期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：9
页码：4317-4322
DOI：10.1073/pnas.0910261107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The completeness of tumor removal during surgery is dependent on the surgeon's ability to differentiate tumor from normal tissue using subjective criteria that are not easily quantifiable. A way to objectively assess tumor margins during surgery in patients would be of great value. We have developed a method to visualize tumors during surgery using activatable cell-penetrating peptides (ACPPs), in which the fluorescently labeled, polycationic cell-penetrating peptide (CPP) is coupled via a cleavable linker to a neutralizing peptide. Upon exposure to proteases characteristic of tumor tissue, the linker is cleaved, dissociating the inhibitory peptide and allowing the CPP to bind to and enter tumor cells. In mice, xenografts stably transfected with green fluorescent protein show colocalization with the Cy5-labeled ACPPs. In the same mouse models, Cy5-labeled free ACPPs and ACPPs conjugated to dendrimers (ACPPDs) delineate the margin between tumor and adjacent tissue, resulting in improved precision of tumor resection. Surgery guided by ACPPD resulted in fewer residual cancer cells left in the animal after surgery as measured by Alu PCR. A single injection of ACPPD dually labeled with Cy5 and gadolinium chelates enabled preoperative whole-body tumor detection by MRI, intraoperative guidance by real-time fluorescence, intraoperative histological analysis of margin status by fluorescence, and postoperative MRI tumor quantification. Animals whose tumors were resected with ACPPD guidance had better long-term tumor-free survival and overall survival than animals whose tumors were resected with traditional bright-field illumination only.
