Xu Qingsong, Niu Xueming, Wang Wenjing, Yang Wen, Du Yuguang, Gu Jianguo, Song Linsheng
College of Fisheries and Life Science, Dalian Ocean University, 52. Heishijiao Street, Shahekou District, Dalian, 116023, China.
Tohoku Medical and Pharmaceutical University, Sendai, Miyagi, 981-8558, Japan.
Glycoconj J. 2017 Apr;34(2):219-227. doi: 10.1007/s10719-016-9754-3. Epub 2016 Dec 29.
Epithelial-mesenchymal transition (EMT) is a process in tumor progression during which cancer cells undergo dramatic changes acquiring highly invasive properties. In a widespread adoption of TGF-β-induced EMT model, we have previously observed that expression of bisecting GlcNAc on N-glycans was dramatically decreased. Herein, we performed in vitro studies with the MCF10A cell line. In response to low cell density, MCF10A cells suffered spontaneously morphologic and phenotypic EMT-like changes, including elongated spindle shape, extended out from edge of the cell sheet, cytoskeleton reorganization, vimentin and fibronectin up-regulation, catenins redistribution, and cadherin switching. Moreover, these phenotypic changes were associated with specific N-glycan alterations. Interestingly, the amounts of bisecting GlcNAc structure were declined, by contrast, the formation of β1-6 GlcNAc branches were obviously up-regulated during the EMT induced by sparse cell conditions. We further investigated N-glycans on the β1-integrin, which is a good target of some glycosyltransferases. The reactivity with E4-PHA lectin decreased, whereas the staining for L4-PHA lectin, which recognizes branched GlcNAc, increased in sparse cell conditions compared with dense cell conditions. Taken together, these results demonstrated that specific N-glycan alterations are coupled in EMT process and promoted cells migration at a low cell density.
上皮-间质转化（EMT）是肿瘤进展过程中的一个过程，在此过程中癌细胞会发生显著变化，获得高度侵袭性。在广泛采用的TGF-β诱导的EMT模型中，我们之前观察到N-聚糖上平分型N-乙酰葡糖胺（GlcNAc）的表达显著降低。在此，我们对MCF10A细胞系进行了体外研究。响应低细胞密度，MCF10A细胞自发经历形态和表型上类似EMT的变化，包括细长的纺锤形、从细胞片边缘伸出、细胞骨架重组、波形蛋白和纤连蛋白上调、连环蛋白重新分布以及钙黏蛋白转换。此外，这些表型变化与特定的N-聚糖改变相关。有趣的是，平分型GlcNAc结构的量减少，相反，在稀疏细胞条件诱导的EMT过程中，β1-6 GlcNAc分支的形成明显上调。我们进一步研究了β1-整合素上的N-聚糖，β1-整合素是一些糖基转移酶的良好靶点。与密集细胞条件相比，在稀疏细胞条件下，与E4-PHA凝集素的反应性降低，而识别分支GlcNAc的L4-PHA凝集素的染色增加。综上所述，这些结果表明特定的N-聚糖改变在EMT过程中相互关联，并在低细胞密度下促进细胞迁移。
