Oyama Tsukasa, Rombel Irene T, Samli Kausar N, Zhou Xin, Brown Kathlynn C
Division of Translational Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Building, Dallas, TX 75390-9185, USA.
Biosens Bioelectron. 2006 Apr 15;21(10):1867-75. doi: 10.1016/j.bios.2005.11.016. Epub 2006 Jan 18.
A technical challenge in the development of biosensor devices for cancer detection and diagnosis is the identification of ligands that recognize cancer cells with high affinity and specificity. Furthermore, it is unlikely that one cell-binding ligand will provide sufficient biological information, thus, multiple ligands for a given cancer type will be needed for confident clinical diagnosis. Biopanning of phage displayed peptide libraries is a route to isolation of specific cell-binding reagents. A potential approach towards isolation of multiple ligands for a single cell type is to pan against the same cell type using different peptide libraries. Here we report the synthesis of a new 20-mer peptide-phage library and its use to select a peptide that binds to the large cell lung carcinoma cell line, H1299. The isolated phage clone binds H1299 cells 80 times better than a control phage and can distinguish between H1299 and normal control cells. The phage clone also binds to the lung pleura epidermoid cell line, Calu-1 but not to all lung carcinoma cell lines. The peptide is functional outside the context of the phage and tetramerization of the peptide on a trilysine core improves the affinity of the peptide. The tetrameric peptide can be used to deliver a fluorescent quantum dot to H1299 cells. Unexpectedly, the peptide shares sequence similarity to a previously isolated H1299-binding peptide isolated from a different 20-mer peptide library. Data suggests that the two peptides target the same cellular receptor. Our results imply that cell-based biopanning can isolate cell-binding ligands that may be of utility for cancer diagnosis, and isolation of cell-targeting peptides from different peptide libraries can expand the repertoire of cell-binding reagents.
用于癌症检测和诊断的生物传感器设备开发中的一个技术挑战是识别能够以高亲和力和特异性识别癌细胞的配体。此外,单一的细胞结合配体不太可能提供足够的生物学信息,因此,对于可靠的临床诊断,给定癌症类型需要多种配体。噬菌体展示肽库的生物淘选是分离特异性细胞结合试剂的一条途径。针对单一细胞类型分离多种配体的一种潜在方法是使用不同的肽库针对同一细胞类型进行淘选。在此,我们报告了一种新的20聚体肽噬菌体库的合成及其用于选择与大细胞肺癌细胞系H1299结合的肽的用途。分离出的噬菌体克隆与H1299细胞的结合能力比对照噬菌体强80倍,并且能够区分H1299细胞和正常对照细胞。该噬菌体克隆也与肺胸膜表皮样细胞系Calu-1结合,但并非与所有肺癌细胞系都结合。该肽在噬菌体背景之外具有功能,并且该肽在三赖氨酸核心上的四聚化提高了肽的亲和力。四聚体肽可用于将荧光量子点递送至H1,299细胞。出乎意料的是,该肽与先前从不同的20聚体肽库中分离出的与H1299结合的肽具有序列相似性。数据表明这两种肽靶向相同的细胞受体。我们的结果表明,基于细胞的生物淘选可以分离出可能对癌症诊断有用的细胞结合配体,并且从不同肽库中分离细胞靶向肽可以扩大细胞结合试剂的种类。