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Results 201 - 250 of 1383
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Takara Kohji - - 2009
The purpose of this study is to examine the effects of doxazosin, an alpha-adrenoceptor antagonist, on P-glycoprotein/MDR1-mediated multidrug resistance (MDR) and the transport of anticancer drugs. The effects of doxazosin, prazosin, and terazosin on MDR1-mediated MDR were assessed in human cervical carcinoma HeLa cells and the MDR1-overexpressing derivative Hvrl00-6, established ...
Zupkó István - - 2009
The aim of the present study was to investigate the anticancer properties of five alkaloids isolated from Amaryllidaceae, including the inhibitory effect on P-glycoprotein (P-gp) and the apoptosis-inducing capacity. The tested alkaloids were evaluated for their multidrug resistance (MDR)-reversing activity on human MDR1-gene-transfected L5178 mouse lymphoma cells, using the rhodamine-123 ...
De Boo Sara - - 2009
BACKGROUND: Doxorubicin is one of the few chemotherapeutic drugs able to exert both cytotoxic and pro-immunogenic effects against cancer cells. Following the drug administration, the intracellular protein calreticulin is translocated with an unknown mechanism onto the plasma membrane, where it triggers the phagocytosis of tumour cells by dendritic cells. Moreover ...
Jin Jing - - 2009
Cellular function is dependent on tight regulation of intracellular pH and numerous reports show cancer cells have abnormal pH values in the cytosol and organelles, such as lysosomes. 5-(and-6)-carboxyl seminaphthorhodafluor (SNARF-1) is a commonly used pH sensitive probe and was used here to determine cytosolic pH of HL-60 leukemia cells ...
Hao Hongying - - 2009
Combination chemotherapy has been shown to be more effective than single-agent therapy for many types of cancer, but both are known to induce drug resistance in cancer cells. Two major culprits in the development of this drug resistance are nuclear factor-kappaB (NF-kappaB) and the multidrug resistance (MDR) gene. For this ...
Yang Cao - - 2009
To identify apoptosis genes involved in the multidrug resistance of osteosarcoma, a multidrug resistant human osteosarcoma cell line (U-2 OS MR) was established. Apoptosis gene microarray analysis demonstrated that GADD45alpha was significantly induced in U-2 OS cells after exposure to paclitaxel (P < 0.0001). However, the induction of GADD45alpha did ...
Takano Mikihisa - - 2009
Paclitaxel-resistant HepG2 (PR-HepG2) cells were established by long-term exposure of HepG2 cells to paclitaxel and expression and function of efflux (P-glycoprotein, MRP2) and influx (OATP1B3) transporters for paclitaxel were examined to understand the mechanisms underlying the resistance. mRNA expression of P-glycoprotein (P-gp) increased in PR-HepG2 more than in HepG2 cells, ...
Im Young Bin - - 2009
The effect of macelignan, a phytoestrogen, on P-gp function was investigated using multidrug resistant cancer cells overexpressing P-gp (NCI/ADR-RES) and the fluorescent P-gp substrates, daunorubicin and rhodamine 123. Macelignan (40 microM) increased the cellular accumulation of daunorubicin by approximately threefold in NCI/ADR-RES cells, whereas it did not alter the cellular ...
Cheng Jian - - 2009
This study aims to evaluate the multidrug resistance (MDR) reversal activity by magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4) and 5-bromotetrandrine (BrTet) MDR cell line K562/A02 solitarily or symphysially. The proliferation of K562 and K562/A02 cells and the cytotoxicity on peripheral blood mononuclear cells (PMBCs) were evaluated by MTT assay. Cellular accumulation ...
Cao Ji - - 2009
Overexpression of multidrug resistance proteins P-glycoprotein (P-gp, MDR1) causes resistance of the tumor cells against a variety of chemotherapeutic agents. 3-(1-methyl-1H-indol-3-yl)-1-phenyl-4-(1-(3-(piperidin-1-yl)propyl)-1H-pyrazolo[3,4-b]pyridine-3-yl)-1H-pyrrole-2,5-dione (YQ36) is a novel analogue of bisindolylmaleimide, which has been reported to overcome multidrug resistance. Here, we dedicated to investigate the anticancer activity of YQ36 on KB/VCR cells. The ...
