title: MBD4 mutations are rare in gastric carcinomas with microsatellite instability.
abstract: MBD4 encodes a protein that interacts with the mismatch repair protein hMLH1. Therefore, it has been postulated that mutations in MBD4 may result in mismatch repair deficiency. Furthermore, it was shown that MBD4 is a target gene in mismatch repair-deficient tumors. We searched for mutations of MBD4 in sporadic gastric carcinomas (SGC) and compared them with the MSI status of the tumors by screening a series of 42 SGC [22 high microsatellte instability (MSI-H) and 20 microsatellite stable (MSS)] for mutations in both the poly(A)10 and (A)6 tracts of the gene as well as in its entire coding sequence. Mutations of the poly(A)10 tract of MBD4 were also screened in 126 MSI-H colon carcinomas. One of the 22 MSI-H gastric carcinomas and 12 of 126 MSI-H colon carcinomas showed MBD4 mutations in the poly(A)10 tract of exon 3. In addition, seven sequence variants were found in SGC, all of them having a polymorphic nature. We conclude that MBD4 mutations in the entire coding sequence, including the two poly(A) tracts, are rare in MSI gastric carcinomas. MBD4 is likely to be a bystander target gene in MSI-H tumors.
authors.affiliation: IPATIMUP-Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Porto, Portugal.
authors.forename: Mafalda
authors.initials: M
authors.lastname: Pinto
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Suriano
authors.forename: Rob G J
authors.initials: RG
authors.lastname: Mensink
authors.forename: Alex
authors.initials: A
authors.lastname: Duval
authors.forename: Carla
authors.initials: C
authors.lastname: Oliveira
authors.forename: Beatriz
authors.initials: B
authors.lastname: Carvalho
authors.forename: Richard
authors.initials: R
authors.lastname: Hamelin
authors.forename: Raquel
authors.initials: R
authors.lastname: Seruca
authors.forename: Robert M W
authors.initials: RM
authors.lastname: Hofstra
mesh_terms: D000241:Adenosine / Q000235:genetics; D002277:Carcinoma / Q000235:genetics*; D004252:DNA Mutational Analysis; D004706:Endodeoxyribonucleases / Q000235:genetics*; D005091:Exons / Q000235:genetics; D006801:Humans; D018895:Microsatellite Repeats; D009154:Mutation; D011108:Polymers; D013274:Stomach Neoplasms / Q000235:genetics*
chemical_list: D011108:Polymers; C069424:polyadenosine; D004706:Endodeoxyribonucleases; C118712:MBD4 protein, human; D000241:Adenosine