| Project/Area Number |
17591128
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Pediatrics
|
|---|
| Research Institution | Chiba Cancer Center Research Institute |
|---|
Principal Investigator |
NAKAMURA Yohko Chiba Cancer Center Research Institute, Division of Biochemistry, Research Fellow, 生化学研究部, 上席研究員 (60260254)
|
|---|
| Project Period (FY) |
2005 – 2006
|
| Project Status |
Completed (Fiscal Year 2006)
|
| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2006: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2005: ¥2,100,000 (Direct Cost: ¥2,100,000)
|
|---|
| Keywords | Neuroblastoma / p53 / Cell Growth Inhibition / BMP |
|---|
| Research Abstract |
Purpose : p53 contains three nuclear localization signals (NLS I, II, III) in its COOH-terminal region. In contrast to other human tumors, p53 is rarely mutated in neuroblastomas. In a recent report, it has been understood that the mutation of p53 exists in about 2% of neuroblastomas. We found p53 mutation in 6 of 30 primary neuroblastoma samples and analyzed p53 and apoptosis-related molecules in BMP-or cisplatin (CDDP)-treated neuroblastomas. In this study, we identified a novel p53 mutant homozygously deleted in SK-N-AS neuroblastoma cells and analyzed its function.
Methods and Results : SH-SY5Y and SK-N-AS cells were treated with CDDP. Their viabilities and apoptotic cell death were investigated by MTT assays, TUNEL assays and FACS analysis. Cell viability was decreased in CDDP-treated SH-SY5Y cells. A higher number of TUNEL-positive and of sub-G0/G1 population cells were observed in CDDP-treated SH-SY5Y cells whereas cisplatin treatment led to the cell cycle arrest in SK-N-AS cells
… More
. p53 was stabilized and phosphorylated at Ser-15 in SH-SY5Y cells exposed to CDDP. Expression of p21^<WAF1>, Box and PUMA were induced in SH-SY5Y cells treated with CDDP whereas only p21^<WAF1> was induced in CDDP-treated SK-N-AS cells. The genome structure of p53 in SK-N-AS was analyzed by the RT-PCR analysis, the PCR analysis and array CGH analysis. As a result, a 3' part of the p53 genomic locus was homozygously deleted in SK-N-AS cells. We found p53 deletion mutant protein with a relative molecular mass of 49 KDa in SK-N-AS cells. Structural analysis revealed that the C-terminal deleted p53 lacks a part of the oligomerization domain as well as nuclear localization signals. The C-terminal deleted p53 was dominantly expressed in cytoplasm and lost the transactivation function. Thus, our present findings suggest that p53 plays an important role in the DNA-damage response in certain neuroblastoma cells and it seems to be important to search for p53 mutations outside of DNA-binding domain. Less
|
