A new series of thiazole-hydrazone hybrids for Akt-targeted therapy of non-small cell lung cancer

In an attempt to identify potent antitumor agents for the fight against non-small cell lung cancer, new thiazolyl hydrazones ( 2a–n ) were synthesized and examined for their in vitro cytotoxic effects on A549 human lung adenocarcinoma and L929 mouse embryonic fibroblast cells by means of the MTT assay. Furthermore, the effects of the most potent anticancer agents on apoptosis and Akt inhibition were investigated. 2-[2-((Isoquinolin-5-yl)methylene)hydrazinyl]−4-(4-methylsulfonylphenyl)thiazole ( 2k ) (IC₅₀ = 1.43 ± 0.12 µM) and 2-[2-((isoquinolin-5-yl)methylene)hydrazinyl]−4-(1,3-benzodioxol-5-yl)thiazole ( 2l ) (IC₅₀ = 1.75 ± 0.07 µM) displayed more pronounced anticancer activity than cisplatin (IC₅₀ = 3.90 ± 0.10 µM) on A549 cell lines; 2-[2-((isoquinolin-5-yl)methylene)hydrazinyl]−4-(4-methoxyphenyl)thiazole ( 2j ) (IC₅₀ = 3.93 ± 0.06 µM) showed anticancer activity close to cisplatin. These compounds were found to induce apoptosis in A549 cells. Compound 2j (IC₅₀ = 3.55 ± 0.64 µM) showed stronger Akt inhibitory activity than GSK690693 (IC₅₀ = 4.93 ± 0.06 µM), while compounds 2k and 2l did not cause Akt inhibition at IC₅₀ concentrations (1.43 and 1.75 µM, respectively). To comprehensively elucidate the binding pose of compound 2j and to provide a detailed understanding on the ligand' binding mechanism, induced-fit docking calculations were also conducted. Both in vitro and in silico studies suggest that compound 2j shows its cytotoxic and apoptotic effects on A549 cell lines via Akt inhibition. However, it is understood that compounds 2k and 2l exert their strong anticancer effects on A549 cells through different pathways.     

Anticancer effect of Cenchrus ciliaris L

Cenchrus ciliaris L total alcohol and successive extracts of both aerial and root parts were tested for their anticancer activities against lung (A-549), intestinal (CACO), colon (HCT-116), cervical (Hela), hepatocellular (HepG-2), and breast (MCF-7) (PC3) cell lines and compared with the standard drug vinblastine sulphate. The obtained results exhibited direct cytotoxic effect with variable inhibiting effect on the growth of the listed cell lines comparing to vinblastine sulphate as reference standard drug, these effects showed different IC₅₀ ranged from 11.1?±?0.3 to 267?±?µg/ml.All root extracts showed the best activities against most of the tested cell lines specially HepG-2 (Hepatocellular carcinoma) (9?±?2.1?µg/ml) which was somewhat closely related to the effect of vinblastine sulphate (2.93?±?0.3?µg/ml).The highest anticancer effect of Cenchrus ciliaris L aerial parts and root extracts were recorded on HepG-2 (Hepatocellular carcinoma) their IC₅₀ were 12?±?0.8 & 9?±?2.1 respectively, CACO (colorectal carcinoma) their IC₅₀ were 27.2?±?1.6 & 20.5?±?0.6 respectively, A-549 (Lung carcinoma) their IC₅₀ were 14.5?±?0.7& 11.1?±?0.3 respectively which were better than the standard drug especially in case the anticancer effect on CACO (colorectal carcinoma) and A-549 (Lung carcinoma). Chloroform extracts of both aerial and roots achieved the best anticancer activities on all of the cell lines especially with colorectal (CACO) and Lung carcinoma (A-549). Cenchrus ciliaris could be a promising source of new chemical moieties used to target cancer cells.     

