A series of four 2‑amino‑3‑cyano‑4‑(3/4‑pyridyl)‑4H‑benzo[h]chromenes 2a-d and their dichlorido(p‑cymene)ruthenium(II) complexes 3a-d were tested for antiproliferative, vascular-disruptive, anti-angiogenic and DNA-binding activity. The coordination of the 4‑pyridyl‑4H‑naphthopyrans 2 to ruthenium led to complexes with pleiotropic effects. Unlike the free ligands 2a-d, their ruthenium complexes 3a-d showed a significant affinity for DNA as demonstrated by electrophoretic mobility shift assays (EMSA) and ethidium bromide assays. Binding of 3a-d to calf thymus DNA proceeded about 10-times faster compared with cisplatin. Treatment of HT-29 colon carcinoma, 518A2 melanoma and MCF-7Topo breast cancer cells with 3a and 3b caused an accumulation of cells in the G2/M phase and an increase of the fraction of mitotic cells in the case of HT-29, due to alterations of the microtubule cytoskeleton as shown by immunofluorescence staining. Complexes 3b-c showed a dual effect on the vascular system. They suppressed angiogenesis in zebrafish embryos and they destroyed the vasculature of the chorioallantoic membrane (CAM) in fertilized chicken eggs. They also inhibited the vasculogenic mimicry, typical of U-87 glioblastoma cells in tube formation assays.
- MeSH
- HT29 Cells MeSH
- Chorioallantoic Membrane drug effects MeSH
- Cisplatin pharmacology MeSH
- Zebrafish MeSH
- DNA chemistry MeSH
- Coordination Complexes chemistry MeSH
- Humans MeSH
- MCF-7 Cells MeSH
- Cell Line, Tumor MeSH
- Antineoplastic Agents chemistry pharmacology MeSH
- Electrophoretic Mobility Shift Assay MeSH
- Ruthenium chemistry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Metastatic cancer remains a formidable challenge in anticancer therapy. Despite efforts to develop effective antimetastasis drugs over the past half-century, currently approved treatments fall short of expectations. This report highlights the promising antiproliferative activity of a ruthenium-based therapeutic agent, namely dichlorido(p-cymene)[2-amino-4-(pyridin-3-yl)-4H-benzo[h]-chromene-3-carbonitrile]ruthenium(II) (complex 1) against metastatic cell lines. Complex 1 shows significant efficacy in metastatic LoVo and Du-145 cell lines at nanomolar concentrations, being markedly more active than clinically used anticancer cisplatin. Studies on the MDA-MB-231 cell line, which displays invasive characteristics, demonstrated that 1 significantly reduces cell invasion. This efficacy was confirmed by its impact on matrix metalloproteinase production in MDA-MB-231 cells. Given that cell migration drives cancer invasion and metastasis, complex 1's effect on MDA-MB-231 cell migration was evaluated via wound healing assay and vimentin network analysis. Results indicated a strong reduction in migration. A re-adhesion assay further demonstrated that 1 significantly lowers the re-adhesion ability of MDA-MB-231 cells compared to cisplatin. To better simulate the human body environment, a 3D spheroid invasion assay was used. This method showed that 1 effectively inhibits tumor spheroids from infiltrating the surrounding extracellular matrix. This study underscores the potential of (arene)ruthenium(II) complexes with naphthopyran ligands as potent antimetastatic agents for chemotherapy.
