Bogush T, Smirnova G, Shubina I, Syrkin A, Robert J
Department of Pharmacology and Toxicology, Russian Academy of Medical Sciences, Moscow.
Cancer Chemother Pharmacol. 1995;35(6):501-5. doi: 10.1007/BF00686835.
Nanoparticulate carriers of anthracyclines are being developed with the aim of improving the pharmacokinetic or pharmacodynamic behavior of these drugs. To understand how the drug reaches its nuclear targets, we have developed two methods that allow the quantification of the interaction between an anthracycline and cellular DNA: (1) by direct evaluation of the quenching of anthracycline fluorescence due to the intercalation of the drug into DNA and (2) by the measurement of Hoechst 33258 fluorescence associated with its displacement from DNA-binding sites for which it competes with the anthracycline. We show that the intracellular accumulation and DNA binding of doxorubicin encapsulated in polyisohexylcyanoacrylate nanospheres (dox-NS) and of daunorubicin bound to polyglutamic acid are reduced by 30%-40% in comparison with those obtained for free doxorubicin (dox) and daunorubicin, respectively. The results obtained with dox or NS-dox are not modified by prior incubation with either of these compounds. The two methods yielded similar results, and we conclude that either technique is applicable to the evaluation of the interaction of carrier-bound anthracyclines with cellular DNA.
正在研发蒽环类药物的纳米颗粒载体，目的是改善这些药物的药代动力学或药效学行为。为了了解药物如何到达其核靶点，我们开发了两种方法来量化蒽环类药物与细胞DNA之间的相互作用：（1）通过直接评估由于药物插入DNA导致的蒽环类药物荧光猝灭；（2）通过测量与Hoechst 33258从DNA结合位点被取代相关的荧光，Hoechst 33258与蒽环类药物竞争该结合位点。我们发现，与游离阿霉素（dox）和柔红霉素相比，包裹在聚异己基氰基丙烯酸酯纳米球（dox-NS）中的阿霉素以及与聚谷氨酸结合的柔红霉素的细胞内积累和DNA结合分别减少了30%-40%。用dox或NS-dox获得的结果不会因预先与这两种化合物中的任何一种孵育而改变。这两种方法产生了相似的结果，我们得出结论，这两种技术都适用于评估与载体结合的蒽环类药物与细胞DNA的相互作用。