High bisphenol A concentrations augment the invasiveness of tumor cells through Snail-1/Cx43/ERRγ-dependent epithelial-mesenchymal transition

Bisphenol A (BPA) is commonly present in plastics used for food storage and preservation. The release of BPA from these products results in a permanent human exposition to BPA; however, the quality and quantity of BPA adverse effects remain a matter of controversy. The common presence of BPA in the human environment and the controversies concerning the relations of human exposition to BPA and cancer incidence justify the research on the interactions between BPA and pro-metastatic signaling in cancer cells. Here, we describe a novel BPA-reactive signaling axis that induces the epithelial-mesenchymal transition (EMT) in lung adenocarcinoma A549 cells. BPA exerted negligible effects on their properties in a wide range of concentrations (10 nM - 100 nM), whereas it considerably induced A549 invasiveness at high concentrations (10 μM). The BPA-induced EMT was illustrated by morphologic changes, E/N-cadherin switch and vimentin/Snail-1/connexin(Cx)43 up-regulation in A549 populations. It was followed by enhancement of A549 drug-resistance. Corresponding effects of BPA were observed in prostate cancer cell populations. Concomitantly, we observed increased levels and perinuclear accumulation of estrogen-related receptor gamma (ERRγ) in BPA-treated cells, its interactions with Cx43/Snail-1, and the corresponding effects of phenol red on A549 cells. Collectively, these data identify a novel, pro-metastatic Snail-1/Cx43/ERRγ signaling pathway. Its reactivity to BPA underlies the induction of cancer cells' invasiveness in the presence of high BPA concentrations in vitro. Thus, the chronic exposition of cancer cells to extrinsic and intrinsic BPA should be considered as a potential obstacle in a cancer therapy.     

Anti-angiogenic activity of salvicine

Abstract

Context: Salvicine is a pharmacologically active derivative from Chinese medicinal plant Salvia prionitis Hance (Labiatae). It has been reported that salvicine inactivates β1 integrin and inhibits integrin-mediated cell adhesion to fibronectin. Given the emerging correlation between integrins and angiogenesis, we propose that salvicine abolishes cell adhesion and subsequent metastasis by inhibiting angiogenisis.

Objective: The anti-angiogenesis activities of salvicine were investigated for the first time.

Materials and methods: The cytotoxicity of salvicine on human microvascular endothelial cells (HMECs) and non-small cell lung adenocarcinoma A549 cells were measured at doses between 0.625 and 200?µM. Changes of cell migration were detected with doses of salvicine at 1.25–5?µM, and basement membrane matrigel matrix was used for the assessment of tube formation at concentrations ranging from 0.078 to 1.25?µM. In addition, mRNA expression of basic fibroblast growth factor (bFGF) in A549 cells was studied with the RT-PCR assay.

Results: In vitro studies revealed that the IC₅₀ of salvicine on A549 cells (18.66?µM) was two-fold higher than that of HMECs (7.91?µM). Salvicine (1.25, 2.5 and 5.0?μM) inhibited significantly the endothelial cell migration up to 56, 73 and 82%, respectively. Salvicine decreased capillary-like tube formation of HMECs with high potency. Furthermore, it (30?µM) markedly reduced the mRNA expression of bFGF in A549 cells, while vascular endothelial growth factor (VEGF) mRNA expression remained unchanged.

Discussion and conclusion: Our results suggest that salvicine has potent anti-angiogenic activity through the inhibition on the sequential angiogenic cascades: proliferation, migration and tube formation and is associated with influence on the expression of bFGF of tumor cell.     

Comparative proteomic analysis of cellular response of human airway epithelial cells (A549) to benzo(a)pyrene

