Role of cell cycle events and apoptosis in mediating the anti-cancer activity of a silver(I) complex of 4-hydroxy-3-nitro-coumarin-bis(phenanthroline) in human malignant cancer cells

2H-Pyrano[3,2-c]chromene-2,5(6H)-diones: Synthesis, Characterization, Photophysical and Redox Studies for Potential Optoelectronic Applications

Herein, we report the preparation of 2H-pyrano[3,2-c]chromene-2,5(6H)-diones 3a-x by reacting 4-hydroxycoumarins 1a-b with Baylis-Hillman adducts 2a-w having electron releasing or electron withdrawing groups on benzyl ring of the pyranochromene moiety and study of their photophysical properties. The study of optical and electrochemical properties of the prepared compounds reveals that the electron releasing and electron withdrawing groups has not much impact on ground and excited state electronic behavior on pyranochromene moiety. The density functional theory suggests the highest occupied molecular orbital and lowest unoccupied molecular orbitals spread on coumarin moiety of pyranochromene unit. Further, these compounds are thermally stable (up to 200 °C) and lead to blue or green emission that should facilitate the development of organic light emitting diodes (OLEDs).

Lysosomal Targeted Cyclometallic Iridium(Ⅲ) Salicylaldehyde-Coumarin Schiff Base Complexes and Anticancer Application

Natural coumarin derivatives and cyclometallic iridium (Ⅲ) (Ir^Ⅲ) complexes have attracted much attention in the field of anticancer. In this study, six coumarin-modified cyclometallic Ir^Ⅲ salicylaldehyde Schiff base complexes ([(ppy)₂Ir(O^N)]/[(ppy-CHO)₂Ir(O^N)]) were designed and synthesized. Compared with coumarin and Ir^Ⅲ complex monomers, target complexes exhibited favorable cytotoxic activity toward A549 and BEAS-2B cells. These complexes could induce extensive apoptosis of A549 cell (late apoptosis), which was represented by the disturbance of cell cycle (G₁-phase) and the accumulation of intracellular reactive oxygen species, exhibiting an anticancer mechanism of oxidation. With the help of suitable fluorescence of these complexes, no conflict with the probes, confocal detection confirmed that complexes showed an energy-dependent cellular uptake mechanism and triggered lysosome-mediated apoptosis in A549 cell line. Above all, our findings reveal the design of a lysosomal targeting cyclometallic Ir^Ⅲ Schiff base complexes and provide a new idea for the design of integrated drugs for diagnosis and treatment.

Synthesis, characterization, biological properties, and molecular docking studies of new phosphoramide-based Ag(i) complexes

The effect of two new synthesized Ag(i) complexes on their biological properties was examined.

Coumarins and Gastrointestinal Cancer: A New Therapeutic Option?

Cancers of the gastrointestinal (GI) tract are often life-threatening malignancies, which can be a severe burden to the health care system. Globally, the mortality rate from gastrointestinal tumors has been increasing due to the lack of adequate diagnostic, prognostic, and therapeutic measures to combat these tumors. Coumarin is a natural product with remarkable antitumor activity, and it is widely found in various natural plant sources. Researchers have explored coumarin and its related derivatives to investigate their antitumor activity, and the potential molecular mechanisms involved. These mechanisms include hormone antagonists, alkylating agents, inhibitors of angiogenesis, inhibitors of topoisomerase, inducers of apoptosis, agents with antimitotic activity, telomerase inhibitors, inhibitors of human carbonic anhydrase, as well as other potential mechanisms. Consequently, drug design and discovery scientists and medicinal chemists have collaborated to identify new coumarin-related agents in order to produce more effective antitumor drugs against GI cancers. Herein, we summarize the therapeutic effects of coumarin and its derivatives against GI cancer.

