title: Somatic mutation of the PTEN/MMAC1 gene in breast cancers with microsatellite instability.
abstract: The extent to which microsatellite instability (MI) contributes to the etiology of breast cancer has not been established in any large-scale studies. We examined 528 samples of tumor DNA from patients with primary breast cancer for MI, using 14 polymorphic CA-repeat markers. The frequency of MI in these tumors was unexpectedly low (10/528, 1.9%). The ten MI+ tumors were analyzed for mutations in five potential target genes that contain simple repeat sequences (TGFBIIR, IGF2R, hMSH6, BAX and PTEN/MMAC1). A somatic insertion of an extra adenine in the (A)6 region at codon 321-323 (exon 8) of the PTEN/MMAC1 gene, leading to a frame-shift, was identified in one tumor. This observation represented the first documented instance of PTEN/MMAC1 alteration in a MI+ primary breast cancer.
authors.affiliation: Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, Kawasaki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Minobe
authors.forename: K
authors.initials: K
authors.lastname: Bando
authors.forename: K
authors.initials: K
authors.lastname: Fukino
authors.forename: S
authors.initials: S
authors.lastname: Soma
authors.forename: F
authors.initials: F
authors.lastname: Kasumi
authors.forename: G
authors.initials: G
authors.lastname: Sakamoto
authors.forename: K
authors.initials: K
authors.lastname: Furukawa
authors.forename: K
authors.initials: K
authors.lastname: Higuchi
authors.forename: M
authors.initials: M
authors.lastname: Onda
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.forename: M
authors.initials: M
authors.lastname: Emi
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics*; D005260:Female; D006801:Humans; D018895:Microsatellite Repeats; D009154:Mutation; D051059:PTEN Phosphohydrolase; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D025521:Tumor Suppressor Proteins
chemical_list: D025521:Tumor Suppressor Proteins; D010744:Phosphoric Monoester Hydrolases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human