TY - JOUR
T1 - Abnormal stability of wild-type p53 protein in a human lung carcinoma cell line
AU - Yamauchi, Motohiro
AU - Suzuki, Keiji
AU - Kodama, Seiji
AU - Watanabe, Masami
N1 - Funding Information:
This work was supported in part by a grant for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan, by the Research Project Fund for “Studies on the Molecular Biological Basis for Low-Dose Radiation Effects” from the Japan Atomic Energy Research Institute through a contract with the Nuclear Safety Research Association, and by a grant from Japan Society for the Promotion of Science.
PY - 2005/5/6
Y1 - 2005/5/6
N2 - We report here that ectopically expressed wild-type p53 protein showed more than 6 times longer half-life than normal human fibroblasts in NCl-H1299, a widely used cell line derived from non-small cell lung carcinoma lacking the expression of p53 protein. We found no abnormality in the phosphorylation and ubiquitination of p53, and the expression levels of MDM2. Although proteasome activity measured in vitro was not significantly different between the tumor cell line and normal human fibroblasts, proteasome inhibitors, ALLN, MG115, and MG132, did not accumulate p53 protein in the tumor cell line, but did accumulate p53 in normal human cells. These results provide a novel mechanism, by which p53 is stabilized in tumor cells, and they suggest that a mediator should exist between ubiquitinated p53 and proteasome, which may be defective in H1299 cells.
AB - We report here that ectopically expressed wild-type p53 protein showed more than 6 times longer half-life than normal human fibroblasts in NCl-H1299, a widely used cell line derived from non-small cell lung carcinoma lacking the expression of p53 protein. We found no abnormality in the phosphorylation and ubiquitination of p53, and the expression levels of MDM2. Although proteasome activity measured in vitro was not significantly different between the tumor cell line and normal human fibroblasts, proteasome inhibitors, ALLN, MG115, and MG132, did not accumulate p53 protein in the tumor cell line, but did accumulate p53 in normal human cells. These results provide a novel mechanism, by which p53 is stabilized in tumor cells, and they suggest that a mediator should exist between ubiquitinated p53 and proteasome, which may be defective in H1299 cells.
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U2 - 10.1016/j.bbrc.2004.11.174
DO - 10.1016/j.bbrc.2004.11.174
M3 - Article
C2 - 15796908
AN - SCOPUS:15744406023
VL - 330
SP - 483
EP - 488
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 2
ER -