Pharmaceutical Institute, Rheinische Friedrich Wilhelms University Bonn, An der Immenburg 4, 53121 Bonn, Germany.
Biochem Pharmacol. 2013 Apr 15;85(8):1077-90. doi: 10.1016/j.bcp.2013.01.028. Epub 2013 Feb 8.
Previously we reported that liposomal cisplatin (CDDP) overcomes CDDP resistance of ovarian A2780cis cancer cells (Krieger et al., Int. J. Pharm. 389, 2010, 10-17). Here we find that the cytotoxic activity of liposomal CDDP is not associated with detectable DNA platination in resistant ovarian cancer cells. This suggests that the mode of action of liposomal CDDP is different from the free drug. To gain insight into mechanisms of liposomal CDDP activity, we performed a transcriptome analysis of untreated A2780cis cells, and A2780cis cells in response to exposure with IC50 values of free or liposomal CDDP. A process network analysis of upregulated genes showed that liposomal CDDP induced a highly different gene expression profile in comparison to the free drug. p53 was identified as a key player directing transcriptional responses to free or liposomal CDDP. The free drug induced expression of essential genes of the intrinsic (mitochondrial) apoptosis pathway (BAX, BID, CASP9) most likely through p38MAPK activation. In contrast, liposomal CDDP induced expression of genes from DNA damage pathways and several genes of the extrinsic pathway of apoptosis (TNFRSF10B-DR5, CD70-TNFSF7). It thus appears that liposomal CDDP overcomes CDDP resistance by inducing DNA damage and in consequence programmed cell death by the extrinsic pathway. Predictions from gene expression data with respect to apoptosis activation were confirmed at the protein level by an apoptosis antibody array. This sheds new light on liposomal drug carrier approaches in cancer and suggests liposomal CDDP as promising strategy for the treatment of CDDP resistant ovarian carcinomas.
先前我们曾报道过脂质体顺铂（CDDP）能够克服卵巢 A2780cis 癌细胞的 CDDP 耐药性（Krieger 等人，Int. J. Pharm. 389, 2010, 10-17）。在这里，我们发现脂质体 CDDP 的细胞毒性活性与耐药性卵巢癌细胞中可检测到的 DNA 铂化无关。这表明脂质体 CDDP 的作用模式与游离药物不同。为了深入了解脂质体 CDDP 活性的机制，我们对未处理的 A2780cis 细胞以及对游离或脂质体 CDDP 的 IC50 值有反应的 A2780cis 细胞进行了转录组分析。上调基因的过程网络分析表明，与游离药物相比，脂质体 CDDP 诱导了高度不同的基因表达谱。p53 被确定为指导游离或脂质体 CDDP 转录反应的关键因子。游离药物诱导了内在（线粒体）凋亡途径（BAX、BID、CASP9）的必需基因的表达，这很可能是通过 p38MAPK 激活。相比之下，脂质体 CDDP 诱导了 DNA 损伤途径和凋亡的外源性途径的几个基因（TNFRSF10B-DR5、CD70-TNFSF7）的表达。因此，脂质体 CDDP 通过诱导 DNA 损伤并通过外源性途径诱导程序性细胞死亡来克服 CDDP 耐药性。基因表达数据对凋亡激活的预测通过凋亡抗体阵列在蛋白质水平上得到了证实。这为癌症中的脂质体药物载体方法提供了新的思路，并表明脂质体 CDDP 是治疗 CDDP 耐药性卵巢癌的有前途的策略。
