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Wnt5A and DKK1 promoter activity is altered in folate deficient cells
Author(s) -
Katula Karen S,
Feimster Jasmin D
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.720
Subject(s) - dkk1 , promoter activity , luciferase , gene , transfection , chemistry , reporter gene , transcription factor , microbiology and biotechnology , gene expression , promoter , biology , biochemistry , wnt signaling pathway
Previous microarray analysis showed that Wnt5A transcripts increase and Dickkopf‐1 (DKK1) transcripts decrease in folate deficient cells. The goal of this study was to determine the molecular basis for this change in gene expression in folate deficient cells. Stably transfected NIH3T3 cells containing luciferase reporter constructs with 2178, 1707, 1358, 773, and 420 base pair of Wnt5A and 1068, 535, 228 base pair of DKK1 upstream sequences, respectively, were generated. Cells were grown for 9 days in folate deficient and sufficient medium and levels of luciferase activity determined. Results indicate that folate deficiency has a direct affect on promoter activity; Wnt5A promoter activity increased and DKK1 promoter activity decreased. For Wnt5A the greatest increase was observed with the 2178 construct. The 425 construct showed the least increase. DKK1 promoter only decreased with the 1068 construct; there was no effect on the 535 or 228 constructs. Possible transcription factor binding sites, including one for NF‐kappaB, were identified within relevant upstream sequences. Wnt5A and DKK1 promoter activity was analyzed using inhibitors of specific signaling pathways and the folate pathway. The results indicate Wnt5A and DKK1 gene expression is linked to different signaling pathways and that DKK1 promoter activity is affected by direct inhibition of the folate pathway. Research Support: NIH R15 DK070581