(Amino)cyclophosphazenes as Multisite Ligands for the Synthesis of Antitumoral and Antibacterial Silver(I) Complexes

The reactivity of the multisite (amino)cyclotriphosphazene ligands, [N₃P₃(NHCy)₆] and [N₃P₃(NHCy)₃(NMe₂)₃], has been explored in order to obtain silver(I) metallophosphazene complexes. Two series of cationic silver(I) metallophosphazenes were obtained and characterized: [N₃P₃(NHCy)₆{AgL}_n](TfO)_n [n = 2, L = PPh₃ (2), PPh₂Me (4); n = 3, L = PPh₃ (3), PPh₂Me (5), TPA (TPA = 1,3,5-triaza-7-phosphaadamantane, 6)] and nongem-trans-[N₃P₃(NHCy)₃(NMe₂)₃{AgL}_n](TfO)_n [n = 2, L = PPh₃ (7), PPh₂Me (9); n = 3, L = PPh₃ (8), PPh₂Me (10)]. 5, 7, and 9 have also been characterized by single-crystal X-ray diffraction, thereby allowing key bonding information to be obtained. Compounds 2-6, 9, and 10 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria strains. Both the IC₅₀ and MIC values revealed excellent biological activity for these metal complexes, compared with their precursors and cisplatin and also AgNO₃ and silver sulfadiazine, respectively. Both IC₅₀ and MIC values are among the lowest values found for any silver derivatives against the cell lines and bacterial strains used in this work. The structure-activity relationships were clear. The most cytotoxic and antimicrobial derivatives were those with the triphenylphosphane and [N₃P₃(NHCy)₆] ligands. A significant improvement in the activity was also observed upon a rise in the number of silver atoms linked to the phosphazene ring.

Fluorescent iridium(iii) coumarin-salicylaldehyde Schiff base compounds as lysosome-targeted antitumor agents

Fluorescent iridium(iii) coumarin-salicylaldehyde Schiff base antitumor compounds change the ROS and ΔΨ_m, induce lysosomal damage, and lead to apoptosis.

Protective effect of hyperoside on heart failure rats via attenuating myocardial apoptosis and inducing autophagy

Heart failure (HF) is one of the most severe heart conditions, which lacks effective therapies. Therefore, it is necessary to develop more efficient drugs for HF. In this study, we investigated the cardioprotective effects of hyperoside against the pathological progression of HF. Thoracic aortic constriction (TAC) was performed to induce HF in rats. Hyperoside treatment improved cardiac function, decreased cardiomyocyte cross-sectional area and heart weight to body weight (HW/BW) ratio in HF rats. Moreover, hyperoside administration repressed apoptosis as evidenced by changing apoptosis-related protein levels, and promoted autophagy in TAC rats and angiotensin II (AngII)-induced H9C2 cells. Inhibition of autophagy by 3-methyladenine (3-MA) attenuated the beneficial effect of hyperoside against apoptosis in H9C2 cells. In summary, these data confirm that hyperoside effectively alleviates HF via suppressing apoptosis and inducing autophagy, which provides evidence that hyperoside may serve as a promising natural drug for treating HF.

Phenethyl isothiocyanate induces IPEC-J2 cells cytotoxicity and apoptosis via S-G2/M phase arrest and mitochondria-mediated Bax/Bcl-2 pathway

Phenethyl isothiocyanate (PEITC) is one of the glucosinolates (GLs) present in cruciferous vegetables. Although there are many reports of livestock and poultry poisoning caused by plants containing GLs, the actual dosage that causes poisoning and the characteristics of GLs and their metabolites are unclear. Herein, we investigated the inhibitory effects of PEITC on IPEC-J2 cells and examined the mechanisms of PEITC-induced apoptosis via the mitochondrial pathway. Cell viability was determined by the MTT assay, and the levels of reactive oxygen species, mitochondrial membrane potential (∆Ψ), intracellular Ca²⁺ concentration, and cell apoptosis were detected by flow cytometry. IPEC-J2 cells were collected to assess the activities of superoxide dismutase, catalase, and glutathione peroxidase, as well as the contents of glutathione, malondialdehyde, H₂O₂, ATP, and lactate dehydrogenase, using biochemical methods. The levels of cytochrome c, Bax, Bcl-2, caspase-3, caspase-9, poly (ADP-ribose) polymerase (PARP)-1, p53, CDC25C, and cyclin A2 were analyzed by western blotting. We found that PEITC effectively inhibited the growth of IPEC-J2 cells, causing apoptosis. PEITC suppressed the level of mitochondrial membrane potential; released cytochrome c from the mitochondria to the cytoplasm; reduced ATP levels; inhibited Bcl-2 expression; increased Bax expression; and activated caspase-9, caspase-3, and PARP-1, leading to apoptosis. PEITC also induced G₂/M and S phase arrest by affecting cell cycle-associated proteins such as p53, CDC25C, and cyclin A2. We conclude that PEITC causes oxidative stress, cell cycle arrest, and apoptosis in IPEC-J2 cells via a mitochondrial-dependent Bax/Bcl-2 pathway.

