Ruthenium(II)/Benzonitrile Complex Induces Cytotoxic Effect in Sarcoma-180 Cells by Caspase-Mediated and Tp53/p21-Mediated Apoptosis, with Moderate Brine Shrimp Toxicity.

Ruthenium(II)/benzonitrile complexes have demonstrated promising anticancer properties. Considering that there are no specific therapies for treating sarcoma, we decided to evaluate the cytotoxic, genotoxic, and lethal effects of cis-[RuCl(BzCN)(phen)(dppb)]PF6 (BzCN = benzonitrile; phen = 1,10-phenanthroline; dppb = 1,4-bis-(diphenylphosphino)butane), as well as the mechanism of cell death induction that occurs against murine sarcoma-180 tumor. Thus, MTT assay was applied to assess the ruthenium cytotoxicity, showing that the compound is a more potent inhibitor for the sarcoma-180 tumor cell viability than normal cells (lymphocytes). The comet assay indicated low genotoxic for normal cells. cis-[RuCl(BzCN)(phen)(dppb)]PF6 also showed moderate lethality in Artemia salina. The complex induced cell cycle arrest in the G0/G1 phase in sarcoma-180 cells. In addition, the complex caused S180 cells to die by apoptosis by an increase in Annexin-V-positive cells and morphological changes typical of apoptotic cells. Additionally, cis-[RuCl(BzCN)(phen)(dppb)]PF6 increased the gene expression of Bax, Casp3, and Tp53 in S180 cells. By using a western blot, we observed an increased protein level of TNF-R2, Bax, and p21. In conclusion, cis-[RuCl(BzCN)(phen)(dppb)]PF6 is active and selective for sarcoma-180 cells, leading to cell cycle arrest at the G0/G1 and cell death through a caspases-mediated and Tp53/p21-mediated pathway.

Heterobimetallic Ru(ii)/Fe(ii) complexes as potent anticancer agents against breast cancer cells, inducing apoptosis through multiple targets.

Antimetastatic activity, high selectivity and cytotoxicity for human tumor cell lines make ruthenium(ii) complexes attractive for the development of new chemotherapeutic agents for cancer treatment. In this study, cytotoxic activities and the possible mechanism of cell death induced by three ruthenium complexes were evaluated, [Ru(MIm)(bipy)(dppf)]PF6 (1), [RuCl(Im)(bipy)(dppf)]PF6 (2) and [Ru(tzdt)(bipy)(dppf)]PF6 (3). The results showed high cytotoxicity and selectivity indexes for the human triple-negative breast tumor cell line (MDA-MB-231) with IC50 value and selectivity index for complex 1 (IC50 = 0.33 ± 0.03 µM, SI = 4.48), complex 2 (IC50 = 0.80 ± 0.06 µM, SI = 2.31) and complex 3 (IC50 = 0.48 ± 0.02 µM, SI = 3.87). The mechanism of cell death induced in MDA-MB-231 cells, after treatment with complexes 1-3, indicated apoptosis of the cells as a consequence of the increase in the percentage of cells in the Sub-G1 phase in the cell cycle analysis, characteristic morphological changes and the presence of apoptotic cells labeled with Annexin-V. Multiple targets of action were identified for complexes 1 and 3 with an induction of DNA damage in cells treated with complexes 1 and 3, mitochondrial depolarization with a reduction in mitochondrial membrane potential, an increase in reactive oxygen species levels and increased expression levels of caspase 3 and p53. In addition, antimetastatic activities for complexes 1 and 3 were observed by inhibition of cell migration by the wound healing assay and Boyden chamber assay, as well as inhibition of angiogenesis caused by MDA-MB-231 tumor cells in the CAM model.

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.

Ru(II)/diphenylphosphine/pyridine-6-thiolate complexes induce S-180 cell apoptosis through intrinsic mitochondrial pathway involving inhibition of Bcl-2 and p53/Bax activation.