This work aimed to investigate the cellular response of human airway epithelial cells (A549) to oxidative stress induced by benzo(a)pyrene [B(a)P]. Levels of intracellular reactive oxygen species (ROS) and lipid peroxidation were investigated in A549 cells treated with varying concentrations of B(a)P. A comparative proteomic analysis of total proteins was performed in cells treated with 1 µM B(a)P [B(a)P-1] and untreated cells. The expression of Mn superoxide dismutase (Mn SOD), one of the identified down-regulated proteins in B(a)P-1 cells, was then analyzed by Western blotting. The total antioxidant activity, total superoxide dismutase activity, catalase (CAT) activity, and glutathione reductase (GR) activity were all analyzed after B(a)P treatment. Our results demonstrated that 1 µM B(a)P could induce ROS generation and lead to lipid peroxidation in A549 cells, and 23 differentially expressed proteins were identified. The expression levels of Mn SOD and the total SOD were induced at 0.1 µM and suppressed at 1 µM and 10 µM. Up-regulation of CAT and GR activity resulted in an increase in total antioxidant activity in A549 after exposure to B(a)P. These findings provide a basis for understanding the mechanisms of mitochondrial dysfunction and perturbation of antioxidant status induced by B(a)P on airway epithelial cells.     

Synthesis and cytotoxic evaluation of some new phthalazinylpiperazine derivatives

A new series of 1,4‐disubstituted phthalazinylpiperazine derivatives 7a–f , 12a–f and 20a–f were designed and synthesized in order to develop potent and selective antitumor agents. The target compounds were screened for their cytotoxic activities against A549, HT‐29 and MDA‐MB‐231 cancer cell lines in vitro. Among them, compounds 7a–f exhibited excellent selectivity for MDA‐MB‐231 with IC₅₀ values ranging from 0.013 µM to 0.079 µM. The most promising compound, 7e (IC₅₀ = 2.19 µM, 2.19 µM, 0.013 µM), was 9.3, 10, and 4.9 × 10³ times more active than vatalanib (IC₅₀ = 20.27 µM, 21.96 µM, 63.90 µM), respectively.     

3′-(4-(Benzyloxy)phenyl)-1′-phenyl-5-(heteroaryl/aryl)-3,4-dihydro-1′H,2H-[3,4′-bipyrazole]-2-carboxamides as EGFR kinase inhibitors: Synthesis,anticancer evaluation,and molecular docking studies

Pyrazoline-linked carboxamide derivatives were designed, synthesized, and evaluated for potential epidermal growth factor receptor (EGFR) kinase inhibition, anticancer activity, and apoptotic and cardiomyopathy toxicity. Compounds 6m and 6n inhibit EGFR kinase at a concentration of 6.5 ± 2.91 and 3.65 ± 0.54 µM, respectively. Some of these compounds showed effects on proliferation, which were also then evaluated against four different human cancer cell lines, that is, MCF-7 (breast cancer), A549 (non-small-cell lung tumor), HCT-116 (colon cancer), and SiHa cells (cancerous tissues of the cervix uteri). The results showed that certain synthetic compounds showed significant inhibitor activity; compounds 6m and 6n were more cytotoxic than doxorubicin against A549 cancer cells, with IC₅₀ values of 10.3 ± 1.07 and 4.6 ± 0.57 µM, respectively. Additionally, compounds 6m and 6n induced apoptosis in A549 cancer cells, as evidenced by 4′,6-diamidino-2-phenylindole (DAPI) staining and phase-contrast microscopy. Potency to induce apoptosis by compound 6n was further confirmed by fluorescence-activated cell sorting using Annexin V-FITC and propidium iodide labeling. Compound 6n showed normal cardiomyocytes with no marked sign of pyknotic nuclei in cardiomyopathy and also normal histological appearance of the renal cortex when compared with that of control. Results of molecular docking studies suggested that compounds 6m and 6n can bind to the hinge region of the adenosine triphosphate-binding site of EGFR kinase, like the standard drug erlotinib. Therefore, the present study suggests that compounds 6m and 6n have potent in vitro antitumor activities against the human non-small-cell lung tumor cell line A549, which can be further explored in other cancer cell lines and in animal studies.     

