Gene alterations of glycosyltransferase during the course of malignant tranformation in uterine endometrium

单克隆抗体MSN-1是针对子宫内膜癌细胞系建立的，并被证明能识别至少Lewis b碳水化合物抗原。该抗体的免疫组化染色在85%以上的子宫内膜腺癌病例中呈阳性反应，但在少数正常子宫内膜病例中呈阳性反应，这表明msn -1反应性抗原能够成为子宫内膜癌的良好组织化学标志物。Lewis组织血型抗原的表达由FucT-III基因（Le基因）编码的Lewis型α(1,3/1,4)聚焦转移酶决定。由于已知lewis阴性个体与该基因的错义突变（le/le）等位基因纯合子，导致酶活性失活，因此我们研究了子宫内膜腺癌标本中msn -1反应抗原的表型表达是否受到腺癌患者中FucT-III基因型的影响。为了确定FucT-III基因的基因型，即检测突变，我们采用聚合酶链反应(PCR) -限制性片段长度多态性方法，从患者外周血白细胞中提取基因组dna作为PCR模板。59例子宫内膜腺癌中，4例为lewis阴性基因型（le/le），采用ABC免疫组织化学技术检测其癌细胞上是否存在msn -1反应性抗原。常规的血凝反应也显示这四个病例都是刘易斯阴性血型。然而，他们的癌组织对MSN-1反应积极。这些结果表明，MSN-1识别的是由focusyltransferases而不是FucT-III构建的一种聚焦碳水化合物。

Monoclonal antibody MSN-1 was established against an endometrial cancer cell line and proven to recognize at least Lewis b carbohydrate antigen. Immunohistochemical staining with this antibody resulted in a positive reaction in more than 85% of the endometrial adenocarcinoma cases examined but in few cases with normal endometria, indicating that MSN-1-reactive antigen is able to be a good histochemical marker for endometrial cancers. Expression of the Lewis histo-blood group antigen is determined by the Lewis type alpha (1,3/1,4) fucosyltransferase enconded by the FucT-III gene (Le gene). Since Lewis-negative individuals are known to be homozygous for an allele with missense mutations of this gene (le/le) which cause inactivation of the enzyme activity, we investigated whether or not phenotypic expression of the MSN-1-reactive antigen in endometrial adenocarcinoma specimens was affected by the genotypes of the FucT-III gene in patients with adenocarcinoma. To determine the genotypesof the FucT-III gene, i.e., to detect the mutations, we employed the polymerase chain reaction (PCR) -restriction fragment length polymorphism method by using genomic DNAs extracted from the patients'peripheral blood leucocytes as PCR templates. Out of 59 cases of endometrial adenocarcinoma, four cases with the Lewis-negative genotype (le/le) were identified and examined by the ABC immunohistochemical technique for the presence of the MSN-1-reactive antigen on their cancer cells. The conventional hemagglutination reaction also revealed all four of these cases to have the Lewis-negative blood type. However, their cancer tissues reacted positively with MSN-1. These results suggest that MSN-1 recognizes a fucosylated carbohydrate that is constructed by fucosyltransferases other than FucT-III.