MUTYH mutations associated with familial adenomatous polyposis: functional characterization by a mammalian cell-based assay.

摘要: MUTYH-associated polyposis (MAP) is a colorectal cancer syndrome, due to biallelic mutations of MUTYH. This Base Excision Repair gene encodes for DNA glycosylase that specifically mitigates the high mutagenic potential 8-hydroxyguanine (8-oxodG) along DNA. Aim this study was characterize biological effects, in mammalian cell background, human MUTYH identified MAP patients (137insIW [c.411_416dupATGGAT; p.137insIleTrp]; R171W [c.511C>T; p.Arg171Trp]; E466del [c.1395_1397delGGA; p.Glu466del]; Y165C [c.494A>G; p.Tyr165Cys]; and G382D [c.1145G>A; p.Gly382Asp]). We set up novel assay which proteins were expressed Mutyh−/− mouse defective cells. Several parameters, including accumulation 8-oxodG genome hypersensitivity oxidative stress, then used evaluate consequences expression. Human also obtained from Escherichia coli their activity tested vitro. The cell-based analysis demonstrated all variants we investigated dysfunctional Repair. In vitro data complemented vivo observations, with exception mutant, showed very similar wild-type protein. Our can provide useful information on significance variants, improving molecular diagnosis genetic counseling families uncertain pathogenicity. Hum Mutat 30:1–8, 2009. © 2009 Wiley-Liss, Inc.