Zheng Li-sheng - - 2009
ABCC1 and ABCG2 are ubiquitous ATP-binding cassette transmembrane proteins that play an important role in multidrug resistance (MDR). In this study, we evaluated the possible interaction of vandetanib, an orally administered drug inhibiting multiple receptor tyrosine kinases, with ABCC1 and ABCG2 in vitro. MDR cancer cells overexpressing ABCC1 or ABCG2 ...
Pan Wen-Chi - - 2009
P-glycoprotein (Pgp) participates in the export of numerous toxins, drugs, and physiological compounds. To examine the involvement of Pgp in smoke-induced oral cell insult, the effects of extracts of the mainstream tobacco smoke (TS) on Pgp were studied in an oral epidermal carcinoma cell line, OECM-1. TS was first extracted ...
Yeheskely-Hayon Daniella - - 2009
The present study aimed to elucidate the contribution of the intracellular binding of drugs to multidrug resistance. For this purpose, uptake of rhodamines was studied in cells whose mitochondria had been uncoupled with carbonyl cyanide m-chlorophenylhydrazone. Surprisingly, in a variety of drug-untreated cells, presumed to be sensitive to multidrug resistance-type ...
Li Guang-Yao - - 2009
This study was designed to investigate the effects of cyclosporine A (CsA) on a multidrug resistance cultured cell line, and its effect on complete remission in patients with acute myeloid leukemia (AML). A multidrug resistant K562/ADM cell line and drug-sensitive K562 cell line was used. The intracellular concentration of daunorubicin ...
Engi Helga - - 2008
Many of the herbal extracts used in the Chinese clinical medical routine inhibit the growth of tumor cells. In the present work, extracts of 12 selected herbs were prepared with methanol, chloroform, ethyl acetate and water, and the effects of these on the multidrug resistance (MDR) and P-glycoprotein of mouse ...
Shaik Naveed - - 2008
The objective was to examine the influence of Pluronic block-copolymers on the interaction between the drug efflux transporter, P-glycoprotein and HIV-1 protease inhibitors (PIs). The ATPase assay determined the effect of various Pluronics on PI-stimulated P-gp ATPase activity. Cellular accumulation studies were conducted using MDCKII and LLC-PK1 cells transfected with ...
Du Wenjun - - 2008
Micelles from amphiphilic star-block copolymers, having a hydrophobic hyperbranched core and amphiphilic fluoropolymer arms, were constructed as drug delivery agent assemblies. A series of polymer structures was constructed from consecutive copolymerizations of 4-chloromethylstyrene with dodecyl acrylate and then 1,1,1- trifluoroethyl methacrylate with tert-butyl acrylate, followed by acidolysis to release the ...
Hariharan Sudharshan - - 2009
PURPOSE: The objectives were (i) to test in vivo functional activity of MRP2 on rabbit corneal epithelium and (ii) to evaluate modulation of P-gp and MRP2 mediated efflux of erythromycin when co-administered with corticosteroids. METHODS: Cultured rabbit primary corneal epithelial cells (rPCECs) was employed as an in vitro model for ...
Pires Marcos M MM Department of Chemistry and Purdue Cancer Center, Purdue University, West Lafayette, Indiana, - - 2009
P-glycoprotein (P-gp), an ATP-dependent drug efflux pump, has been implicated in multidrug resistance of several cancers as a result of its overexpression. In this work, rationally designed second-generation P-gp inhibitors are disclosed, based on dimerized versions of the substrates quinine and quinidine. These dimeric agents include reversible tethers with a ...