Self-Assembled Metal-Organic Biohybrids (MOBs) Using Copper and Silver for Cell Studies

The novel synthesis of metal-containing biohybrids using self-assembly methods at physiological temperatures (37 °C) was compared for copper and silver using the amino acid dimer cystine. Once assembled, the copper containing biohybrid is a stable, high-aspect ratio structure, which we call CuHARS. Using the same synthesis conditions, but replacing copper with silver, we have synthesized cystine-capped silver nanoparticles (AgCysNPs), which are shown here to form stable colloid solutions in contrast to the CuHARS, which settle out from a 1 mg/mL solution in 90 min. Both the copper and silver biohybrids, as synthesized, demonstrate very low agglomeration which we have applied for the purpose of applications with cell culture methods, namely, for testing as anti-cancer compounds. AgCysNPs (1000 ng/mL) demonstrated significant toxicity (only 6.8% viability) to glioma and neuroblastoma cells in vitro, with concentrations as low as 20 ng/mL causing some toxicity. In contrast, CuHARS required at least 5 μg/mL. For comparative purposes, silver sulfate at 100 ng/mL decreased viability by 52% and copper sulfate at 100 ng/mL only by 19.5% on glioma cells. Using these methods, the novel materials were tested here as metal–organic biohybrids (MOBs), and it is anticipated that the functionalization and dynamics of MOBs may result in building a foundation of new materials for cellular applications, including cell engineering of both normal and diseased cells and tissue constructs.

Spectroscopic, Computational, Antimicrobial, DNA Interaction, In Vitro Anticancer and Molecular Docking Properties of Biochemically Active Cu(II) and Zn(II) Complexes of Pyrimidine-Ligand

Biochemically active Cu(II) and Zn(II) complexes [CuL(ClO₄)₂(1) and ZnL(ClO₄)₂(2)] have been synthesized from N,N donor Schiff base ligand L derived from4,6-dichloropyrimdine-5-carboxaldehyde with 4-(2-aminoethyl)morpholine. The L, complexes 1 and 2 have been structurally characterized by elemental analysis, ¹H-NMR, FTIR, MS, UV-Visible and ESR techniques. The results obtained from the spectral studies supports the complexes 1 and 2 are coordinated with L through square planar geometry. DFT calculations results supports, the ligand to metal charge transfer mechanism can occur between L and metal(II) ions. The antimicrobial efficacy results have been recommended that, complexes 1 and 2 are good anti-pathogenic agents than ligand L. The interaction of complexes 1 and 2 with calf thymus (CT) DNA has been studied by electronic absorption, viscometric, fluorometric and cyclic voltammetric measurements. The calculated K_b values for L, complexes 1 and 2 found from absorption titrations was 4.45 × 10⁴, L; 1.92 × 10⁵, 1 and 1.65 × 10⁵, 2. The Ksv values were found to be 3.0 × 10³, 3.68 × 10³and 3.52 × 10³ for L, complexes 1 and 2 by using competitive binding with ethidium bromide (EB). These results suggest that, the compounds are interacted with DNA may be electrostatic binding. The molecular docking studies have been carried out to confirm the interaction of compounds with DNA. Consequently, in vitro anticancer activities of L, complexes 1 and 2 against selected cancer (lung cancer A549, liver cancer HepG2 and cervical carcinoma HeLa) and normal (NHDF) cell lines were assessed by MTT assay.