The aim of this work was the synthesis, characterization, and cytotoxicity evaluation of three new Ru(II) complexes with a general formula [Ru(Spy)(bipy)(P-P)]PF6 [Spy = pyridine-6-thiolate; bipy = 2,2'-bipyridine; P-P = 1,2-bis(diphenylphosphine)ethane (1); 1,3-bis(diphenylphosphine) propane (2); and 1,1'-bis(diphenylphosphino)ferrocene] (4). Complex (3) with the 1,4-bis(diphenylphosphine)butane ligand, already known from the literature, was also synthesized, to be better studied here. The cytotoxicities of the complexes toward two kinds of cancerous cells (K562 and S-180 cells) were evaluated and compared to normal cells (L-929 and PBMC) by MTT assay. The complex [Ru(Spy)(bipy)(dppb)]PF6 (3) was selected to study both the cellular and molecular mechanisms underlying its promising anticancer action in S-180 cells. The results obtained from this study indicated that complex (3) induces cell cycle arrest in the G0/G1 phase in S-180 cells associated with a decrease in the number of cells in S phase. After 24 and 48 h of exposure to complex (3), the cell viability decreased when compared to the negative control. Complex (3) does not appear to be involved in the DNA damage, but induced changes in the mitochondrial membrane potential in S-180 cells. Furthermore, there was also an increase in the gene expression of Bax, Caspase 9, and Tp53. According to our results, complex (3) induces cell apoptosis through p53/Bax-dependent intrinsic pathway and suppresses the expression of active antiapoptotic Bcl-2 protein.

Antitumor effectiveness and mechanism of action of Ru(II)/amino acid/diphosphine complexes in the peritoneal carcinomatosis progression.

Peritoneal carcinomatosis is considered as a potentially lethal clinical condition, and the therapeutic options are limited. The antitumor effectiveness of the [Ru(l-Met)(bipy)(dppb)]PF6(1) and the [Ru(l-Trp)(bipy)(dppb)]PF6(2) complexes were evaluated in the peritoneal carcinomatosis model, Ehrlich ascites carcinoma-bearing Swiss mice. This is the first study that evaluated the effect of Ru(II)/amino acid complexes for antitumor activity in vivo. Complexes 1 and 2 (2 and 6 mg kg-1) showed tumor growth inhibition ranging from moderate to high. The mean survival time of animal groups treated with complexes 1 and 2 was higher than in the negative and vehicle control groups. The induction of Ehrlich ascites carcinoma in mice led to alterations in hematological and biochemical parameters, and not the treatment with complexes 1 and 2. The treatment of Ehrlich ascites carcinoma-bearing mice with complexes 1 and 2 increased the number of Annexin V positive cells and cleaved caspase-3 levels and induced changes in the cell morphology and in the cell cycle phases by induction of sub-G1 and G0/G1 cell cycle arrest. In addition, these complexes reduce angiogenesis induced by Ehrlich ascites carcinoma cells in chick embryo chorioallantoic membrane model. The treatment with the LAT1 inhibitor decreased the sensitivity of the Ehrlich ascites carcinoma cells to complexes 1 and 2 in vitro-which suggests that the LAT1 could be related to the mechanism of action of amino acid/ruthenium(II) complexes, consequently decreasing the glucose uptake. Therefore, these complexes could be used to reduce tumor growth and increase mean survival time with less toxicity than cisplatin. Besides, these complexes induce apoptosis by combination of different mechanism of action.

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.

Cytotoxicity of glass ionomer cements containing silver nanoparticles.