Chen Lei - - 2009
Multidrug resistance (MDR) is a significant problem underlying the poor prognosis associated with gliomas. Hypoxia-inducible factor-1alpha (HIF-1alpha) is thought to induce the genes expression involved in MDR. To evaluate the effect of silencing HIF-1alpha in human glioma T98G cells, cells were transfected with HIF-1alpha-small interference RNA (HIF-1alpha-siRNA) and cultured under ...
Lu Ying - - 2008
We have investigated the involvement of intracellular pH (pH(i)) in the regulation of P-glycoprotein (P-gp) in K562/DOX cells. The selective Na(+)/H(+) exchanger1 (NHE1) inhibitor cariporide and the "high K(+)" buffer were used to induce the sustained intracellular acidification of the K562/DOX cells that exhibited more alkaline pH(i) than the K562 ...
Ċubgan Dorota - - 2009
Neoplastic cells frequently have an increased number of transferrin receptors. Coupling transferrin to an anti-neoplastic drug has the potential to overcome multidrug resistance (MDR). The purpose of this study was to examine the distribution and action of doxorubicin-transferrin conjugate (DOXTRF) in a leukaemia cell line (HL60), a multidrug-resistant leukaemia cell ...
Shin Dae Hwan - - 2008
We investigated the anticancer activity of 11-hydroxyaclacinomycin X (ID-6105), a novel anthracycline, on weakly doxorubicin (Dox)-resistant SK-OV-3 ovarian cancer cells, and elucidated the relationship between its anticancer activity and accumulation in cells compared with those of Dox. Accumulation of ID-6105 in the cells was time-and concentration-dependent, a result of drug-induced ...
Kuang Ye-Hong - - 2008
There is a correlation between the multidrug-resistance (MDR) of cancer cells and their enhanced invasive or metastatic potential. We studied the expression of CD147, a plasma membrane glycoprotein that plays a key role in tumor metastasis by stimulating the production of matrix metalloproteinases (MMPs), in sensitive human oral squamous KB ...
Koo Jin-Suk - - 2008
AIMS: The resistance to chemotherapeutic drugs is a major problem for successful cancer treatment. Multidrug resistance (MDR) phenotype is characterized by over-expression of P-glycoprotein (P-gp) on the cancer cell plasma membrane that extrudes drugs out of the cells. Therefore, novel MDR reversal agents are desirable for combination therapy to reduce ...
Gupta Divya - - 2008
PURPOSE: We examined the presence of the pregnane X receptor (PXR) and its effects on ovarian cancer cells after activation by its cognate ligand. EXPERIMENTAL DESIGN: SKOV-3 and OVCAR-8 ovarian carcinoma cells were analyzed for expression of PXR by quantitative reverse transcription-PCR and Western blot. Human ovarian cancer tissue was ...
Li Zhao - - 2008
OBJECTIVE: To investigate the effect and mechanism of nociceptin/orphanin FQ (OFQ) reversing multi-drug resistance of K562/ADM cells in vitro. METHODS: MTT assay, Wright staining, flow cytometry, transmission electron microscope and gel electrophoresis were used to evaluate the effect and mechanism of OFQ in reversing multi-drug resistance of K562/ADM cells. RESULTS: ...
Mishra Jayshree - - 2008
Increasingly, it is recognized that commensal microflora regulate epithelial cell processes through the dynamic interaction of pathogen-associated molecular patterns and host pattern recognition receptors such as Toll-like receptor 4 (TLR4). We therefore investigated the effects of bacterial lipopolysaccharide (LPS) on intestinal P-glycoprotein (P-gp) expression and function. Human SW480 (P-gp+/TLR4+) and ...
Hildebrand Jennifer L - - 2009
An assessment of energetic costs associated with P-glycoprotein (P-gp)-mediated xenobiotic efflux is important in understanding the energy budgets, tradeoffs, and fitness of organisms inhabiting contaminated environments. Here, a functional characterization and determination of the energetic costs associated with doxorubicin (DOX) efflux was examined in isolated hepatocytes of rainbow trout. The ...
