Doxorubicin In A549 Cells Research Articles

Optimized spirooxindole-pyrazole hybrids targeting the p53-MDM2 interplay induce apoptosis and synergize with doxorubicin in A549 cells

Recently, cancer research protocols have introduced clinical-stage spirooxindole-based MDM2 inhibitors. However, several studies reported tumor resistance to the treatment. This directed efforts to invest in designing various combinatorial libraries of spirooxindoles. Herein, we introduce new series of spirooxindoles via hybridization of the chemically stable core spiro[3H-indole-3,2′-pyrrolidin]-2(1H)-one and the pyrazole motif inspired by lead pyrazole-based p53 activators, the MDM2 inhibitor BI-0252 and promising molecules previously reported by our group. Single crystal X-ray diffraction analysis confirmed the chemical identity of a representative derivative. Fifteen derivatives were screened for cytotoxic activities via MTT assay against a panel of four cancer cell lines expressing wild-type p53 (A2780, A549, HepG2) and mutant p53 (MDA-MB-453). The hits were 8h against A2780 (IC50 = 10.3 µM) and HepG2 (IC50 = 18.6 µM), 8m against A549 (IC50 = 17.7 µM), and 8k against MDA-MB-453 (IC50 = 21.4 µM). Further MTT experiments showed that 8h and 8j potentiated doxorubicin activity and reduced its IC50 by at least 25% in combinations. Western blot analysis demonstrated that 8k and 8m downmodulated MDM2 in A549 cells. Their possible binding mode with MDM2 were simulated by docking analysis.

Ribosomal protein L5 mediated inhibition of c-Myc is critically involved in sanggenon G induced apoptosis in non-small lung cancer cells.

Though Sanggenon G (SanG) from root bark of Morus alba was known to exhibit anti-oxidant and anti-depressant effects, its underlying mechanisms still remain unclear. Herein SanG reduced the viability of A549 and H1299 non-small lung cancer cells (NSCLCs). Also, SanG increased sub-G1 population via inhibition of cyclin D1, cyclin E, CDK2, CDK4 and Bcl-2, cleavages of poly (ADP-ribose) polymerase (PARP) and caspase-3 in A549 and H1299 cells. Of note, SanG effectively inhibited c-Myc expression by activating ribosomal protein L5 (RPL5) and reducing c-Myc stability even in the presence of cycloheximide and 20% serum in A549 cells. Furthermore, SanG enhanced the apoptotic effect with doxorubicin in A549 cells. Taken together, our results for the first time provide novel evidence that SanG suppresses proliferation and induces apoptosis via caspase-3 activation and RPL5 mediated inhibition of c-Myc with combinational potential with doxorubicin.

PH-Responsive i-motif Conjugated Hyaluronic Acid/Polyethylenimine Complexes for Drug Delivery Systems.

i-motif is cytosine (C)-rich oligonucleotide (ODN) which shows pH-responsive structure change in acidic condition. Therefore, it has been utilized for the trigger of intercalated drug release, responding to environmental pH change. In this study, 2.76 molecules of i-motif binding ODNs (IBOs) were conjugated to each hyaluronic acid (HA) via amide bond linkages. Synthesis of HA-IBO conjugate (HB) was confirmed by FT-IR and agarose gel electrophoresis with Stains-All staining. After hybridization of HB with i-motif ODN (IMO), it was confirmed that doxorubicin (DOX) could be loaded in HB-IMO hybrid structure (HBIM) with 65.6% of drug loading efficiency (DLE) and 25.0% of drug loading content (DLC). At pH 5.5, prompt and significant DOX release from HBIM was observed due to the disruption of HBIM hybrid structure via i-motif formation of IMO, contrary to pH 7.4 condition. Then, HBIM was complexed with low molecular weight polyethylenimine (PEI1.8k), forming positively charged nanostructures (Z-average size: 126.0 ± 0.4 nm, zeta-potential: 16.1 ± 0.3 mV). DOX-loaded HBIM/PEI complexes displayed higher anticancer efficacy than free DOX in A549 cells, showing the potential for pH-responsive anticancer drug delivery systems.

Methionine gamma lyase from Clostridium sporogenes increases the anticancer effect of doxorubicin in A549 cells and human cancer xenografts.

The anti-cancer efficacy of methionine γ-lyase (MGL) from Clostridium sporogenes (C. sporogenes) is described. MGL was active against cancer models in vitro and in vivo. The calculated EC50 values for MGL were 4.4U/ml for A549, 7.5U/ml for SK-BR3, 2.4U/ml for SKOV3, and 0.4U/ml for MCF7 cells. The combination of doxorubicin (DOX) and MGL was more effective for A549 human lung cancer growth inhibition than either agent alone in vitro and in vivo. MGL reduced the EC50 of doxorubicin from 35.9μg/mL to 0.01-0.265μg/mL. The growth inhibitory effect of DOX + MGL on A549 xenografts in vivo was reflective of the results obtained in vitro. The inhibition rate of tumor growth in the combined arm was 57%, significantly higher than that in the doxorubicin (p = 0.033)-alone arm.

