魚藤酮對MCF7乳癌細胞株引起的細胞凋亡現象之機制探討

Rotenone天然存在於豆科植物Derris根部，rotenone可以抑制粒線體內膜上電子傳遞鏈複合物Ι (electron transfer chain complex Ι)，而引起細胞凋亡(apoptosis)現象。Rotenone所引起的細胞凋亡早被認知，然而rotenone所引起的細胞凋亡現象究竟是經由什麼機制並不是很清楚。在本篇研究中，我們發現rotenone可以促使人類乳癌細胞MCF7細胞生長率下降、細胞死亡率上升，此種結果隨著rotenone劑量和時間的增加而更明顯。以流式細胞儀分析細胞內DNA含量和對細胞核內之染色質進行染色，可得知rotenone確實可以使MCF7細胞發生細胞凋亡現象。用流式細胞儀進一步分析，發現rotenone會使細胞內粒線體內膜的跨膜電位消失且會促使活性氧(ROS)產生。再用西方點墨法分析和引起細胞凋亡現象有關的蛋白質procaspase-9、 PARP、 Bcl-2、及Bax，我們發現rotenone可以促使procaspase-9、 PARP被活化，抗細胞凋亡現象的蛋白質Bcl-2 表現下降，及促進細胞凋亡現象發生的蛋白質Bax表現上升。由這些結果可以得知，rotenone所引起的細胞凋亡現象是和caspase及粒線體有關的。我們進一步研究rotenone所引起細胞凋亡所經過的訊息傳遞途徑，發現rotenone所引起的細胞凋亡現象是需要extracellular signal-regulated kinases (ERK1/2), N-terminal protein kinase (JNK)和p38 mitogen activated protein (MAP) kinase活化的。本篇研究結果發現rotenone可抑制乳癌細胞之生長，而rotenone是否能作為治療乳癌的有效物質，仍需進一步的動物試驗證明。

關鍵字

魚藤酮；細胞凋亡

並列摘要

Rotenone, an inhibitor of NADH dehydrogenase complex, is a naturally occurring insecticide, and it is capable of inducing apoptosis. However, little is known about the mechanism for the induction of apoptosis by rotenone. Here we report that in vitro treatment of human breast cancer MCF7 cells with rotenone decreased cell viability and induced cell death in a dose- and time-dependent manner. DNA flow cytometric analysis and staining of nuclear chromatin indicated that rotenone actively induced apoptosis in MCF7 cells. Loss of mitochondrial transmembrane potential and reactive oxygen species (ROS) generation were also detected by flow cytometry. We used Western blot analysis to evaluate the apoptosis-related proteins in MCF7 cells. The levels of procaspase-9, poly (ADP-ribose) polymerase (PARP), and Bcl-2 were decreased in a time-dependent manner, while the level of Bax was increased. These findings suggest that rotenone-induced apoptosis may be a caspase- and mitochondrial-dependent pathway. Furthermore, rotenone treatment induces phosphorylation of extracellular signal-regulated kinases (ERK1/2), N-terminal protein kinase (JNK), and the p38 mitogen activated protein (MAP) kinase, indicated that ERK1/2, JNK and p38 MAP kinases are activated. Taken together, this study demonstrated rotenone as an inhibitory agent against human breast cancer MCF7 cells in vitro. Further in vivo studies are required to determine whether rotenone could be an effective chemotherapeutic agent for the management of breast cancers.

並列關鍵字

rotenone ； apoptosis

參考文獻

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魚藤酮對MCF7乳癌細胞株引起的細胞凋亡現象之機制探討

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