Sterically modulated silver(I) complexes of coumarin substituted benzimidazol-2-ylidenes: Synthesis, crystal structures and evaluation of their antimicrobial and antilung cancer potentials

In this contribution, a series of sterically-encumbered coumarin substituted benzimidazole-based N-heterocyclic carbene (NHC) precursors (1-12) and their silver(I)-NHC complexes (13-24) are reported. Molecular structure of NHC precursors 8 and 12 and cationic complexes 15 and 16 was established by single crystal X-ray diffraction method. The silver(I) complexes demonstrated various significant intramolecular agostic-like interactions operating between the metal center and the hydrogen atoms of the substituents alongside a variety of feeble π-π stacking interactions. A distorted linear coordination geometry is documented at the silver(I) center with the anti-arrangement of the ligands. Further, the complexes demonstrated promising antibacterial properties against Gram positive and Gram negative bacterial strains, especially complex 18 displayed a minimum inhibitory concentration (MIC) of 2 and 4 μg/mL against S. aureus and E. coli, and P. aeruginosa, respectively. Furthermore, complexes 14, 15, 16 and 18 were found cytotoxic against the human lung cancer cell lines A549 and H1975 with the IC₅₀ (concentration of the test sample required to kill 50% of the cell population) value under 10 μM, while mono-NHC complex 20 displayed a potential drug window with the IC₅₀ of 13.7 ± 2.70 and 14.5 ± 1.20 μM against the cancer cell lines H1975 and A549, respectively. Notably, these complexes displayed relatively lesser cytotoxic behaviour against the normal skin fibroblast cell line, Hs68. All the NHC precursors displayed significantly lower biological activities compared with their respective complexes, indicating the utility of silver(I) ions in antimicrobial and antilung cancer applications.

The ability of silver(I) thiocyanate 4-methoxyphenyl phosphine to induce apoptotic cell death in esophageal cancer cells is correlated to mitochondrial perturbations

First generation silver(I) phosphines have garnered much interest due to their vast structural diversity and promising anticancer activity. Increasing incidences of cancer, side-effects to chemotherapeutic agents and redevelopment of tumors due to resistance prompts the exploration of alternative compounds showing anticancer activity. This study revealed the effective induction of cell death by a silver(I) thiocyanate 4-methoxyphenyl phosphine complex in a malignant esophageal cell line. Apoptotic cell death was confirmed in treated cells. Moreover, mitochondrial targeting via the intrinsic cell death pathway was evident due to low levels of ATP, altered ROS activity, mitochondrial membrane depolarization, cytochrome c release and caspase-9 cleavage. The complex displayed low cytotoxicity towards two human non-malignant, skin and kidney, cell lines. The findings reported herein give further insight into the selective targeting of silver(I) phosphines and support our belief that this complex shows great promise as an effective chemotherapeutic drug.

Cytotoxic, anti-proliferative and apoptotic effects of silver nitrate against H-ras transformed 5RP7

Metal based drugs have successfully been used in both the detection and treatment of different disease states. The antibacterial features of metal ion silver are well documented. Most recently, metal ion silver has been tested and applied in anticancer activity. The present study observed the cytotoxic, anti-proliferative and apoptotic effects of metal complex silver nitrate in H-ras transformed 5RP7 cell lines for 24 h. In addition, the toxic effects of silver nitrate was investigated on NIH/3T3 primary mouse embryonic fibroblast cells for 24 h. Cytotoxic effects were determined by MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay. Apoptosis and necrosis were evaluated by flow cytometric analysis (Annexin-V FITC/PI). Caspase-3 activation was researched by flow cytometric analysis. Apoptotic morphology was observed by DAPI staining. Structure and ultra-structure changes of cells were assessed using transmission electron microscopy. The results indicate silver nitrate has high cytotoxicity and a strong capacity to induce apoptosis in H-ras 5RP7 cells. Furthermore silver nitrate was not toxic against NIH/3T3 primary mouse embryonic fibroblast cells at low doses for 24 h.

