ヒト培養口腔扁平上皮癌細胞における蛋白質脱リン酸化酵素阻害剤のアポトーシス誘導と蛋白質脱リン酸化酵素 1 型の細胞内局在
スポンサーリンク
概要
- 論文の詳細を見る
To determine whether protein phosphorylation and dephosphorylation can affect apoptosis in oral epithelial cells, we examined the effects of protein phosphatase (PP) inhibitors, okadaic acid and calyculin A, on induction of apoptosis in oral squamous carcinoma cell line, SCC-25 cells. After reaching subconfuluence, these cells were treated with varying concentrations of okadaic acid and calyculin A. Both reagents induced cell death in SCC-25 cells in dose-dependent fashions as determined by phase-contrast microscopy and WST-1 cell viability assay. By using the Hoechst 33342 staining, marked nuclear condensation and fragmentation of chromatin were observed. Both inhibitors also induced DNA ladder formation in SCC-25 cells in dose-dependent manners with the maximal effective concentrations being 20 nM okadaic acid and 2 nM calyculin A, respectively. Okadaic acid also induced DNA ladder formation in other human oral SCC cell line SCCKN and SCCTF. To further determine if new gene transcription and protein synthesis are required for okadaic acid-induced apoptosis in SCC-25 cells, the cells were treated for 48h with varying concentrations of cycloheximide under the presence of 20 nM okadaic acid. Cycloheximide did not protect the cells against okadaic acid-induced cytotoxicity and DNA ladder formation. The present results indicate that the pathway of the apoptosis in the cultured oral SCC cells is regulated by protein phosphatase type 1 and type 2A, and also that newly synthesized proteins are not involved in okadaic acid-induced apoptosis in SCC-25 cells. Cytolocalization of PP1 isozymes in cultured SCC-25 cells was examined. The results revealed that PP1s are differentially localized in SCC-25 cells. PP1α and PP1δ antibodies recognized proteins with estimated molecular weight of 38 kDa and 37 kDa, respectively, present in the nuclear regions of SCC-25 cells, whereas PP1γ1 interacted with the 36 kDa proteins in cytoplasm. It is quite interesting that PP1δ was specifically distributde in the nucleolus-like bodies of cultured SCC-25 cells.
- 九州歯科学会の論文
- 2000-10-25
著者
関連論文
- 頬粘膜下に発生した比較的大きな粘液貯留嚢胞の1例
- 植物性異物(竹)が頬部に迷入した1例
- 上顎骨に発生した筋線維腫の1例
- オカダ酸によるヒト口腔扁平上皮癌細胞アポトーシス誘導とFasレセプターおよびFasリガンド発現の制御
- ヒト培養口腔扁平上皮癌細胞における蛋白質脱リン酸化酵素阻害剤のアポトーシス誘導と蛋白質脱リン酸化酵素 1 型の細胞内局在 : 主論文の要旨
- ヒト培養口腔扁平上皮癌細胞における蛋白質脱リン酸化酵素阻害剤のアポトーシス誘導と蛋白質脱リン酸化酵素 1 型の細胞内局在