Accurate SPR methods for DNA/drug interactions

铂类抗癌药物是目前医学上应用最广泛的化疗药物。铂基抗癌药物的生物活性可能部分地由药物与DNA结合模式的差异来解释。一种新型三核铂化合物（BBR3464）最近已进入II期临床试验。这种真正的新型铂类药物，不是基于顺铂的结构，代表了一类新的抗肿瘤药物，其与DNA相互作用的机制，虽然与顺铂明显不同，但仍然知之甚少。本研究的目的是实时探测一类新型高亲和多核铂化合物与固定在表面等离子体共振（SPR）传感器表面的未标记单链和双链DNA低聚物的结合动力学。这项工作将比较多核和单核铂化合物，包括顺铂，与DNA的相互作用模式。这项工作的特点是界面动力学。此外，原位温度依赖的SPR将用于有或没有药物结合的原位熔化（去杂化）研究。静电相互作用对药物与DNA寡聚物结合的贡献将通过研究不同溶液离子强度的影响以及通过SPR与电化学方法的新组合来确定，这将选择性地改变传感器界面上的过量表面电荷。最后，MALDI MS将用于补充我们的原位SPR动力学测量，并添加铂化药物DNA加合物的质谱表征。这项工作提供了对新型多核铂类药物与更深入研究的顺铂在与DNA相互作用的首选模式方面的根本差异的更深入的理解。这一信息可能对体内单核铂化合物的活性差异提供见解。

Platinum anticancer drugs are currently the most widely used chemotherapeutic agents in medicine. The biological activity of platinum based anticancer drugs may, in part, be explained by differences in the mode of drug binding with DNA. A novel trinuclear platinum compound (BBR3464), has recently entered phase II clinical trials. This genuinely new platinum agent, not based on the cisplatin structure, represents a new class of antitumor drugs for which the mechanism of interaction with DNA, while clearly different than of cisplatin, remains poorly understood. The ain of this research is to probe, in real time, the kinetics of binding of a novel class of high-affinity polynuclear platinum compounds with un- labeled single and double stranded DNA oligomers immobilized on a surface plasmon resonance (SPR) sensor surface. This work will compare the modes of interaction for polynuclear and mononuclear platinum compounds, including cisplatin, with DNA. This work is distinguished of kinetics at interfaces. In addition, in situ temperature dependent SPR will be used for in-situ melting (dehybridization) studies with and without drug binding. The contribution of electrostatic interactions to drug binding with DNA oligomers will be determined by investigating the effect of varying solution ionic strength and by novel combination of SPR with electrochemical methods which will selectively alter the excess surface charge at the sensor interface. Finally, MALDI MS will be used to supplement our in-situ SPR kinetics measurements with addition mass spectrometric characterization of the platinated drug DNA adducts. This work provide a deeper understanding of the fundamental differences between novel multinuclear platinum drugs and the more well-studied cisplatin regarding the preferred modes of interaction with DNA. This information may offer insight on the differences in activity between mono- nuclear platinum compounds in vivo.