Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
|
pubmed:dateCreated |
1994-10-25
|
pubmed:abstractText |
Okadaic acid (OA), a specific protein phosphatase inhibitor, has various biological functions. To elucidate the mechanism of OA resistance, we have established a small-cell lung-cancer subline (H69/OA100) resistant to the growth-inhibitory effect of OA; this was done by using the parental cell line (H69) and increasing the concentration of OA. H69/OA100 was about 8 times more resistant to OA than H69. Intracellular retention of the fluorescent OA derivative in H69/OA100 was the same as that in H69. The catalytic activity of protein phosphatase from H69/OA100 was significantly reduced compared with that from H69. The protein phosphatase from H69/OA100 was 3.6 times more resistant to OA than that from H69. We examined the effect of OA on the activity of the immunoprecipitated protein phosphatase type I (PPI) and type 2A (PP2A) from the 2 cell lines. The PPI and PP2A from H69/OA100 showed more resistance to OA than those from H69. We next examined the effect of OA on the cell cycle of H69 and H69/OA100. In H69, G2/M block was observed at an OA concentration of 30 ng/ml whereas in H69/OA100, no G2/M block was observed at concentrations up to 100 ng/ml OA. We finally evaluated the amount of p34cdc2 kinase expression and the phosphorylation status of p34cdc2. There was no difference in p34cdc2 expression between H69 and H69/OA100 at several concentrations of OA. However, dephosphorylation of p34cdc2 was observed at 30 ng/ml OA in H69, but not in H69/OA100 up to 100 ng/ml OA. These data suggest that the resistance to OA and the resistance of the cell-cycle block to OA in H69/OA100 might be due to alteration of protein phosphatase activity.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
Sep
|
pubmed:issn |
0020-7136
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
15
|
pubmed:volume |
58
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
882-90
|
pubmed:dateRevised |
2007-11-15
|
pubmed:meshHeading |
pubmed-meshheading:7927883-Base Sequence,
pubmed-meshheading:7927883-Blotting, Western,
pubmed-meshheading:7927883-Carcinoma, Small Cell,
pubmed-meshheading:7927883-Catalysis,
pubmed-meshheading:7927883-Cell Division,
pubmed-meshheading:7927883-Drug Resistance,
pubmed-meshheading:7927883-Ethers, Cyclic,
pubmed-meshheading:7927883-Flow Cytometry,
pubmed-meshheading:7927883-Gene Expression,
pubmed-meshheading:7927883-Humans,
pubmed-meshheading:7927883-Lung Neoplasms,
pubmed-meshheading:7927883-Macromolecular Substances,
pubmed-meshheading:7927883-Molecular Sequence Data,
pubmed-meshheading:7927883-Okadaic Acid,
pubmed-meshheading:7927883-Phosphoprotein Phosphatases,
pubmed-meshheading:7927883-Polymerase Chain Reaction,
pubmed-meshheading:7927883-Tumor Cells, Cultured
|
pubmed:year |
1994
|
pubmed:articleTitle |
Establishment of a human small-cell lung-cancer subline resistant to okadaic acid.
|
pubmed:affiliation |
Pharmacology Division, National Cancer Center Research Institute, Tokyo, Japan.
|
pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
|