Barthel Steven R, Gavino Jacyln D, Wiese Georg K, Jaynes Jennifer M, Siddiqui Javed, Dimitroff Charles J
Department of Dermatology, Brigham and Women's Hospital, Harvard Skin Disease Research Center, Boston, MA 02115, USA.
Glycobiology. 2008 Oct;18(10):806-17. doi: 10.1093/glycob/cwn070. Epub 2008 Jul 22.
Prostate cancer (PCa) cell tethering and rolling on microvascular endothelium has been proposed to promote the extravasation of PCa cells. We have shown that these adhesive events are mediated through binding interactions between endothelial (E)-selectin and Lewis carbohydrates on PCa cells. Prior data indicate that E-selectin-mediated rolling of bone-metastatic PCa MDA PCa 2b (MDA) cells is dependent on sialyl Lewis X (sLe(X))-bearing glycoproteins. To explore the molecular basis of sLe(X) synthesis and E-selectin ligand (ESL) activity on PCa cells, we compared and contrasted the expression level of glycosyltransferases, characteristically involved in sLe(X) and ESL synthesis, in ESL(+) MDA cells among other ESL(-) metastatic PCa cell lines. We also created and examined ESL(hi) and ESL(lo) variants of MDA cells to provide a direct comparison of the glycosyltransferase expression level. We found that normal prostate tissue and all metastatic PCa cell lines expressed glycosyltransferases required for sialo-lactosamine synthesis, including N-acetylglucosaminyl-, galactosyl-, and sialyltransferases. However, compared with expression in normal prostate tissue, ESL(+) MDA cells expressed a 31- and 10-fold higher level of alpha1,3 fucosyltransferases (FT) 3 and 6, respectively. Moreover, FT3 and FT6 were expressed at 2- to 354-fold lower levels in ESL(-) PCa cell lines. Consistent with these findings, ESL(hi) MDA cells expressed a 131- and 51-fold higher level of FT3 and FT6, respectively, compared with expression in ESL(lo) MDA cells. We also noted that alpha1,3 FT7 was expressed at a 5-fold greater level in ESL(hi) MDA cells. Furthermore, ESL(lo) MDA cells did not display sLe(X) on glycoproteins capable of bearing sLe(X), notably P-selectin glycoprotein ligand-1. These results implicate the importance of alpha1,3 FT3, FT6, and/or FT7 in sLe(X) and ESL synthesis on metastatic PCa cells.
前列腺癌细胞在微血管内皮细胞上的拴系和滚动被认为可促进前列腺癌细胞的外渗。我们已经表明，这些黏附事件是通过内皮（E）-选择素与前列腺癌细胞上的Lewis碳水化合物之间的结合相互作用介导的。先前的数据表明，E-选择素介导的骨转移性前列腺癌MDA PCa 2b（MDA）细胞的滚动依赖于携带唾液酸化路易斯X（sLe(X)）的糖蛋白。为了探索前列腺癌细胞上sLe(X)合成和E-选择素配体（ESL）活性的分子基础，我们比较并对比了糖基转移酶的表达水平，这些糖基转移酶通常参与sLe(X)和ESL的合成，在ESL(+) MDA细胞以及其他ESL(-)转移性前列腺癌细胞系中进行比较。我们还创建并检测了MDA细胞的ESL(hi)和ESL(lo)变体，以直接比较糖基转移酶的表达水平。我们发现正常前列腺组织和所有转移性前列腺癌细胞系均表达唾液酸乳糖胺合成所需的糖基转移酶，包括N-乙酰葡糖胺基转移酶、半乳糖基转移酶和唾液酸转移酶。然而，与正常前列腺组织中的表达相比，ESL(+) MDA细胞中α1,3岩藻糖基转移酶（FT）3和6的表达水平分别高31倍和10倍。此外，ESL(-)前列腺癌细胞系中FT3和FT6的表达水平低2至354倍。与这些发现一致，与ESL(lo) MDA细胞中的表达相比，ESL(hi) MDA细胞中FT3和FT6的表达水平分别高131倍和51倍。我们还注意到，α1,3 FT7在ESL(hi) MDA细胞中的表达水平高5倍。此外，ESL(lo) MDA细胞在能够携带sLe(X)的糖蛋白上未显示sLe(X)，特别是P-选择素糖蛋白配体-1。这些结果表明α1,3 FT3、FT6和/或FT7在转移性前列腺癌细胞上的sLe(X)和ESL合成中具有重要作用。
