Induction of cell cycle arrest and apoptosis by ruthenium complex cis-(dichloro)tetramineruthenium(III) chloride in human lung carcinoma cells A549

Synthesis, characterization and in vitro cytotoxicity of ruthenium(II) metronidazole complexes: Cell cycle arrest at G1/S transition and apoptosis induction in MCF-7 cells

Ruthenium compounds are known to be potential drug candidates since they offer the potential for reduced toxicity. Furthermore, the various oxidation states, different mechanisms of action and ligand substitution kinetics give them advantages over platinum-based complexes, making them suitable for use in biological applications. So, herein, novel ruthenium(II) complexes with metronidazole as ligand were obtained [RuCl(MTNZ)(dppb)(4,4'-Mebipy)]PF₆ (1), [RuCl(MTNZ)(dppb)(4,4'-Methoxybipy)]PF₆ (2), [RuCl(MTNZ)(dppb)(bipy)]PF₆ (3) and [RuCl(MTNZ)(dppb)(phen)]PF₆ (4) where, MTNZ = metronidazole, dppb = 1,4-bis(diphenylphosphino)butane, 4,4'-Mebipy = 4,4'-dimethyl-2,2'-bipyridine, 4,4'-Methoxybipy = 4,4'-dimethoxy-2,2'-bipyridine, bipy = 2,2'-bipyridine and phen = 1,10-phenanthroline. The complexes were characterized by elemental analysis, molar conductivity, infrared and UV-Vis spectroscopy, cyclic voltammetry, ³¹P{¹H}, ¹H, ¹³C{¹H} and Dept 135 NMR and mass spectrometry. The interaction of complexes 1-4 with DNA was evaluated, and their cytotoxicity profiles were determined on four different tumor cell lines derived from human cancers (SK-MEL-147, melanoma; HepG2, hepatocarcinoma; MCF-7, estrogen-positive breast cancer; A549, non-small cell lung cancer). We demonstrated that complexes (1) and (3) are promising antitumor agents once inhibited the proliferative behavior of MCF-7 cells and induced apoptosis.

Ru(II)/amino acid complexes inhibit the progression of breast cancer cells through multiple mechanism-induced apoptosis

For some cancer subtypes, such as triple-negative breast cancer, there are no specific therapies, which leads to a poor prognosis associated with invasion and metastases. Ruthenium complexes have been developed to act in all steps of tumor growth and its progression. In this study, we investigated the effects of Ruthenium (II) complexes coupled to the amino acids methionine (RuMet) and tryptophan (RuTrp) on the induction of cell death, clonogenic survival ability, inhibition of angiogenesis, and migration of MDA-MB-231 cells (human triple-negative breast cancer). The study also demonstrated that the RuMet and RuTrp complexes induce cell cycle blockage and apoptosis of MDA-MB-231 cells, as evidenced by an increase in the number of Annexin V-positive cells, p53 phosphorylation, caspase 3 activation, and poly(ADP-ribose) polymerase cleavage. Moreover, morphological changes and loss of mitochondrial membrane potential were detected. The RuMet and RuTrp complexes induced DNA damage probably due to reactive oxygen species production related to mitochondrial membrane depolarization. Therefore, the RuMet and RuTrp complexes acted directly on breast tumor cells, leading to cell death and inhibiting their metastatic potential; this reveals the potential therapeutic action of these drugs.

Ru(II)-Based Amino Acid Complexes Show Promise for Leukemia Treatment: Cytotoxicity and Some Light on their Mechanism of Action

