Transfection of the c-erbB2/neu gene upregulates the expression of sialyl Lewis X, α1,3-fucosyltransferase VII, and metastatic potential in a human hepatocarcinoma cell line
Transfection of the c-erbB2/neu gene upregulates the expression of sialyl Lewis X, α1,3-fucosyltransferase VII, and metastatic potential in a human hepatocarcinoma cell line
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DOI：
10.1046/j.1432-1327.2001.02254.x
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发表时间：
2001-06-01
期刊：
影响因子：
--
通讯作者：
Chen, HL
中科院分区：
文献类型：
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作者：
Liu, F;Qi, HL;Chen, HL
将含有促癌基因c-erbB2/neu的pCMV4质粒与含有“neo”选择标记的pcDNA3载体共转染人肝癌细胞系7721。建立了几个稳定表达c-erbB2/neu的克隆，并通过测定c-erbB2/neu mRNA及其编码蛋白p185进行了鉴定。以pCMV4和pcDNA3载体转染的模拟细胞为对照，研究c-erbB2/neu转染7721细胞后Lewis抗原和alpha1,3- focusyltransferase的表达及生物学行为。SLe(x)在模拟细胞表面表达较高，而SDLe(x)、Le(x)和SLe(a)表达不存在或可以忽略。这与模拟细胞中α 1,3- focusyltransferase VII表达丰富，α focusyltransferase III/VI表达极低，α 1,3- focusyltransferase IV几乎不表达相一致。转染c-erbB2/neu后，SLe(x)和α 1,3- focusyltransferase VII的表达同时升高，而α focusyltransferase III/VI的表达未发生改变。SLe(x)和alpha1,3- focusyltransferase VII的表达与c-erbB2/neu在不同克隆中的表达呈正相关，克隆13的表达最高，克隆6的表达中等，克隆7的表达最低。此外，c-erbB2/ new转染后，7721细胞与人脐静脉内皮细胞（HUVECs）或p -选择素的粘附能力、细胞迁移和侵袭能力均增强。这些增加也与不同克隆中c-erbB2/neu、SLe(x)和alpha1,3- focusyltransferase VII的表达强度呈正相关，而细胞对纤维连接蛋白的粘附与这些变量呈负相关。对SLe(x) （KM93）和SDLe(x) （FH6）的单抗分别显著和轻微地抑制了细胞对HUVECs或p -选择素的粘附和细胞的迁移和侵袭。针对SDLe(x)和SLe(a)的单克隆抗体不抑制细胞对huvec的粘附，也不抑制细胞的迁移和侵袭。转染alpha1,3- focusyltransferase VII cDNA到7721细胞的结果与转染c-erbB2/neu的结果相似，KM93也显著抑制了对HUVECs的粘附、细胞迁移和侵袭，FH6则略有抑制。这些结果表明，alpha1,3- focusyltransferase VII及其特异性产物SLe(x)的表达与其细胞粘附、迁移和侵袭能力密切相关。因此，c-erbB2/neu基因被认为是一种促进转移的基因，其作用至少部分是由α 1,3-焦点转移酶VII和SLe的表达增加介导的(x)。
The pCMV4 plasmid containing the cancer-promoting gene, c-erbB2/neu, was cotransfected into the human hepatocarcinoma cell line 7721 with the pcDNA3 vector, which contains the 'neo' selectable marker. Several clones showing stable expression of c-erbB2/neu were established and characterized by determination of c-erbB2/neu mRNA and its encoded protein p185. Expression of Lewis antigens and alpha1,3-fucosyltransferases and the biological behavior of 7721 cells after c-erbB2/neu transfection were studied using mock cells transfected with the vectors pCMV4 and pcDNA3 as controls. SLe(x) expression on the surface of mock cells was high, whereas expression of SDLe(x), Le(x) and SLe(a) was absent or negligible. This is compatible with the abundant expression of alpha1,3-fucosyltransferase VII, very low expression of alpha fucosyltransferase III/VI, and almost absent expression of alpha1,3-fucosyltransferase IV in the mock cells. After transfection of c-erbB2/neu, expression of SLe(x) and alpha1,3-fucosyltransferase VII were simultaneously elevated, but that of alpha fucosyltransferase III/VI was not altered. The expression of both SLe(x) and alpha1,3-fucosyltransferase VII correlated positively with the expression of c-erbB2/neu in different clones, being highest in clone 13, medium in clone 6, and lowest in clone 7. In addition, the adhesion of 7721 cells to human umbilical vein endothelial cells (HUVECs) or P-selectin, as well as cell migration and invasion, were increased in c-erbB2/neu-transfected cells. These increases also correlated positively with the expression intensities of c-erbB2/neu, SLe(x) and alpha1,3-fucosyltransferase VII in the different clones, whereas cell adhesion to fibronectin correlated negatively with these variables. mAbs to SLe(x) (KM93) and SDLe(x) (FH6) significantly and slightly, respectively, abolished cell adhesion to HUVECs or P-selectin and cell migration and invasion. mAbs to SDLe(x) and SLe(a) did not suppress cell adhesion to HUVECs nor inhibit cell migration and invasion. Transfection of alpha1,3-fucosyltransferase VII cDNA into 7721 cells showed similar results to transfection of c-erbB2/neu, and the increased adhesion to HUVECs, cell migration, and invasion were also inhibited significantly by KM93 and slightly by FH6. These results indicate that expression of alpha1,3-fucosyltransferase VII and its specific product, SLe(x), and their capacity for cell adhesion, migration and invasion are closely related. Therefore, the c-erbB2/neu gene is proposed to be a metastasis-promoting gene, and its effects are at least partially mediated by the increased expression of alpha1,3-fucosyltransferase VII and SLe(x).