Apical membrane expression of distinct sulfated glycans represents a novel marker of cholangiolocellular carcinoma
Apical membrane expression of distinct sulfated glycans represents a novel marker of cholangiolocellular carcinoma
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DOI：
10.1038/labinvest.2016.104
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发表时间：
2016-12-01
影响因子：
5
通讯作者：
Kobayashi, Motohiro
中科院分区：
文献类型：
--
作者：
Hoshino, Hitomi;Ohta, Makoto;Kobayashi, Motohiro
肝内胆管细胞癌（ICC）是第二常见的原发性肝脏肿瘤，其次是肝细胞癌。ICC可进一步细分为（i）肝门周围型和（ii）外周型，后者在组织学上类似于小型肝内胆管，如小叶间胆管、胆管/小管和Hering管。胆管细胞癌（Cholangiolocellular carcinoma，CoCC）是肝细胞-胆管细胞癌的一个亚型，目前被认为是外周型ICC的一个亚型。本研究旨在确定MECA-79单克隆抗体识别的硫酸化聚糖是否可以作为CoCC标记物。使用免疫组织化学，我们发现，MECA-79硫酸多糖优先表达在正常肝脏中的小尺寸肝内胆管和在形成的胆管结构中的胆管细胞的顶膜。我们还报告了顶膜MECA-79硫酸化聚糖表达与粘蛋白1（MUC 1）核心蛋白共定位。我们还提出过表达FLAG标记MUC 1的中国仓鼠卵巢细胞的免疫印迹，以显示MUC 1作为MECA-79支架。此外，我们报告过表达N-乙酰葡糖胺-6-O-磺基转移酶2（GlcNAc 6ST-2）而非GlcNAc 6ST-1的SSP-25人ICC细胞表现出MECA-79硫酸化聚糖的膜表达，表明GlcNAc 6ST-2催化胆管细胞中MECA-79表位的生物合成。此外，野生型和GlcNAc 6ST-1敲除小鼠在小尺寸肝内胆管（即小叶间胆管）中均表现出顶膜MECA-79表达，而在来自GlcNAc 6ST-1和GlcNAc 6ST-2双敲除小鼠的可比组织中完全不存在MECA-79表达。这些数据共同表明，顶端膜定位MUC 1蛋白修饰的GlcNAc 6ST-2依赖性MECA-79硫酸聚糖可以标记胆管细胞与胆管/导管分化，并可以作为一个有用的CoCC标记。
Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver neoplasm, followed by hepatocellular carcinoma. ICC can be further subclassified as (i) perihilar and (ii) peripheral types, the latter histologically resembling small-sized intrahepatic bile ducts, such as interlobular bile ducts, cholangioles/ductules and the canals of Hering. Cholangiolocellular carcinoma (CoCC), now classified by the World Health Organization as a subtype of combined hepatocellular-cholangiocarcinoma, is currently regarded as a subtype of peripheral-type ICC. The present study was undertaken to determine whether sulfated glycans recognized by the MECA-79 monoclonal antibody could serve as a CoCC marker. Using immunohistochemistry, we show that MECA-79 sulfated glycans are preferentially expressed at the apical membrane of cholangiocytes found in small-sized intrahepatic bile ducts in normal liver and in canalicular structures formed in CoCC. We also report that apical membrane MECA-79 sulfated glycan expression colocalizes with that of mucin 1 (MUC1) core proteins. We also present immunoblotting of Chinese hamster ovary cells overexpressing FLAG tagged MUC1 to show that MUC1 serves as a MECA-79 scaffold. Furthermore, we report that SSP-25 human ICC cells overexpressing N-acetylglucosamine-6-O-sulfotransferase 2 (GIcNAc6ST-2), but not GIcNAc6ST-1, exhibit membrane expression of MECA-79 sulfated glycans, suggesting that GIcNAc6ST-2 catalyzes MECA-79 epitope biosynthesis in cholangiocytes. Moreover, both wild-type and GIcNAc6ST-1 knockout mice exhibit apical membrane MECA-79 expression in small-sized intrahepatic bile ducts, namely interlobular bile ducts, whereas MECA-79 expression was completely absent in comparable tissues from GIcNAc6ST-1 and GIcNAc6ST-2 double knockout mice. These data collectively indicate that apical membrane localization of MUC1 proteins decorated with GIcNAc6ST-2-dependent MECA-79 sulfated glycans may mark cholangiocytes with cholangiolar/ductular differentiation and could serve as a useful CoCC marker.