Enhanced P53 and BAX gene expression and apoptosis in A549 cells by cis-Pt(II) complex of 3-aminoflavone in comparison with cis-DDP

Lung cancer remains one of the most common causes of cancer-related death worldwide. Approximately 80% is histologically non-small cell lung carcinoma (NSCLC) and in about 70% of patients it is an unresectable type. Clinical studies indicated that application of platinum derivatives caused good results and combinations of platinum with other agents could improve median survivals. In view of the central problem of sufficient efficiency of drugs in chemotherapy, efforts have focused on the development of alternative platinum-based analogues that can be more effective in cancer treatment. cis-bis(3-aminoflavone)dichloroplatinum(II) (cis-Pt(II) complex of 3-aminoflavone) represents a novel class of platinum-based potential antitumour agents. In order to evaluate the degree of apoptosis, acridine orange/ethidium bromide and Hoechst 33258/propidum iodide double staining as well as RT-PCR (P53 and BAX expression evaluation) were used in lung cancer cell line A549 after treatment with this compound in comparison with cis-diamminedichloroplatinum(II) (cis-DDP). Apoptotic cells at early and late stages and also necrotic ones were observed after usage of cis-Pt(II) complex of 3-aminoflavone and the percentage of these cells outnumbered the values obtained after cis-DDP application. The former compound induced a higher percentage of P53 and BAX expression in A549 cells in comparison with the latter one. Results indicate the beneficial properties of cis-Pt(II) complex of 3-aminoflavone as a potential antitumor drug.     

Antiproliferative and apoptotic activities of extracts of Asclepias subulata

Abstract

Context: Asclepias subulata Decne. (Apocynaceae) is a shrub used in the Mexican traditional medicine for the treatment of cancer.

Objective: The objective of this study was to evaluate the antiproliferative activity of methanol extract of aerial parts of A. subulata and its fractions against different cancer cell lines. Additionally, we analyzed the mechanism of action of the active fractions.

Materials and methods: Methanol extract fractions were prepared by serial extraction with n-hexane, ethyl acetate, and ethanol. The antiproliferative activity of methanol extract and its fractions was evaluated, against several murine (M12.C3.F6, RAW 264.7, and L929) and human (HeLa, A549, PC-3, LS 180, and ARPE-19) cell lines by the MTT assay, using concentrations of 0.4–400?µg/mL for 48?h. Ethanol and residual fractions were separated using silica gel column. Apoptosis induction of cancer cells was evaluated by Annexin and JC-1 staining using flow cytometry.

Results: Methanol extract and its fractions showed antiproliferative activity against all human cancer cell lines tested. Methanol extract had the highest antiproliferative activity on A549 and HeLa cells (IC₅₀ values?<?0.4 and 8.7?µg/mL, respectively). Ethanol and residual fractions exerted significant antiproliferative effect on A549 (IC₅₀?<?0.4?µg/mL) and PC3 cells (IC₅₀ 1.4 and 5.1?µg/mL). Apoptotic assays showed that CEF7, CEF9, CRF6, and CRF5 fractions induced mitochondrial depolarization in A549 cells, 70, 73, 77, and 80%, respectively. Those fractions triggered the apoptosis mitochondrial pathway.

Conclusion: Our data show that A. subulata extracts have potent antiproliferative properties on human cancer cell lines. This plant should be considered an important source of potent anticancer compounds.     

Design and synthesis of pyrazole–pyrazoline hybrids as cancer‐associated selective COX‐2 inhibitors

In continuation of our previous work on cancer and inflammation, 15 novel pyrazole–pyrazoline hybrids ( WSPP1 – 15 ) were synthesized and fully characterized. The formation of the pyrazoline ring was confirmed by the appearance of three doublets of doublets in ¹H nuclear magnetic resonance spectra exhibiting an AMX pattern for three protons (H_A, H_M, and H_X) of the pyrazoline ring. All the synthesized compounds were screened for their in vitro anticancer activity against five cell lines, that is, MCF‐7, A549, SiHa, COLO205, and HepG2 cells, using the MTT growth inhibition assay. 5‐Fluorouracil was taken as the positive control in the study. It was observed that, among them, WSPP11 was found to be active against A549, SiHa, COLO205, and HepG2 cells, with IC₅₀ values of 4.94, 4.54, 4.86, and 2.09 µM. All the derivatives were also evaluated for their cytotoxicity against HaCaT cells. WSPP11 was also found to be nontoxic against normal cells (cell line HaCaT), with an IC₅₀ value of more than 50 µM. The derivatives were also evaluated for their in vitro anti‐inflammatory activity by the protein (egg albumin) denaturation assay and the red blood cell membrane stabilizing assay, using diclofenac sodium and celecoxib as standard. Compounds that showed significant anticancer and anti‐inflammatory activities were further studied for COX‐2 inhibition. The manifestation of a higher COX‐2 selectivity index of WSPP11 as compared with other derivatives and an in vitro anticancer activity against four cell lines further established that compounds that were more selective toward COX‐2 also exhibited a better spectrum of activity against various cancer cell lines.     