BACKGROUND: Some studies have investigated the possibility of incorporating silver nanoparticles (NAg) into dental materials to improve their antibacterial properties. However, the potential toxic effect of this material on pulp cells should be investigated in order to avoid additional damage to the pulp tissue. This study evaluated the cytotoxicity of conventional and resin-modified glass ionomer cements (GIC) with and without addition of NAg. MATERIAL AND METHODS: NAg were added to the materials at two different concentrations by weight: 0.1% and 0.2%. Specimens with standardized dimensions were prepared, immersed in 400 µL of culture medium and incubated at 37°C and 5% CO2 for 48 h to prepare GIC liquid extracts, which were then incubated in contact with cells for 48 h. Culture medium and 0.78% NAg solution were used as negative and positive controls, respectively. Cell viability was determined by MTT and Trypan Blue assays. ANOVA and the Tukey test (α=0.05) were used for statistical analyses. RESULTS: Both tests revealed a significant decrease in cell viability in all groups of resin modified cements (p<0.001). There were no statistically significant differences between groups with and without NAg (p>0.05). The differences in cell viability between any group of conventional GIC and the negative control were not statistically significant (p>0.05). CONCLUSIONS: NAg did not affect the cytotoxicity of the GIC under evaluation. KEY WORDS: Glass ionomer cements, totoxicity, cell culture techniques, nanotechnology, metal nanoparticles.

Cytoxicity and apoptotic mechanism of ruthenium(II) amino acid complexes in sarcoma-180 tumor cells.

Over the past several decades, much attention has been focused on ruthenium complexes in antitumor therapy. Ruthenium is a transition metal that possesses several advantages for rational antitumor drug design and biological applications. In the present study, five ruthenium complexes containing amino acids were studied in vitro to determine their biological activity against sarcoma-180 tumor cells. The cytotoxicity of the complexes was evaluated by an MTT assay, and their mechanism of action was investigated. The results demonstrated that the five complexes inhibited the growth of the S180 tumor cell line, with IC50 values ranging from 22.53 µM to 50.18 µM, and showed low cytotoxicity against normal L929 fibroblast cells. Flow cytometric analysis revealed that the [Ru(gly)(bipy)(dppb)]PF6 complex (2) inhibited the growth of the tumor cells by inducing apoptosis, as evidenced by an increased number of Annexin V-positive cells and G0/G1 phase cell cycle arrest. Further investigation showed that complex 2 caused a loss of mitochondrial membrane potential; activated caspases 3, caspase-8, and caspase-9 and caused a change in the mRNA expression levels of caspase 3, caspase-9 as well as the bax genes. The levels of the pro-apoptotic Bcl-2 family protein Bak were increased. Thus, we demonstrated that ruthenium amino acid complexes are promising drugs against S180 tumor cells, and we recommend further investigations of their role as chemotherapeutic agents for sarcomas.

Cytotoxic effects of the compound cis-tetraammine(oxalato)ruthenium(III) dithionate on K-562 human chronic myelogenous leukemia cells.

Chemotherapy is a common treatment for leukemia. Ruthenium complexes have shown potential utility in chemotherapy and photodynamic therapy. The identification of new chemotherapeutics agents is critical for further progress in the treatment of leukemia. Ruthenium complexes generally have lower toxicities compared to cisplatin attributed to their specific accumulation in cancer tissues. Based on these evidences, in the present work we studied the cytotoxic activity of the ruthenium(III) compound cis-tetraammine(oxalato)ruthenium(III) dithionate - {cis-[Ru(C2O4)(NH3)4]2(S2O6)} against human chronic myelogenous leukemia cells (K-562) tumor cell line. The tested compound induces cell death in a dose and time dependent manner on K-562 cells. It is found that the effect was improved linearly while prolonging the incubation time. Compared to the cell cycle profiles of untreated cells, flow cytometric analysis indicated the sub-G1 arresting effect of ruthenium compound on K-562 cells. In our study, {cis-[Ru(C2O4)(NH3)4]2(S2O6)} shows a significant increase in tailed cells in any of the concentrations tested compared with negative control. Consequently, the concentration of {cis-[Ru(C2O4)(NH3)4]2(S2O6)} might be associated cytotoxicity with direct effect on K-562 cells DNA. Thus, it can be deducted that ruthenium-based compounds present selectivity to enter both tumor and normal cells. Additional studies are needed to determine the molecular mechanisms of the active components and to evaluate the potential in vivo anticancer activity of the cis-tetraammine(oxalato)ruthenium(III) dithionate.