and leukemic patients, the latter being more sensitive. Our data demonstrate that the toxicity of the investigated cyclohexyl compounds against leukemic cell lines is mediated by caspase-independent apoptosis associated with oxidative stress, mitochondrial dysfunction, and AIF translocation.Ministry of Science of the Republic of Serbia [41025, 172035

Cyclohexyl Analogues of Ethylenediamine Dipropanoic Acid Induce Caspase-Independent Mitochondrial Apoptosis in Human Leukemic Cells

We investigated the cytotoxicity of recently synthesized (S,S)-ethyleridiamine-N,N'-di-2-(3-cyclohexyl)propanoic acid esters toward human leukemic cell lines and healthy blood mononuclear cells. Cell viability was assessed by acid phosphatase assay, apoptosis, and differentiation were analyzed by flow cytometry and electron microscopy, while intracellular localization of apoptosis-inducing factor (AIF) was determined by immunoblotting. It was demonstrated that methyl, ethyl, and n-propyl esters were toxic to HL-60, REH, MOLT-4, KG-1, JVM-2, and K-562 leukemic cell lines, while the nonesterified parental compound and n-butyl ester were devoid of cytotoxic action. The ethyl ester exhibited the highest cytotoxic activity (IC50 10.7 mu M-45.4 mu M), which was comparable to that of the prototypical anticancer drug cisplatin. The observed cytotoxic effect in HL-60 cells was associated with an increase in superoxide production and mitochondrial membrane depolarization, leading to apoptotic cell death characterized by phosphatidylserine externalization and DNA fragmentation in the absence of autophagic response. DNA fragmentation preceded caspase activation and followed AIF translocation from mitochondria to nucleus, which was indicative of caspase-independent apoptotic cell death. HL-60 cells treated with subtoxic concentration of the compound displayed morphological signs of granulocytic differentiation (nuclear indentations and presence of cytoplasmic primary granules), as well as an increased expression of differentiation markers CD11b and CD15. The cyclohexyl analogues of ethylenediamine dipropanoic acid were also toxic to peripheral blood mononuclear cells of both healthy controls and leukemic patients, the latter being more sensitive. Our data demonstrate that the toxicity of the investigated cyclohexyl compounds against leukemic cell lines is mediated by caspase-independent apoptosis associated with oxidative stress, mitochondrial dysfunction, and AIF translocation.Ministry of Science of the Republic of Serbia [41025, 172035