Kitada, Noriaki
The purpose of this study was to clarify the effects of oxaliplatin on the function and expression of the multidrug efflux transporter P-glycoprotein/MDR1 in a porcine kidney epithelial cell line, LLC-PK, as a renal tubular epithelial model. LLC-PK cells were pretreated with or without oxaliplatin for 48 h, and the ...
Bisi Alessandra - - 2008
A series of easily affordable phenothiazine derivatives bearing a rigid but-2-ynyl amino side chain were synthesized and tested to evaluate the MDR reverting activity and full antitumor profile. Some compounds endowed with remarkable MDR reverting effect were identified, and the most active one (6c) was shown to increase doxorubicin retention ...
Maruszewska Agnieszka - - 2008
The aim of this study was to examine the effect of selected pyridinium salts, 1-methyl-3-nitropyridine chloride (MNP(+)Cl(-)) and 3,3,6,6,10-pentamethyl-3,4,6,7-tetrahydro-[1,8(2H,5H)-dion]acridine chloride (MDION(+)Cl(-)), on the activity of doxorubicin (DOX) and vincristine (VINC) towards human promyelocytic leukaemia HL60 cells as well as its multidrug resistant (MDR) sublines exhibiting two different phenotypes of MDR ...
Andjelkovic Tijana - - 2008
Multidrug resistance (MDR) is the main obstacle to a successful chemotherapy of lung cancer. We tested the potential of sulfinosine and curcumin, alone and in combination, for modulating MDR in the human resistant, non-small cell lung carcinoma cell line (NCI-H460/R). First, we determined the mutational status of the p53 gene ...
Zhang Wenxia - - 2008
The effects of eight components from six commonly consumed spices on P-glycoprotein (P-gp) transport and CYP3A4 metabolism were evaluated in vitro. P-gp-mediated [(3)H]digoxin fluxes across the L-MDR1 (LLC-PK1 cells transfected with human MDR1 gene) and Caco-2 (human colon carcinoma) cell monolayers showed a marked asymmetry compared with that in the ...
Hou Yue - - 2008
Multidrug resistance presents a serious problem in cancer chemotherapy. Recent studies have shown that the multidrug resistance of tumor cells can be reversed by tetrandrine by potentiating the cytotoxicity of chemotherapeutic agents. However, whether tetrandrine has such potentiating effect on epirubicin has not been reported. Thus, the combined effect of ...
Pop Iliodora - - 2008
The objective of this study was to generate new P-glycoprotein (P-gp)-expressing multidrug resistant (MDR) cell lines by drug selection. Since our previous studies have been carried out with cells infected with a P-gp-containing vector, it was important to confirm our findings in cells generated by drug selection. In this report, ...
De Jong Laetitia - - 2008
The synthesis of an amphiphilic polymethacrylate copolymer containing cholesterol hydrophobic moieties and rhodamine as a fluorescent probe, the formation of microspheres, and the uptake of these microspheres in an invertebrate are reported. The cholesterol-derived methacryloyl monomer, which was prepared via a one-step synthesis, was copolymerized with methacrylic acid and methacryloxyethyl ...
Gruber Beata M - - 2008
NFkappaB (nuclear factor kappaB) is a transcription factor controlling, among others, cell proliferation and apoptosis. The potent activators of NFkappaB are anthracyclines which can activate apoptotic processes. As shown by some authors, NFkappaB activated by these drugs well correlated with their cytotoxic activity. The aim of this study was to ...
Shen Jing - - 2008
PURPOSE: This study aimed to evaluate the multidrug resistance (MDR) reversal activity of quercetin (Que) in combination with hyperthermia (HT) in human myelogenous leukemia cells K562/A. METHODS: The cytotoxicity of Que alone and the effect of Que and HT to doxorubicin (Dox) cytotoxicity were determined using MTT assay in K562 ...
Nabekura Tomohiro - - 2008
The effects of dietary plant sterols on human drug efflux transporters P-glycoprotein (P-gp, ABCB1) and multidrug resistance protein 1 (MRP1, ABCC1) were investigated using P-gp-overexpressing human carcinoma KB-C2 cells and human MRP1 gene-transfected KB/MRP cells. The effects of natural phytosterols found in foods, herbs, and dietary supplements such as beta-sitosterol, ...
