Ko J H, Miyoshi E, Noda K, Ekuni A, Kang R, Ikeda Y, Taniguchi N
Department of Biochemistry, Osaka University Medical School, Room B1, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
J Biol Chem. 1999 Aug 13;274(33):22941-8. doi: 10.1074/jbc.274.33.22941.
Although the precise role of oligosaccharides in metastasis is presently unknown, numerous studies suggest that the beta1-6 branching structure of N-linked oligosaccharides plays a role in tumor metastasis. N-Acetylglucosaminyltransferase V (GnT-V), which catalyzes the formation of the beta1-6 branch, therefore appears to play a crucial role in tumor metastasis. Recently, we demonstrated that the expression of the GnT-V gene is regulated by a transcriptional factor, Ets-1 (Kang, R., Saito, H., Ihara, Y., Miyoshi, E., Koyama, N., Sheng, Y., and Taniguchi, N. (1996) J. Biol. Chem. 271, 26706-26712). In this study, we report an investigation of the general requirement for Ets-1 in the expression of GnT-V in cancer cell lines. In 16 cancer cell lines, the levels of GnT-V mRNA were closely correlated with ets-1 expression (r = 0.97; p < 0.0001). An increase in ets-1 levels by transfection of its cDNA led to an enhancement in GnT-V expression in cells that normally expressed low levels of ets-1. In contrast, the transfection of dominant negative ets-1 into cells that express high levels of ets-1 resulted in a decrease in GnT-V expression. Although Ets-1 cooperates with c-Jun in certain gene expressions, this was not the case in the regulation of the GnT-V gene. These results suggest that Ets-1 plays a significant role in regulating the expression of GnT-V in a variety of cancers and might be involved in the potential for malignancy via the action of GnT-V.
尽管目前尚不清楚寡糖在转移过程中的确切作用,但大量研究表明,N-连接寡糖的β1-6分支结构在肿瘤转移中发挥作用。因此,催化β1-6分支形成的N-乙酰葡糖胺基转移酶V(GnT-V)似乎在肿瘤转移中起关键作用。最近,我们证明GnT-V基因的表达受转录因子Ets-1调控(Kang, R., Saito, H., Ihara, Y., Miyoshi, E., Koyama, N., Sheng, Y., and Taniguchi, N. (1996) J. Biol. Chem. 271, 26706 - 26712)。在本研究中,我们报告了对癌细胞系中GnT-V表达时Ets-1总体需求的研究。在16种癌细胞系中,GnT-V mRNA水平与ets-1表达密切相关(r = 0.97;p < 0.0001)。通过转染ets-1的cDNA来增加其水平,导致在正常表达低水平ets-1的细胞中GnT-V表达增强。相反,将显性负性ets-1转染到高表达ets-1的细胞中,导致GnT-V表达下降。尽管Ets-1在某些基因表达中与c-Jun协同作用,但在GnT-V基因的调控中并非如此。这些结果表明,Ets-1在调节多种癌症中GnT-V的表达方面发挥重要作用,并且可能通过GnT-V的作用参与恶性潜能。