Decrease in paracellular permeability and chemosensitivity to doxorubicin by claudin-1 in spheroid culture models of human lung adenocarcinoma A549 cells

Chemotherapy resistance is a major problem in the treatment of cancer, but the underlying mechanisms are not fully understood. We found that the expression levels of claudin-1 (CLDN1) and 3, tight junctional proteins, are upregulated in cisplatin (CDDP)-resistant human lung adenocarcinoma A549 (A549R) cells. A549R cells showed cross-resistance to doxorubicin (DXR). Here, the expression mechanism and function of CLDN1 and 3 were examined. CLDN1 and 3 were mainly localized at tight junctions concomitant with zonula occludens (ZO)-1, a scaffolding protein, in A549 and A549R cells. The phosphorylation levels of Src, MEK, ERK, c-Fos, and Akt in A549R cells were higher than those in A549 cells. The expression levels of CLDN1 and 3 were decreased by LY-294002, a phosphoinositide 3-kinase (PI3K) inhibitor, and BAY 11-7082, an NF-κB inhibitor. The overexpression of CLDN1 and 3 decreased the paracellular permeability of DXR in A549 cells. Hypoxia levels in A549R and CLDN1-overexpressing cells (CLDN1/A549) were greater than those in A549, mock/A549, and CLDN3/A549 cells in a spheroid culture model. In contrast, accumulation in the region inside the spheroids and the toxicity of DXR in A549R and CLDN1/A549 cells were lower than those in other cells. Furthermore, the accumulation and toxicity of DXR were rescued by CLDN1 siRNA in A549R cells. We suggest that CLDN1 is upregulated by CDDP resistance through activation of a PI3K/Akt/NF-κB pathway, resulting in the inhibition of penetration of anticancer drugs into the inner area of spheroids.

Chemosensitizing indomethacin-conjugated chitosan oligosaccharide nanoparticles for tumor-targeted drug delivery.

Chemosensitizing nanoparticles (NPs) based on amphiphilic chitosan oligosaccharide-indomethacin (CSO-IDM; CI) conjugate were developed for tumor-targeted delivery of doxorubicin (DOX). IDM was introduced to the CSO backbone as a hydrophobic residue to synthesize an amphiphilic conjugate and a chemosenstizer of DOX for improving antitumor efficacies. IDM, conjugated to CSO, may inhibit the efflux of cellular uptaken DOX via multidrug resistance-associated protein (MRP) and subsequently augment the anti-proliferation potentials of DOX in A549 cells (MRP-expressed human lung cancer cells). Chemosensitizing properties of developed CI NPs were assessed in cell culture models and the tumor targetability of CI/DOX NPs was demonstrated in A549 tumor-xenografted mouse model by a real-time optical imaging. Developed CI NPs can be used as a multifunctional nanosystem for the therapy of MRP-expressed cancers.

P0185 Molecular mechanisms of a novel imidazopyridine Cdk-inhibitor alone and in combination with doxorubicin

<h3>Background</h3> Dysregulation of the mechanisms that control normal cell cycle progression is a prominent characteristic of cancer cells. Cyclin-dependent kinases (Cdks) are molecules that facilitate the progression of the cell cycle by binding to cyclins and phosphorylating downstream proteins that assist in cell cycle propagation. Cdk inhibitors have been reported as valuable agents for cancer therapy because of their role in inhibition of cell proliferation and induction of apoptosis. <h3>Methods</h3> We investigated the cytotoxic effects of a newly designed Cdk inhibitor, an imidazopyridine derivative, alone and in combination with other anticancer drugs in three cancer cell lines (MCF7, A549, and M8). In addition, we investigated the effect of this new compound on induction of apoptosis, DNA damage, and repair and cell cycle progression. <h3>Findings</h3> This compound is more cytotoxic against the lung cancer cell line (A549) than against other cell lines. It enhanced the cytotoxic effects of doxorubicin in A549 cells. Mechanistic investigations showed that the drug inhibits A549 cells from crossing the G1–S checkpoint and arrests cells at the G1 phase of the cell cycle. The drug induces caspase-3 activity in a concentration and time dependent manner. Combination of this compound with the anticancer drug doxorubicin showed inhibition of the repair of doxorubicin-induced DNA damage. <h3>Interpretation</h3> These results indicate that the newly designed compound is promising, and could enhance the cytotoxicity of other anticancer agents.