Design,synthesis, and antitumor evaluation of quinoline‐imidazole derivatives

A series of compounds bearing quinoline‐imidazole ( 8a–e , 9a–e , 10a–e , 11a–e , and 12a–e ) not reported previously were designed and synthesized. The target compounds were evaluated for antitumor activity against A549, PC‐3, HepG2, and MCF‐7 cells by the MTT method, with NVP‐BEZ235 being the positive control. Most compounds showed moderate activity and compound 12a showed the best activity against HepG2, A549, and PC‐3 cells, with half‐maximal inhibitory concentration (IC₅₀) values of 2.42 ± 1.02 µM, 6.29 ± 0.99 µM, and 5.11 ± 1.00 µM, respectively, which was equal to NVP‐BEZ235 (0.54 ± 0.13 µM, 0.36 ± 0.06 µM, 0.20 ± 0.01 µM). Besides, the IC₅₀ value of 12a against the cell line WI‐38 (human fetal lung fibroblasts) was 32.8 ± 1.23 µM, indicating that the target compounds were selective for cancer cells. So, 11a and 12a were evaluated against PI3Kα and mTOR to find out if the compounds acted through the PI3K‐Akt‐mTOR signal transduction pathway. The inhibition ratios to PI3Kα and mTOR were slightly lower than that of NVP‐BEZ235, suggesting there may be some other mechanisms of action. The structure–activity relationships and docking study of 11a and 12a revealed that the latter was superior. Moreover, the target compounds showed better in vitro anticancer activity when the C‐6 of the quinoline ring was replaced by a bromine atom.

     

Effects of acrolein in comparison to its prodrug cyclophosphamide on human primary endothelial cells in vitro

Cyclophosphamide (CPA) is one of the most successful anticancer prodrugs that becomes effective after biotransformation in the liver resulting in the toxic metabolite acrolein. Cancer is often accompanied by thromboembolic events, which might be a result of dysfunctional endothelial cells due to CPA treatment.Here, the effect of 1 mM CPA or acrolein (10/50/100/500 μM) on human umbilical vein endothelial cells (HUVECs) was analyzed after two days of treatment.The addition of CPA or 10 μM acrolein did not affect HUVECs. However, concentrations of 100 μM and 500 μM acrolein significantly reduced the number of adherent cells by 86 ± 13% and 99 ± 1% and cell viability by 51 ± 29% and 93 ± 8% compared to the control. Moreover, pronounced stress fibers as well as multiple nuclei were observed and von Willebrand factor (vWF) was completely released. Lactate dehydrogenase was 8.5 ± 7.0-fold and 252.9 ± 42.9-fold increased showing a loss of cell membrane integrity. The prostacyclin and thromboxane secretion was significantly increased by the addition of 500 μM acrolein (43.1 ± 17.6-fold and 246.4 ± 106.3-fold) indicating cell activation/pertubation.High doses of acrolein led to HUVEC death and loss of vWF production. This effect might be associated with the increased incidence of thromboembolic events in cancer patients treated with high doses of CPA.     

