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Various Cell Lines (various + cell_line)
Selected AbstractsPhytanoyl-CoA hydroxylase activity is induced by phytanic acidFEBS JOURNAL, Issue 13 2000Anna W. M. Zomer Phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) is a branched-chain fatty acid present in various dietary products such as milk, cheese and fish. In patients with Refsum disease, accumulation of phytanic acid occurs due to a deficiency of phytanoyl-CoA hydroxylase, a peroxisomal enzyme containing a peroxisomal targeting signal 2. Recently, phytanoyl-CoA hydroxylase cDNA has been isolated and functional mutations have been identified. As it has been shown that phytanic acid activates the nuclear hormone receptors peroxisome proliferator-activated receptor (PPAR), and all three retinoid X receptors (RXRs), the intracellular concentration of this fatty acid should be tightly regulated. When various cell lines were grown in the presence of phytanic acid, the activity of phytanoyl-CoA hydroxylase increased up to four times, depending on the particular cell type. In one cell line, HepG2, no induction of phytanoyl-CoA hydroxylase activity was observed. After addition of phytanic acid to COS-1 cells, an increase in phytanoyl-CoA hydroxylase activity was observed within 2 h, indicating a quick cell response. No stimulation of phytanoyl-CoA hydroxylase was observed when COS-1 cells were grown in the presence of clofibric acid, 9- cis -retinoic acid or both ligands together. This indicates that the activation of phytanoyl-CoA hydroxylase is not regulated via PPAR, or RXR. However, stimulation of PPAR, and all RXRs by clofibric acid and 9- cis -retinoic acid was observed in transient transfection assays. These results suggest that the induction of phytanoyl-CoA hydroxylase by phytanic acid does not proceed via one of the nuclear hormone receptors, RXR or PPAR,. [source] t(10;11)-Acute leukemias with MLL-AF10 and MLL-ABI1 chimeric transcripts: Specific expression patterns of ABI1 gene in leukemia and solid tumor cell linesGENES, CHROMOSOMES AND CANCER, Issue 1 2001Noriko Shibuya The recurrent translocation t(10;11) is associated with acute myeloid leukemia (AML). The AF10 gene on chromosome 10 at band p12 and MLL at 11q23 fuse in the t(10;11)(p12;q23). Recently, we have identified ABI1 as a new partner gene for MLL in an AML patient with a t(10;11)(p11.2;q23). The ABI1 is a human homologue of the mouse Abl -interactor 1 (Abi1), encoding an Abl-binding protein. The ABI1 protein exhibits sequence similarity to homeotic genes, and contains several polyproline stretches and a src homology 3 (SH3) domain. To clarify the clinical features of t(10;11)-leukemias, we investigated 6 samples from acute leukemia patients with t(10;11) and MLL rearrangement and detected MLL-AF10 chimeric transcripts in 5 samples and MLL-ABI1 in one. The patient with MLL-ABI1 chimeric transcript is the second case described, thus confirming that the fusion of the MLL and ABI1 genes is a recurring abnormality. Both of the patients with MLL-ABI1 chimeric transcript are surviving, suggesting that these patients have a better prognosis than the patients with MLL-AF10. To investigate the roles of AF10 and ABI1 further, we examined the expression of these genes in various cell lines and fresh tumor samples using the reverse transcriptase-polymerase chain reaction method. Although AF10 was expressed in almost all cell lines similarly, the expression patterns of ABI1 were different between leukemia and solid tumor cell lines, suggesting the distinctive role of each isoform of ABI1 in these cell lines. We also determined the complete mouse Abi1 sequence and found that the sequence matched with human ABI1 better than the originally reported Abi1 sequence. Further functional analysis of the MLL-AF10 and MLL-ABI1 fusion proteins will provide new insights into the leukemogenesis of t(10;11)-AML. © 2001 Wiley-Liss, Inc. [source] Cyclin D1 overexpression associates with radiosensitivity in oral squamous cell carcinomaINTERNATIONAL JOURNAL OF CANCER, Issue 3 2001Ph.D., Satoru Shintani D.D.S. Abstract Overexpression of cyclin D1, a G1 cell cycle regulator, is often found in many different tumor types, including