Ruthenium is attracting considerable interest as the basis for new compounds to treat diseases, and studies have shown that complexes with different structures have significant antineoplastic and antimetastatic potential against several types of tumors, including tumors resistant to cisplatin drugs. We examined the cytotoxic, genotoxic, and pro-apoptotic activities of six ruthenium complexes containing amino acid with general formulation [Ru(AA)(bipy)(dppb)]PF₆, where AA = amino acid (alanine, glycine, leucine, lysine, methionine, or tryptophan); bipy = 2,2´-bipyridine; and dppb = [1,4-bis(diphenylphosphine)butane], against A549 (lung carcinoma) and K562 (chronic myelogenous leukemia) cancer cells. The results show that the ruthenium complexes tested were able to induce cytotoxicity in A549 and K562 cancer cells. Complex 1 containing alanine inhibited the cell viability of A549 and K562 tumor cells by inducing apoptosis, as evidenced by an increased number of Annexin V-positive cells and the induction of DNA damage and cell cycle arrest. Complex 1 was able to induce caspase-mediated apoptosis in K562 cells through the mitochondrial dysfunction, the upregulation of apoptotic genes, and the downregulation of Bcl2 anti-apoptotic gene. Besides being cytotoxic to K562 and A549 cells, ruthenium complex containing alanine shows low cytotoxicity and genotoxicity against non-tumor cells. These results suggest that the ruthenium (II) complex is a potential safe and efficient antineoplastic candidate for leukemia treatment.

In vitro cytotoxicity and in vivo zebrafish toxicity evaluation of Ru(ii)/2-mercaptopyrimidine complexes

In this paper, four new ruthenium complexes, [Ru(N-S)(dppm)2]PF6 (1), [Ru(N-S)(dppe)2]PF6 (2), [Ru(N-S)2(dppp)] (3) and [Ru(N-S)2(PPh3)2] (4) [dppm = 1,1-bis(diphenylphosphino)methane, dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, PPh3 = triphenylphosphine and N-S = 2-mercaptopyrimidine anion] were synthesized and characterized using spectroscopy techniques, molar conductance, elemental analysis, electrochemical techniques and X-ray diffraction. The DNA binding studies were investigated using voltammetry and spectroscopy techniques. The results show that all complexes exhibit a weak interaction with DNA. HSA interaction with the complexes was studied using fluorescence emission spectroscopy, where the results indicate a spontaneous interaction between the species by a static quenching mechanism. The cytotoxicity of the complexes was evaluated against A549, MDA-MB-231 and HaCat cells by MTT assay. Complexes (1) and (2), which are very active against triple negative MDA-MB-231, were subjected to further biological tests with this cell line. The cytotoxic activity triggered by the complexes was confirmed by clonogenic assay. Cell cycle analyses demonstrated marked anti-proliferative effects, especially at the G0/G1 and S phases. The morphological detection of apoptosis and necrosis - HO/PI and Annexin V-FITC/PI assay, elucidated that the type of cell death triggered by these complexes was probably by apoptosis. The in vivo toxicological assessment performed on zebrafish embryos revealed that complexes (1) and (2) did not present embryotoxic or toxic effects during embryonic and larval development showing that they are promising new prototypes of safer and more effective drugs for triple negative breast cancer treatment.

Anticancer Ruthenium(III) Complexes and Ru(III)-Containing Nanoformulations: An Update on the Mechanism of Action and Biological Activity

The great advances in the studies on metal complexes for the treatment of different cancer forms, starting from the pioneering works on platinum derivatives, have fostered an increasingly growing interest in their properties and biomedical applications. Among the various metal-containing drugs investigated thus far, ruthenium(III) complexes have emerged for their selective cytotoxic activity in vitro and promising anticancer properties in vivo, also leading to a few candidates in advanced clinical trials. Aiming at addressing the solubility, stability and cellular uptake issues of low molecular weight Ru(III)-based compounds, some research groups have proposed the development of suitable drug delivery systems (e.g., taking advantage of nanoparticles, liposomes, etc.) able to enhance their activity compared to the naked drugs. This review highlights the unique role of Ru(III) complexes in the current panorama of anticancer agents, with particular emphasis on Ru-containing nanoformulations based on the incorporation of the Ru(III) complexes into suitable nanocarriers in order to enhance their bioavailability and pharmacokinetic properties. Preclinical evaluation of these nanoaggregates is discussed with a special focus on the investigation of their mechanism of action at a molecular level, highlighting their pharmacological potential in tumour disease models and value for biomedical applications.

