Anti-cancer chemoagents-triggered centrosome aberrance and its relationship with mitotic cell death in pancreatic cancer cells.

抗癌化疗是抗癌策略的主要途径。这些药物通过不同的机制起作用，但对目标细胞实施类似的细胞死亡过程。中心体过度复制可被记录为辐射诱导的细胞死亡的一个事件。为了阐明这种中心体异常是核DNA损伤后的独特结果还是与细胞凋亡有关的普遍现象，在本研究中，我们使用了一系列具有不同机制的化学药物导致被处理细胞凋亡。实验采用人胰腺癌细胞系Suit-2和Capan-2。研究中使用的抗癌化学药物包括依托泊苷（VP-16）、丝裂霉素（MMC）、顺铂和5-氟尿嘧啶（5-FU）。用特异性抗α-微管蛋白和抗心周蛋白标记中心体后，用间接免疫荧光显微镜观察中心体。微核形成法观察细胞凋亡，碘化丙啶荧光强度法观察细胞死亡。所有使用的化学制剂均可引起两种细胞系的中心体出现一定程度的异常，尽管在不同的细胞中存在不同的异常特征。vp -16诱导的中心体异常具有明显的剂量依赖性。持续低剂量VP-16 （1 μM）可引起sui -2细胞明显的多中心体异常，但仅引起中度细胞死亡。10 μM VP-16连续处理后，微核形成率高，多核巨细胞形成率高。我们还观察到这些巨细胞中更多的中心体数目异常。多核巨细胞和中心体异常的频繁可视化提供了有丝分裂失败的强烈印象，这反过来可能导致有丝分裂细胞死亡。然而，有丝分裂失败的新概念需要更深入的研究。

Anti-cancer chemotherapy constitutes the major approach of anti-cancer strategy. Such agents act by different mechanisms, but commit a similar cell death process on targeted cells. Centrosome overduplication could be documented as one event involving in radiation-induced cell death. In order to elucidate whether this centrosome abverrance is an unique outcome followed by nuclear DNA damage or a universal phenomenon in relation to cell apoptosis, in this study, we utilized a series of chemo-agents with different mechanism leading treated cells to apoptosis.Human pancreatic cancer cell lines Suit-2 and Capan-2 were used in these experiments. Anti-cancer chemo-agents used in the study included etoposide (VP-16), mitomycin (MMC), cisplatin and 5-fluorouracil (5-FU). Centrosomes were visualized with indirect immunofluorescent microscopy after labeled by special anti-α-tubulin and anti-pericentrin. Cell apoptosis was evaluated by the micronucleus formation and cell death was determined by measuring fluorescence intensity of propidium iodide.All used chemo-agents could cause some degree of centrosome abnormality in the two cell lines, even though distinct profile of the abnormality were present in different cells. VP-16-induced centrosome aberrance was apparently dose dependent. The continuous low dose VP-16 administration (1 μM) caused a marked multi-centrosome abnormality but only moderate cell death in Suit-2 cells. Same continuous treatment with 10 μM of VP-16 in turn resulted in high occurrence of micronuclei formation as well as that of multi-nuclear giant cell formation. We also observed more centrosome number abnormality within these giant cells.The frequent visualizations of multinuclear giant cells and centrosome aberrance provide a strong impression of mitosis failure, which in turn could contribute to mitosis cell death. However, the novel concept of mitosis failure would undergo more intensive investigation.