Kwon Hyog-Young - - 2008
Multidrug resistance (MDR) is a major problem in cancer chemotherapy. It was previously reported that a red ginseng saponin, 20(S)-ginsenoside Rg3 could modulate MDR in vitro and extend the survival of mice implanted with ADR-resistant murine leukemia P388 cells. This study examined the cytotoxicity of Rg3 on normal and transformed ...
Filomeni Giuseppe - - 2008
In the present work, we have investigated the antitumor activity of 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX) on aggressive small cell lung cancer. NBDHEX not only is cytotoxic toward the parental small cell lung cancer H69 cell line (LC(50) of 2.3 +/- 0.6 micromol/L) but also overcomes the multidrug resistance of its variant, H69AR, ...
Mizutani Takaharu - - 2008
P-glycoprotein (P-gp, ABCB1, MDR1) was recognized as a drug-exporting protein from cancer cells three decade ago. Apart from the multidrug transporter side effects of P-gp, normal physiological functions of P-gp have been reported. P-gp could be responsible for translocating platelet-activating factor (PAF) across the plasma membrane and PAF inhibited drug ...
Dai Xiaowen - - 2008
Frequency domain fluorescence lifetime imaging microscopy (FLIM) has been used in combination with laser scanning confocal microscopy to study the cellular uptake behavior of the antitumor drug doxorubicin (DOX) and micellar-encapsulated DOX (PLyAd-DOX). The endocytosis uptake process of PLyAd-DOX was monitored over 72 hours using confocal microscopy, with a maximum ...
Lv Gang - - 2008
Novel nanocomposites of polylactide (PLA) nanofibers and tetraheptylammonium-capped Fe3O4 magnetic nanoparticles have been prepared and utilized to realize the efficient accumulation of anticancer drug daunorubicin in target cancer cells. The observations of optical microscopy and confocal fluorescence microscopy indicate that the PLA nanofibers and Fe3O4 nanoparticles may contribute to their ...
Wang Yaohua - - 2008
Previous reports have demonstrated that N-l-leucyl-doxorubicin (LeuDox) is less toxic than its parent drug, Dox, but the underlying causes of this reduced toxicity have yet to be fully elucidated. In this study, the incorporation of LeuDox into (i) the MES-SA human uterine sarcoma cell line and (ii) its Dox resistant ...
Nazer Babak B Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, - - 2008
The pathogenesis of Alzheimer's disease is characterized by aggregation of the amyloid-beta protein (Abeta) into neurotoxic plaques. Recent in vivo studies have suggested the non-proteolytic clearance of Abeta via receptor-mediated transport across the blood-brain barrier (BBB). The aim of this study was to investigate the role of P-glycoprotein (Pgp) and ...
Magnarin Monica - - 2008
ABSTRACT The transport of doxorubicin and rhodamine 123, substrates of ABC transporters, was evaluated in the BeWo stabilized trophoblast cell line. Both compounds were taken up by BeWo cells, but their intracellular concentrations were highly dependent on temperature, and significantly reduced at 4 degrees C. The P-glycoprotein inhibitors verapamil and ...
Sánchez María del C Mdel - - 2008
INTRODUCTION: P-glycoprotein (P-gp), a membrane protein that pumps drugs out of cells, affects the availability and effectiveness of drugs and their extrusion from cells. HIV-1 protease inhibitors (PIs), part of the antiretroviral treatment known as highly active antiretroviral treatment, are substrates and possibly inhibitors of the P-gp pump. Their interaction ...
Rao Prema S - - 2008
P-glycoprotein (Pgp), a plasma membrane (PM) glycoprotein, is responsible for the development of multidrug resistance. The mechanism by which Pgp is targeted to the PM is not defined. To identify proteins that influence Pgp trafficking, we utilized the yeast two-hybrid analysis procedure, which identified a new isoform of endoplasmic reticulum ...
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