Ruthenium Complex Induce Cell Death in G-415 Gallbladder Cancer Cells

PURPOSE

In this work, we present a recently developed ruthenium complex that shows anticancer activity in gallbladder cancer cells.

METHODS

After the synthesis of the new ruthenium complexes, the antiproliferative, cytotoxicity, and apoptosis activities were evaluated in vitro by the triple assay ApoTox-Glo. Then, the transcription levels of genes related to apoptosis were evaluated by real-time PCR (q-PCR).

RESULTS

The ruthenium complex, called Ru-UCN3, inhibits the proliferation of gallbladder cancer cells G-415 by means of apoptosis, which was demonstrated by the overexpression of the pro-apoptotic genes Puma, Diablo, and Caspasa-9 together with the repression of the anti-apoptotic genes Bcl-xL and Bcl-2. In addition, we found strong caspase 3/7 activity in the cells at 24 h of the Ru-UCN3 exposure, which was evaluated by the triple ApoTox-Glo assay.

CONCLUSION

The new ruthenium complexes evaluated had an inhibitory effect on G-415 cells. We think that Ru-UCN3 could be a promising anticancer agent, which should be explored with more in vitro and in vivo assays and probably with the chemical modulation of this molecule.

cis-[RuCl(BzCN)(bipy)(dppe)]PF6 induces anti-angiogenesis and apoptosis by a mechanism of caspase-dependent involving DNA damage, PARP activation, and Tp53 induction in Ehrlich tumor cells

Antimetastatic activities, low toxicity to normal cells and high selectivity for tumor cells make of the ruthenium complexes promising candidates in the search for develop new chemotherapeutic agents for the treatment of cancer. This study aimed to determine the cytotoxic, genotoxic and to elucidate the signaling pathway involved in the death cell process induced by cis-[RuCl(BzCN)(bipy)(dppb)]PF₆(1) and cis-[RuCl(BzCN)(bipy)(dppe)]PF₆(2) in Ehrlich ascites carcinoma (EAC) in vitro. Moreover, we report for the first time the anti-angiogenic potential on chick embryo chorioallantoic membrane (CAM) model. Peripheral blood mononuclear cells (PBMC) were isolated from healthy controls with an age range of 20-30 years and used to calculate the selectivity index (SI). The complex 2 (IC₅₀ = 8.5 ± 0.4/SI = 6.3) showed high cytotoxic and selectivity index against EAC cells than complex 1 (IC₅₀ = 14.9 ± 0.2/SI = 0.2) using the MTT assay. Complex 2 induced DNA damage on Ehrlich tumor cells at concentrations and time periods evalueted. In consequence, it was observed an increase of Tp53 gene expression, G0/G1-arrest cells, and increased levels of cleaved PARP protein. Beside that, the treatment of EAC with complex 2 led to an increase in Annexin V-positive cells and apoptosis induction by Caspase-7. Additionally, the complex 2 inhibited the angiogenesis caused by Ehrlich tumor cells in CAM model. This complex is active and selective for Ehrlich tumor cells, inducing DNA damage, cell cycle arrest and cell death by caspase-dependent apoptosis involving PARP activation (PARP1), and Tp53 induction.

[Ru(pipe)(dppb)(bipy)]PF6: A novel ruthenium complex that effectively inhibits ERK activation and cyclin D1 expression in A549 cells

Lung cancer is the most frequent type of cancer worldwide. In Brazil, only 14% of the patients diagnosed with lung cancer survived 5years in the last decades. Although improvements in the therapeutic approach, it is relevant to identify new chemotherapeutic agents. In this framework, ruthenium metal compounds emerge as a promising alternative to platinum-based compounds once they displayed lower cytotoxicity and more selectivity for tumor cells. The present study aimed to evaluate the antitumor potential of innovative ruthenium(II) complex, [Ru(pipe)(dppb)(bipy)]PF₆ (PIPE) on A549 cells, which is derived from non-small cell lung cancer. Results demonstrated that PIPE effectively reduced the viability and proliferation rate of A549 cells. When PIPE was used at 9μM there was increase in G0/G1 cell population with concomitant reduction in frequency of cells in S-phase, indicating cell cycle arrest in G1/S transition. Antiproliferative activity of PIPE was associated to its ability of reducing cyclin D1 expression and ERK phosphorylation levels. Cytotoxic activity of PIPE on A549 cells was observed when PIPE was used at 18μM, which was associated to its ability of inducing apoptosis by intrinsic pathway. Taken together, the data demonstrated that PIPE is a promising antitumor agent and further in vivo studies should be performed.