Sensitive neurotoxicity assessment of bisphenol A using double immunocytochemistry of DCX and MAP2

Bisphenol A (BPA) is an environmental toxin widely used in manufacturing industries. Studies conducted on the neurotoxicity of BPA demonstrated that at excessive, high concentrations (≥?200 µM) adverse responses occurred which were not detectable using traditional toxicity tests at lower chemical quantities than 200 µM. Thus, a method capable of effectively detecting neurotoxicity at low concentrations (≤?100 µM) was devised. Bisphenol A-mediated neurotoxicity was examined in primary cultured neurons using various methods, including Western blot, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity and reactive oxygen species assays. These methods confirmed BPA-induced toxicity at 200 μM, but no marked effect was observed at concentrations below 200 μM. However, when immunocytochemistry (ICC) was performed using a co-immunofluorescence assay of doublecortin (DCX) and microtubule-associated protein 2 (MAP2), BPA adversely affected neuronal maturation in neural progenitor cells at concentrations as low as 100 µM, at which the three traditional methods failed to detect any neurotoxic effect. Our DCX/MAP2 ICC findings indicate that low concentrations of BPA are toxic to developing neurons, and suggest that the devised double ICC technique might provide an effective means of assessing neurotoxic effects of environmental toxins at low concentrations.     

Evaluation of cytotoxicity of new trans-palladium(II) complex in human cells in vitro

Studies of cytotoxicity allow to elucidate the mechanisms by which chemical compounds influence cells and tissues. On the basis of the structural analogy between platinum(II) and palladium(II) complexes, a variety of studies on palladium(II) compounds as potential anticancer drugs have been carried out (1, 2). The cytotoxicity was evaluated by MTT assay. Abilities of trans-palladium(II) complex containing diethyl (pyridin-2-ylmethyl)phosphates as non-leaving ligands (trans-[PdCl2(2-pmOpe 2)]) to induce apoptosis and necrosis in normal lymphocytes, A549 cells and HT29 cell lines were performed by use of fluorochrome staining. The obtained results revealed, that the new trans-palladium(II) complex was more cytotoxic against A549 and HT29 tumor cells than on the normal lymphocytes in vitro. The novel complex induces apoptosis in all tested cells, but in lymphocytes to a lesser degree. The compound tested also induced significant amounts of necrotic cells, which exceeded the level of apoptotic cell fractions. The results demonstrate that the trans-Pd(II) complex showed substantial cytotoxic activity against A549 and HT29 tumor cells and indicate that the new trans-palladium(II) complex effectively inhibited cancer cells growth.     

A bibenzyl from <Emphasis Type="Italic">Dendrobium ellipsophyllum</Emphasis> induces apoptosis in human lung cancer cells

Failure of current chemotherapeutic drugs leads to the recurrence of tumor pathology and mortality in lung cancer patients. This study aimed to evaluate the anticancer activity and related mechanisms of 4,5,4′-trihydroxy-3,3′-dimethoxybibenzyl (TDB), a bibenzyl extracted from Dendrobium ellipsophyllum Tang and Wang, in human lung cancer cells. Cytotoxicity of TDB (0–300 µM) in different types of human lung cancer cells (H460, H292 and H23) and human dermal papilla cells (DPCs) was evaluated via MTT viability assay. Selective anticancer activity of TDB against human lung cancer cells was demonstrated with a high IC₅₀ (approximately > 300 µM) in DPCs, while IC₅₀ in human lung cancer H460, H292 and H23 cells was approximately 100 ± 5.18, 100 ± 8.73 and 188.89 ± 8.30 µM, respectively. After treatment with 50 µM of TDB for 24 h, flow cytometry analysis revealed the significant increase of early and late apoptosis with absence of necrosis cell death in human lung cancer cells. The up-regulation of p53, a tumor-suppressor protein, was elucidated in human lung cancer cells treated with 10–50 µM of TDB. Alteration to down-stream signaling of p53 including activation of pro-apoptosis protein (Bcl-2-associated X protein; Bax), reduction of anti-apoptosis (B cell lymphoma 2; Bcl-2 and myeloid cell leukemia 1; Mcl-1) and suppression on protein kinase B (Akt) survival pathway were notified in TDB-treated lung cancer cells. The information obtained from this study strengthens the potential development of TDB as an anticancer compound with a favorable human safety profile and high efficacy.     

