Key Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, PR China.
Eur J Pharm Biopharm. 2012 Feb;80(2):379-86. doi: 10.1016/j.ejpb.2011.10.020. Epub 2011 Nov 12.
In several groups of malignant tumors including head and neck tumors, a protein named Hsp47/CBP2 leaked from the cell was expressed on the tumor cell surface. Several synthetic peptides have been identified as effective ligands for binding to Hsp47/CBP2. This study has focused on the synthesis and in vitro characterization of a targeting delivery system of 5-fluorouracil (5-FU) to human head and neck squamous cell carcinoma (HNSCC) in order to improve anti-cancer efficacy and reduce dose-limiting toxicity of 5-FU. An N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer, with Hsp47/CBP2 binding peptide sequence (namely WHYPWFQNWAMA) as a targeting ligand, was synthesized by a novel and simplified synthetic route. Under the controlled synthetic conditions, 1,3-dimethylol-5-FU, derived from 5-FU, was attached to the HPMA copolymer backbone via the lysosomally degradable GFLG linker, while the WHYPWFQNWAMA was conjugated via a non-degradable Gly-Gly (GG) linker. A control polymer without targeting moiety was also synthesized (P-FU). The in vitro cytotoxicity, internalization and apoptosis assays of the polymeric conjugates were evaluated. The characteristic apoptotic morphological changes were also assessed. Compared to 5-FU and P-FU, the HPMA copolymer containing the Hsp47/CBP2 binding peptide (P-FU-peptide) exhibited the highest cytotoxic efficacy to cell line of human head and neck squamous cell carcinoma (p<0.05) and was internalized much faster than P-FU, especially after being incubated for 30 min. Both of the morphology and apoptosis analyses demonstrated that the treatment of P-FU-peptide resulted in more apoptotic and necrotic induction of tumor cells than P-FU. Meanwhile, the rate of apoptosis induced by P-FU-peptide was higher than that of necrosis. In summary, the HPMA copolymer-Hsp47/CBP2 binding peptide conjugates showed a promising future for the treatment of HNSCC with improved efficacy.
在包括头颈部肿瘤在内的几组恶性肿瘤中，一种名为 Hsp47/CBP2 的蛋白质从细胞中漏出并表达在肿瘤细胞表面。已经鉴定出几种合成肽作为与 Hsp47/CBP2 有效结合的配体。本研究专注于合成和体外鉴定 5-氟尿嘧啶（5-FU）递药系统，以提高对人头颈鳞癌（HNSCC）的抗癌疗效并降低 5-FU 的剂量限制毒性。一种 N-(2-羟丙基)甲基丙烯酰胺（HPMA）共聚物，具有 Hsp47/CBP2 结合肽序列（即 WHYPWFQNWAMA）作为靶向配体，通过一种新颖且简化的合成途径合成。在受控的合成条件下，来自 5-FU 的 1,3-二羟甲基-5-FU 通过溶酶体可降解的 GFLG 接头连接到 HPMA 共聚物主链上，而 WHYPWFQNWAMA 通过不可降解的 Gly-Gly (GG) 接头连接。还合成了一种没有靶向部分的对照聚合物（P-FU）。评估了聚合物缀合物的体外细胞毒性、内化和细胞凋亡测定。还评估了特征性的凋亡形态变化。与 5-FU 和 P-FU 相比，含有 Hsp47/CBP2 结合肽的 HPMA 共聚物（P-FU-肽）对人头颈鳞癌细胞系表现出最高的细胞毒性效力（p<0.05），并且内化速度比 P-FU 快得多，特别是在孵育 30 分钟后。形态学和凋亡分析均表明，与 P-FU 相比，P-FU-肽处理导致肿瘤细胞的凋亡和坏死诱导更多。同时，P-FU-肽诱导的凋亡率高于坏死率。总之，HPMA 共聚物-Hsp47/CBP2 结合肽缀合物显示出在提高疗效的情况下治疗 HNSCC 的广阔前景。