Study on Inhibitory Effect of MaiMenDong Decoction and WeiJing Decoction Combination with Cisplatin on NCI-A549 Xenograft in Nude Mice and Its Mechanism

MaiMenDong Decoction and WeiJing Decoction (Jin formula) is a traditional Chinese medication that consists of 8 medicinal plants, which recorded in the classical TCM literature Jin Kui Yao Lue and has been utilized in the treatment of lung diseases for hundreds of years in China. The present study aimed to determine the anti-tumor activity and the underlying mechanisms of Jin formula combined with cisplatin in the treatment of non-small cell lung cancer (NSCLC). Xenograft model of NCI-A549 was established in Balb/c nude mice. Five groups, including normal, MOCK, Jin, cisplatin (DDP), and Jin+DDP were included in the study. We found that Jin formula ameliorated the body weight loss caused by DDP 15 days after drug administration. Moreover, the combination of Jin with DDP enhanced the anti-tumor function of DDP. Microarray analysis showed that Jin suppressed gene expression of certain pathways which regulating cell cycle and apoptosis. Furthermore, DDP mainly decreased the gene expression level of angiogenesis associated factors, such as VEGFA, TGF-β and MMP-1. Moreover, co-treatment with Jin and DDP not only down-regulated Bcl-2 and E2F1, but also decreased the expression of MYC, MET, and MCAM. In addition, co-formula decreased the levels of p-AKT (thr308) and p-PTEN, increased Bax/Bcl-2 value, and resulted in apoptosis of tumor cells. Taken together, Jin+DDP significantly inhibited the growth of A549 cell transplanted solid tumor with slight side effect compared to the treatment by DDP only, and had a better effect than the Jin group. The mechanisms may be mainly associated with inactivation of PI3K/AKT pathway and apoptosis induction.

Solvent assisted formation of ruthenium(III) and ruthenium(II) hydrazone complexes in one-pot with potential in vitro cytotoxicity and enhanced LDH, NO and ROS release

A set each of new bivalent and trivalent ruthenium complexes, [Ru(III)(HL)Cl2(EPh3)2] and [Ru(II)(L)(CO)(EPh3)2] (E = P (complexes and ) or As (complexes and )) were synthesised from the reactions of [Ru(III)Cl3(EPh3)3] with 2-hydroxynaphthaldehyde benzoic acid hydrazone (H2L) in methanol-chloroform and characterized by elemental analysis, spectral data and XRD study. A suitable mechanism to account for the formation of bivalent ruthenium carbonyl complexes from the corresponding trivalent precursors is provided by considering the role of added base in the reaction. Interaction of complexes with CT-DNA/bovine serum albumin was analysed with absorption and emission spectral titration studies. In vitro cytotoxic potential of the above ruthenium hydrazone complexes assayed against the A549 cell line revealed a significant growth inhibition. The test complexes added in IC50 concentration into the cell culture medium enhanced the release of lactate dehydrogenase, NO and reactive oxygen species in comparison with the control. Cell death induced by the complexes was studied using a propidium iodide staining assay and showed noticeable changes in the cell morphology which resembled apoptosis.

Antitumor and biological investigation of doubly cyclometalated ruthenium(ii) organometallics derived from benzimidazolyl derivatives

In this study, we report the synthesis, anticancer and biological properties of three doubly cyclometalated phenylbenzimidazole derived ruthenium(ii) organometallics (1–3) and their corresponding three organic ligands.

