The mechanism of carcinogenesis of choriocarcinoma with glycosyltransferases for hyperglycosylated hCG

滋养细胞肿瘤中hCG糖链结构与正常妊娠和葡萄胎相比有很大的不同，这是由于N-乙酰氨基葡萄糖转移酶IVa（GnT-IVa）和核心2 β-1，6-N-乙酰氨基葡萄糖转移酶（C2 GNT）的存在。GnT-IVa和C2 GNT在绒毛膜癌和侵蚀性葡萄胎中表达较强，在正常胎盘和葡萄胎中表达较弱。两种糖基转移酶参与绒毛膜癌侵袭能力的增强。免疫沉淀结果表明Gnt-IVa通过β 1整合素的糖基化促进侵袭能力。荧光素酶分析表明cRel可能通过与GnT-IVa启动子结合来调控GnT-IVa的转录。

The structures of sugar chains of hCG are quite different in trophoblastic neoplasia compared with normal pregnancy and hydatidiform mole, and it is because of N-acetylglucosaminyltransferase IVa (GnT-IVa)and core 2 beta-1, 6-N-acetylglucosaminyltransferase (C2GNT). The expression of GnT-IVa and C2GNT was strong in choriocarcinoma and invasive mole, but very weak in normal placenta and hydatidiform mole. The two glycosyltransferases involoved in promoting of invasion ability in choriocarcinoma. The result of immunoprecipitation suggested that Gnt-IVa promotes invasion ability via glycosylation of beta1 integrin. Luiferase assay suggested that cRel may regulate transcription of GnT-IVa via binding to the promoter of GnT-IVa.