Human colon cancer targeted pro-apoptotic, anti-metastatic and cytostatic effects of binuclear Silver(I)-N-Heterocyclic carbene (NHC) complexes

The current mechanistic study was conducted to explore the effects of increased lipophilicity of binuclear silver(I)-NHC complexes on cytotoxicity. Two new silver(I)-N-Heterocyclic Carbene (NHC) complexes (3 and 4), having lypophilic terminal alkyl chains (Octyl and Decyl), were derived from meta-xylyl linked bis-benzimidazolium salts (1 and 2). Each of the synthesized compounds was characterized by microanalysis and spectroscopic techniques. The complexes were tested for their cytotoxicity against a panel of human cancer c as well normal cell lines using MTT assay. Based on MTT assay results, complex 4 was found to be selectively toxic towards human colorectal carcinoma cell line (HCT 116). Complex 4 was further studied in detail to explore the mechanism of cell death and findings of the study revealed that complex 4 has promising pro-apoptotic and anti-metastatic activities against HCT 116 cells. Furthermore, it showed pronounced cytostatic effects in HCT 116 multicellular spheroid model. Hence, binuclear silver(I)-NHC complexes with longer terminal aliphatic chains have worth to be further studied against human colon cancer for the purpose of drug development.

Synthesis, chemical identification, antioxidant capacities and immunological evaluation studies of a novel silver(I) carbocysteine complex

A new silver-carbocysteine (Ccy-Ag) complex [Ag2(Ccy)2(H2O)2] has been synthesized and characterized by using a combination of FTIR, Raman, molar conductivity, (1)H NMR, electronic spectra, thermal analyses, X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The infrared spectrum of Ccy-Ag complex in comparison with carbocysteine ligand prove that Ccy behaves as monobasic bidentate chelate to the silver metal ions via the deprotonated carboxylate O atom. The assessments of Ccy and its complexation with Ag(+) in treating COPD, evaluating immune activities through measuring IL-8, TGF-β1, VEGF and TNF-α, antioxidant activities of (Ccy-Ag) complex by measuring SOD, MDA and GPX and bronchial asthma were discussed.

Synthesis and characterization of two novel dicyanidoargentate(i) complexes containing N-(2-hydroxyethyl)ethylenediamine exhibiting significant biological activity

Two novel cyanido-complexes having very significant antibacterial, antifungal and anticancer activities in vitro were synthesized and characterized using various techniques.

Anti-proliferative and anti-tumor activity of silver(I) compounds

Silver is proving to have a number of medicinal applications; as an antiseptic, an antibacterial, and an anti-inflammatory, while any biological role for it is currently unknown. Silver compounds and their therapeutic potentials are under consideration from many research groups, while a number of early reviews recording the advances of silver(I) chemistry are also available. However there is no recent report on the screening for the antitumor potential of silver(I) compounds. This review focuses upon results obtained on the anti-proliferative activity of silver compounds in the past years. This survey shows that silver(I) complexes containing various type of ligands such as carboxylic acids, amino acids, nitrogen, phosphorus or sulfur donor ligands, exhibit selectivity against a variety of cancer cells. The role of the coordination number, which is related to either the stability or hydrophilicity-lipophilicity of a complex, is not clearly elucidated within this review.

Phenethyl isothiocyanate triggers apoptosis in human malignant melanoma A375.S2 cells through reactive oxygen species and the mitochondria-dependent pathways

