Modulation of the prostaglandin-endoperoxide synthase 2 gene expression by variant haplotypes: influence of the 3'-untranslated region.
Braz J Med Biol Res
; 51(2): e6546, 2017 Nov 30.
Article
em En
| MEDLINE
| ID: mdl-29211250
ABSTRACT
The inducible inflammatory enzyme cycloxigenase-2 is up-regulated in cancer, and favors tumor progression. Cycloxigenase-2 is encoded by the prostaglandin-endoperoxide synthase 2 (PTGS2) gene, which presents sequence variations in the promoter region (PR) and in the 3'-untranslated region (3'-UTR). Different PR (rs689465, rs689466, rs20417) and 3'-UTR (rs5275) variants were generated by site-directed mutagenesis, and combined in haplotypes to access expression levels using a reporter system (luciferase) in human cells (MCF-7 and HEK293FT). Luciferase activity did not differ significantly among PTGS2 PR constructs, except for pAAC (containing variant allele rs20417 C), with 40% less activity than pAAG (wild-type sequence) in MCF-7 cells (P<0.01). Despite the lack of individual significant differences, PTGS2 PR constructs enclosing rs689466 G (pAGG and pAGC) showed an approximate two-fold increase in luciferase activity when compared to those containing rs689466 A (pAAG, pGAC, pAAC and pGAG) in both cell lines (P<0.001 for MCF-7 and P=0.03 for HEK293FT). The effect of PTGS2 3'-UTR sequences varied between MCF-7 and HEK293FT MCF-7 cells showed significant reduction (40-60%) in luciferase activity (at least P<0.01), whereas HEK293FT cells showed more diverse results, with an average 2-fold increase when combined constructs (PR and 3'-UTR) were compared to respective parental PR sequences. The contribution of 3'-UTR variant (rs5275) was not consistent in either cell line. Despite the modulation of the 3'-UTR, with variable effects of rs5275, the enhancing transcriptional effect of rs689466 G was still detectable (P<0.0001 in MCF-7 or P=0.03 in HEK293FT cells).
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Base de dados:
MEDLINE
Assunto principal:
Regulação Neoplásica da Expressão Gênica
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Regiões 3' não Traduzidas
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Ciclo-Oxigenase 2
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article