Glycosyltransferase ST6Gal-I promotes the epithelial to mesenchymal transition in pancreatic cancer cells.
Glycosyltransferase ST6Gal-I promotes the epithelial to mesenchymal transition in pancreatic cancer cells.
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DOI：
10.1074/jbc.ra120.014126
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发表时间：
2021-01
期刊：
影响因子：
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通讯作者：
Bellis SL
中科院分区：
文献类型：
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作者：
Britain CM;Bhalerao N;Silva AD;Chakraborty A;Buchsbaum DJ;Crowley MR;Crossman DK;Edwards YJK;Bellis SL
ST6Gal-I是一种在许多恶性肿瘤中上调的酶，它添加α2-6-链唾液酸来选择膜受体，从而调节受体信号传导和细胞表型。在这项研究中，我们利用具有低内源性ST6Gal-I和有限转移潜力的Suit2胰腺癌细胞系，以及两个转移性Suit2衍生的亚克隆S2-013和S2-LM7AA，研究了ST6Gal-I在上皮到间质转化（EMT）中的作用。RNA-Seq结果表明，转移亚克隆比亲代Suit2细胞具有更大的EMT相关基因网络激活，并且在Suit2细胞系中强制过表达ST6Gal-I足以激活EMT通路。因此，我们在ST6Gal-I过表达或不过表达的Suit2细胞，以及ST6Gal-I敲低或不敲低的S2-013和S2-LM7AA细胞中评估了EMT标记物的表达和细胞侵袭性（EMT的一个关键表型特征）。相对于ST6Gal-I低表达的细胞，ST6Gal-I高表达的细胞在间质标志物（n -钙粘蛋白、蛞蝓、蜗牛、纤维连接蛋白）和细胞侵袭性方面表现出富集。相反，上皮标志物（E-cadherin, occludin）在st6gal - i高的细胞中被抑制。为了深入了解st6gal - 1在EMT中的作用机制，我们检测了表皮生长因子受体（EGFR）的活性，这是一种已知的EMT驱动因子。st6gal - i高的细胞α - 2-6唾液化和EGFR活化程度高于st6gal - i低的细胞。EGFR抑制剂厄洛替尼可以中和st6gal - i依赖性的EGFR激活、间充质标志物表达和侵袭性差异，在Suit2和S2-LM7AA细胞系中，但在S2-013细胞系中不起作用。总的来说，这些结果通过强调ST6Gal-I在EMT中的作用，提高了我们对ST6Gal-I的肿瘤促进功能的理解，这可能至少部分由α2-6唾液化的EGFR介导。
ST6Gal-I, an enzyme upregulated in numerous malignancies, adds α2-6-linked sialic acids to select membrane receptors, thereby modulating receptor signaling and cell phenotype. In this study, we investigated ST6Gal-I’s role in epithelial to mesenchymal transition (EMT) using the Suit2 pancreatic cancer cell line, which has low endogenous ST6Gal-I and limited metastatic potential, along with two metastatic Suit2-derived subclones, S2-013 and S2-LM7AA, which have upregulated ST6Gal-I. RNA-Seq results suggested that the metastatic subclones had greater activation of EMT-related gene networks than parental Suit2 cells, and forced overexpression of ST6Gal-I in the Suit2 line was sufficient to activate EMT pathways. Accordingly, we evaluated expression of EMT markers and cell invasiveness (a key phenotypic feature of EMT) in Suit2 cells with or without ST6Gal-I overexpression, as well as S2-013 and S2-LM7AA cells with or without ST6Gal-I knockdown. Cells with high ST6Gal-I expression displayed enrichment in mesenchymal markers (N-cadherin, slug, snail, fibronectin) and cell invasiveness, relative to ST6Gal-I-low cells. Contrarily, epithelial markers (E-cadherin, occludin) were suppressed in ST6Gal-I-high cells. To gain mechanistic insight into ST6Gal-I’s role in EMT, we examined the activity of epidermal growth factor receptor (EGFR), a known EMT driver. ST6Gal-I-high cells had greater α2-6 sialylation and activation of EGFR than ST6Gal-I-low cells. The EGFR inhibitor, erlotinib, neutralized ST6Gal-I-dependent differences in EGFR activation, mesenchymal marker expression, and invasiveness in Suit2 and S2-LM7AA, but not S2-013, lines. Collectively, these results advance our understanding of ST6Gal-I’s tumor-promoting function by highlighting a role for ST6Gal-I in EMT, which may be mediated, at least in part, by α2-6-sialylated EGFR.