Analysis of mitosis and antimitotic drug responses in tumors by in vivo microscopy and single-cell pharmacodynamics.
Analysis of mitosis and antimitotic drug responses in tumors by in vivo microscopy and single-cell pharmacodynamics.
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DOI：
10.1158/0008-5472.can-11-0412
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发表时间：
2011-07-01
期刊：
影响因子：
11.2
通讯作者：
Mitchison TJ
中科院分区：
文献类型：
--
作者：
Orth JD;Kohler RH;Foijer F;Sorger PK;Weissleder R;Mitchison TJ
癌症依赖于频繁或异常的细胞分裂，但肿瘤微环境如何影响体内有丝分裂过程仍不清楚，主要是由于光学访问，空间分辨率和运动的技术挑战。我们开发了高分辨率的体内显微镜方法，以可视化人类癌症的小鼠异种移植模型中的有丝分裂。使用这些方法，我们确定了抗有丝分裂药物紫杉醇在肿瘤中的单细胞反应是否与细胞培养中相同;观察了紫杉醇（Ptx）对肿瘤反应的整体影响;并评估了紫杉醇的单细胞药效学（通过体内药效学显微镜[IPDM]）。有丝分裂开始在肿瘤中通常比在细胞培养中更不频繁，但随后正常进行。紫杉醇处理引起纺锤体组装缺陷和有丝分裂停滞，随后从有丝分裂停滞滑脱，多核化和凋亡。与细胞培养相比，暴露于紫杉醇的肿瘤中的峰值有丝分裂指数较低，并且肿瘤细胞在有丝分裂停滞后存活更长时间，变成多核而不是直接死于有丝分裂停滞。因此，肿瘤微环境比细胞培养物少得多的促凋亡。与有丝分裂阻滞相关的形态学具有剂量和时间依赖性，从而提供了药效学的半定量、单细胞测量。尽管许多肿瘤细胞没有通过Ptx诱导的有丝分裂停滞而进展，但在模型中肿瘤显著消退。我们的研究结果表明，在体内显微镜提供了一个有用的工具，可视化有丝分裂在肿瘤进展，药物反应，细胞命运在单细胞水平。
Cancer relies upon frequent or abnormal cell division but how the tumor microenvironment affects mitotic processes in vivo remains unclear, largely due to the technical challenges of optical access, spatial resolution, and motion. We developed high-resolution in vivo microscopy methods to visualize mitosis in a murine xenograft model of human cancer. Using these methods, we determined whether the single-cell response to the anti-mitotic drug paclitaxel was the same in tumors as in cell culture; observed the impact of paclitaxel (Ptx) on the tumor response as a whole; and evaluated the single-cell pharmacodynamics of paclitaxel (by in vivo pharmacodynamic microscopy [IPDM]). Mitotic initiation was generally less frequent in tumors than in cell culture, but subsequently it proceeded normally. Paclitaxel treatment caused spindle assembly defects and mitotic arrest, followed by slippage from mitotic arrest, multinucleation and apoptosis. Compared to cell culture, the peak mitotic index in tumors exposed to paclitaxel was lower and the tumor cells survived longer after mitotic arrest, becoming multinucleated rather than dying directly from mitotic arrest. Thus, the tumor microenvironment was much less pro-apoptotic than cell culture. The morphologies associated with mitotic arrest were dose- and time-dependent, thereby providing a semi-quantitative, single-cell measure of pharmacodynamics. Although many tumor cells did not progress through Ptx-induced mitotic arrest, tumor significantly regressed in the model. Our findings demonstrate that in vivo microscopy offers a useful tool to visualize mitosis during tumor progression, drug responses, and cell fate at the single cell level.