- MeSH
- Cell Adhesion drug effects MeSH
- Coordination Complexes * pharmacology chemistry therapeutic use MeSH
- Humans MeSH
- Neoplasm Metastasis prevention & control drug therapy MeSH
- Cell Line, Tumor MeSH
- Cell Movement * drug effects MeSH
- Cell Proliferation drug effects MeSH
- Antineoplastic Agents * pharmacology chemistry therapeutic use MeSH
- Ruthenium * chemistry pharmacology therapeutic use MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The present study was performed to examine the affinity of Escherichia coli mismatch repair (MMR) protein MutS for DNA damaged by an intercalating compound. We examined the binding properties of this protein with various DNA substrates containing a single centrally located adduct of ruthenium(II) arene complexes [(eta(6)-arene)Ru(II)(en)Cl][PF(6)] [arene is tetrahydroanthracene (THA) or p-cymene (CYM); en is ethylenediamine]. These two complexes were chosen as representatives of two different classes of monofunctional ruthenium(II) arene compounds which differ in DNA-binding modes: one that involves combined coordination to G N7 along with noncovalent, hydrophobic interactions, such as partial arene intercalation (tricyclic-ring Ru-THA), and the other that binds to DNA only via coordination to G N7 and does not interact with double-helical DNA by intercalation (monoring Ru-CYM). Using electrophoretic mobility shift assays, we examined the binding properties of MutS protein with various DNA duplexes (homoduplexes or mismatched duplexes) containing a single centrally located adduct of ruthenium(II) arene compounds. We have shown that presence of the ruthenium(II) arene adducts decreases the affinity of MutS for ruthenated DNA duplexes that either have a regular sequence or contain a mismatch and that intercalation of the arene contributes considerably to this inhibitory effect. Since MutS initiates MMR by recognizing DNA lesions, the results of the present work support the view that DNA damage due to intercalation is removed from DNA by a mechanism(s) other than MMR.
- MeSH
- DNA Adducts chemistry drug effects MeSH
- Anthracenes chemistry MeSH
- Base Pair Mismatch drug effects MeSH
- DNA chemistry drug effects MeSH
- Escherichia coli chemistry MeSH
- Ethylenediamines chemistry MeSH
- Financing, Organized MeSH
- Intercalating Agents pharmacology chemistry MeSH
- Molecular Structure MeSH
- Monoterpenes chemistry MeSH
- Organometallic Compounds pharmacology chemistry MeSH
- DNA Damage MeSH
- Ruthenium chemistry MeSH
- Base Sequence MeSH
- Protein Binding MeSH
- Binding Sites MeSH
- MutS DNA Mismatch-Binding Protein chemistry drug effects MeSH
- Structure-Activity Relationship MeSH
The synthesis and characterization of ruthenium(II) arene complexes [(eta(6)-arene)Ru(N,N)Cl](0/+), where N,N = 2,2'-bipyridine (bipy), 2,2'-bipyridine-3,3'-diol (bipy(OH)(2)) or deprotonated 2,2'-bipyridine-3,3'-diol (bipy(OH)O) as N,N-chelating ligand, arene = benzene (bz), indan (ind), biphenyl (bip), p-terphenyl (p-terp), tetrahydronaphthalene (thn), tetrahydroanthracene (tha) or dihydroanthracene (dha), are reported, including the X-ray crystal structures of [(eta(6)-tha)Ru(bipy)Cl][PF(6)] (1), [(eta(6)-tha)Ru(bipy(OH)O)Cl] (2) and [(eta(6)-ind)Ru(bipy(OH)(2))Cl][PF(6)] (8). Complexes 1 and 2 exibit CH (arene)/pi (bipy or bipy(OH)O) interactions. In the X-ray structure of protonated complex 8, the pyridine rings are twisted (by 17.31 degrees). In aqueous solution (pH = 2-10), only deprotonated (bipy(OH)O) forms are present. Hydrolysis of the complexes was relatively fast in aqueous solution (t(1/2) = 4-15 min, 310 K). When the arene is biphenyl, initial aquation of the complexes is followed by partial arene loss. Complexes with arene = tha, thn, dha, ind and p-terp, and deprotonated bipyridinediol (bipy(OH)O) as chelating ligands, exhibited significant cytotoxicity toward A2780 human ovarian and A549 human lung cancer cells. Complexes [(eta(6)-bip)Ru(bipy(OH)O)Cl] (7) and [(eta(6)-bz)Ru(bipy(OH)O)Cl] (5) exhibited moderate cytotoxicity toward A2780 cells, but were inactive toward A549 cells. These activity data can be contrasted with those of the parent bipyridine complex [(eta(6)-tha)Ru(bipy)Cl][PF(6)] (1) which is inactive toward both A2780 ovarian and A549 lung cell lines. DFT calculations suggested that hydroxylation and methylation of the bipy ligand have little effect on the charge on Ru. The active complex [(eta(6)-tha)Ru(bipy(OH)O)Cl] (2) binds strongly to 9-ethyl-guanine (9-EtG). The X-ray crystal structure of the adduct [(eta(6)-tha)Ru(bipy(OH)O)(9-EtG-N7)][PF(6)] shows intramolecular CH (arene)/pi (bipy(OH)O) interactions and DFT calculations suggested that these are more stable than arene/9-EtG pi-pi interactions. However [(eta(6)-ind)Ru(bipy(OH)(2))Cl][PF(6)] (8) and [(eta(6)-ind)Ru(bipy)Cl][PF(6)] (16) bind only weakly to DNA. DNA may therefore not be the major target for complexes studied here.
