Expression of N-acetylglucosaminyltransferase III in hepatic nodules generated by different models of rat liver carcinogenesis.
Expression of N-acetylglucosaminyltransferase III in hepatic nodules generated by different models of rat liver carcinogenesis.
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N-乙酰氨基葡萄糖转移酶III在不同大鼠肝癌模型产生的肝结节中的表达。
DOI：
10.1093/carcin/10.5.961
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发表时间：
1989
期刊：
影响因子：
4.7
通讯作者：
Rajalakshmi,S
中科院分区：
文献类型：
--
作者：
Pascale,R;Narasimhan,S;Rajalakshmi,S
我们早期的研究表明，n -乙酰氨基葡萄糖转移酶III （GnTase III）可以催化n -乙酰氨基葡萄糖（bi-Gn）在细胞糖蛋白的复合体型连接聚糖中插入，这种酶存在于由乳清酸模型促进的肝结节中。在大鼠的正常肝脏和周围的非结节性肝脏中均检测不到双gn残基和GnTase III的活性。本研究旨在找出GnTase III活性的表达是肝结节的表型特征，还是仅仅是由乳香酸模型产生的结节所特有的。Fischer雄性344大鼠以1,2-二甲基肼或二乙基亚硝胺两种不同的致癌物启动，并通过其他模型，如耐药肝细胞模型和胆碱缺乏饮食模型，以及乳清酸模型促进。三种不同模型产生的肝结节和肝细胞癌均表现出显著水平的GnTase III活性，而非结节性肝周围、2/3部分肝切除后的再生肝或年龄和性别匹配的对照大鼠肝脏均未检测到GnTase III活性。在结节和癌症中检测到GnTase III的活性与在大鼠癌组织γ-谷氨酰转肽酶中报道的双gn残基的存在是一致的。这些结果与GnTase III的表达在肝癌发生过程中被激活的结论是一致的，并且与任何特定的启动子或启动子无关。
Our earlier studies revealed thatN-acetylglucosaminyltransferase III (GnTase III), which catalyzes the insertion of a bisecting N-acetylglucosamine (bi-Gn) in the complex-typeN-linked glycans of cellular glycoproteins, is present in hepatic nodules promoted by the orotic acid model. Neither the bi-Gn residues nor the activity of GnTase III is detectable in normal livers and in the surrounding non-nodular liver of the rat. The present study was designed to find out whether an expression of activity of GnTase III is a phenotypic property characteristic of hepatic nodules or simply unique to nodules produced by the orotic acid model. Fischer male 344 rats were initiated with two different carcinogens namely 1,2-dimethyl-hydrazine or diethylnitrosamine and promoted by other models such as the resistant hepatocyte model and the choline deficient diet model, in addition to the orotic acid model. The hepatic nodules generated by these three different models and hepatocellular carcinomas exhibited significant levels of activity of GnTase III while non-nodular surrounding liver, regenerating liver after 2/3 partial hepatectomy or livers of age and sex matched control rats, had no detectable activity. The detection of the activity of GnTase III in nodules and in cancer is in agreement with the presence of bi-Gn residues reported in γ-glutamyltranspeptidase of cancer tissues of rats. These results are consistent with the conclusion that the expression of GnTase III is activated during hepato-carcinogenesis and is not related to any particular initiator or promoter.