Polyglycerol-coated nanodiamond as a macrophage-evading platform for selective drug delivery in cancer cells

A successful targeted drug delivery device for cancer chemotherapy should ideally be able to avoid non-specific uptake by nonmalignant cells, particularly the scavenging monocyte-macrophage system as well as targeting efficacy to bring the drug preferentially into tumor cells. To this purpose, we developed a platform based on detonation nanodiamond (dND) with hyperbranched polyglycerol (PG) coating (dND-PG). dND-PG was first demonstrated to evade non-specific cell uptake, particularly by macrophages (U937). RGD targeting peptide was then conjugated to dND-PG through multistep organic transformations to yield dND-PG-RGD that still evaded macrophage uptake but was preferentially taken up by targeted A549 cancer cells (expressing RGD peptide receptors). dND-PG and dND-PG-RGD showed good aqueous solubility and cytocompatibitlity. Subsequently, the anticancer agent doxorubicin (DOX) was loaded through acid-labile hydrazone linkage to yield dND-PG-DOX and dND-PG-RGD-DOX. Their cellular uptake and cytotoxicity were compared against DOX in A549 cells and U937 macrophages. It was found that dND-PG-DOX uptake was substantially reduced, displaying little toxicity in either type of cells by virtue of PG coating, whereas dND-PG-RGD-DOX exerted selective toxicity to A549 cells over U937 macrophages that are otherwise highly sensitive to DOX. Finally, dND-PG was demonstrated to have little influence on U937 macrophage cell functions, except for a slight increase of TNF-α production in resting U937 macrophages. dND-PG is a promising drug carrier for realization of highly selective drug delivery in tumor cells through specific uptake mechanisms, with minimum uptake in and influence on macrophages.

Cardioprotective Effects of 20(S)-Ginsenoside Rh2 against Doxorubicin-Induced CardiotoxicityIn VitroandIn Vivo

Doxorubicin (DOX) is considered as one of the best antineoplastic agents. However, its clinical use is restricted by its associated cardiotoxicity, which is mediated by the production of reactive oxygen species. In this study, 20(S)-ginsenoside Rh2 (Rh2) was explored whether it had protective effects against DOX-induced cardiotoxicity. In vitro study on H9C2 cell line, as well as in vivo investigation in one mouse and one rat model of DOX-induced cardiomyopathy, was carried out. The results showed that pretreatment with Rh2 significantly increased the viability of DOX-injured H9C2 cells. In the mouse model, Rh2 could suppress the DOX-induced release of the cardiac enzymes into serum and improved the occurred pathological changes through ameliorating the decreased antioxidant biomolecules and the cumulated lipid peroxidation malondialdehyde in heart tissues. In the rat model, Rh2 could attenuate the change of ECG resulting from DOX administration. Furthermore, Rh2 enhanced the antitumor activity of DOX in A549 cells. Our findings thus demonstrated that Rh2 pretreatment could effectively alleviate heart injury induced by DOX, and Rh2 might act as a novel protective agent in the clinical usefulness of DOX.

Features of senescence and cell death induced by doxorubicin in A549 cells: organization and level of selected cytoskeletal proteins

Senescence and cell death are fail-safe mechanisms protecting against tumorigenesis. Both these forms of cellular response could be induced in cancer cells, thus suppressing tumor progression. Therefore, to fully understand chemotherapeutic effects, not only symptoms of cell death, but also of senescence should be evaluated. Since the involvement of cytoskeleton components in these processes has been reported, changes in the organization and level of some cytoskeletal proteins may be indicative of cell fate. We analyzed selected markers of senescence and cell death, including possible alterations in vimentin and G-actin cytoskeleton in A549 cells after treatment with doxorubicin. Light (SA-beta-galactosidase), fluorescent (vimentin and G-actin labeling) and electron microscopic examinations along with flow cytometry methods (TUNEL, Annexin V/PI staining, cell cycle analysis, intracellular level of vimentin) were employed to determine the outcome of the treatment. Uncoupling between senescent cell morphology and stable cell cycle arrest occurred. Some differences in the organization and level of cytoskeletal proteins, especially of vimentin, like fluctuations in its level, were observed. On the other hand, G-actin seemed to be more stable than vimentin. G-actin stability may imply its potential usefulness for permanent senescence detection. Along with slight to moderate cytoskeletal alterations, the obtained results suggest transient senescence-like state induction, followed by morphology typical of mitotic catastrophe in part of the A549 cells.

Modulation of function of multidrug resistance associated-proteins by Kaempferia parviflora extracts and their components

In this study, the effects of extracts and flavone derivatives from the rhizome of Kaempferia parviflora on multidrug resistance associated-proteins (MRP)-mediated transport in A549 cells were examined. The cells employed express MRP1 and MRP2, but not P-glycoprotein. The cellular accumulation of calcein, an MRP substrate, was significantly increased by various MRP inhibitors without being affected by verapamil, a typical P-glycoprotein inhibitor. Ethanol and aqueous extracts from K. parviflora rhizome increased the accumulation of calcein and doxorubicin in A549 cells in a concentration-dependent manner. The inhibitory potency of the ethanol extract for MRP function was greater than that of the aqueous extract. Among six flavone derivatives isolated from K. parviflora rhizome, 5,7-dimethoxyflavone exhibited a maximal stimulatory effect on the accumulation of doxorubicin in A549 cells. The accumulation of doxorubicin was increased by four flavone derivatives without 5-hydroxy group, but not by the other two flavone derivatives with 5-hydroxy group. In addition, 5,7-dimethoxyflavone and 3,5,7,3′,4′-pentamethoxyflavone decreased resistance to doxorubicin in A549 cells. These findings indicate that extracts and flavone derivatives from the rhizome of K. parviflora suppress MRP function, and therefore may be useful as modulators of multidrug resistance in cancer cells.