- MeSH
- 2,2'-Dipyridyl toxicity MeSH
- Spectrometry, Mass, Electrospray Ionization methods MeSH
- Hydrolysis MeSH
- Cations chemistry MeSH
- Crystallography, X-Ray methods MeSH
- Humans MeSH
- Magnetic Resonance Spectroscopy methods MeSH
- Models, Molecular MeSH
- Cell Line, Tumor drug effects MeSH
- Tumor Cells, Cultured pathology drug effects MeSH
- Lung Neoplasms pathology MeSH
- Ovarian Neoplasms pathology MeSH
- Ruthenium * toxicity MeSH
- Cell Survival * drug effects MeSH
- Hydrogen Bonding MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
We report DNA cleavage by ruthenium(II) arene anticancer complex [(η(6)-p-terp)Ru(II)(en)Cl](+) (p-terp=para-terphenyl, en=1,2-diaminoethane, complex 1) after its photoactivation by UVA and visible light, and the toxic effects of photoactivated 1 in cancer cells. It was shown in our previous work (T. Bugarcic et al., J. Med. Chem. 51 (2008) 5310-5319) that this complex exhibits promising toxic effects in several human tumor cell lines and concomitantly its DNA binding mode involves combined intercalative and monofunctional (coordination) binding modes. We demonstrate in the present work that when photoactivated by UVA or visible light, 1 efficiently photocleaves DNA, also in hypoxic media. Studies of the mechanism underlying DNA cleavage by photoactivated 1 reveal that the photocleavage reaction does not involve generation of reactive oxygen species (ROS), although contribution of singlet oxygen ((1)O2) to the DNA photocleavage process cannot be entirely excluded. Notably, the mechanism of DNA photocleavage by 1 appears to involve a direct modification of mainly those guanine residues to which 1 is coordinatively bound. As some tumors are oxygen-deficient and cytotoxic effects of photoactivated ruthenium compounds containing {Ru(η(6)-arene)}(2+) do not require the presence of oxygen, this class of ruthenium complexes may be considered potential candidate agents for improved photodynamic anticancer chemotherapy.
- MeSH
- DNA chemistry MeSH
- Ethylenediamines chemistry MeSH
- Photochemotherapy MeSH
- Cations, Divalent MeSH
- Coordination Complexes chemical synthesis pharmacology MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Organometallic Compounds chemical synthesis pharmacology MeSH
- Plasmids chemistry MeSH
- Antineoplastic Agents chemical synthesis pharmacology MeSH
- Ruthenium chemistry MeSH
- Base Sequence MeSH
- Singlet Oxygen chemistry MeSH
- DNA Cleavage drug effects radiation effects MeSH
- Light MeSH
- Terphenyl Compounds chemistry MeSH
- Cell Survival drug effects radiation effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Glycoconjugation is a powerful tool to improve the anticancer activity of metal complexes. Herein, we modified commercial arylphosphanes with carbohydrate-derived fragments for the preparation of novel glycoconjugated ruthenium(II) p-cymene complexes. Specifically, d-galactal and d-allal-derived vinyl epoxides (VEβ and VEα) were coupled with (2-hydroxyphenyl)diphenylphosphane, affording the 2,3-unsaturated glycophosphanes 1β and 1α. Ligand exchange with [Ru(C2O4)(η6-p-cymene)(H2O)] gave the glycoconjugated complexes Ru1β and Ru1α which were subsequently dihydroxylated with OsO4/N-methylmorpholine N-oxide to Ru2β and Ru2α containing O-benzyl d-mannose and d-gulose units respectively. Besides, aminoethyl tetra-O-acetyl-β-d-glucopyranoside was condensed with borane-protected (4-diphenylphosphanyl)benzoic acid by HATU/DIPEA under MW heating, to afford the amide 3∙BH3. Zemplén deacylation with MeONa/MeOH gave the deprotected d-glucopyranoside derivative 4∙BH3. The glycoconjugated