The main aim of this study was to investigate the roles of GST-π and polβ genes in the chemoresistance of esophageal carcinoma cells. Eukaryotic expression vectors containing each gene were constructed and transfected into EC9706 cells, and the biological effects of the two genes assessed based on a resistance index. We additionally investigated the in vitro and in vivo anti-resistance effects of GST-π and polβ genes using recombinant lentiviruses carrying siRNAs against the two genes. Our results showed that upregulation of GST-π and polβ genes suppresses chemosensitivity of esophageal carcinoma cells to cisplatin, while downregulation of these two genes with RNAi technology reverses this chemoresistance. Multi-site injection of recombinant lentivirus targeting the GST-π gene into transplanted cDDP tumors effectively reversed their chemoresistant phenotype. However, the same treatment against the polβ gene did not lead to significant efficacy against chemoresistance.
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http://dx.doi.org/10.7314/apjcp.2013.14.12.7375 | DOI Listing |
J Pineal Res
August 1999
Doheny Eye Institute, Department of Cell and Neurobiology, University of Southern California School of Medicine, Los Angeles 90033, USA.
Pineal and retinal melatonin synthesis is controlled by the enzymatic activity of arylalkylamine N-acetyltransferase (AA-NAT, EC 2.3.1.
View Article and Find Full Text PDFNihon Naibunpi Gakkai Zasshi
September 1985
A new isozyme of Glutathione-S-transferase (GST) with more acidic pI (6.7) than other forms of GST hitherto reported was isolated from rat liver cytosol by consecutive chromatographies on a DEAE cellulose column, lysyl-GSH affinity column and Sephadex G-100 column. This anionic form of GST represented approximately one third of total GST activity in rat liver cytosol.
View Article and Find Full Text PDFPreliminary experiments confirmed the work of others showing that the total glutathione peroxidase (GSH-px) activity of rat liver supernatant fraction may be resolved into two peaks of activity (peaks I and II) by gel filtration, and that peak I is the selenium-containing enzyme and peak II is another peroxidase indistinguishable from glutathione S-transferase (GST). In selenium and vitamin E deficiency, the total activity of the GSH-px became very low, and the total activity of GST with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate was enhanced. Study of the time course of these changes as deficiency progressed indicated that the stimulus for the rise in GST (CDNB) activity was the fall in GSH-px activity which preceded it.
View Article and Find Full Text PDFPharmacol Res Commun
February 1984
The in vitro interaction of dithiocarb (DTC) with rat liver glutathione S-transferase was studied, using reduced glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB) as substrates. The inhibition of the GST activity by DTC was dose dependent, but not linear. The different GST isoenzymes were inhibited to different degrees.
View Article and Find Full Text PDFFood Chem Toxicol
October 1983
The in vitro interaction of four chlorophenoxyalkyl (CPA) acid herbicides with rat-liver glutathione S-transferase (GST) was studied using reduced glutathione and 1-chloro-2,4-dinitrobenzene as substrates. Inhibition of GST activity by the CPA acids in crude extracts was dose dependent. Ring substitution and side-chain length were shown to be of importance in determining the extent of GST inhibition.
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