We have reported previously that phenethyl isothiocyanate (PEITC) induces apoptosis in human osteosarcoma U-2 OS cells. Cytotoxic activity of PEITC towards other cancer cells such as human malignant melanoma and skin cancer cells has not been reported. In this study, the anticancer activity of PEITC towards human malignant melanoma cancer A375.S2 cells was investigated. To determine the mechanisms of PEITC inhibition of cell growth, the following end points were determined in A375.S2 cells: cell morphological changes, cell cycle arrest, DNA damage and fragmentation assays and morphological assessment of nuclear change, reactive oxygen species (ROS) and Ca(2+) generations, mitochondrial membrane potential disruption, and nitric oxide and 10-N-nonyl acridine orange productions, expression and activation of caspase-3 and -9, B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), Bcl-2, poly (adenosine diphosphate-ribose) polymerase, and cytochrome c release, apoptosis-inducing factor and endonuclease G. PEITC induced morphological changes in time- and dose-dependent manner. PEITC induced G2/M phase arrest and induced apoptosis via endoplasmic reticulum stress-mediated mitochondria-dependent pathway. Western blot analysis showed that PEITC promoted Bax expression and inhibited Bcl-2 expression associated with the disintegration of the outer mitochondrial membrane causing cytochrome c release, and activation of caspase-9 and -3 cascade leading to apoptosis. We conclude that PEITC-triggered apoptotic death in A375.S2 cells occurs through ROS-mediated mitochondria-dependent pathways.

7,8-Dihydroxycoumarin inhibits A549 human lung adenocarcinoma cell proliferation by inducing apoptosis via suppression of Akt/NF-κB signaling

The Akt/NF-κB pathways are involved in numerous anti-apoptotic and drug-resistance events that occur in non-small cell lung cancer (NSCLC). In the present study, the role of 7,8-dihydroxycoumarin in the regulation of the anti-apoptotic Akt and NF-κBp65 signaling pathways was explored. A549 human lung adenocarcinoma cells were exposed to 7,8-dihydroxycoumarin with a final concentration of 25, 50 and 100 μmol/l for 48 h. Quantitative polymerase chain reaction (PCR) and western blotting were performed to detect mRNA and protein expression, respectively. The MTT assay was performed to detect cell proliferation. The results demonstrated that anti-apoptotic phospho-Akt1 (pAkt1), phospho-IκBα (pIκBα), NF-κBp65 and Bcl-2 were inhibited and pro-apoptotic caspase-3 was upregulated in a concentration-dependent manner. At a concentration of 100 μmol/l, the anti-apoptotic NF-κBp65 and Bcl-2 mRNA expression levels decreased 0.12 (5.82/48.5, treated/control)-fold and 0.17 (6.7/39.4, treated/control)-fold, respectively. The pro-apoptotic caspase-3 mRNA was upregulated 4.43 (39.4/8.9, treated/control)-fold. The anti-apoptotic pAkt1, pIκBα, NF-κBp65 and Bcl-2 proteins were downregulated, with blot grayscale values of 7.3 (vs. 52.4 control), 4.3 (vs. 42.2 control), 5.08 (vs. 44.5 control) and 5.92 (vs. 38.5 control), respectively. The proapoptotic caspase-3 was upregulated to a blot grayscale value of 27.8 (vs. 5.8 control). The proliferative activity of A549 cells was reduced significantly compared with that of the control cells (83.7, 27.2 and 9.5 vs. 100%, respectively; P<0.05 for each). 7,8-Dihydroxycoumarin plays an important role in the induction of apoptosis via suppression of Akt/NF-κB signaling in A549 human lung adenocarcinoma cells in a concentration-dependent manner. 7,8-Dihydroxycoumarin may be a candidate naturally-occurring drug for the treatment and prevention of lung adenocarcinoma.

Chamaejasmine arrests cell cycle, induces apoptosis and inhibits nuclear NF-κB translocation in the human breast cancer cell line MDA-MB-231

In this study, the anticancer activity of chamaejasmine was characterized in the human breast cancer cell line, MDA-MB-231. Cell viability and cell cycle distribution were determined by MTT assay and flow cytometry, respectively. Western blotting was performed to determine changes in levels of various proteins. Results showed that treatment with chamaejasmine (4–16 μM) inhibited cell proliferation, which correlated with G2/M phase arrest and apoptosis in MDA-MB-231 cells. Chamaejasmine treatment of MDA-MB-231 cells resulted in induction of WAF1/p21 and KIP1/p27, decrease in cyclins A and cyclins B1. Cyclin-dependent kinase (cdk) 2 and cdc2 was also decreased after chamaejasmine treatment. Moreover, inhibition of nuclear translocation, phosphorylation of NF-κB, activation of IKKα and IKKβ, inhibition of phosphorylation and degradation of IκBα were also detected in this work. Our findings suggested that chamaejasmine could be explored as a preventive and perhaps as a chemotherapeutic agent in the management of breast cancer.

