|Budget Amount *help
¥3,700,000 (Direct Cost : ¥3,700,000)
Fiscal Year 2003 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 2002 : ¥2,100,000 (Direct Cost : ¥2,100,000)
In pediatric solid tumors including hepatoblastomas, mutations of β-batenin and its relating gene, Axin, were comprehensively investigated.
1. Regarding β-batenin gene, mutations were detected in 77% of hepatoblastomas and 25% of nephroblastomas investigated. All mutations were predicted to result in alteration at the specific residues which were phosphorylation targets of GSK-3 b. Addition to hepatoblastomas and nephroblastomas, similar mutations were observed in solid and cystic tumors of the pancreas
2. Regarding Axin genes, all ten exons of the gene were thoroughly investigated in a total of 102 tumors composed of various types of malignancies. In 22 hepatoblastomas investigated, 12 different nucleotide changes were detected. Eleven of these were predicted to result in no amino acid substitution and observed in multiple cases, suggesting that these were polymorphisms. However, a nucletide change at codon 95 (AGG->ATG) was thought to result in amino acid substitution, Thr->Met, and observed in only one hepatoblastoma case.
3. Analysis of the Axin gene in 80 other tumors detected a total of 10 nucleotide changes, and 9 of these were considered to be polymorphisms. However, the remaining one nucleotide change which was observed in one teratoma case, occurred at codon 98 (CCG->CTG) and was predicted to result in Pro->Leu amino acid substitution.
4. Axin mutations were considered to be less involved in the tumorigenesis of most pediatric solid tumors compared to mutations of β-batenin, however, may have a role in particular caseS' including hepatoblastoma.