Zhang Mei, Boyer Michael, Rivory Laurent, Hong Angela, Clarke Stephen, Stevens Graham, Fife Kate
Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales 2050, Australia.
Int J Radiat Oncol Biol Phys. 2004 Feb 1;58(2):353-60. doi: 10.1016/j.ijrobp.2003.09.032.
Results from recent clinical studies of gemcitabine and vinorelbine have encouraged the use of this combination concurrently with radiotherapy in the treatment of non-small-cell lung cancer, although preclinical data are limited. The present study aimed to quantify the in vitro interaction and radiosensitizing effect of gemcitabine and vinorelbine individually and in combination.
Cytotoxicity was measured by exposing NCI-H460 cells to gemcitabine and/or vinorelbine simultaneously or sequentially, followed by irradiation at 0-10 Gy. Clonogenic cell survival assays were performed. Flow cytometry was used to measure the effects of both drug and radiation on cell cycle distribution. Apoptosis was assessed by morphologic criteria, by sub-G1 changes using flow cytometry assay, and by Annexin-V binding assay.
Both drugs showed single-agent activity against NCI-H460 cells and targeted different phases of the cell cycle. When both drugs were used in combination, they showed schedule-dependent interaction. An antagonistic effect was observed with simultaneous exposure to the two drugs. The optimum combination schedule was sequential exposure to vinorelbine followed by gemcitabine 24 h later. Both drugs showed radiosensitization effects. The radiosensitization effect of gemcitabine was evident when radiation was given immediately after 4-h incubation. However, the radiosensitization effect of vinorelbine was time dependent and observed with radiation given at 24 h postincubation. Apoptosis induced by gemcitabine increased gradually, reaching 20% at 72 h posttreatment. In contrast, apoptotic cell death was an early feature in vinorelbine-treated cells, reaching approximately 40% at 24 h.
The individual cytotoxic effects of gemcitabine and vinorelbine on NCI-H460 cells are phase specific, and the combined effect of gemcitabine and vinorelbine is sequence dependent. The radiosensitizing effects of both drugs seem to be related to enhanced apoptosis.
尽管临床前数据有限，但吉西他滨和长春瑞滨近期的临床研究结果促使人们在非小细胞肺癌治疗中尝试将这种联合疗法与放疗同时使用。本研究旨在量化吉西他滨和长春瑞滨单独及联合使用时的体外相互作用和放射增敏效果。
通过将NCI-H460细胞同时或先后暴露于吉西他滨和/或长春瑞滨，随后给予0-10 Gy的辐射来测量细胞毒性。进行克隆形成细胞存活分析。使用流式细胞术测量药物和辐射对细胞周期分布的影响。通过形态学标准、使用流式细胞术分析亚G1期变化以及膜联蛋白-V结合分析来评估细胞凋亡。
两种药物对NCI-H460细胞均显示出单药活性，并靶向细胞周期的不同阶段。当两种药物联合使用时，它们表现出与给药顺序相关的相互作用。同时暴露于两种药物时观察到拮抗作用。最佳联合给药方案是先给予长春瑞滨，24小时后再给予吉西他滨。两种药物均显示出放射增敏作用。在孵育4小时后立即给予辐射时，吉西他滨的放射增敏作用明显。然而，长春瑞滨的放射增敏作用具有时间依赖性，在孵育24小时后给予辐射时观察到该作用。吉西他滨诱导的细胞凋亡逐渐增加，在治疗后72小时达到20%。相比之下，凋亡性细胞死亡是长春瑞滨处理细胞的早期特征，在24小时时达到约40%。
吉西他滨和长春瑞滨对NCI-H460细胞的个体细胞毒性作用具有阶段特异性，且吉西他滨和长春瑞滨的联合作用与给药顺序有关。两种药物的放射增敏作用似乎都与增强的细胞凋亡有关。
