[Effects of NGX6 on the transcriptional activation of beta-catenin/TCF/LEF in Wnt/beta-catenin signal pathway].

OBJECTIVE: To explore the effects of NGX6 on the transcriptional activation of beta-catenin/TCF/LEF in Wnt/beta-catenin signal pathway, and to identify the role of NGX6 in Wnt signal pathway. METHODS: The eukaryotic expression vector pcDNA3.1(+)-beta-catenin (WT) was constructed. pcDNA3.1(+)-beta-catenin (WT) and pCMV-myc-NGX6 were cotransfected to COS-7 and the transcriptional activity of TCF/LEF was detected by TCF-4 luciferase report system. Without extro-genous beta-catenin, pCMV-myc-NGX6 was transfected alone to COS-7 and colon cancer cell line SW620, and the transcriptional activity of TCF/LEF was detected by TCF-4 luciferase report system, and then the expression of nucleus beta-catenin and TCF-4 was detected by Western blot. RESULTS: The eukaryotic expression vector pcDNA3.1(+)-beta-catenin (WT) was successfully constructed. The activation of TCF-4 luciferase report gene in the cotransfection group in COS-7 was less than that in NGX6 alone transfection group (P<0.05). The activation of TCF-4 luciferase report gene in NGX6 alone transfection group without extro-genous beta-catenin was less than that in pCMV-myc transfection group in COS-7 and SW620. The expression of beta-catenin and TCF-4 was decreased after the NGX6 transfection in COS-7 and SW620 cells. CONCLUSION: NGX6 can inhibit the transcriptional activation of beta-catenin/TCF/LEF in Wnt signal pathway by its negative regulation in the nuclear translocation of beta-catenin.