Apoptosis in BEL-7402 cells induced by ruthenium(II) complexes through a ROS-mediated mitochondrial pathway

Anticancer effect evaluation of iridium(III) complexes targeting mitochondria and endoplasmic reticulum

Ligand HMSPIP (2-(4-(methylsulfonyl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) and its iridium(III) complexes [Ir(ppy)₂(HMSPIP)]PF₆ (ppy = 2-phenylpyridine, Ir1) and [Ir(bzq)₂(HMSPIP)]PF₆ (bzq = benzo[h]quinoline, Ir2) were synthesized. The complexes were characterized by ¹H NMR, ¹³C NMR, and UV/Vis spectra. The cytotoxicity of the complexes toward cancer cells were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, the scratch wound healing and colony-forming were also investigated. MTT assay certificated that the complexes show high toxic effect on the HeLa cells. The cell cycle assay illustrated that the complexes blocked cell growth at G₀/G₁ phase in HeLa cells. A series of subsequent experiments showed that the complexes first enter the endoplasmic reticulum (ER) and then enter the mitochondria, leading to an increase in intracellular Ca²⁺ and reactive oxygen species (ROS) content, depolarizing mitochondrial membrane potential (MMP), and ultimately resulting in apoptosis. In addition, the experimental results revealed that the complexes not only increase the level of ROS but also inhibit the production of GSH and eventually produce large amounts of MDA and further leading to cell death. Taken together, we consider that the complexes can be used as potential candidate drugs for HeLa cancer treatment.

Evaluation of anticancer role of a novel ruthenium(II)-based compound compared with NAMI-A and cisplatin in impairing mitochondrial functionality and promoting oxidative stress in triple negative breast cancer models

Platinum-based compounds are the most widely used anticancer drugs but, their elevated toxicity and chemoresistance has stimulated the study of others, such as ruthenium-based compounds. NAMI-A and UNICAM-1 were tested in vitro, comparing the mechanisms of toxicity, in terms of mitochondrial functionality and cellular oxidative stress. UNICAM-1, showed a clear mitochondrial target and a cytotoxic dose-dependent response thanks to its ability to promote an imbalance of cellular redox status. It impaired directly mitochondrial respiratory chain, promoting mitochondrial superoxide anion production, leading to mitochondrial membrane depolarization. All these aspects, could make UNICAM-1 a valid alternative for chemotherapy treatment of breast cancer.

Chiral ruthenium(II) complex Δ-[Ru(bpy)2(o-FMPIP)] (bpy = bipyridine, o-FMPIP = 2-(2'-trifluoromethyphenyl) imidazo[4,5-f][1,10]phenanthroline) as potential apoptosis inducer via DNA damage

Chiral ruthenium(II) complexes have long been considered as potential anticancer agents. Herein, in vivo inhibitory activity of a chiral ruthenium(II) complex coordinated by ligand 2-(2'-trifluoromethyphenyl) imidazo [4,5-f][1,10]phenanthroline, Δ-[Ru(bpy)₂(o-FMPIP)] (D0402) on Kunming(KM) mice bearing tumor (H22 hepatic cancer) has been evaluated, and the results showed that the tumor weight of mice treated with 0.22 mg/(kg·day) D0402 via i.v. administration for 7 days decreased about 31.79% compared to the control group, while the body weight, as well as the thymus, spleen, liver, lung, and kidney indices of mice treated with D0402 observed almost no loss compared to the control group. Furthermore, the mechanism studies on anti-angiogenic showed that D0402 could inhibit the formation of angiogenesis in the transgenic Tg(fli1a: EGFP) zebrafish. After treated with D0402, the sub-intestinal vessels(SIVs) of the zebrafish became disordered and chaotic, and was dosage dependent. Moreover, the TUNEL analysis and comet assays revealed that D0402 can induce apoptosis of HepG2 cell through DNA damage, and this was further demonstrated by immunofluorescence analysis with the number of γ-H2AX increased following the increasing amount of D0402. Besides, in vivo toxicity of D0402 has also been investigated on the development of zebrafish embryo, and the results showed that there were no death or development delay occurred for zebrafish embryo treated with D0402 up to concentration of 60 μM. All in together, this study suggested that D0402 can be developed as a potential inhibitor against liver cancer through co-junction of anti-angiogenesis and apoptosis-inducing via DNA damage in the near future.

"Chemistry-on-the-complex": functional RuII polypyridyl-type sensitizers as divergent building blocks

Ruthenium polypyridyl type complexes are potent photoactive compounds, and have found - among others - a broad range of important applications in the fields of biomedical diagnosis and phototherapy, energy conversion schemes such as dye-sensitized solar cells (DSSCs) and molecular assemblies for tailored photo-initiated processes. In this regard, the linkage of RuII polypyridyl-type complexes with specific functional moieties is highly desirable to enhance their inherent photophysical properties, e.g., with a targeting function to achieve cell selectivity, or with a dye or redox-active subunits for energy- and electron-transfer. However, the classical approach of performing ligand syntheses first and the formation of Ru complexes in the last steps imposes synthetic limitations with regard to tolerating functional groups or moieties as well as requiring lengthy convergent routes. Alternatively, the diversification of Ru complexes after coordination (termed "chemistry-on-the-complex") provides an elegant complementary approach. In addition to the Click chemistry concept, the rapidly developing synthesis and purification methodologies permit the preparation of Ru conjugates via amidation, alkylation and cross-coupling reactions. In this regard, recent developments in chromatography shifted the limits of purification, e.g., by using new commercialized surface-modified silica gels and automated instrumentation. This review provides detailed insights into applying the "chemistry-on-the-complex" concept, which is believed to stimulate the modular preparation of unpreceded molecular assemblies as well as functional materials based on Ru-based building blocks, including combinatorial approaches.

Anticancer activity studies of a ruthenium(II) polypyridyl complex against human hepatocellular (BEL-7402) cells

A Ru(II) polypyridyl complex [Ru(bpy)2(HMSPIP)](ClO4)2 (1) (bpy=2,2'-bipyridine, HMSPIP=2-(4-methylsulfonyl)phenyl-1H-imidazo[4,5-f][1,10] phenanthroline) was synthesized. The IC50 value of the complex against human hepatocellular cell BEL-7402 is 21.6±2.7 μM. The complex shows no cytotoxic activity toward human lung adenocarcinoma cell A549, human osteosarcoma cell MG-63 and human breast cancer cell SK-BR-3 cells. It is easily for complex 1 to be taken up by BEL-7402 cells. The complex can enhance the reactive oxygen species (ROS) levels and induce the decrease in the mitochondrial membrane potential. The complex inhibits the cell growth in BEL-7402 cells at G2/M phase. Complex 1 can regulate the expression of Bcl-2 family proteins. The results show that the complex induces apoptosis of BEL-7402 cells through a ROS-mediated mitochondrial dysfunction pathway.