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Objective To determine the acetylation level of nucleophosmin(NPM)in female breast cancer and to discuss its function through mutation of modified lysine sites.To construct positive and negative NPM mutants on its acetylated lysine sites and to express them in breast cancer cells.Methods Acetylation level and acetylated lysine sites of NPM in three breast cancer tissues and para-carcinoma tissues were detected by acetylome technology;NPM mutants were constructed by site-directed mutagenesis PCR,specific PCR products were digested by DpnI and transformed into Escherichia coli(E.coli)to obtain specific plasmids for mutants;The accuracy of mutants were verified by double restriction enzyme digestion and sequencing;The mutants were expressed in BT-549 cells by transient transfection and verified by RT-PCR method.Protein expression and acetylation level of NPM were validated by Western blotting;Function of NPM acetylation was analyzed by proteomic detection and bioinformatic analysis.Results The 27th and 32nd lysine of NPM were highly acetylated in breast cancer tissues,which were 2.76 and 2.22 times higher than those in adjacent normal tissues,respectively;The NPM mutants showed the same molecular weight as that of wild type NPM and contained expected mutation sites;Corresponding NPM mRNA levels of BT-549 cells transfected with NPM mutants were significantly increased.With the increase of wild type NPM expression level,NPM acetylation level increased,while decreased after 27th lysine underwent negative mutation.NPM acetylation can significantly change the expression levels of 101 proteins in BT-549 cells,which are enriched in regulation of cellular macromolecule biosynthesis,DNA-template transcription,RNA biosynthesis and RNA metabolism process.Conclusion NPM is highly acetylated in breast cancer and can play a key role in cellular macromolecule biosynthesis,DNA-templated transcription,RNA biosynthesis and RNA metabolism process.
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Studied the optimum extraction process of polysaccharide from Phaeoporus obliquus and the effect of Phaeoporus obliquus polysaccharide on carbon tetrachloride (CCl4)- or alcohol-induced acute liver injury in mice. The main factor in influencing the extraction rate of Phaeoporus obliquus polysaccharide were extraction power and time, which was a kind of pyran glucose by infrared spectroscopy. CCl4 and alcohol were employed respectively to establish CCl4 and alcohol-induced acute liver injury mouse models. Compared with model groups mice, Phaeoporus obliquus polysaccharide treatment at the doses of 100mg/kg and 200mg/kg exhibited an obvious reduction liver index, ALP, ALT, AST levels, MDA content and TNF-α level (p<0.01) and SOD activity was increased, which was in a dose-dependent manner. Compared with the model group, the necrosis degree of hepatocytes was obviously reduced and the small fat droplets were formed in some cytoplasm, especially in high dose group, which the liver cells recovered to the level of normal group. Rt-PCR results showed that the expression of CYP2E1 mRNA in liver tissues of Phaeoporus obliquus polysaccharide groups were significantly reduced, and the difference were statistically significant compared with the model group (p<0.05). These results demonstrated that Phaeoporus obliquus polysaccharide has significantly hepatoprotective effect on CCl4 and alcohol-induced acute liver injury in mice.