Cis-[RuCl(BzCN)(N-N)(P-P)]PF6 complexes: Synthesis and in vitro antitumor activity: (BzCN=benzonitrile; N-N=2,2'-bipyridine; 1,10-phenanthroline; P-P=1,4-bis(diphenylphosphino) butane, 1,2-bis(diphenylphosphino)ethane, or 1,1'-(diphenylphosphino)ferrocene)

The motivation to use ruthenium complexes in cancer treatment has led our research group to synthesize complexes with this metal and test them against several types of tumor cells, yielding promising results. In this paper the results of biological tests, assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, were carried out on the complexes cis-[RuCl(BzCN)(bipy)(dppe)]PF6 (1), cis-[RuCl(BzCN)(bipy)(dppb)]PF6 (2), cis-[RuCl(BzCN)(bipy)(dppf)]PF6 (3) and cis-[RuCl(BzCN)(phen)(dppb)]PF6 (4) which are described [BzCN = b enzonitrile; bipy = 2,2'-bipyridine; phen = 1,10-phenanthroline; dppe = 1,2-bis(diphenylphosphino) ethane; dppb = 1,4-bis-(diphenylphosphino)butane; dppf = 1,1'-bis(diphenylphosphino)ferrocene]. The present study is focused on the cytotoxic activity of complexes (1)-(4) against four tumor cell lines and on the apoptosis and changes in the cell cycle and gene expression observed in the sarcoma 180 (S180) tumor cell line treated with complex (1). The results demonstrated that this complex inhibits S180 cell growth, with an IC50 of 17.02 ± 8.21 μM, while exhibiting lower cytotoxicity (IC50 = 53.73 ± 5.71 μM) towards lymphocytes (normal cells). Flow cytometry revealed that the complex inhibits the growth of tumor cells by inducing apoptosis as evidenced by an increase in the proportion of cells positive for annexin V staining and G0/G1 phase cell-cycle arrest. Further investigation showed that complex (1) induces a drop in the mitochondrial membrane potential and provokes a decrease in Bcl-2 protein expression and increase in caspase 3 activation, while the increased activation of caspase 8 caused a decrease in the gene expression in caspases 3 and 9. Increases in Tp53 and Bax expressions were also observed.

Cationic liposomes as efficient nanocarriers for the drug delivery of an anticancer cholesterol-based ruthenium complex

Cationic nanovectors loaded with Ru-based nucleolipids exert a high growth-inhibitory activity against human cancer cells (MCF-7 (A), WiDr (B), and HeLa (C)).

The ruthenium complexes cis-(dichloro)tetramineruthenium(III) chloride and cis-tetraammine(oxalato)ruthenium(III) dithionate overcome resistance inducing apoptosis on human lung carcinoma cells (A549)

Lung cancer is one of the leading causes of death in the world, and non-small cell lung carcinoma accounts for approximately 75-85 % of all lung cancers. In the present work, we studied the antitumor activity of the compound cis-(dichloro)tetramineruthenium(III) chloride {cis-[RuCl2(NH3)4]Cl} against human lung carcinoma tumor cell line A549. The present study aimed to investigate the relationship between the expression of MDR1 and CYP450 genes in human lung carcinoma cell lines A549 treated with cisCarboPt, cisCRu(III) and cisDRu(III). The ruthenium-based coordinated complexes presented low cytotoxic and antiproliferative activities, with high IC50 values, 196 (±15.49), 472 (±20.29) and 175 (±1.41) for cisCarboPt, cisCRu(III) and cisDRu(III), respectively. The tested compounds induced apoptosis in A549 tumor cells as evidenced by caspase 3 activation, but only at high concentrations. Results also revealed that the amplification of P-gp gene is greater in A549 cells exposed to cisCarboPt and cisCRu(III) than cisDRu(III). Taken together all these results strongly demonstrate that MDR-1 over-expression in A549 cells could be associated to a MDR phenotype of these cells and moreover, it is also contributing to the platinum, and structurally-related compound, resistance in these cells. The identification and characterization of novel mechanisms of drug resistance will enable the development of a new generation of anti-cancer drugs that increase cancer sensitivity and/or represent more effective chemotherapeutic agents.