Relationship of the methylenetetrahydrofolate reductase C677T polymorphism with microsatellite instability and promoter hypermethylation in sporadic colorectal cancer
Genet. mol. res. (Online)
;
5(2): 315-322, 2006. tab
Article
Dans Anglais
| LILACS
| ID: lil-442567
ABSTRACT
The methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is associated with the expression of a thermolabile enzyme with decreased activity that influences the pool of methyl-donor molecules. Several studies have reported an association between C677T polymorphism and susceptibility to colorectal cancer (CRC). Considering that methylation abnormalities appear to be important for the pathogenesis of CRC, we examined the correlation between the genotype of the MTHFR C677T polymorphism, hypermethylation of the promoter region of five relevant genes (DAPK, MGMT, hMLH1, p16(INK4a), and p14(ARF)), and microsatellite instability, in 106 patients with primary CRCs in Brazil. We did not find significant differences in the genotypic frequencies of the MTHFR C677T polymorphism when one or more loci were hypermethylated. However, we did find a significant excess of 677TT individuals among patients with CRC who had microsatellite instability. This strong association was independent of the methylation status of hMLH1 and of the biogeographical genomic ancestry of the patients. Although the mechanism responsible for the link between the C677T polymorphism and microsatellite instability was not apparent, this finding may provide a clue towards a better understanding of the pathogenesis of microsatellite instability in human colorectal cancer.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
Polymorphisme génétique
/
Tumeurs colorectales
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Marqueurs biologiques tumoraux
/
Méthylation de l'ADN
Type d'étude:
Étude observationnelle
/
Facteurs de risque
Limites du sujet:
Femelle
/
Humains
/
Mâle
langue:
Anglais
Texte intégral:
Genet. mol. res. (Online)
Thème du journal:
Biologie moléculaire
/
Génétique
Année:
2006
Type:
Article
Pays d'affiliation:
Brésil
Institution/Pays d'affiliation:
Hospital A. C. Camargo/BR
/
Ludwig Institute for Cancer Research/US
/
Universidade Federal de Minas Gerais/BR
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