Mutation analyses of the NFAT1 gene in chondrosarcomas and enchondromas.
Mice lacking nuclear factor of activated T cell 1 (NFAT1) showed an abnormal proliferation of chondrocytes in articular cartilage and formed an extraosseous cartilaginous mass resembling a neoplastic lesion, suggesting that the NFAT1 gene is a tumor suppressor gene in cartilaginous neoplasms. Here we performed mutation analyses of the NFAT1 gene in human cartilaginous tumors including 30 chondrosarcomas and 15 enchondromas. Reverse transcription-polymerase chain reaction (PCR) analysis revealed the expression of the NFAT1 gene in 15/15 chondrosarcomas and 12/13 enchondromas. To find subtle alterations, the genomic structure of the NFAT1 gene was determined using human genome draft sequences, and a mutation analysis was performed using the exon-by-exon PCR-single-strand conformation polymorphism method. Two heterozygous missense mutations, A1557T (His446Leu) and C2859T (Pro880Leu), were found in eight tumor samples, but the same mutation was also present in the constitutional cells of corresponding patients. The incidence of the mutant alleles in the patient and control groups showed no significant difference, suggesting that these mutations are rare single nucleotide polymorphisms unrelated with tumorigenesis. These results suggest that the NFAT1 gene is not likely to be a tumor suppressor gene in human cartilaginous tumors.
Aoyama
Tomoki
T
Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Nagayama
Satoshi
S
Okamoto
Takeshi
T
Hosaka
Taisuke
T
Nakamata
Takeharu
T
Nishijo
Koichi
K
Tsuboyama
Tadao
T
Nakayama
Tomitaka
T
Nakamura
Takashi
T
Toguchida
Junya
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D002812:Chondroma / Q000235:genetics*; D002813:Chondrosarcoma / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D016147:Genes, Tumor Suppressor; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; C494003:NFATC1 protein, human; C494006:NFATC2 protein, human; D009687:Nuclear Proteins; D014157:Transcription Factors