Comparison Between the Genotoxicity of cis-Pt(II) Complex of 3-Aminoflavone and cis-DDP in Lymphocytes Evaluated by the Comet Assay

cis-bis(3-aminoflavone)dichloroplatinum(II) [cis-Pt(II) complex of 3-aminoflavone] is an analog of cis-DDP characterized by low cytotoxicity and anticancer properties in vivo. In order to evaluate genotoxic properties of this chemical compound, the comet assay in human lymphocytes was used. The analysis of DNA damage after 1-h cell incubation with cis-Pt(II) complex of 3-aminoflavone and cis-DDP was carried out, and DNA repair kinetics were evaluated after 0.5-h, 1-h, and 1.5-h postexposure incubation. It has been shown that cis-Pt(II) complex of 3-aminoflavone causes the increase in tail moments in comparison with cis-DDP. On the other hand, the decrease in these values caused by cis-DDP was connected mainly with the presence of DNA and DNA–protein cross-links. The decrease in tail moments after cis-Pt(II) complex of 3-aminoflavone lymphocyte treatment was already observed after 0.5-h postexposure incubation, whereas in the variant with hydrogen peroxide application these values after cis-Pt(II) complex of 3-aminoflavone addition were higher in comparison with cis-DDP. Results obtained on the basis of the comet assay could confirm the occurrence of DNA breaks and cross-links induced by cis-Pt(II) complex of 3-aminoflavone.     

OSU-A9 inhibits angiogenesis in human umbilical vein endothelial cells via disrupting Akt–NF-κB and MAPK signaling pathways

Since the introduction of angiogenesis as a useful target for cancer therapy, few agents have been approved for clinical use due to the rapid development of resistance. This problem can be minimized by simultaneous targeting of multiple angiogenesis signaling pathways, a potential strategy in cancer management known as polypharmacology. The current study aimed at exploring the anti-angiogenic activity of OSU-A9, an indole-3-carbinol-derived pleotropic agent that targets mainly Akt–nuclear factor-kappa B (NF-κB) signaling which regulates many key players of angiogenesis such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Human umbilical vein endothelial cells (HUVECs) were used to study the in vitro anti-angiogenic effect of OSU-A9 on several key steps of angiogenesis. Results showed that OSU-A9 effectively inhibited cell proliferation and induced apoptosis and cell cycle arrest in HUVECs. Besides, OSU-A9 inhibited angiogenesis as evidenced by abrogation of migration/invasion and Matrigel tube formation in HUVECs and attenuation of the in vivo neovascularization in the chicken chorioallantoic membrane assay. Mechanistically, Western blot, RT-PCR and ELISA analyses showed the ability of OSU-A9 to inhibit MMP-2 production and VEGF expression induced by hypoxia or phorbol-12-myristyl-13-acetate. Furthermore, dual inhibition of Akt–NF-κB and mitogen-activated protein kinase (MAPK) signaling, the key regulators of angiogenesis, was observed. Together, the current study highlights evidences for the promising anti-angiogenic activity of OSU-A9, at least in part through the inhibition of Akt–NF-κB and MAPK signaling and their consequent inhibition of VEGF and MMP-2. These findings support OSU-A9's clinical promise as a component of anticancer therapy.     

Self-assembled nanoparticles of reduction-sensitive poly (lactic-co-glycolic acid)-conjugated chondroitin sulfate A for doxorubicin delivery: preparation,characterization and evaluation

