Bigioni M, Salvatore C, Bullo A, Bellarosa D, Iafrate E, Animati F, Capranico G, Goso C, Maggi C A, Pratesi G, Zunino F, Manzini S
Department of Pharmacology, Menarini Ricerche S.p.A., Pomezia, Rome, Italy.
Biochem Pharmacol. 2001 Jul 1;62(1):63-70. doi: 10.1016/s0006-2952(01)00645-1.
MEN 10755 is a disaccharide anthracycline endowed with a broader spectrum of antitumour activity than doxorubicin (DOX). To investigate the cellular and molecular basis of its action, cytotoxic activity, drug uptake, subcellular localisation, induction of DNA damage, and apoptosis were assessed in the human A2780 ovarian carcinoma cell line. Experiments with radiolabelled anthracyclines indicated that MEN 10755 exhibited reduced cellular accumulation and a different subcellular distribution (higher cytoplasmic/nuclear ratio) than DOX. In spite of the lower nuclear concentration, MEN 10755 was as potent as DOX in eliciting DNA single- and double-strand breaks, G2/M cell arrest, and apoptosis. Sequencing of drug-induced topoisomerase II cleavage sites showed a common DNA cleavage pattern for MEN 10755 and DOX. Cleavage sites were always characterised by the presence of adenine in -1 position. However, the extent of DNA cleavage stimulation induced by MEN 10755 was greater than that produced by DOX. Reversibility studies showed that MEN 10755-stimulated DNA cleavage sites were more persistent than those induced by DOX, thus suggesting a more stable interaction of the drug in the ternary complex. As a whole, the study indicated that the cellular pharmacokinetics of MEN 10755 substantially differs from that of DOX, showing a lower uptake and a different subcellular disposition. In spite of the apparently unfavourable cellular pharmacokinetics, MEN 10755 was still as potent as DOX in inducing topoisomerase-mediated DNA damage. Although the extent and persistence of protein-associated DNA breaks may contribute to the cytotoxic effects, the drug's efficacy as apoptosis inducer and antitumour agent could not be adequately explained on the basis of DNA damage mediated by the known target (i.e. topoisomerase II), thus supporting additional cellular effects that may be relevant in cellular response.
MEN 10755是一种二糖蒽环类药物，其抗肿瘤活性谱比阿霉素（DOX）更广。为了研究其作用的细胞和分子基础，在人A2780卵巢癌细胞系中评估了细胞毒性活性、药物摄取、亚细胞定位、DNA损伤诱导和凋亡情况。用放射性标记蒽环类药物进行的实验表明，MEN 10755与DOX相比，细胞蓄积减少，亚细胞分布不同（细胞质/细胞核比率更高）。尽管核浓度较低，但MEN 10755在引发DNA单链和双链断裂、G2/M期细胞阻滞及凋亡方面与DOX一样有效。对药物诱导的拓扑异构酶II切割位点进行测序显示，MEN 10755和DOX具有共同的DNA切割模式。切割位点总是以-1位存在腺嘌呤为特征。然而，MEN 10755诱导的DNA切割刺激程度大于DOX产生的程度。可逆性研究表明，MEN 10755刺激的DNA切割位点比DOX诱导的更持久，这表明药物在三元复合物中的相互作用更稳定。总体而言，该研究表明MEN 10755的细胞药代动力学与DOX有很大不同，表现为摄取较低和亚细胞分布不同。尽管细胞药代动力学明显不利，但MEN 10755在诱导拓扑异构酶介导的DNA损伤方面仍与DOX一样有效。虽然与蛋白质相关的DNA断裂的程度和持久性可能有助于细胞毒性作用，但基于已知靶点（即拓扑异构酶II）介导的DNA损伤，无法充分解释该药物作为凋亡诱导剂和抗肿瘤剂的疗效，因此支持可能与细胞反应相关的其他细胞效应。
