INDUCTION OF APOPTOSIS IN CULTURED RETINOBLASTOMA CELLS BY THE PROTEIN PHOSPHATASE INHIBITOR, OKADAIC ACID
INDUCTION OF APOPTOSIS IN CULTURED RETINOBLASTOMA CELLS BY THE PROTEIN PHOSPHATASE INHIBITOR, OKADAIC ACID
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DOI：
10.1007/bf01213319
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发表时间：
1995-12-01
影响因子：
3.6
通讯作者：
TANAKA, Y
中科院分区：
文献类型：
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作者：
INOMATA, M;SAIJO, N;TANAKA, Y
通过分析细胞凋亡的标志DNA片段化，研究了不同药物对视网膜母细胞瘤细胞的诱导凋亡作用。首先，用依托泊苷(30微克/毫升，20小时)检测6种视网膜母细胞瘤细胞株的凋亡能力。本实验室建立的NCC-RBC-60细胞株显示明显的DNA片段化，而其他细胞株，包括具有代表性的视网膜母细胞瘤细胞株Y-79，则没有表现出明显的DNA片段化。A23187、Forskolin、维甲酸、佛波醇12-肉豆蔻酸酯13-乙酸酯和冈田酸等生化调节剂作用于NCC-RBC-60和Y-79细胞20h后，观察它们是否能诱导NCC-RBC-60和Y-79细胞凋亡。流式细胞仪分析和显微镜检查显示，冈田酸作用24-48h后，Y-79细胞在DNA断裂前积累于G2/M期，尤其是M期。诺可达唑、秋水仙胺和紫杉醇等其他有丝分裂毒物也能诱导Y-79细胞凋亡。在从非恶性视网膜色素上皮建立的K1034细胞系中，冈田酸未能诱导G(2)/M期阻滞和DNA片段化。这些发现表明冈田酸诱导的细胞凋亡是中期停滞的结果。
The induction of apoptosis in cultured retinoblastoma cells by diverse drugs was examined by analyzing DNA fragmentation, a hallmark of apoptosis. First, the ability of six retinoblastoma cell lines to undergo apoptosis was surveyed using etoposide (30 mu g/ml, 20 h exposure). The NCC-RbC-60 cell line, established in this laboratory, showed DNA fragmentation clearly, whereas the other cell lines tested, including the representative retinoblastoma cell line, Y-79, did not show distinct DNA fragmentation. Biochemical modulators, such as A23187, forskolin, retinoic acid, phorbol 12-myristate 13-acetate and okadaic acid, were examined to ascertain whether they could induce apoptosis in NCC-RbC-60 and Y-79 cells after exposure for 20 h. Only okadaic acid induced DNA fragmentation in all the retinoblastoma cell lines tested and it induced DNA fragmentation in Y-79 cells in a time- and concentration-dependent manner. Flowcytometric analysis and microscopic examination revealed that Y-79 cells treated with okadaic acid for 24-48 h accumulated at the G2/M, especially M, phases, before undergoing DNA fragmentation. Other mitotic poisons, nocodazole, colcemid and taxol, also induced apoptosis in Y-79 cells. In the K1034 cell line, established from non-malignant retinal pigmental epithelium, okadaic acid failed to induce both G(2)/M arrest and DNA fragmentation. These findings suggest that okadaic-acid-induced apoptosis occurs as a result of metaphase arrest.