This experiment was conducted to address the question of whether acquired paclitaxel resistance is dependent upon whether it is given as a single brief exposure or as a long-term exposure. PX2 and PX24 were established from 2008 human ovarian cancer cells by 2-h single exposure or 24-h continuous exposure to paclitaxel. PX2 acquired paclitaxel resistance faster than PX24 by twofold. Drug resistant pattern was exposure-time dependent. In 2-h exposure, PX2 showed 53.86 ± 4.96 (mean ± standard deviation [SD]) fold paclitaxel resistance while PX24 showed 9.51 ± 1.01 fold resistance (P = 0.002). In 24-h exposure, PX2 showed 2.31 ± 0.3 fold paclitaxel resistance while PX24 showed 28.1 7 ± 0.98 fold resistance (P = 0.040). PX2 and PX24 acquired cross-resistance to docetaxel and SN38 and the resistance degrees were significantly higher in PX2 than PX24. They displayed approximately twofold cisplatin collateral sensitivity. PX24 also displayed sensitivity to other platinum drugs, oxaliplatin and ZD0473, whereas PX2 acquired significant resistance to both of them. Although differential tubulin-isotype expressions were noted among 2008, PX2 and PX24, they were not significant. In electron microscopy, prominent, densely stained lysosomes were observed more in the resistant cells than 2008. Two independent, exposure-time dependent paclitaxel-resistant human ovarian carcinoma cell lines were established. Understanding the characteristics of the differential resistance pattern could be clinically beneficial for the selection of second line chemotherapy for relapsed ovarian cancer.

中文翻译：

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两种独立的、暴露时间依赖性紫杉醇抗性人卵巢癌细胞系的表征。

进行该实验是为了解决获得性紫杉醇抗性是否取决于它是作为单次短暂暴露还是作为长期暴露给予的问题。PX2 和 PX24 是从 2008 年人类卵巢癌细胞通过 2 小时单次暴露或 24 小时连续暴露于紫杉醇而建立的。PX2 获得紫杉醇抗性的速度比 PX24 快两倍。耐药模式依赖于暴露时间。在 2 小时暴露中，PX2 显示 53.86 ± 4.96（平均值 ± 标准偏差 [SD]）紫杉醇抗性，而 PX24 显示 9.51 ± 1.01 倍抗性（P = 0.002）。在 24 小时暴露中，PX2 显示 2.31 ± 0.3 倍的紫杉醇耐药性，而 PX24 显示 28.1 7 ± 0.98 倍的耐药性（P= 0.040）。PX2和PX24对多西紫杉醇和SN38产生交叉耐药，PX2的耐药程度明显高于PX24。他们表现出大约两倍的顺铂侧支敏感性。PX24 还显示出对其他铂类药物奥沙利铂和 ZD0473 的敏感性，而 PX2 对这两种药物都产生了显着的耐药性。尽管在 2008、PX2 和 PX24 之间注意到微管蛋白同种型表达的差异，但它们并不显着。在电子显微镜下，与 2008 年相比，在抗性细胞中观察到显着的、染色密集的溶酶体。建立了两个独立的、暴露时间依赖性紫杉醇抗性人卵巢癌细胞系。