Induction of apoptosis in human oral squamous carcinoma cell lines by protein phosphatase inhibitors
Induction of apoptosis in human oral squamous carcinoma cell lines by protein phosphatase inhibitors
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DOI：
10.1016/s1368-8375(99)00013-5
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发表时间：
1999-07-01
期刊：
影响因子：
4.8
通讯作者：
Haneji, T
中科院分区：
文献类型：
--
作者：
Fujita, M;Seta, C;Haneji, T
为了确定蛋白磷酸化和去磷酸化是否可以影响口腔上皮细胞的凋亡，我们研究了蛋白磷酸酶抑制剂冈田酸（OA）和calyculin A（CA）对培养的人口腔鳞状细胞癌（SCC）细胞系SCC-25细胞的影响。在达到亚融合后，将这些细胞暴露于不同浓度的蛋白磷酸酶抑制剂OA和CA。通过相差显微镜和WST-1细胞活力测定，OA和CA均以剂量依赖性方式诱导SCC-25细胞死亡。采用Hoechst 33342染色，观察到明显的核浓缩和染色质断裂。OA和CA处理SCC-25细胞后，DNA梯状条带形成。诱导的核碎裂和DNA梯状条带形成具有剂量依赖性，分别在20 nM OA和2 nM CA浓度下具有最大效应。OA还诱导其他人口腔鳞癌细胞系SCCKN和SCCTF中DNA梯状条带的形成。为了进一步确定是否需要新的基因转录和蛋白质合成的OA诱导的细胞凋亡SCC-25细胞，细胞处理48小时，在20 nM OA的存在下，不同浓度的放线菌酮。放线菌酮不能保护细胞免受OA诱导的细胞毒性和DNA梯状条带的形成。基于已知的OA和CA的选择性，本研究结果表明，在培养的口腔鳞癌细胞的凋亡途径部分是由蛋白磷酸酶1型和2A型调节。我们的研究结果还表明，新的蛋白质合成不参与OA诱导的SCC-25细胞凋亡。(C)1999爱思唯尔科技有限公司。保留所有权利。
To determine whether protein phosphorylation and dephosphorylation can affect apoptosis in oral epithelial cells we examined the effects of protein phosphatase inhibitors, okadaic acid (OA) and calyculin A (CA), on cultured human oral squamous carcinoma (SCC) cell line, SCC-25 cells. After reaching subconfluence these cells were exposed to varying concentrations of the protein phosphatase inhibitors, OA and CA. Both OA and CA induced cell death in SCC-25 cells in st dose-dependent fashion 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 was observed. DNA ladder formation also was detected in SCC-25 cells by treatment with OA and CA. The induced nuclear fragmentation and DNA ladder formation were dose-dependent with maximal effect at concentrations of 20 nM OA and 2 nM CA, respectively. OA also induced DNA ladder formation in other human oral SCC cell lines, SCCKN and SCCTF. To further determine if new gene transcription and protein synthesis are required for OA-induced apoptosis in SCC-25 cells, the cells were treated for 48 h with varying concentrations of cycloheximide in the presence of 20 nM OA. Cycloheximide did not protect the cells against OA-induced cytotoxicity and DNA ladder formation. Based on the known selectivity of OA and CA, the present results indicate that the pathway of the apoptosis in the cultured oral SCC cells is in part regulated by protein phosphatase type 1 and type 2A. Our results also indicate that new protein synthesis is not involved in OA-induced apoptosis in SCC-25 cells. (C) 1999 Elsevier Science Ltd. All rights reserved.