In this study, reduction-sensitive self-assembled polymer nanoparticles based on poly (lactic-co-glycolic acid) (PLGA) and chondroitin sulfate A (CSA) were developed and characterized. PLGA was conjugated with CSA via a disulfide linkage (PLGA-ss-CSA). The critical micelle concentration (CMC) of PLGA-ss-CSA conjugate is 3.5?µg/mL. The anticancer drug doxorubicin (DOX) was chosen as a model drug, and was effectively encapsulated into the nanoparticles (PLGA-ss-CSA/DOX) with high loading efficiency of 15.1%. The cumulative release of DOX from reduction-sensitive nanoparticles was only 34.8% over 96?h in phosphate buffered saline (PBS, pH 7.4). However, in the presence of 20?mM glutathione-containing PBS environment, DOX release was notably accelerated and almost complete from the reduction-sensitive nanoparticles up to 96?h. Moreover, efficient intracellular DOX release of PLGA-ss-CSA/DOX nanoparticles was confirmed by CLSM assay in A549 cells. In vitro cytotoxicity study showed that the half inhibitory concentrations of PLGA-ss-CSA/DOX nanoparticles and free DOX against A549 cells were 1.141 and 1.825?µg/mL, respectively. Therefore, PLGA-ss-CSA/DOX nanoparticles enhanced the cytotoxicity of DOX in vitro. These results suggested that PLGA-ss-CSA nanoparticles could be a promising carrier for drug delivery.     

Monocyte adhesion induced by multi-walled carbon nanotubes and palmitic acid in endothelial cells and alveolar–endothelial co-cultures

Free palmitic acid (PA) is a potential pro-atherogenic stimulus that may aggravate particle-mediated cardiovascular health effects. We hypothesized that the presence of PA can aggravate oxidative stress and endothelial activation induced by multi-walled carbon nanotube (MWCNT) exposure in vitro. We investigated the interaction between direct exposure to MWCNTs and PA on THP-1 monocyte adhesion to human umbilical vein endothelial cells (HUVECs), as well as on indirect exposure in an alveolar–endothelial co-culture model with A549 cells and THP-1-derived macrophages exposed in inserts and the effect measured in the lower chamber on HUVECs and THP-1 cells. The exposure to MWCNTs, including a short (NM400) and long (NM402) type of entangled fibers, was associated with elevated levels of reactive oxygen species as well as a decrease in the intracellular glutathione concentration in HUVEC and A549 monocultures. Both effects were found to be independent of the presence of PA. MWCNT exposure significantly increased THP-1 monocyte adhesion to HUVECs, and co-exposure to PA aggravated the NM400-mediated adhesion but decreased the NM402-mediated adhesion. For the co-cultures, the exposure of A549 cells did not promote THP-1 adhesion to HUVECs in the lower chamber. When THP-1 macrophages were present on the cell culture inserts, there was a modest increase in the adhesion and an increase in interleukin-6 and interleukin-8 levels in the lower chamber whereas no tumor necrosis factor was detected. Overall, this study showed that direct exposure of HUVECs to MWCNTs was associated with oxidative stress and monocyte adhesion and the presence of PA increased the adhesion when exposed to NM400.     

Salvianolic acid A inhibits angiotensin II-induced proliferation of human umbilical vein endothelial cells by attenuating the production of ROS

Aim:

To investigate the action of salvianolic acid A (SalA) on angiotensin II (Ang II)-induced proliferation of human umbilical vein endothelial cells (HUVECs) and the possible signaling pathways mediating this action.

Methods:

Cell proliferation was examined with MTT assay. The expression levels of Src phosphorylation (phospho-Src), Akt phosphorylation (phospho-Akt), and NADPH oxidase 4 (Nox4) in HUVECs were determined by Western blot. The production of reactive oxygen species (ROS) was estimated using fluorescence-activated cell sorting (FACS).

Results:

SalA (6.25–50 μmol/L) did not affect the viability of HUVECs. Treatment of HUVECs with Ang II (1 μmol/L) markedly increased the cell viability; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) prevented Ang II-induced increase of the cell viability in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) markedly up-regulated the protein expression levels of phospho-Src, phospho-Akt (473) and Nox4; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked all the effects in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) dramatically increased ROS production in HUVECs; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked the ROS production in a concentration-dependent manner.

Conclusion:

SalA inhibits Ang II-induced proliferation of HUVECs via reducing the expression levels of phospho-Src and phospho-Akt (473), thereby attenuating the production of ROS.