phosphane complexes Ru3 and Ru4 were obtained by reaction of the phosphane-boranes 3∙BH3 and 4∙BH3 with [Ru(C2O4)(η6-p-cymene)(H2O)]. The employed synthetic strategies were devised to circumvent unwanted phosphine oxidation. The compounds were purified by silica chromatography, isolated in high yield and purity and characterized by analytical and spectroscopic (IR and multinuclear NMR) techniques. The behaviour of the six glycoconjugated Ru complexes in aqueous solutions was assessed by NMR and MS measurements. All compounds were screened for their in vitro cytotoxicity against A2780/A2780R human ovarian and MCF7 breast cancer cell lines, revealing a significant cytotoxicity for complexes containing the 2,3-unsaturated glycosyl unit (Ru1β, Ru1α). Additional studies on five other human cancer cells, as well as time-dependent toxicity and cell-uptake analyses on ovarian cancer cells, confirmed the prominent activity of these two compounds - higher than cisplatin - and the better performance of the β anomer. However, Ru1β, Ru1α did not show preferential activity against cancer cells with respect to fetal lung fibroblast and human embryonic kidney cells as models of normal cells. The effects of the two ruthenium glycoconjugated compounds in A2780 ovarian cancer cells were further investigated by cell cycle analysis, induction of apoptosis, intracellular ROS production, activation of caspases 3/7 and disruption of mitochondrial membrane potential. The latter is a relevant factor in the mechanism of action of the highly cytotoxic Ru1β, inducing cell death by apoptosis.
- MeSH
- Phosphines MeSH
- Coordination Complexes * chemistry pharmacology MeSH
- Humans MeSH
- Ligands MeSH
- Cell Line, Tumor MeSH
- Ovarian Neoplasms * MeSH
- Antineoplastic Agents * chemistry MeSH
- Ruthenium * chemistry pharmacology MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Piano stool ruthenium complexes of the composition [Ru(II)(eta6-arene)(en)Cl](+/2+) (en = ethylenediamine) represent an emerging class of cisplatin-analogue anticancer drug candidates. In this study, we use computational quantum chemistry to characterize the structure, stability and reactivity of these compounds. All these structures were optimized at DFT(B3LYP)/6-31G(d) level and their single point properties were determined by the MP2/6-31++G(2df,2pd) method. Thermodynamic parameters and rate constants were determined for the aquation process, as a replacement of the initial chloro ligand by water and subsequent exchange reaction of aqua ligand by nucleobases. The computations were carried out at several levels of DFT and ab initio theories (B3LYP, MP2 and CCSD) utilizing a range of bases sets (from 6-31G(d) to aug-cc-pVQZ). Excellent agreement with experimental results for aquation process was obtained at the CCSD level and reasonable match was achieved also with the B3LYP/6-31++G(2df,2pd) method. This level was used also for nucleobase-water exchange reaction where a smaller rate constant for guanine exchange was found in comparison with adenine. Although adenine follows a simple replacement mechanism, guanine complex passes by a two-step mechanism. At first, Ru-O6(G) adduct is formed, which is transformed through a chelate TS2 to the Ru-N7(G) final complex. In case of guanine, the exchange reaction is more favorable thermodynamically (releasing in total by about 8 kcal/mol) but according to our results, the rate constant for guanine substitution is slightly smaller than the analogous constant in adenine case when reaction course from local minimum is considered. Copyright 2008 Wiley Periodicals, Inc.
