Ríhová B, Strohalm J, Hovorka O, Subr V, Etrych T, Chytil P, Pola R, Plocová D, Boucek J, Ulbrich K
Institute of Microbiology, AS CR, v.v.i., Vídenská 1083, 142 20 Prague 4, Czech Republic.
J Control Release. 2008 Apr 21;127(2):110-20. doi: 10.1016/j.jconrel.2008.01.003. Epub 2008 Jan 16.
A systematic study was designed to elucidate differences in cytostatic activity in vitro between HPMA-based doxorubicin conjugates synthesized using different polymerization techniques and differing in peptidyl side chain. A polymer-drug conjugate containing doxorubicin (DOX) bound to HPMA copolymer backbone through the enzymaticaly non-cleavable sequence GlyGly shows low but significant cytotoxicity in vitro in seven cancer cell lines of mouse (EL4, 38C13, 3T3, BCL1) and human (SW620, Raji, Jurkat) origin. The low cytotoxicity can be considerably increased by the presence of additional drug-free GlyPheLeuGly side chains. P1 conjugate, i.e. non-targeted HPMA copolymer bearing doxorubicin bound via a biodegradable GlyPheLeuGly sequence, synthesized by direct copolymerization of HPMA with monomeric doxorubicin and thus without additional drug-free GlyPheLeuGly sequences is less effective compared to PK1 synthesized by polymer analogous reaction and thus containing extra drug-free GlyPheLeuGly sequences. Significant activity-enhancing effect was not seen with other amino acid/oligopeptide sequences (e.g., Gly or GlyGly). The activity-enhancing effect of GlyPheLeuGly sequences is more obvious in the conjugate containing doxorubicin bound to HPMA through GlyGly sequence. Derivatization of the terminal carboxyl group of the extra GlyPheLeuGly side chains (amide, N-substituted amide, free carboxyl) does not significantly influence the cytotoxicity of the conjugates. The presence of the GlyPheLeuGly sequence in the conjugate structure increases its rate of intracellular accumulation. Normal cells (Balb/c splenocytes) accumulate less polymer-doxorubicin conjugate compared to cancer cells (T cell lymphoma EL4, B cell lymphoma Raji and T cell leukemia JURKAT).
设计了一项系统性研究，以阐明使用不同聚合技术合成且肽基侧链不同的基于HPMA的阿霉素缀合物在体外的细胞生长抑制活性差异。一种含有通过酶不可裂解序列GlyGly与HPMA共聚物主链结合的阿霉素（DOX）的聚合物-药物缀合物，在源自小鼠（EL4、38C13、3T3、BCL1）和人类（SW620、Raji、Jurkat）的七种癌细胞系中显示出低但显著的体外细胞毒性。额外的无药物GlyPheLeuGly侧链的存在可显著提高低细胞毒性。P1缀合物，即通过HPMA与单体阿霉素直接共聚合成的、带有通过可生物降解的GlyPheLeuGly序列结合的阿霉素的非靶向HPMA共聚物，因此没有额外的无药物GlyPheLeuGly序列，与通过聚合物类似反应合成并因此含有额外无药物GlyPheLeuGly序列的PK1相比效果较差。其他氨基酸/寡肽序列（如Gly或GlyGly）未观察到显著的活性增强作用。GlyPheLeuGly序列的活性增强作用在通过GlyGly序列与HPMA结合的阿霉素缀合物中更为明显。额外GlyPheLeuGly侧链末端羧基的衍生化（酰胺、N-取代酰胺、游离羧基）对缀合物的细胞毒性没有显著影响。缀合物结构中GlyPheLeuGly序列的存在增加了其细胞内积累速率。与癌细胞（T细胞淋巴瘤EL4、B细胞淋巴瘤Raji和T细胞白血病JURKAT）相比，正常细胞（Balb/c脾细胞）积累的聚合物-阿霉素缀合物较少。