Effects of the cyclin-dependent kinase 10 (CDK10) on the tamoxifen sensitivity of keloid samples

Cyclin-dependent kinase 10 (CDK10) is a cell cycle regulating protein kinase, which has just been discriminated in recent years. In this paper, mRNA and protein expression of CDK10 were first investigated by a comparative study between 23 human keloid tissue samples and their adjacent normal skin. To further address its potential as a therapeutic target in the treatment of keloid, a plasmid expressing the CDK10 gene was transfected into keloid fibroblast. The effects on tamoxifen-induced apoptosis were then investigated using Western blot assay and flow cytometry. Results showed that there is a generally down-regulated expression of CDK10 in keloid compared to normal skin samples. Transfection with the recombinant CDK10 plasmid significantly decreased the viability of cells and increased the apoptosis rates. Tamoxifen sensitivity in keloid fibroblasts was observed after treatment with the recombinant CDK10 plasmid. The results suggested that CDK10 may play an important role in enhancement of tamoxifen efficiency, and its expression may have a synergistic effect on keloid treatments.

Modulation of the differentiation of dental pulp stem cells by different concentrations of β-glycerophosphate

Dentinogenesis is a necessary prerequisite for dental tissue engineering. One of the steps for dentinogenesis is to obtain large quantities of highly purified odontoblasts. Therefore, we have undertaken an experiment applying different concentrations of β-glycerophosphate (β-GP) to induce the differentiation of dental pulp stem cells (DPSCs) in a long-term 28-day culture. In the meanwhile, we have studied the time- and maturation-dependent expression of matrix extracellular phosphoglycoprotein (MEPE) and that of the odontoblast-like marker-dentin sialoprotein (DSP), in order to investigate an optimized mineralized condition. Western blot results revealed that the expression of DSP became lower when accompanied by the increase of the β-GP concentration, and there was also an influence on MEPE expression when different concentrations of β-GP were applied. Meanwhile, the mineralized groups had an inhibitory function on the expression of MEPE as compared with the control group. Above all, all experimental groups successfully generated mineralized nodules by Alizarin Red S and the 5 mM β-GP group formed more mineralized nodules quantitated using the CPC extraction method. In conclusion, there is a significant modulation of the β-GP during the differentiation of the DPSCs. The degree of odontoblast differentiation is β-glycerophosphate concentration dependent. A low concentration of β-GP (5 mM) has been shown to be the optimal concentration for stimulating the maturation of the DPSCs. Moreover, MEPE accompanied with DSP clearly demonstrates the degree of the differentiation.

Chamaejasmine inactivates Akt to trigger apoptosis in human HEp-2 larynx carcinoma cells

In the present study, we investigated the mechanisms of chamaejasmine action on human HEp-2 larynx carcinoma cells, which possess constitutively active Akt. Results indicated that chamaejasmine showed more notable anticancer activity than apigenin against HEp-2, PC-3, NCI-H1975, HT-29 and SKOV-3. Moreover, chamaejasmine presented most significantly inhibition towards HEp-2, with IC₅₀ values of 1.92 µM. Treatment of HEp-2 cells with chamaejasmine (1–4 μM) resulted in significant dose-dependent decrease in Akt phosphorylation at Serine473. Chamaejasmine-mediated dephosphorylation of Akt resulted in inhibition of its kinase activity, which was confirmed by reduced phosphorylation of proapoptotic proteins BAD and glycogen synthase kinase-3, essential downstream targets of Akt. Inactivation of Akt seems to be associated with downregulation of insulin-like growth factor receptor 1 protein level and inhibition of its autophosphorylation upon chamaejasmine treatment. Exposure to chamaejasmine significantly induced caspase-9 and caspase-3 activity. In vivo, chamaejasmine intake through gavage resulted in inactivation of Akt and induction of apoptosis in HEp-2 tumors. These results suggest that Akt inactivation and dephosphorylation of BAD is a critical event, at least in part, in chamaejasmine-induced HEp-2 cells apoptosis.