- MeSH
- Adenine chemistry metabolism MeSH
- Cytosine chemistry metabolism MeSH
- Ethylenediamines pharmacology chemistry MeSH
- Guanine chemistry metabolism MeSH
- Quantum Theory MeSH
- Models, Molecular MeSH
- Molecular Structure MeSH
- Antineoplastic Agents pharmacology chemistry MeSH
- Purines chemistry metabolism MeSH
- Pyrimidinones chemistry metabolism MeSH
- Ruthenium pharmacology chemistry MeSH
- Thermodynamics MeSH
- Thymine chemistry metabolism MeSH
- Uracil chemistry metabolism MeSH
- Binding Sites MeSH
- Water chemistry metabolism MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
We have compared the cancer cell cytotoxicity, cell uptake, and DNA binding properties of the isomeric terphenyl complexes [(eta(6)-arene)Ru(en)Cl](+), where the arene is ortho- (2), meta- (3), or para-terphenyl (1) (o-, m-, or p-terp). Complex 1, the X-ray crystal structure of which confirms that it has the classical "piano-stool" geometry, has a similar potency to cisplatin but is not cross-resistant and has a much higher activity than 2 or 3. The extent of Ru uptake into A2780 or A2780cis cells does not correlate with potency. Complex 1 binds to DNA rapidly and quantitatively, preferentially to guanine residues, and causes significant DNA unwinding. Circular and linear dichroism, competitive binding experiments with ethidium bromide, DNA melting, and surface-enhanced Raman spectroscopic data are consistent with combined intercalative and monofunctional (coordination) binding mode of complex 1. This unusual DNA binding mode may therefore make a major contribution to the high potency of complex 1.
- MeSH
- Nucleic Acid Denaturation MeSH
- DNA chemistry metabolism drug effects MeSH
- Guanine metabolism MeSH
- Crystallography, X-Ray MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Neoplasms drug therapy pathology MeSH
- Organometallic Compounds pharmacokinetics pharmacology metabolism MeSH
- Antineoplastic Agents * pharmacology chemistry MeSH
- Ruthenium * MeSH
- Spectrum Analysis MeSH
- DNA, Superhelical MeSH
- Terphenyl Compounds pharmacology chemistry MeSH
- Binding Sites MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
While ruthenium arene complexes have been widely investigated for their medicinal potential, studies on homologous compounds containing a tridentate tris(1-pyrazolyl)methane ligand are almost absent in the literature. Ruthenium(II) complex 1 was obtained by a modified reported procedure; then, the reactions with a series of organic molecules (L) in boiling alcohol afforded novel complexes 2-9 in 77-99% yields. Products 2-9 were fully structurally characterized. They are appreciably soluble in water, where they undergo partial chloride/water exchange. The antiproliferative activity was determined using a panel of human cancer cell lines and a noncancerous one, evidencing promising potency of 1, 7, and 8 and significant selectivity toward cancer cells. The tested compounds effectively accumulate in cancer cells, and mitochondria represent a significant target of biological action. Most notably, data provide convincing evidence that the mechanism of biological action is mediated by the inhibiting of mitochondrial calcium intake.
- MeSH
- Homeostasis MeSH
- Coordination Complexes * pharmacology MeSH
- Humans MeSH
- Mitochondria MeSH
- Cell Line, Tumor MeSH
- Neoplasms * drug therapy MeSH
- Antineoplastic Agents * pharmacology therapeutic use MeSH
- Ruthenium * pharmacology MeSH
- Calcium MeSH
- Water MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
We recently synthesized and characterized water-soluble dinuclear Ru(II) arene complexes, in which two {(eta(6)-p-isopropyltoluene)RuCl[3-(oxo-kappaO)-2-methyl-4-pyridinonato-kappaO(4)]} units were linked by flexible chains of different length [(CH(2))(n) (n=4, 6, 8, 12)]. These new dinuclear ruthenium drugs were found to exert promising cytotoxic effects in human cancer cells. In the present work DNA modifications by these new dinuclear Ru(II) arene compounds, which differed in the length of the linker between the two Ru(II) centers, were examined by biochemical and biophysical methods. The complexes bind DNA forming intrastrand and interstrand cross-links in one DNA molecule in the absence of proteins. An intriguing aspect of the DNA-binding mode of these dinuclear Ru(II) compounds is that they can cross-link two DNA duplexes and also proteins to DNA--a feature not observed for other antitumor ruthenium complexes. Thus, the concept for the design of interhelical and DNA-protein cross-linking agents based on dinuclear Ru(II) arene complexes with sufficiently long linkers between two Ru centers may result in new compounds which exhibit a variety of biological effects and can be also useful in nucleic acids research.
