Germline variation in O6-methylguanine-DNA methyltransferase (MGMT) as cause of hereditary colorectal cancer.
Cancer Lett
; 447: 86-92, 2019 04 10.
Article
em En
| MEDLINE
| ID: mdl-30677446
ABSTRACT
Somatic epigenetic inactivation of the DNA repair protein O6-methylguanine DNA methyltransferase (MGMT) is frequent in colorectal cancer (CRC); however, its involvement in CRC predisposition remains unexplored. We assessed the role and relevance of MGMT germline mutations and epimutations in familial and early-onset CRC. Mutation and promoter methylation screenings were performed in 473 familial and/or early-onset mismatch repair-proficient nonpolyposis CRC cases. No constitutional MGMT inactivation by promoter methylation was observed. Of six rare heterozygous germline variants identified, c.346Câ¯>â¯T (p.H116Y) and c.476Gâ¯>â¯A (p.R159Q), detected in three and one families respectively, affected highly conserved residues and showed segregation with cancer in available family members. In vitro, neither p.H116Y nor p.R159Q caused statistically significant reduction of MGMT repair activity. No evidence of somatic second hits was found in the studied tumors. Case-control data showed over-representation of c.346Câ¯>â¯T (p.H116Y) in familial CRC compared to controls, but no overall association of MGMT mutations with CRC predisposition. In conclusion, germline mutations and constitutional epimutations in MGMT are not major players in hereditary CRC. Nevertheless, the over-representation of c.346Câ¯>â¯T (p.H116Y) in our familial CRC cohort warrants further research.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias Colorretais
/
Metilases de Modificação do DNA
/
Mutação em Linhagem Germinativa
/
Proteínas Supressoras de Tumor
/
Enzimas Reparadoras do DNA
/
Células Germinativas
Tipo de estudo:
Observational_studies
/
Risk_factors_studies
Limite:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Cancer Lett
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Espanha