title: Analysis of β-catenin expression and exon 3 mutations in pediatric sporadic aggressive fibromatosis.
abstract: Aggressive fibromatosis is a benign tumor with a high recurrence rate after surgical resection, particularly in children. Abnormal regulation of β-catenin in the presence or absence of a change of genotype has been identified in adult sporadic aggressive fibromatosis. However, the status of β-catenin expression and mutation remains unclear in pediatric patients. The present study was designed to analyze the expression and mutation status of β-catenin in pediatric aggressive fibromatosis. B-catenin expression was analyzed by immunohistochemistry in 32 samples from pediatric patients with aggressive fibromatosis (21 recurrent cases and 11 primary-onset cases) and 15 control subjects. Somatic point mutations in β-catenin exon 3 were identified by sequencing of polymerase chain reaction products. Nuclear expression of β-catenin was detected in 94% (30/32) of aggressive fibromatosis samples and 13% (2/15) of control samples (P < 0.001). Mutations in exon 3 of the β-catenin gene were identified in 78% (25/32) of aggressive fibromatosis samples (19/21 recurrent cases, 6/11 primary-onset cases; P  =  0.032). The primary mutation in the recurrent cases occurred at codon 45 (S45F), while codon 41 (T41A) was most frequently mutated in the primary-onset cases (P  =  0.002). Abnormal expression of β-catenin appears to occur frequently in pediatric aggressive fibromatosis. Muftations in exon 3 of the β-catenin gene, particularly the S45F mutation, may represent risk factors for recurrence in pediatric patients and could potentially be used as prognostic factors.
authors.affiliation: Department of Pediatric Orthopaedics, Children's Hospital of Fudan University, Shanghai, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Bo
authors.forename: Dahui
authors.initials: D
authors.lastname: Wang
authors.forename: Bingbing
authors.initials: B
authors.lastname: Wu
authors.forename: Lian
authors.initials: L
authors.lastname: Chen
authors.lastname: Ruixue Ma
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D005260:Female; D018222:Desmoid Tumors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D017354:Point Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051176:beta Catenin / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: C495270:CTNNB1 protein, human; D051176:beta Catenin