oral squamous cell carcinomas (SCC). Recent laboratory experiments have demonstrated that cyclin D1 levels can influence radiosensitivity in various cell lines. This study evaluated the relationship between cyclin D1 expression levels and radiosensitivity in nine oral SCC cell lines (HSC2, HSC3, HSC4, SCC15, SCC25, SCC66, SCC111, Ca9-22, and NAN2) and 41 clinical patients with oral SCC who underwent preoperative radiation therapy. Radiosensitivity of the nine oral SCC cell lines differed greatly in their response to radiation, assessed by a standard colony formation assay. Likewise, the expression of cyclin D1 varied, and the magnitude of the cyclin D1 expression correlated with increased tumor radiosensitivity. The similar significant association between the response to preoperative radiation therapy and cyclin D1 overexpression was observed in the oral SCC patients who were treated with preoperative radiation therapy. These results suggest that cyclin D1 expression levels correlate to radiosensitivity and could be used to predict the effectiveness of radiation therapy on oral SCC. © 2001 Wiley-Liss, Inc. [source] A brief introduction to cell-penetrating peptidesJOURNAL OF MOLECULAR RECOGNITION, Issue 5 2003Pontus Lundberg Abstract Cell membranes act as protective walls to exclude most molecules that are not actively imported by living cells. This is an efficient way for a cell to prevent uncontrolled influx or efflux of solutes, which otherwise would be harmful to it. Only compounds within a narrow range of molecular size, polarity and net charge are able to diffuse effectively through cell membranes. In order to overcome this barrier for effective delivery of membrane-impermeable molecules, several chemical and physical methods have been developed. These methods, e.g. electroporation, and more recent methods as cationic lipids/liposomes, have been shown to be effective for delivering hydrophobic macromolecules. The drawbacks of these harsh methods are, primarily, the unwanted cellular effects exerted by them, and, secondly, their limitation to in vitro applications. The last decade's discovery of cell-penetrating peptides translocating themselves across cell membranes of various cell lines, along with a cargo 100-fold their own size, via a seemingly energy-independent process, opens up the possibility for efficient delivery of DNA, antisense peptide nucleic acids, oligonucleotides, proteins and small molecules into cells both in vitro and in vivo. Copyright © 2003 John Wiley & Sons, Ltd. [source] Correlation between translation efficiency and outcome of combination therapy in chronic hepatitis C genotype 3JOURNAL OF VIRAL HEPATITIS, Issue 2 2006A. Yasmeen Summary., Combination therapy with interferon- , (IFN- ,) and ribavirin (RBV) in chronic hepatitis C demonstrates the best responses against hepatitis C virus (HCV) of genotype 3. Still, it has proven to be ineffective in 20,30% of patients infected with this genotype. In the present study, we analysed the translation efficiency mediated by the internal ribosome entry site (IRES) region in HCV genotype 3 genomes isolated from sustained responders (SR) and non-responders (NR), assuming that this may influence the outcome of treatment. Pretreatment isolates of genotype 3 from 22 individuals (15 SR, seven NR) were selected for such analyses. The IRES region [nucleotide (nt) 1,407] was cloned into a dual luciferase vector and IRES activity assessed following transfection into various cell lines. Low relative translation efficiency was observed for IRES elements derived from SR patients, whereas those of NR patients showed significantly greater translation efficiency (29.7 ± 13 vs 69.4 ± 22; P < 0.01). Subsequently, the effect of IFN- , plus RBV on IRES-driven translation in vitro was determined. A greater suppressive effect was observed on IRES activity isolated from seven SR patients, when compared with seven NR patients. In conclusion, IRES efficiency in vitro correlated with treatment response for HCV genotype 3. Further studies are warranted to investigate whether IRES efficiency in vitro, or sequence motifs associated with IRES efficiency, will be worthwhile to explore as prognostic tools for other HCV genotypes in the