[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.


CONCLUSIONS
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.
Liu
Fen
F
Department of Gastroenterology, Third Xiangya Hospital, Central South University, Changsha 410013, China.
Shen
Shou-rong
SR
Li
Hong-tao
HT
Wang
Xiao-yan
XY
Peng
Ya
Y
Liao
Man-tian
MT
Guo
Qin
Q
D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D017930:Genes, Reporter; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D000073940:Transcription Factor 4; D014157:Transcription Factors / Q000235:genetics; D015533:Transcriptional Activation; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C495270:CTNNB1 protein, human; D008565:Membrane Proteins; C532096:TCF4 protein, human; C477325:TMEM8B protein, human; D000073940:Transcription Factor 4; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D051176:beta Catenin