Chamaejasmine induces apoptosis in human lung adenocarcinoma A549 cells through a Ros-mediated mitochondrial pathway

In the present study, the anticancer activity of chamaejasmine towards A549 human lung adenocarcinoma cells was investigated. In order to explore the underlying mechanism of cell growth inhibition of chamaejasmine, cell cycle distribution, ROS generation, mitochondrial membrane potential (Δψ_m) disruption, and expression of cytochrome c, Bax, Bcl-2, caspase-3, caspase-9 and PARP were measured in A549 cells. Chamaejasmine inhibited the growth of A549 cells in a time and dose-dependent manner. The IC₅₀ value was 7.72 µM after 72 h treatment. Chamaejasmine arrested the cell cycle in the G2/M phase and induced apoptosis via a ROS-mediated mitochondria-dependent pathway. Western blot analysis showed that chamaejasmine inhibited Bcl-2 expression and induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascade, and active-caspase-3 was involved in PARP cleavage. All of these signal transduction pathways are involved in initiating apoptosis. To the best of our knowledge, this is the first report demonstrating the cytotoxic activity of chamaejasmine towards A549 in vitro.

Copper, gold and silver compounds as potential new anti-tumor metallodrugs

Although platinum-based drugs such as cisplatin are powerful anticancer agents, they have undesirable side effects and are effective against only a few kinds of cancers. There is, therefore, a need for new drugs with an improved spectrum of efficacy and lower toxicity. Complexes of copper, gold and silver (coinage metals) are potential candidates to fullfill this need. The development of anticancer drugs based on these metals is currently a very active field. Considerable effort has also been put into elucidating the mechanisms of action of these complexes and optimizing their bioactivity through structural modification. In this review, we highlight recent developments in the design of coinage metal complexes with anti-tumor activity and discuss the emerging importance of quantitative structure–activity relationship methods in the study of anticancer metal complexes. Future work in this field, including likely coinage metal complexes that will attract attention, are proposed.

Cajanol, a novel anticancer agent from Pigeonpea [Cajanus cajan (L.) Millsp.] roots, induces apoptosis in human breast cancer cells through a ROS-mediated mitochondrial pathway

Cajanol (5-hydroxy-3-(4-hydroxy-2-methoxyphenyl)-7-methoxychroman-4-one) is an isoflavanone from Pigeonpea [Cajanus cajan (L.) Millsp.] roots. As the most effective phytoalexin in pigeonpea, the cytotoxic activity of cajanol towards cancer cells has not been report as yet. In the present study, the anticancer activity of cajanol towards MCF-7 human breast cancer cells was investigated. In order to explore the underlying mechanism of cell growth inhibition of cajanol, cell cycle distribution, DNA fragmentation assay and morphological assessment of nuclear change, ROS generation, mitochondrial membrane potential (DeltaPsim) disruption, and expression of caspase-3 and caspase-9, Bax, Bcl-2, PARP and cytochrome c were measured in MCF-7 cells. Cajanol inhibited the growth of MCF-7 cells in a time and dose-dependent manner. The IC(50) value was 54.05 microM after 72 h treatment, 58.32 microM after 48 h; and 83.42 microM after 24h. Cajanol arrested the cell cycle in the G2/M phase and induced apoptosis via a ROS-mediated mitochondria-dependent pathway. Western blot analysis showed that cajanol inhibited Bcl-2 expression and induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascade, and active-caspase-3 was involved in PARP cleavage. All of these signal transduction pathways are involved in initiating apoptosis. To the best of our knowledge, this is the first report demonstrating the cytotoxic activity of cajanol towards cancer cells in vitro.