treatment of chronic HCV infection. [source] Curcumin and its analogues: Potential anticancer agentsMEDICINAL RESEARCH REVIEWS, Issue 5 2010Dinesh Kumar Agrawal Abstract This review chronicles the exploration of the curcumin in terms of development of analogues for the anticancer activity over the last century. Curcumin is a natural phytochemical obtained from dried root and rhizome of Turmeric (Curcuma Longa). It has been shown to interfere with multiple cell signaling pathways, including apoptosis (activation of caspases and downregulation of antiapoptotic gene products), proliferation (HER-2, EGFR, and AP-1), angiogenesis (VEGF), and inflammation (NF-,B, TNF, IL-6, IL-1, COX-2, and 5-LOX). In the last decade it has been much explored and various synthetic analogues have been prepared and evaluated for various pharmacological activities. Most of the analogues have shown very good anticancer activity in various models and various cell lines. However, some analogues have also shown antioxidant, anti-HIV, antimutagenic, antiangiogenic, antimalarial, antitubercular, antiandrogenic, COX inhibitory activities. Few analogues have shown very potent results and may be considered as clinical candidates for the development of future anticancer agent. This review contains 728 curcumin analogues and covers the literature from 1815 to mid 2009 and 93 references are cited. © 2009 Wiley Periodicals, Inc. Med Res Rev, 30, No. 5, 818,860, 2010 [source] Observation of different ceramide species from crude cellular extracts by normal-phase high-performance liquid chromatography coupled to atmospheric pressure chemical ionization mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2003Benjamin J. Pettus Normal-phase high-performance liquid chromatography (NP-HPLC) coupled to atmospheric pressure chemical ionization mass spectrometry (APCI-MS) allows qualitative analysis of endogenous ceramide and dihydroceramide species from crude lipid extracts utilizing chromatographic methods readily adaptable from commonly used thin layer chromatography (TLC) conditions. Qualitative information for the species comes from observation of differences in chromatographic and mass spectrometric behavior between species. Application to the analysis of ceramide and dihydroceramide from various cell lines is demonstrated. The results show the species profile in each cell line to be unique despite growth under identical conditions. The results from APCI-MS analysis corroborate and enhance information acquired from use of the diacylglycerol kinase assay for total ceramide measurement. This technique readily allows the previously difficult distinction between ceramide and dihydroceramide species. Copyright © 2003 John Wiley & Sons, Ltd. [source] Expression levels of human P-glycoprotein in In Vitro cell lines: correlation between mRNA and protein levels for P-glycoprotein expressed in cellsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 3 2009Yoshiyuki Shirasaka Abstract The purpose of this study was to investigate the correlation between mRNA and protein levels for P-glycoprotein (P-gp) expressed in various cell lines to validate the estimation of P-gp activity from its mRNA levels. P-gp expression levels in various cell monolayers, normal, P-gp-induced, P-gp-highly induced, (multidrug resistance, MDR) MDR1-knockdown (A2-2) and MDR1-knockdown (B2-2) Caco-2 cells and MDCKII/MDR1 cells, were quantified by real-time quantitative polymerase chain reaction (PCR) and western blot analysis. Both mRNA and protein levels of P-gp were lowest in the MDR1-knockdown (B2-2) Caco-2 cells, followed by the MDR1-knockdown (A2-2) Caco-2, normal Caco-2, P-gp-induced Caco-2 and P-gp-highly induced Caco-2 cells, and highest in the MDCKII/MDR1 cells. Except for the MDCKII/MDR1 cells, the protein levels of P-gp in all Caco-2 cell lines showed a linear correlation with its mRNA levels; however, although the MDR1 mRNA level in MDCKII/MDR1 cells was much higher than in the P-gp-highly induced Caco-2 cells, the protein levels were almost the same in both cells. From these findings, it was suggested that P-gp activity in MDCKII/MDR1 cells could not be estimated from its mRNA levels. 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